Newsy – Flies Carry Even More Bacteria Than You Might Think

Link: https://www.newsy.com/stories/flies-carry-hundreds-of-species-of-bacteria/

“Our Tiny Super Heroes” (Channel News Asia) – Documentary inspired by our work on microbiomes of flies:

Link: https://www.channelnewsasia.com/news/video-on-demand/our-tiny-superheroes/our-tiny-superheroes-11773182

Rund 100 verschiedene Wirbellosenarten leben in jedem durchschnittlichen Haushalt – das zeigte eine Studie in “Scientific Reports”. Zu den bekanntesten und unbeliebtesten dieser Mitbewohner gehören sicherlich die Stuben- und Schmeißfliegen. Sie surren nicht nur lästig um das Essen, sondern gelten auch als Überträger allerlei Krankheitserreger. Dass sie diese Aufgabe sogar noch besser erledigen als bislang angenommen, zeigt eine weitere Veröffentlichung in den “Scientific Reports”. Ana Carolina Junqueira von der Bundesstaatlichen Universität Rio de Janeiro und ihr Team untersuchten dazu 116 Stuben- und Schmeißfliegen von drei Kontinenten und aus unterschiedlichen menschlichen Umfeldern im Hinblick auf die Bakterienlast, welche die Tiere mit sich herumtragen.

Insgesamt konnten die Wissenschaftler 316 unterschiedliche Bakterienarten auf den Schmeiß- und sogar 351 auf den Stubenfliegen nachweisen, wobei einzelne Exemplare tatsächlich mit jeweils mehreren hundert Keimarten unterwegs sein konnten. Die höchste Dichte wiesen naturgemäß die Beine auf, mit denen die Tiere auf Fäkalien oder Aas stehen, aber auch die Flügel waren stark kontaminiert. “Die Bakterien nutzen die Fliegen quasi wie ein Taxi”, so der beteiligte Biologe Stephan Schuster. Unter den nachgewiesenen Bakterien befanden sich zahlreiche Pathogene, die bei Menschen heftige Durchfallerkrankungen oder andere Malaisen auslösen können. Fliegen aus Brasilien schleppten sogar Helicobacter pylori mit sich herum, der bei Betroffenen Magengeschwüre auslösen kann – als potenzielle Überträger habe man diese Insekten jedoch noch nicht im Visier gehabt, warnt Schuster. Etwa die Hälfte aller Bakterien kam sowohl bei den Stuben- als auch bei den Schmeißfliegen vor, was angesichts ähnlicher Nahrungsvorlieben wenig überrascht. Beide suchen Aas und Kot auf, um ihre Eier abzulegen und sich zu ernähren.

Erstaunlicherweise fanden die Forscher starke Stadt-Land-Gegensätze vor: In dicht besiedelten Regionen wiesen die Fliegen mehr Bakterien auf als Artgenossen, die im Umfeld von Viehställen auf dem Land gefangen wurden. Offensichtlich bildet der Zugang zu offenen Latrinen oder Sickergruben eine wichtige Quelle für humanpathogene Erreger auf Insekten, während Viehhaltung zwar die Fliegenzahl an sich fördert, sie aber weniger stark für uns kritischen Bakterien aussetzt. Das könne man zukünftig vielleicht bei der Wahl des Picknickplatzes berücksichtigen, sagt Schneider – auf einer Waldlichtung setzt man sich geringeren Risiken durch Fliegen aus als vielleicht im Stadtpark.

Trotz des hohen Ekelfaktors sehen die Biologen allerdings ebenso einen positiven Nebenaspekt: Die Fliegen könnten als einfache Bioindikatoren dienen. Anhand ihrer Bakterien ließen sich Hinweise ermitteln, wo in definierten Bereichen Krankheitserreger vorhanden sein könnten. Wegen ihrer geringen Größe dringen sie in Bereiche vor, die Menschen praktisch verschlossen sind – in denen beispielsweise Aas vergammelt.

O tym, że muchy “roznoszą zarazki” słyszymy niemal od dziecka. Okazuje się, jednak, że do tej pory mimo wszystko… nie docenialiśmy związanych z tym zagrożeń. Wyniki najnowszych badań, przeprowadzonych przez naukowców z Eberly College of Science przy Pennsylvania State University wskazują, że dokuczliwe owady przenoszą wiecej bakterii, niż myśleliśmy. Na łamach czasopisma “Scientific Reports” po raz pierwszy piszą między innymi o tym, że muchy mogą przenosić bakterie z gatunku Helicobacter pylori. W ten sposób mogą przyczyniać się do zachorowań na wrzody żołądka. Wcześniej nie bralismy tego pod uwagę.

Autorzy pracy przebadali florę bakteryjną 116 much domowych i plujek pospolitych zebranych na trzech kontynentach. Stwierdzili, że muchy przenoszą setki różnych bakterii, z których wiele ma dla człowieka działanie chorobotwórcze. Pokryty licznymi włoskami owad feruje mikroorganizmom wyjatkowo dogodne warunki rozprzestrzeniania się, a częste przebywanie wsród ludzi sprawia, że mogą roznosić choroby wyjątkowo łatwo.

Jesteśmy przekonani, że nasze wyniki wskazują na mechanizm transmisji chorób, który nie był do tej pory dostatecznie zbadany, a może się przyczyniać do gwałtownego roznoszenia patogenów w sytuacji epidemii – mówi prof. Donald Bryant z Penn State.

Naukowcy byli w stanie przebadać florę bakteryjną utrzymującą się na różnych częściach ciała muchy, w tym skrzydach i odnóżach. Jak przyznaje współautor pracy, prof. Stephan Schuster, odnóża są szczególnie “skuteczne” przenosząc z miejsca na miejsce większosć z obecnych na muchach mikroorganizmów.

Odnóża i skrzydła much przenoszą najwięcej bakterii, co wskazuje na to, że mikroorganizmy faktycznie wykorzystują te owady do transportu powietrznego – mówi Schuster. Jeśli bakterie przetrwają taką podróż, trafiają na nowa powierzchnię, na której mogą wzrastać. Nasze badania pokazały, że dosłownie kazdy krok muchy zostawia za soba kolonie bakterii, które rozwijają się jeśli tylko nowa powierzchnia temu sprzyja.

Muchy tradycyjnie rozwijają się w warunkach dalekich od higieny, często też zaglądają nam do domów i siadają na spożywanych przez nas pokarmach. Opisane w “Scientific Reports” badania wskazują, że mniej więcej połowa ich flory bakteryjnej ma z nimi ścisły zwiazek, połowa zaś to mikroorganizmy zebrane z ich otoczenia. Co ciekawe, więcej chrobotwórczych bakterii znaleziono na owadach złapanych w miastach, niż w wiejskich oborach i stajniach. To potwierdza przypuszczenie, że muchy skuteczniej przenoszą choroby tam, gdzie jest wiecej ludzi. Prawdziwym zaskoczeniem była obecność na 15 muchach złapanych w Brazylii bakterii Helicobacter pylori. Do tej pory nie brano pod uwagę, że te owady mogą przyczyniać się do rozprzestrzeniania tych zwiekszających ryzyko wrzodów żołądka mikroorganizmów.

Bezprecedensowa dokładność przeprowadzonych badań była możliwa dzięki zastosowaniu najnowszych technik badania DNA. To pierwsze badania, które opisują w obiektywny sposób całą florę bakteryjną tych owadów – mówi prof. Ana Carolina Junqueira z Federal University of Rio De Janeiro. Muchy domowe i plujki na całym świecie uznaje się za istotnych nosicieli chorób, ale do tej pory ich prawdziwy potencjał nie był z użyciem takich najnowocześniejszych metod badany. 

Autorzy pracy mają w tej sprawie jedną dobrą wiadomość. Są przekonani, że muchy moga posłużyć jako element systemu wczesnego ostrzegania. Wyłapywanie ich i badania ich flory bakteryjnej mogą pokazać, z jakim zagrożeniem bakteriologicznym na danym terenie możemy mieć do czynienia.

Микробиологи впервые провели тотальную перепись бактерий, которых разносят на своих телах мухи. Оказалось, что на мухах путешествуют десятки разновидностей опасных микробов, включая тех, что вызывают язву желудка.

Об этом говорится в статье ученых из Бразилии, США и Сингапура, опубликованной в журнале Scientific Reports.

Еще с советских времен многие помнят плакаты с грозной надписью «муха – источник заразы». Однако до сих пор никто не пытался количественно оценить, сколько именно видов бактерий переносят на себе эти надоедливые создания. Авторы статьи решили восполнить этот пробел, воспользовавшись новейшими технологиями секвенирования ДНК.

В ходе исследования ученые проанализировали бактериальную ДНК, содержащуюся на разных частях тела 116 падальных и домашних мух (Calliphoridae и Muscidae). Представители этих семейств часто садятся на фекалии и гниющие остатки, чтобы отложить туда яйца, а потом залетают в человеческие дома, чтобы полакомится пищей с нашего стола.

На падальных мухах ученые выявили 316 различных видов бактерий, а на домашних – 351, причем примерно на 50% видовой состав микрофлоры обеих семейств перекрывается. В 16 случаях на мухах были выявлены бактерии Helicobacter pylori – их присутствие в организме человека связано с развитием гастрита и язвы желудка. В основном эта бактерия была найдена у падальных мух из Бразилии (исследователями были изучены мухи с трех континентов). Интересно, что раньше мухи не рассматривались среди возможных механизмов передачи Helicobacter pylori.

Как и ожидалось, больше всего бактерий присутствовало на мушиных лапках. «Исследование показало, что каждый шаг из сотен тех, что делает муха, оставляет после себя след, который способен дать начало микробной колонии при наличии благоприятных условий», — пояснил Стефан Шустер, соавтор статьи. Интересно, что мухи, пойманные в районе конюшен, несли на себе меньше бактерий, чем те, которые были пойманы в городе.

Впрочем, по словам ученых, мухи могут принести и пользу людям, если использовать их для выявления вспышек инфекционных заболеваний на начальном этапе. Каждое такое насекомое – это бесплатный контейнер для анализов, который в постоянном режиме собирает образцы бактерий в таких местах, куда не проникнет никакая санитарная инспекция.    

Ученые исследовали микробиомы комнатных мух и обнаружили большое разнообразие патогенных микроорганизмов.
Известно, что мухи способны переносить микроорганизмы-возбудители многих заболеваний, включая холеру, брюшной тиф и некоторые болезни глаз. Международная группа ученых исследовала микробиомы 116 комнатных и мясных мух и пришла к выводу: эти насекомые могут оказаться переносчиками гораздо большего количества болезней, чем было принято считать.
Мухи не могут питаться твердой пищей, они растворяют ее с помощью слюны. Насекомых часто привлекают экскременты и сравнительно мягкие продукты, например, испорченные фрукты или мясо. Из-за этих особенностей питания муха постоянно контактирует со множеством микроорганизмов, включая опасные для человека.
Авторы работы изучили геномы совокупности микроорганизмов, обитающих в теле 116 мух, пойманных в Бразилии, Сингапуре и США. Исследователи учли не только разницу в регионе происхождения, но и место обитания каждой мухи: город, сельская местность или дикая природа. Интересно, что у городских насекомых ученые нашли больше патогенов, чем у сельских. Для многих обнаруженных бактерий мухи ранее не считались значимым переносчиком. Например, ученые обнаружили в исследуемом материале бразильских мух следы бактерии Helicobacter pylori, которую связывают с развитием хронического гастрита и некоторых случаев язвы желудка.
Ученые пришли к выводу, что наибольшим разнообразием микроорганизмов отличаются лапки и крылья мух. «По сути, исследование показывает, что каждый из сотен шагов мухи оставляет за собой след колонии микроорганизмов, если поверхность позволяет бактериям размножаться», — говорит один из авторов работы Стивен Шустер (Stephan Schuster).
Новые данные еще раз подтверждают: мухи, садящиеся на еду, могут быть опасны для человека. Тем не менее, есть и положительная сторона этой проблемы. Ученые считают, что мух можно использовать в качестве уникальной системы оповещения о распространении патогенов. Насекомые станут живыми «дронами», собирающими бактерии на определенной территории. Если опасные микроорганизмы начнут распространяться, анализ местных мух может рассказать об этом еще до начала эпидемии. Возможно, в перспективе такие технологии помогут предотвращать вспышки заболеваний.
Исследование опубликовано в журнале Scientific Reports.
Ранее ученые установили, что в жилых домах обитает более 100 видов членистоногих.

Les mouches sont connues pour répandre des maladies et détériorer les activités alimentaires, de santé et pharmaceutiques. Dans ces secteurs d’activité, les pratiques d’hygiène standards, les barrières physiques et les destructeurs d’insectes volants sont des composants obligatoires afin d’assurer une bonne hygiène des lieux. Ces derniers empêchent les mouches de contaminer la nourriture par laquelle elles sont attirées.

Une équipe de chercheurs des États-Unis, du Singapour, du Brésil et d’Allemagne ont montré que les mouches domestiques et les mouches bleues peuvent transporter une variété bien plus large de bactéries. Une des découvertes clés, c’est que les mouches contaminent principalement par contact avec une surface.

Ces chercheurs ont collecté des mouches domestiques et des mouches bleues de trois continents dans divers environnements, de la forêt amazonienne au Brésil jusqu’aux villes. Ils ont ensuite utilisé des nouvelles techniques d’analyses génétiques afin d’identifier tous les micro-organismes portées par les mouches et les parties de leur corps sur lesquelles ils sont présents.

De toutes les parties de leur corps, les pattes et les ailes montrent la plus grande diversité microbienne, ce qui démontre qu’en se posant simplement sur de la nourriture ou toute autre surface, les mouches peuvent répandre un grand nombre de bactéries.

Les mouches, porteuses de maladies

La plupart des études réalisées sur les mouches se sont concentrées sur les micro-organismes présents dans leur flore intestinale. Les mouches domestiques et bleues se nourrissent et s’accouplent sur des excréments et des matières en décomposition.

De par leur simple existence, les mouches entreront en contact avec un grand nombre de micro-organismes qui peuvent causer des maladies ou dégrader les matières végétales ou animales. Il est donc plausible que les moyens mécaniques de dissémination soient d’importants facteurs.

Le Docteur Ana Junqueira, entomologiste moléculaire à l’université fédérale de Rio de Janeiro, qui a co-mené cette étude, a dit :

“Les mouches de la viande ont des poils microscopiques sur tout leur corps hormis leurs yeux, et ces poils font d’elles les parfaites porteuses de pollen mais aussi de bactéries. Il s’agit d’un véhicule optimisé par le processus d’évolution destiné à la dissémination de micro-organismes dans l’environnement.”

De nombreuses techniques ont été utilisées afin d’analyser l’information génétique qui permettait de déterminer quels micro-organismes étaient présents. La majorité de l’ADN “lue” appartenait aux bactéries, et seule une mouche collectée avait une quantité d’ADN virale considérable.

À travers cette étude, on a découvert que chaque mouche peut porter plusieurs centaines d’espèces de bactéries qu’elles attrapent de l’environnement dans lequel elle vit. Une certaine technique d’analyse a permis d’identifier 1396 espèces, une deuxième 316 et la dernière 49. 33 espèces de bactéries en commun ont été identifiées par les trois techniques. Les types de bactéries se ressemblaient d’un environnement à un autre, mais variait plus d’une mouche à une autre.

Entre les mouches bleues et les mouches domestiques, on a trouvé qu’elles partageaient à peu près 50% des micro-organismes qu’elles portaient, certainement à cause des environnements qu’elles partagent.

Leur abdomen a deux fois plus d’ADN à lire que les autres parties de leur corps, les chercheurs estiment que la flore intestinale de ces insectes y est sûrement pour beaucoup. Les pattes et les ailes avaient en revanche la plus grande diversité de bactéries.

Les bactéries, causes de maladies

Le micro-organisme le plus commun chez les mouches bleues était de loin la Wolbachia, un genre de bactérie parasitaire qui a été retrouvé sur plus de 60% des espèces d’insectes à travers le monde. La Wolbachia entretient des relations très compliquées avec ses insectes hôtes, comme les empêcher à se reproduire, l’élimination des mâles, la parthénogenèse, la féminisation des mâles et la protection contre les virus comme le Norovirus, le Virus West Nile et le Chikungunya. Elle n’a cependant pas d’effet connu sur l’homme.

Sur les mouches, la bactérie la plus commune retrouvée était le genre Psychrobacter PRwf-1, qui comptait pour 25% des lectures d’ADN détectées dans les échantillons de mouches domestiques. Cette souche de bactérie trouvable normalement dans les environnements froids et le pergélisol (sol gelé en permanence), mais cette souche s’est adaptée aux environnements plus chauds et est associée avec la détérioration des denrées alimentaires.

Des centaines d’espèces de bactéries retrouvées sur les mouches, un certain nombre a pu être identifié avec chaque technique d’analyse. Certaines de ces bactéries retrouvées sur les mouches domestiques et les mouches bleues sont connues pour transmettre des maladies à l’homme, notamment des infections nosocomiales (attrapées dans des établissements de santé), ou en contaminant des denrées.

Quelques-unes des bactéries plus importantes trouvées sur les mouches étaient :

• Enterobacter cloacae :facilement trouvable dans l’environnement, dans les systèmes digestifs humains et animaux ; infections nosocomiales du système respiratoire et urinaire, endocardite, infections des tissus mous et de la peau ; contamine les appareils médicaux, intraveineux et autres
• Salmonella enterica: cause d’intoxication alimentaire commune
• Staphylocoque : facilement trouvable dans l’environnement ; cause de gastro-entérite et infection des plaies dans les hôpitaux
• Bacillus cereus : cause d’intoxication alimentaire ; les spores survivent dans les aliments pas assez cuits ; créé des toxines qui peuvent causer une intoxication alimentaire
• Acinetobacter baumanii : facilement trouvable dans la nature, mais connu pour les infections nosocomiales comme la bactériémie, les infections urinaires, les méningites secondaires, les endocardites infectieuses, et autres infections de plaies et brûlures
• Vibrio parahaemolyticus : cause d’intoxication alimentaire commune retrouvée dans les fruits de mer pas assez cuits, mais peut aussi causer une infection des yeux, des oreilles et de la peau de par sa présence dans de l’eau contaminée
• Enterococcus faecalis: composant commun de la flore intestinale, mais peut causer des infections létales dans les hôpitaux ; très résistants aux antibiotiques
• Morganella morgana: composant commun de la flore intestinale humaine et animale, cause des infections nosocomiales, souvent urinaires ou dans les plaies chirurgicales
• coli: composant commun de la flore intestinale, mais six types d’E. coli peuvent causer une gastro-entérite via de la nourriture, de l’eau ou une surface contaminée
• Helicobacter pylori : cause des ulcères gastriques et certains cancers
• Clostridium butyricum : composant commun de la flore intestinale ; utilisé comme probiotique dans certains pays de l’Asie et trouvable communément dans le lait fermenté et le fromage

Les chercheurs ont comparé les bactéries qu’ils ont découvert sur les mouches domestiques et les mouches bleues (mouches de la viande) avec celles retrouvées dans un projet d’analyse de microbiotes de la flore intestinale humaine, puis celles d’un autre projet réalisé dans le métro New Yorkais.

Ils ont découvert que 19 espèces de bactéries étaient communes à toutes ces études, 49 espèces de l’étude sur les mouches ont été retrouvées dans la flore intestinale humaine, et 79 dans le métro de New York.

L’une des trouvailles les plus intéressantes était la forte présence de l’Helicobacter pylori, qui peut causer des ulcères gastriques et certains cancers. La bactérie n’avait auparavant jamais été retrouvée sur des insectes dans la nature. Elle a cependant été retrouvée sur 15 des 116 mouches échantillonnées et sur toutes les parties de leur corps, mais principalement sur leurs pattes et leurs ailes. Toutes ces mouches ont été collectées au Brésil.

Les chercheurs ont considéré que les mouches bleues ont très certainement attrapé la bactérie dans des égouts ou dans des toilettes en extérieur. Ils ont conclu sur le besoin d’études plus approfondies sur les sources de transmissions alternatives de la bactérie H. pylori.

Contamination : transmission à chaque étape

Les mouches peuvent transmettre des micro-organismes aux aliments et aux surfaces par trois leviers :

1. Régurgitation pendant leur repas
2. Excréments
3. Contamination mécanique via le contact de leur corps

Les chercheurs ont étudié chacun de ces leviers de contamination en permettant à des mouches bleues d’atterrir sur des boîtes de Pétri, inoculées d’une souche spéciale de l’E.coli, et en les laissant ensuite marcher sur des plats d’agar-agar stériles.

Les plats d’agar-agar ont ensuite été incubés afin que toute trace d’E. coli puisse se cultiver en colonie et devenir visible.

Les motifs des colonies de bactéries ressemblaient à ceux des traces de pas des mouches, et persistaient à travers de nombreux pas. La première et la troisième paire de pattes sur chaque côté produisait une ligne, tandis que la paire de pattes au milieu dessinait des points en dehors des lignes.

Il n’y avait que quelques signes de contamination de l’agar-agar par d’autres parties du corps, avec quelques points contaminés par leur bouche, ce qui a démontré que les vecteurs principaux de contamination chez la mouche sont vraiment leurs pattes et leurs ailes.

Cette expérience a aussi démontré que même après avoir parcouru une longue distance, leurs pattes peuvent quand même continuer à contaminer la surface sur laquelle elles marchent.

Le professeur Donald Bryant de l’université de l’état de Pennsylvanie a indiqué :

“Nous pensons que ceci démontre un mécanisme de transmission d’agents pathogènes qui a été par les services de santé publique, et les mouches peuvent contribuer à la transmission rapide de pathogènes dans un cas d’épidémie.”

Contrôle de la population des mouches et santé publique

Les bactéries détectées sur les échantillons de mouches bleues et mouches domestiques coïncident avec celles retrouvées dans la flore intestinale humaine et les matériaux en décomposition dans un environnement urbain. Cette étude démontre que la surface extérieure d’une mouche, en particulier ses pattes, est un vecteur efficace dans la transmission de bactéries d’une surface à une autre. Les agents pathogènes humains ne sont pas les seuls concernés, puisque les bactéries peuvent également transmettre des maladies végétales et animales.

Les mouches domestiques, les mouches bleues et les mouches en général peuvent ainsi servir de repère pour connaître les dangereuses bactéries qui se trouvent dans un environnement donné.

Les chercheurs ont conclu que les techniques d’analyses génétiques développées dans le cadre de cette étude peuvent être utilisées pour prédire et prévenir la transmission potentielle de bactéries causant des maladies.

Elles pourraient être un outil très efficace dans le contrôle des vecteurs et dans les programmes de surveillance de la santé publique.

Όταν βλέπετε την μανούλα σας να γίνεται υστερική με τις μύγες που βλέπει στην κουζίνα, να ξέρετε, δεν έχει άδικο.

Τώρα έχει και την επιστήμη να την υποστηρίξει στην μανία της να προστατεύσει το φαγητό της οικογένειας από αυτά τα (ας το παραδεχτουμε) εκνευριστικά πετούμενα.

Νέα έρευνα από τρία πανεπιστήμια (Pennsylvania State University, Nanyang Technological University της Σιγκαπούρης και Federal University του Ρίο ντε Τζανέιρο) βρήκε ότι τα έντομα αυτά κουβαλάνε πολύ περισσότερα βλαπτικά μικρόβια από αυτά που νομίζαμε. Τα ευρήματα της έρευνας δημοσιεύθηκαν στο Scientific Reports και μάλλον θα σας σοκάρουν.

Βρήκαν ότι η μέση μύγα συχνά κουβαλάει στα πόδια της και τα φτερά της εκατοντάδες διαφορετικά είδη βακτηρίων, τα οποία προέρχονται ακόμη και από κόπρανα που έχει προηγουμένως κάτσει. Αυτά μεταφέρονται πολύ εύκολα στις επιφάνειες που κάθεται στη συνέχεια (από φαγητό, πάγκους κτλ).

Αηδία!

Η έρευνα περιγράφει τις μύγες ως «αερομεταφορείς βακτηρίων» αφού είναι το τέλειο όχημα για τη διασπορά τους.

Ο καθηγητής Stephan Schuster του Nanyang, λέει στη Daily Mail: «Τα πόδια τους και τα πτερύγια παρουσιάζουν την υψηλότερη μικροβιακή ποικιλομορφία στο σώμα της μύγας, υποδηλώνοντας ότι τα βακτήρια χρησιμοποιούν τις μύγες σαν αερομεταφορείς».

Ένα από τα βακτήρια που βρέθηκαν ήταν το ελικοβακτηρίδιο του πυλωρού, το οποίο μπορεί να προκαλέσει σοβαρά προβλήματα στο γαστρεντερικό.

Τα καλά νέα (αν μπορούμε να τα χαρακτηρίσουμε έτσι) είναι ότι οι μύγες της επαρχίας κουβαλάνε λιγότερα βακτήρια από εκείνες της πόλης.

Ο καθηγητής Donald Bryant, σχολιάζει: «Η έρευνα θα σε κάνει να το σκεφτείς πολύ πριν φας την πατατοσαλάτα σου, εάν έχεις προηγουμένως δει μια μύγα να κάθεται πάνω της».

Πηγές: Independent, Daily Mail

Nikada ne biste smjeli jesti s tanjura na koji je sletjela muha. Oni koji jedu s tanjura na kojem je bila muha, riskiraju različite opasne bolesti. Prema najnovijoj studiji, muhe, na svojim nogama, nose puno više bolesti nego se prije mislilo.

Na nogama i krilima muha nalaze se stotine različitih vrsta bakterija koje su pokupile sliječući na lešine ili izmet. Bakterije s njihovih nogu se lako prenose na površne na koje slete. Bakterije koriste muhe za zračni prijevoz. Bakterija može preživjeti let, rasti i širiti se po novim površinama.

GRADSKE MUHE OPASNIJE OD SEOSKIH

Znanstvenici su već dugo sumnjali da muhe kojih ima svuda oko nas, imaju značajnu ulogu u prenošenju i širenju uzročnika bolesti. Tim znanstvenika s Pennsylvania State Sveučilišta, Nanyang Sveučilišta iz Singapura i Federalnog Sveučilišta u Rio de Janeiru, proučavali su mikrobiome 116 kućnih muha i muha zunzara s tri različita kontinenta.

Studija, objavljena u časopisu Scientific Reports, utvrdila je da su u nekim slučajevima muhe nosile stotine različitih bakterija, od kojih je puno štetno za ljude. Tu je, na primjer, helicobacter pylori, patogena bakterija koja često izaziva čir u crijevima. Muhe iz grada nose puno više bakterija nego seoske muhe.

VAŽAN MEHANIZAM PRIJENOSA BOLESTI

Vrste muha kao zunzare i kućne muhe koriste izmet i raspadajuće organske tvari da bi othranile podmladak. Znači, mogu pokupiti bakterije koje su patogene za ljude, biljke i životinje.

Znanstvenici vjeruju da ovo istraživanje pokazuje važan mehanizam prijenosa bolesti koji su zdravstvene službe previdjele jer muhe mogu pridonijeti brzom prijenosu patogena kod epidemija.

La naturaleza está llena de seres llenos de ambición, pequeños y grandes conquistadores que quieren ampliar sus dominios y los de su especie. Los humanos podemos parecer un grupo con éxito, pero nada si se nos compara con las bacterias. Estos microorganismos tienen una capacidad de adaptación sorprendente y, aunque no han sido capaces de construir aviones con los que expandirse por el planeta, han encontrado aliados numerosos para suplir sus carencias ingenieriles.

Esta semana, un equipo internacional de científicos ha realizado un estudio que trata de entender el papel de las moscas en la transmisión de enfermedades bacterianas. En un artículo que se publica en la revista Scientific Reports explican que estudiaron los microbiomas de 116 moscas de tres continentes distintos. Según explican en un comunicado, en algunos casos estas moscas eran auténticas portabacterias, cargando cientos de especies diferentes, muchas de las cuales son capaces de hacer enfermar a las personas.

Los autores del trabajo, liderados por Donald Bryant, de la Universidad Penn State (EE UU), analizaron los microbios alojados en las distintas partes de los cuerpos de los insectos. Esto permitió observar que las patas son los apéndices a través de los que se transmiten la mayor parte de los microbios al recogerlos en una superficie y depositarlos en otra. “Las patas y las alas muestran la diversidad microbiana más elevada en el cuerpo de la mosca, algo que sugiere que las bacterias utilizan a las moscas como transbordadores”, señala Stephan Schuster, director de la Universidad Tecnológica de Nanyang en Singapur.

El estudio obtuvo algunos resultados interesantes. Por un lado, aunque las moscas tienen querencia por entornos poco higiénicos donde encuentran la materia orgánica en descomposición y las heces que les sirven de alimento para sus crías, las moscas con mayor diversidad bacteriana a bordo no se encontraron en granjas sino en entornos urbanos. Además, los investigadores encontraron en varias moscas recogidas en Brasil la bacteria Helicobacter pylori, causa frecuente de las úlceras. Según Schuster, las moscas no se habían considerado hasta ahora un posible transmisor de estas enfermedades.

Bryant considera que su estudio apunta a un mecanismo para la transmisión de patógenos “que se le podía haber pasado por alto a los responsables de salud pública” y que “las moscas pueden contribuir a la rápida transmisión de patógenos durante brotes”.

Además, los responsables del artículo consideran que este sistema para analizar el ADN de los microbios que transportan insectos puede convertir a estos pequeños animales en mensajeros para la recolección de muestras en lugares inaccesibles e incluso en sistemas de alerta temprana frente a epidemias.

An international research team led by Nanyang Technological University, Singapore (NTU Singapore) have proposed that swarms of flies can be used to help monitor disease outbreaks. This follows their research that shows how whole communities of bacteria – known as a microbiome – can “hitch a ride” on common carrion flies and can be transferred to any surface where the flies land. 

Their research is published in Scientific Reports today by a global team led by NTU geneticist, Professor Stephan Schuster.

By sequencing the genetic material of 116 houseflies and blowflies along with all the microorganisms that they are carrying, the team found that each of these flies carried up to several hundred different species of bacteria, some of which may be harmful to humans.

One of these, Helicobacter pylori, is a pathogen that can cause stomach ulcers in humans and is the strongest known risk factor for gastric cancer. Although known to be spread via body fluid and smear infections, this is the first time that H. pylori has been shown to be spread via flies in the environment.

“Our study has shown that bacteria can ‘fly’ by hitching a ride on common flies,” said Prof Schuster, a research director at the Singapore Centre for Environmental Life Sciences Engineering (SCELSE) at NTU Singapore. “They pick up the microbiome on their feet, spread them across their wings in a similar way like how we might comb our hair, and then proceed to disperse them on surfaces that they land on.”

Dr Ana Carolina Martins Junqueira, a molecular entomologist who co-led the research, said flies are an important part of nature’s eco-system, as they are also pollinators like bees.

“Carrion flies have microscopic hairs on every part of the body excluding the eye and these bristles make them the perfect carrier for pollen and also bacteria. It is an evolutionarily optimised vehicle for the dispersal of microorganisms in the environment,” said Dr Junqueira, a faculty member at the Federal University of Rio de Janeiro.

Flies as part of early health warning system

The team believes that their new technique could put flies into service in public health surveillance programs.

They suggest that germ-free flies, bred without any microorganisms in their microbiome, could pick up latent microbiomes in any environment they are released into since they are small enough to enter even the smallest of cracks and crevices.

When the flies are recaptured using bait traps, their microbiomes can be sequenced, giving clues to the type of bacteria they have encountered in the environment, thus acting as an early warning system.

“Such ‘autonomous bionic drones’ could be particularly useful in agriculture, if we want to detect a plant pathogen outbreak,” said Prof Schuster. “Through regular monitoring, if we know that a particular pathogen is affecting the crops and is becoming an outbreak, then farmers could organise a targeted treatment that only eradicates that pathogen, leaving the other parts of the ecosystem intact.”

“To date, diseases transmitted by a mechanical vector like flies have been a major overlooked pathway by both the medical and academic community. This is a great example of how observations from basic research on how diseases spread might be translated into viable and useful applications, opening up new avenues for future technology.”

New way of sequencing flies

The research findings were made possible thanks to a new way to collect flies without contaminating them with additional microorganisms, and then sequencing every single part of a fly’s body from its head and thorax to its legs and wings.

First, the flies are baited by a piece of rotting fish, followed by the researchers holding a container with dry ice close to the flies. The cold vapour from the dry ice sedates the fly and it falls into the cold container untouched and uncontaminated.

After the fly is defrosted in a sterile environment, the various parts are separated, crushed and then put into a gene sequencing machine. The resulting data is then sorted out by a supercomputer.

After filtering the genetic data from the fly’s own chromosomes, mitochondria and symbiotic bacteria, what is left is the microbiome that can be matched to a database of all known bacteria DNA and RNA.

Flies in the study were collected from four different continents around the world: Australia, Brazil, the United States and Singapore.

This new procedure was inspired by a research trip to Australia, where Prof Schuster and Dr Junqueira were discussing their research with NTU’s Visiting Professor and Nobel Laureate Barry Marshall, who was awarded the Nobel Prize in Physiology or Medicine in 2005 for the discovery of Helicobacter pylori.

“There were quite a lot of flies landing on our sweaters at Prof Marshall’s farm and it was really easy just putting small containers with dry ice to capture them. They were literally dropping like flies,” said Prof Schuster.

Source: NTU News

Flies can be more than pesky picnic crashers, they may be potent pathogen carriers, too, according to an international team of researchers.

In a study of the microbiomes of 116 houseflies and blowflies from three different continents, researchers found, in some cases, these flies carried hundreds of different species of bacteria, many of which are harmful to humans. Because flies often live close to humans, scientists have long suspected they played a role in carrying and spreading diseases, but this study, which was originally initiated at Penn State’s Eberly College of Science, adds further proof, as well as insights into the extent of that threat.

“We believe that this may show a mechanism for pathogen transmission that has been overlooked by public health officials, and flies may contribute to the rapid transmission of pathogens in outbreak situations,” said Donald Bryant, Ernest C. Pollard Professor of Biotechnology and professor of biochemistry and molecular biology, Penn State.

According to Stephan Schuster, former professor of biochemistry and molecular biology, Penn State, and now research director at Nanyang Technological University, Singapore, the researchers were able to investigate the microbial content of individual fly body parts, including legs and wings. The legs appear to transfer most of the microbial organisms from one surface to another, he added.

“The legs and wings show the highest microbial diversity in the fly body, suggesting that bacteria use the flies as airborne shuttles,” said Schuster. “It may be that bacteria survive their journey, growing and spreading on a new surface. In fact, the study shows that each step of hundreds that a fly has taken leaves behind a microbial colony track, if the new surface supports bacterial growth.”

Blowflies and houseflies—both carrion fly species—are often exposed to unhygienic matter because they use feces and decaying organic matter to nurture their young, where they could pick up bacteria that could act as pathogens to humans, plants and animals. The study also indicates that blowflies and houseflies share over 50 percent of their microbiome, a mixture of host-related microorganisms and those acquired from the environments they inhabit. Surprisingly, flies collected from stables carried fewer pathogens than those collected from urban environments.

The researchers, who report their findings in the current issue of Scientific Reports, found 15 instances of the human pathogen Helicobacter pylori, a pathogen often causing ulcers in the human gut, largely in the blowfly samples collected in Brazil. The known route of transmission of Helicobacter has never considered flies as a possible vector for the disease, said Schuster.

The potential, then, for flies to carry diseases may increase when more people are present.

“It will really make you think twice about eating that potato salad that’s been sitting out at your next picnic,” Bryant said. “It might be better to have that picnic in the woods, far away from urban environments, not a central park.”

Ana Carolina Junqueira, professor of genetics and genomics at the Federal University of Rio De Janeiro and previous postdoctoral fellow at the Singapore Centre for Environmental Life Sciences Engineering (SCELSE), said that the novel genomic and computational methods used for the study allowed the team an unprecedented look at the microbial community carried by flies.

“This is the first study that depicts the entire microbial DNA content of insect vectors using unbiased methods,” Junqueira said. “Blowflies and houseflies are considered major mechanical vectors worldwide, but their full potential for microbial transmission was never analyzed comprehensively using modern molecular techniques and deep DNA sequencing.”

Flies may not be all bad, however. The researchers suggest they could turn into helpers for human society, perhaps even serving as living drones that can act as an early-warning system for diseases.

“For one, the environmental sequencing of flies may use the insects as proxies that can inform on the microbial content of any given environment that otherwise would be hard or impossible to sample,” said Schuster. “In fact, the flies could be intentionally released as autonomous bionic drones into even the smallest spaces and crevices and, upon being recaptured, inform about any biotic material they have encountered.”

Source: Phys.org

In news bound to make the commongermophobe even more paranoid about that fly buzzing around thepicnic table, a team of researchers has found that house flies andblow flies can spread a whole host of bacteria that was previously unsuspected to hitch a ride on the insects. The recently published study also suggests that a fly’sbacteria-carrying capability could be hijacked and used in a publichealth surveillance capacity to track pathogen outbreaks.

We’ve long known that the commonhousefly can spread a number of diseases, but a new study has justrevealed that we may have underestimated the volume, and breadth, ofbacteria that these annoying insects can transmit. An internationalteam led by Nanyang Technological University developed a new way tocollect flies without contaminating them with other microorganisms and then sequence theDNA of every part of their body. This allowed species of bacteria they picked up on their travels to be identified.

“Our study has shown that bacteriacan ‘fly’ by hitching a ride on common flies,” says StepheanSchuster, a research director leading the study. “They pick up themicrobiome on their feet, spread them across their wings in a similarway like how we might comb our hair, and then proceed to dispersethem on surfaces that they land on.”

The researchers sequenced the geneticmaterial of 116 species of housefly and blow fly. After separating outall the genetic data that corresponded with the fly’s own chromosomesand symbiotic bacteria, the remaining DNA and RNA was sorted againsta database of all known bacteria.

The study frighteningly found thatflies have the capacity to carry, and spread, hundreds of differentbacteria, some linked to human diseases. One bacteria, for example,called Helicobacter pylori was found on some flies. This bacteria, which is known to causestomach ulcers and is a major risk factor for gastric cancer, had never before been shown to be transmittedby flies.

It’s not all bad news though, with theresearchers suggesting this discovery could be put to a positive use.The study notes that lab-reared flies could be successfully bred tobe germ-free and released into the environment to act as bacterial surveillance drones. With the ability to get into tiny nooks and crannies, the flies could then be recaptured using bait traps and their microbiome sequenced to reveal the types of bacteria they had encountered on their travels.

“Such ‘autonomous bionic drones’could be particularly useful in agriculture, if we want to detect aplant pathogen outbreak,” says Professor Schuster. “Through regular monitoring, if weknow that a particular pathogen is affecting the crops and isbecoming an outbreak, then farmers could organize a targetedtreatment that only eradicates that pathogen, leaving the other partsof the ecosystem intact.”

The study was published in the journalScientific Reports.

Source: Nanyang TechnologicalUniversity, Singapore

Source: New Atlas

SEEING a fly land on the food you have been tucking into isn’t an uncommon occurrence and most of us just shoo the fly away and continue eating.

After all, it’s not like you are going to throw the whole meal away just because of one little fly right?

Well, according to a new study, that is exactly what you should be doing.

Researchers at Penn State University’s Eberly College of Science, Singapore’s Nanyang Technological University and the Federal University of Rio de Janeiro have found that insects carry a lot more dangerous bacteria than previously thought.

The research, published in Scientific Reports, studied 116 house and blowflies and found that they carry a plethora of potentially harmful bacteria such as to carry salmonella, e-coli and others that can result in stomach ulcers and deadly sepsis.

Flies pick up bacteria from faeces and carcasses where they are often the first organisms to arrive and subsequently feed, breed and lay eggs.

They then transfer these germs to other surfaces and hosts, with the study describing them as the perfect “airborne shuttles” for bacteria.

So when a fly lands on your lunch it is bringing all those nasty germs with it.

“People had some notion that there were pathogens that were carried by flies but had no idea of the extent to which this is true and the extent to which they are transferred,” Professor Donald Bryant of Penn State University told BBC News.

Houseflies and blowflies were found to carry a number of harmful germs that have the potential to make a person extremely ill.Source:News Limited

The research reveals that the insect’s legs appear to transfer the most microbial content from one surface to another, with the results suggesting that flies contribute to the rapid spread of pathogens during the outbreak of a disease among humans.

“We believe that this may show a mechanism for pathogen transmission that has been overlooked by public health officials, and flies may contribute to the rapid transmission of pathogens in outbreak situations,” said Professor Bryant.

“It will really make you think twice about eating that potato salad that’s been sitting out at your next picnic.”

Source: news.com.au

Houseflies carry as many as several hundred different species of bacteria, some of which may be harmful to humans, new research shows. The international research team behind the study, led by Nanyang Technological University in Singapore, also proposed that swarms of flies can be used to help monitor disease outbreaks.

The researchers sequenced the genetic material of 116 houseflies and blowflies along with all the microorganisms that they are carrying.

One of the bacteria found, Helicobacter pylori, is a pathogen that can cause stomach ulcers in humans and is the strongest known risk factor for gastric cancer. Although known to be spread by body fluid and smear infections, this is the first time that H. pylori has been shown to be spread by flies in the environment.

Hitching A Ride

The study follows up on research that shows how whole communities of bacteria, known as a microbiome, can “hitch a ride” on common carrion flies and can be transferred to any surface where the flies land.

“Our study has shown that bacteria can ‘fly’ by hitching a ride on common flies. They pick up the microbiome on their feet, spread them across their wings in a similar way like how we might comb our hair, and then proceed to disperse them on surfaces that they land on.”

said team leader Professor Stephan Schuster, a research director at the Singapore Centre for Life Sciences Engineering (SCELSE) at NTU Singapore.

Dr Ana Carolina Martins Junqueira, a molecular entomologist who co-led the research, said flies are an important part of nature’s eco-system, as they are also pollinators like bees.

“Carrion flies have microscopic hairs on every part of the body excluding the eye and these bristles make them the perfect carrier for pollen and also bacteria. It is an evolutionarily optimised vehicle for the dispersal of microorganisms in the environment,”

said Dr Junqueira, a faculty member at the Federal University of Rio de Janeiro.

Health Surveillance

The team envisions their new technique putting flies into public service in health surveillance programs.

Germ-free flies, bred without any microorganisms in their microbiome, could pick up latent microbiomes in any environment they are released into, because they are tiny enough to enter even the smallest of cracks and crevices.

When the flies are recaptured using bait traps, their microbiomes can be sequenced, giving clues to the type of bacteria they have encountered in the environment, thus acting as an early warning system.

“Such ‘autonomous bionic drones’ could be particularly useful in agriculture if we want to detect a plant pathogen outbreak. Through regular monitoring, if we know that a particular pathogen is affecting the crops and is becoming an outbreak, then farmers could organise a targeted treatment that only eradicates that pathogen, leaving the other parts of the ecosystem intact.

To date, diseases transmitted by a mechanical vector like flies have been a major overlooked pathway by both the medical and academic community. This is a great example of how observations from basic research on how diseases spread might be translated into viable and useful applications, opening up new avenues for future technology,”

said Prof Schuster.

The work was funded by the Singapore Ministry of Education Academic Research Fund, the Singapore Centre for Environmental Life Sciences Engineering, the National Research Foundation Singapore, Ministry of Education, Nanyang Technological University, and National University of Singapore.

Ana Carolina M. Junqueira, Aakrosh Ratan, Enzo Acerbi, Daniela I. Drautz-Moses, Balakrishnan N. V. Premkrishnan, Paul I. Costea, Bodo Linz, Rikky W. Purbojati, Daniel F. Paulo, Nicolas E. Gaultier, Poorani Subramanian, Nur A. Hasan, Rita R. Colwell, Peer Bork, Ana Maria L. Azeredo-Espin, Donald A. Bryant, Stephan C. Schuster
The microbiomes of blowflies and houseflies as bacterial transmission reservoirs
Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-16353-x

Source: Sciencebeta

The international study, launched at Penn State Eberly College of Science in the United States, examined microbiomes on 116 houseflies and blowflies from three different continents.

The results, published in the journal Scientific Reports, found that flies contribute to the rapid spread of germs during an outbreak of disease among people – something scientists have long thought.

Scientists found 15 instances of helicobacter pylori bacteria – which causes stomach ulcers – on Brazilian blowflies.

Donald Bryant, a professor of biotechnology at Penn State University, said: “We believe that this may show a mechanism for pathogen transmission that has been overlooked by public health officials.”

Researchers also examined the level of germs on individual areas of the fly, including the legs and wings.

Stephan Schuster, research director at Nanyang Technological University, said the fly’s legs transfer the most microbes from one surface to another.

Flies most likely pick up the bacteria from poo and decaying organic matter which they use to nurture their young, the study found.

“It may be that bacteria survive their journey, growing and spreading on a new surface,” Schuster said.

“In fact, the study shows that each step of hundreds that a fly has taken leaves behind a microbial colony track, if the new surface supports bacterial growth.”

“It will really make you think twice about eating that potato salad that’s been sitting out at your next picnic,” Professor Bryant said.

“It might be better to have that picnic in the woods, far away from urban environments, not a central park.”

Ana Carolina Junqueira, a professor of genetics and genomics at the Federal University of Rio De Janeiro, added: “This is the first study that depicts the entire microbial DNA content of insect vectors using unbiased methods.

“Blowflies and houseflies are considered major mechanical vectors worldwide, but their full potential for microbial transmission was never analysed comprehensively using modern molecular techniques and deep DNA sequencing.”

But the study also suggested that flies could help protect humans by acting as living “drones” or acting as early warning systems for disease.

Schuster added: “For one, the environmental sequencing of flies may use the insects as proxies that can inform on the microbial content of any given environment that otherwise would be hard or impossible to sample.

“In fact, the flies could be intentionally released as autonomous bionic drones into even the smallest spaces and crevices and, upon being recaptured, inform about any biotic material they have encountered.”

Source: The Sun

An international research team led by Nanyang Technological University, Singapore (NTU Singapore) have proposed that swarms of flies can be used to help monitor disease outbreaks. This follows their research that shows how whole communities of bacteria — known as a microbiome — can “hitch a ride” on common carrion flies and can be transferred to any surface where the flies land.

AsianScientist (Nov. 28, 2017) – An international research team led by Nanyang Technological University, Singapore (NTU Singapore) have proposed that swarms of flies can be used to help monitor disease outbreaks. They published their findings in Scientific Reports.

Flies are known to be carriers of disease, responsible for the spread of harmful microbes (pathogens). They are widely regarded as pests, but scientists may now have found a use for them.

In this study, scientists from NTU Singapore sequenced the genetic material of 116 houseflies and blowflies along with all the microorganisms found on the flies. They first baited the flies with a piece of rotting fish, then sedated the attracted flies by holding a container with dry ice close to the flies. The cold vapor from the dry ice sedated the flies and they fell into the cold container untouched and uncontaminated.

After the flies were defrosted in a sterile environment, the various parts were separated, then crushed, and the extracted DNA was put into a gene sequencing machine. A supercomputer was subsequently used to analyze the resultant data, separating the fly’s genes from that of symbiotic bacteria. The researchers thus discerned the fly’s microbiome by referencing a database of all known bacteria DNA and RNA.

The researchers discovered that each of these flies carried up to several hundred different species of bacteria, some of which may cause disease humans. Among the species of bacteria detected, the researchers identified Helicobacter pylori, a pathogen that can cause stomach ulcers in humans and is the strongest known risk factor for gastric cancer. Although known to be spread via body fluid and smear infections, this is the first time that  H. pylori has been shown to be carried by flies in the environment.

“Our study has shown that bacteria can ‘fly’ by hitching a ride on common flies,” said Professor Stephan Schuster, a research director at the Singapore Centre for Environmental Life Sciences Engineering (SCELSE) at NTU Singapore. “They pick up the microbiome on their feet, spread them across their wings in a similar way like how we might comb our hair, and then proceed to disperse them on surfaces that they land on.”

The team believes that their new technique could put flies into service in public health surveillance programs. They suggest that germ-free flies, bred without any microorganisms in their microbiome, could pick up latent microbiomes in any environment they are released into since they are small enough to enter even the smallest of cracks and crevices.

When the flies are recaptured using bait traps, their microbiomes can be sequenced, giving clues to the type of bacteria they have encountered in the environment, thus acting as an early warning system.

“Such ‘autonomous bionic drones’ could be particularly useful in agriculture, if we want to detect a plant pathogen outbreak,” said Schuster. “Through regular monitoring, if we know that a particular pathogen is affecting the crops and is becoming an outbreak, then farmers could organize a targeted treatment that only eradicates that pathogen, leaving the other parts of the ecosystem intact.”

“To date, diseases transmitted by a mechanical vector like flies have been a major overlooked pathway by both the medical and academic community. This is a great example of how observations from basic research on how diseases spread might be translated into viable and useful applications, opening up new avenues for future technology,” he added.

The article can be found at: Junqueira et al. (2017) The Microbiomes of Blowflies and Houseflies as Bacterial Transmission Reservoirs

Source: Asian Scientist

It’s never a nice feeling to watch a fly land on your next bite of food, but as new research shows, you may be justified in wanting to toss that delicious morsel in the garbage.

New research published in Scientific Reports shows that two common flies—houseflies and blowflies—are capable of carrying hundreds of different bacteria—a good portion of which are harmful to humans. Flies are born from fecal matter and rot, so this isn’t a complete surprise, but it’s the first study to analyze the gut contents of these insects in detail, and evaluate the ability of flies to carry and deliver germs. Flies like to hang around humans, as we’re all painfully aware, so these findings are a bit troublesome.

“We believe that this may show a mechanism for pathogen transmission that has been overlooked by public health officials, and flies may contribute to the rapid transmission of pathogens in outbreak situations,” Donald Bryant, co-author of the new study and a professor at Penn State, said in a press release.

 

For the study, the researchers analyzed the microbiome of 116 houseflies and blowflies from three different continents. In addition to detecting and characterizing the host of germs found within the flies’ stomachs, the researchers also looked at the microbial content of individual body parts, finding that the legs were responsible for transferring most of the microbial organisms from one surface to another.

“The legs and wings show the highest microbial diversity in the fly body, suggesting that bacteria use the flies as airborne shuttles,” said study co-author Stephan Schuster. “It may be that bacteria survive their journey, growing and spreading on a new surface. In fact, the study shows that each step of hundreds that a fly has taken leaves behind a microbial colony track, if the new surface supports bacterial growth.”

 

Which, yuck. In 15 cases, traces of the human pathogen Helicobacter pylori—the blight that causes ulcers in the human gut—were found on blowflies taken from Brazil. Prior to this study, scientists had never even considered flies as a possible vector for this disease.

The researchers also learned that blowflies and houseflies are very similar in terms of their stomach contents, sharing over 50 percent of their microbiome—an unholy mixture of microorganisms that the flies pick up from their surroundings. Interestingly, flies collected from farm stables had fewer germs than those collected from urban environments.

“It will really make you think twice about eating that potato salad that’s been sitting out at your next picnic,” said Bryant. “It might be better to have that picnic in the woods, far away from urban environments, not a central park.”

Source: Gizmodo

We all know that with their penchant to feast on rotting flesh and partiality for poop, flies are pretty unhygienic creatures. It now seems that we have been underestimating just how gross these insects are, if that is even possible.

A new study published last week in Scientific Reports has found that both houseflies and blowflies are a positive haven for bacteria, with some insects carrying hundreds of different species on their wings and legs, depositing them where they land, be it the surfaces in your kitchen or the sausage rolls at your picnic. Many of these bacteria can have a significant impact on human health, and as a result, the authors argue that health organizations have been overlooking the role the insects may play in disease outbreaks.

“The legs and wings show the highest microbial diversity in the fly body, suggesting that bacteria use the flies as airborne shuttles,” explained Stephan Schuster, who coauthored the research. “It may be that bacteria survive their journey, growing and spreading on a new surface. In fact, the study shows that each step of hundreds that a fly has taken leaves behind a microbial colony track, if the new surface supports bacterial growth.”

The team sequenced the microbiomes of 116 houseflies and blowflies from three different continents to build up a picture of the diversity of microorganisms that live on the insects, and even the researchers were stunned by what they found. They discovered that overall, the creatures harbored over 600 different types of bacteria, with many of these being linked to human health. Interestingly, they found that the flies sampled from horse stables had a lower diversity of bacteria on their bodies than those from urban environments.

It is well known that flies can transmit diseases, but up to now scientists had no idea just how extensive this can be. For example, the researchers discovered 15 flies that were carrying the bacteria Helicobacter pylori, which is known to cause stomach ulcers in humans. Until now, flies have never before been considered a vector for Helicobacter.

While this obviously has important implications for human health, with the researchers suggesting that perhaps the next time you have a picnic, choose a spot in the woods rather than that park in the middle of the city, it could have some other exciting applications.

The insects could be used as natural biomonitoring “drones”. The authors suggest that flies could be sent into certain regions that might be hard to sample, and then the microbiomes of the insects tested to see what microorganisms are present.

Source: IFL Science

Flies really do spread germs, a new study confirmed.

The insects are not only annoying by trying to land on your meal or crawling over kitchen countertops, they also carry more diseases than previously thought.

And their legs and their wings are teeming with pathogens that hitch a ride after the flies land on dead carcasses or feces and then spread them to new surfaces.

Scientists studied the microbiomes of 116 houseflies and blowflies from three different continents.

They found that in some cases these flies carried hundreds of different species of bacteria, many harmful to humans.

And the risk of picking up a nasty bug increases the more people are around because city flies are more germ-ridden than their country cousins.

Professor Donald Bryant of Penn State said: “It will really make you think twice about eating that potato salad that’s been sitting out at your next picnic”

“It might be better to have that picnic in the woods, far away from urban environments, not a central park.”

“We believe that this may show a mechanism for pathogen transmission that has been overlooked by public health officials, and flies may contribute to the rapid transmission of pathogens in outbreak situations.”

Scientists had long suspected flies played a role in carrying and spreading diseases because they are all around us.

The study published in the journal Scientific Reports investigated the microbial content of individual fly body parts, including legs and wings.

The legs appear to transfer most of the microbial organisms from one surface to another.

Research director Stephan Schuster, from Singapore’s Nanyang Technological University, said: “The legs and wings show the highest microbial diversity in the fly body, suggesting that bacteria use the flies as airborne shuttles.”

“It may be that bacteria survive their journey, growing and spreading on a new surface.”

“In fact, the study shows that each step of hundreds that a fly has taken leaves behind a microbial colony track, if the new surface supports bacterial growth.”

Blowflies and houseflies, both carrion fly species, are often exposed to unhygienic matter because they use feces and decaying organic matter to nurture their young.

They can then pick up bacteria that could act as pathogens to humans, plants and animals.

The study also indicated blowflies and houseflies share over 50 percent of their microbiome, a mixture of host-related microorganisms and those acquired from the environments they inhabit.

Surprisingly, flies collected from stables carried fewer pathogens than those collected from urban environments.

The researcher found 15 instances of the human pathogen Helicobacter pylori, a pathogen often causing ulcers in the human gut, largely in the blowfly samples collected in Brazil.

The known route of transmission of Helicobacter has never considered flies as a possible vector for the disease.

Professor of genetics and genomics Ana Carolina Junqueira from the Federal University of Rio De Janeiro said that the novel genomic and computational methods used for the study allowed the team an unprecedented look at the microbial community carried by flies.

Junqueira added: “This is the first study that depicts the entire microbial DNA content of insect vectors using unbiased methods.”

“Blowflies and houseflies are considered major mechanical vectors worldwide, but their full potential for microbial transmission was never analyzed comprehensively using modern molecular techniques and deep DNA sequencing.”

Source: New York Post

Do you want flies with your food? The answer should almost always be no, and a study published in Scientific Reports gives more reasons why such a side dish is not good.

News flash. Flies are dirty. Not in a moral or political way. But in a bacteria- and other pathogen-carrying way. For the study, a team of researchers from the Universidade Federal do Rio de Janeiro, University of Virginia, Nanyang Technological University, European Molecular Biology Laboratory, the Universidade Estadual de Campinas, the University of Georgia, and CosmosID, Inc. collected 63 samples of blowfly species Chrysomya megacephala and 53 samples of the housefly species Musca domestica from three different continents in urban, rural, and natural settings. They then used a procedure called whole-genome shotgun sequencing (WGS) to determine the types of pathogens that the flies were carrying.

The results were a bit icky. You’ve heard the saying: “on it like flies on poop” (except some use another word equivalent to the word “poop”)? Well, if someone says that about you, it’s an insult, in case you are wondering. Flies don’t exactly hang out in the cleanest environments, unless you count excrement, garbage, and carcasses as clean environments. And whenever and wherever flies land and crawl, bacteria in that location can stick to their bodies, especially their legs and wings. For flies, “shake a leg” may mean dropping bacteria. Indeed, flies seem to be like little Boeing 747s carrying different types of bacteria as passengers (probably with very little legroom as well).

Not all of these bacteria are dangerous. But some could cause diseases in plants, animals, or humans. For example, in humans, Erysipelothrix rhusiopathiae could lead to a skin infection called erysipeloid, Proteus mirabilis can cause urinary tract infections, and Helicobacter pylori has been associated with stomach ulcers, stomach cancer, and mucosa-associated lymphoid tissue lymphoma.

The study also raises the possibility that in the future scientists could use flies to monitor the pathogens in the environment. Testing the flies in a location could show what types of bacteria are common in the area and how the bacteria may be spreading over time. Yes, such testing can show how bacteria flies over time.

So how do you keep flies away from your food and your living quarters? Screens on doors and windows can keep them outside. Also, make sure that you don’t leave poop and food out too long. (If you tend to leave poop out in your house, please don’t invite me over). Insect repellents can also keep flies away. If you aren’t a fan of spraying chemicals around your house, you can look for a repellent without chemicals or use substances that seem to naturally repel flies. Writing for Lifehack, Jenny Marchal mentioned herbs like basil, essential oils like lavender, camphor, orange peels, cloves in citrus fruit, and hanging a bag of water. Now I haven’t tried all of these possibilities, but there are worse things in the world than being surrounded by basil.

If you want to catch flies, you can either purchase a fly trap, fly paper, or a Venus Fly Trap plant or make your own fly trap. Marchal described how you can use vinegar, wine, or honey to lure flies into a container that they can’t escape. Note: don’t use your mouth as that container.

Should you then freak out if a single fly lands on you or your food? Just because a fly carries bacteria doesn’t mean it can carry enough to cause an infection. Future scientific studies are necessary to determine the specific role that flies can play in spreading different diseases. Flies could be like episodes of a reality television show. Chances are that a single one won’t have too much of an effect. But many episodes of “Real Houseflies”? You may want to be wary of a kitchen swarming with flies, in case you didn’t know.

Source: Forbes Magazine

Researchers have undertaken a massive sequencing effort to analyze the whole genomes of 116 houseflies (Musca domestica) and blowflies (Chrysomya megacephala)—plus all their resident microbes. These metagenomes, along with laboratory experiments, point to flies’ ability to pick up bacteria on their legs and deposit their microbial passengers elsewhere, revealing the potential for flies to transfer potentially pathogenic bacteria.

“We believe that this may show a mechanism for pathogen transmission that has been overlooked by public health officials, and flies may contribute to the rapid transmission of pathogens in outbreak situations,” coauthor Donald Bryant of Penn State University tells BBC News. “It will really make you think twice about eating that potato salad that’s been sitting out at your next picnic.”

The insects were captured from various sites around the world. The most-common bacterial phyla represented among the flies’ microbiomes were Proteobacteria, Bacteroidetes, and Firmicutes—similar to what has been observed in other insect microbiomes, the researchers reported in Scientific Reports last week (November 24).

The team also broke down the blowfly microbiome by host body part, namely, head, thorax, abdomen, and leg plus wing. The limbs and wings were distinguishable by the presence of Helicobacter species, including H. pylori, which can cause ulcers. All 15 of the host flies that had Helicobacter species had been caught in Brazil, and the authors suspect the flies picked the bacteria up from sewage.

“Whether H. pylori survives and persists on the outer body of the fly has not been determined,” the researchers wrote in their report. However, a laboratory experiment demonstrated flies could pick up E. coli after walking on a Petri dish covered in the bacteria, and then spread the colonies to sterile plates they later visited.

“Our study has shown that bacteria can ‘fly’ by hitching a ride on common flies,” coauthor Stephan Schuster, a research director at the Singapore Centre for Environmental Life Sciences Engineering at Nanyang Technological University, Singapore, says in a press release. “They pick up the microbiome on their feet, spread them across their wings in a similar way like how we might comb our hair, and then proceed to disperse them on surfaces that they land on.”

Source: The Scientist

Scientists have discovered that flies carry more diseases than suspected.

The house fly and the blowfly together harbour more than 600 different bacteria, according to a DNA analysis.

Many are linked with human infections, including stomach bugs, blood poisoning and pneumonia.

Flies can spread bacteria from place-to-place on their legs, feet and wings, experiments show. In fact, every step taken by a fly can transfer live bacteria, researchers said.

”People had some notion that there were pathogens that were carried by flies but had no idea of the extent to which this is true and the extent to which they are transferred,” Prof Donald Bryant of Penn State University, a co-researcher on the study, told BBC News.

Outbreaks

DNA sequencing techniques were used to study the collection of microbes found in and on the bodies of the house fly (Musca domestica) and the blowfly (Chrysomya megacephala).

The house fly, which is ubiquitous around the world, was found to harbour 351 types of bacteria. The blowfly, which is found in warmer climates, carried 316. A large number of these bacteria were carried by both types of fly.

The researchers, who published their study in the journal Scientific Reports, say flies may have been overlooked by public health officials as a source of disease outbreaks.

“We believe that this may show a mechanism for pathogen transmission that has been overlooked by public health officials, and flies may contribute to the rapid transmission of pathogens in outbreak situations,” said Prof Bryant.

“It will really make you think twice about eating that potato salad that’s been sitting out at your next picnic,” he added.

However, the researchers believe flies could have their uses – acting as early warning systems for disease or even living drones sent into tight spaces to search for microbes.

“In fact, the flies could be intentionally released as autonomous bionic drones into even the smallest spaces and crevices and, upon being recaptured, inform about any biotic material they have encountered,” said Stephan Schuster, research director at Nanyang Technological University, Singapore.

House flies are well known for their poor hygiene habits – visiting rubbish tips and feeding on all sorts of decaying food, animal corpses and faecal matter. They are suspected of carrying a range of human, animal and plant diseases.

Blow flies are one of the most common flies found around dead animals. They are common in urban areas and are often found near meat-processing plants, rubbish dumps and slaughterhouses.

Source: BBC

Um novo estudo conduzido por investigadores do Brasil, Singapura e Estados Unidos revelou que nunca se deve comer nada que tenha sido tocado por uma mosca. Porquê? As bactérias que estes insectos albergam são transferidas para a comida.

Publicado na Scientific Reports, o estudo analisou os microbiomas – microrganismos que se situam no interior de um organismo vivo – de 116 moscas por todo o mundo. Os resultados comprovaram que a mosca comum transporta centenas de bactérias de fezes e seres mortos nas suas patas e asas – bactérias que são facilmente transportadas para as superfícies onde pousam.

No estudo, as moscas são descritas como “transportes aéreos” de bactérias. “As patas e as asas mostram a maior diversidade microbial da mosca, sugerindo que as bactérias utilizam estes insectos como transporte aéreo”, disse Stephan Schuster, investigador da Universidade de Singapura, citado pelo Daily Mail. “O mais provável é que a bactéria sobreviva, crescendo e espalhando-se na nova superfície”.

Os investigadores acreditam que, se se comer algo que uma mosca tenha tocado, se ingiram as bactérias que o insecto transporta.

Source: Ciência e Saúde

Elas entram no lixo, passam por esgotos e cadáveres, vomitam em tudo, estão cobertas de microorganismos do cocô, e, ao fim, pousam na sua comida. As moscas são super nojentas, mas a situação pode ser pior do que pensávamos.

De acordo com novas pesquisas, o corpinho desses insetos pode estar carregando toda espécie de agentes patogênicos, contribuindo para espalhá-los. Tudo isso por conta de suas patas “mucosas”, que contém uma substância para grudar vírus, fungos e bactérias.

Especialistas da Universidade Estadual da Pensilvânia, nos Estados Unidos, estudaram os microbiomas de 116 moscas domésticas de três continentes diferentes. Com isso, descobriram que alguns desses bichos levam centenas de diferentes espécies de bactérias de um lugar para o outro, transmitindo-as às superfícies que pousam.

“As pernas e as asas mostram a maior diversidade microbiana no corpo da mosca, sugerindo que as bactérias usam as moscas como ‘ônibus aéreos'”, afirma Stephan Schuster, ex-professor de bioquímica e biologia molecular da PennState, ao Phys. “Pode ser que as bactérias sobrevivam nessa jornada, crescendo e se espalhando em uma nova superfície.”

Os pesquisadores encontraram mais patógenos nos insetos coletados em ambientes urbanos do que os provenientes do meio rural. Quinze casos de um patógeno chamado Helicobacter pylori, que causa úlceras intestinais, foram descobertos (principalmente em moscas originárias do Brasil).

O bioquímico Donald Bryant alerta que esses bichinhos têm sido negligenciados em políticas de saúde pública, quando notavelmente tem um papel importante na trasmissão de doenças. “Isso realmente vai fazer você pensar duas vezes sobre comer aquela salada de batatas que foi deixada [ao ar livre] no seu próximo piquenique”, disse o especialista em entrevista ao Phys.

Embora essas informações possam aumentar sua aversão às moscas (com razão), vale ressaltar que esses insentos nojentos podem ajudar a ciência em outros sentidos. A amostragem de microbiomas de uma mosca, por exemplo, poderia ajudar no estudo do conteúdo microbiano de alguns ambientes mais difíceis de alcançar com os métodos tradicionais.

(Com informações de Science Alert.)

Source: Galileu

Se você acha que moscas são animais pouco higiênicos, a ciência acaba de encontrar evidências de que você tem toda a razão. Um estudo publicado na última semana no periódico Scientific Reports e você acha que sugere que os pequenos insetinhos podem carregar centenas de bactérias causadoras de doenças.

“Acreditamos que isso pode evidenciar um mecanismo para a transmissão de patógenos [microrganismos causadores de doenças] que foi negligenciado por oficiais de saúde pública. As moscas podem contribuir para a transmissão rápida de agentes patogênicos em situações de surto”, afirma em comunicado o bioquímico e coautor do estudo Donald Bryant, da Universidade Estadual da Pensilvânia, nos Estados Unidos. Segundo os pesquisadores, cada parada que uma mosca faz em uma superfície – como, por exemplo, no seu prato de almoço – deixa uma trilha de colônias de micróbios.

O estudo analisou os germes presentes em 116 moscas comuns e varejeiras, coletadas em três continentes diferentes. Segundo os resultados, as asas e as patas são as partes do corpo dos insetos com maior concentração de bactérias. Os cientistas encontraram o patógeno Helicobacter pylori, causador da úlcera em humanos, em 15 das moscas analisadas – a grande maioria delas coletada aqui no Brasil.

Além disso, o estudo indica que moscas urbanas costumam apresentar mais patógenos do que as que foram encontradas em zonas rurais. Isso sugere que o número de bactérias presentes nos insetos aumenta em ambientes onde há maior concentração de pessoas.

“Isso realmente vai fazer você pensar duas vezes antes de comer uma salada de batata que ficou ali por um tempo no seu próximo piquenique”, brinca Bryant. “Talvez seja melhor fazer esse piquenique na floresta, longe dos ambientes urbanos, e não em um parque.”

Source: Veja

Basta uma única mosquinha sobrevoando a mesa para ligar o sinal de alerta: quem está por perto corre para espantar o inseto, na tentativa de evitar seu contato com a comida a todo custo. Quando já é tarde demais, o jeito é reparar o estrago. Os mais precavidos tratam de descartar o pedaço em que o bicho pousou e isolar a área, para garantir que o visitante indesejado não volte a dar as caras durante a refeição.

Embora possa parecer para alguns, não se trata apenas de excesso de cuidado. Alimentos de fato podem ficar contaminados graças à breve visita de uma mosca, tudo por conta dos hábitos pouco higiênicos desses insetos. Durante seus voos, eles acabam se alimentando de tudo que é tipo de detrito. Restos como fezes, animais mortos e matéria orgânica em decomposição estão recheados de micróbios, que ficam grudados em suas asas e patas e podem se desprender na próxima aterrissagem.

Um estudo recente, publicado no jornal Scientific Reports, cravou que uma mosca doméstica, por exemplo, pode carregar até 351 bactérias diferentes. No caso da varejeira, também conhecida como mosca verde, são 316 tipos de microrganismos — alguns deles, inclusive, nocivos à saúde humana.

“Em geral, estas bactérias são oportunistas e potencialmente patogênicas, causando doenças do trato gastrointestinal, do trato urinário, úlceras estomacais, infecções cutâneas e respiratórias”, explicou Ana Carolina Martins Junqueira, professora de genética e genômica da Universidade Federal do Rio de Janeiro (UFRJ), em entrevista a SUPER. Coordenando uma equipe internacional de cientistas, ela analisou 116 exemplares dessas moscas, coletados em áreas urbanas do Brasil, EUA e Cingapura.

Para capturar as moscas, os pesquisadores utilizaram um método inovador, testado pela primeira vez em insetos. Cada mosquinha era atraída  pelo cheiro de restos de peixe em decomposição, até ficar presa em um recipiente com gelo seco. O vapor do gelo seco era capaz de sedá-las, fazendo-as cair “desmaiadas” — e, o melhor de tudo, sem estar contaminadas por agentes externos.

Com as mosquinhas fora de combate, o grupo tinha o caminho livre para analisá-las geneticamente. Isolando o DNA presente em partes como as asas, pés e patas dos insetos, conseguiu-se identificar os corpos estranhos que estavam presentes ali. O resultado você já conhece: as amostras das duas moscas indicaram a presença de mais de centenas de microrganismos diferentes.

Exemplares de moscas coletados aqui no Brasil, por exemplo, indicaram a presença de  Helicobacter pylori , bactéria que causa úlceras e gastrite em humanos. “É a primeira vez que se propõe que moscas varejeiras podem ter um papel na dispersão de H. pylori. Isso significa que esta pode ser uma via de dispersão da bactéria que jamais foi considerada”, pontua Junqueira. Entre as formas de contágio mais comuns estão o contato com alimentos, água, salivas e fezes contaminadas.

A sobrevivência dessas bactérias no corpo dos insetos depende de sua capacidade de formar esporos — estruturas que garantem sua proteção até que  encontrem um lugar propício para crescerem —, o que varia de espécie para espécie. “No caso da H. pylori, já foi demonstrado que as células podem sobreviver por 12 horas expostas ao ar”. Considerando que o tempo de vida de uma mosquinha costuma ser de 28 dias, a chance de que um inseto que teve contato com algo contaminado pouse em seu sanduíche é maior que se imagina.

Segundo o estudo, moscas urbanas costumam carregar mais bactérias do que as que as encontradas em zonas rurais. Isso sugere que o potencial nocivo desses insetos aumenta onde há maior concentração de pessoas. Para a pesquisadora, o potencial desses insetos como transmissores de doenças tem sido subestimado. As pragas urbanas mais visadas por ações de saúde pública acabam sendo os mosquitos, que, por sua vez, costumam carregar um número de microrganismos bem menor. “As moscas servem como meios de transporte de bactérias e, neste processo, são mais genéricas em relação à quantidade e diversidade de microrganismos que carregam”.

Source: Superinteressante

By Karina Toledo  |  Agência FAPESP – At the same time as the dinosaurs began to disappear – during the transition from the Cretaceous to the Paleocene over 60 million years ago – a group of insects called Schizophora began to flourish.

The clade Schizophora, which belongs to the Brachycera suborder of Diptera (the order of true flies), is an adaptive radiation, a term used in evolutionary biology to refer to lineages that diversified rapidly in a given period. The clade comprises thousands of species, representing approximately 3% of the Earth’s animal diversity, surpassing even the number of all terrestrial species of vertebrates.

Blow flies and flesh flies (from families such as Calliphoridae and Sarcophagidae) date from 22 million years ago. Their appearance on earth coincided with that of the browsing and grazing mammals, and millions of years later some species became parasites of such mammals. An example is the New World screw-worm fly Cochliomyia hominivorax.

These are some of the findings of a study published in Scientific Reports, an online journal that belongs to Nature Publishing Group. The authors are researchers at the University of Campinas (UNICAMP) and the University of São Paulo (USP) at Ribeirão Preto in Brazil, the University of Virginia in the US, and Nanyang Technological University in Singapore.

To investigate the evolutionary histories of these insects, the scientists adapted techniques from large-scale mitogenomics, the simultaneous sequencing of mitochondrial DNA in hundreds of samples. The study was conducted with support from FAPESP as part of Ana Carolina Martins Junqueira’s postdoctoral research under the supervision of Ana Maria Lima de Azeredo-Espin, a professor at UNICAMP.

“Mitogenomics is a variant of genomics that analyzes mitochondrial nucleotide sequences instead of cell nucleus DNA,” explained Junqueira, currently a researcher at Nanyang Technological University’s Singapore Center for Environmental Life Sciences Engineering (SCELSE).

Mitochondrial genome sequencing is relatively fast, so this is the most commonly used marker in evolutionary studies. “The technology was originally developed for research on vertebrates and has been intensively used in studies of human migration,” Junqueira said. “But it’s been underused in the case of insects, even though they represent the greatest animal diversity on the planet.”

To develop large-scale mitogenomics in insects, the group chose the Schizophora radiation as a model. Thirty-two species of flies from different families were collected in the US, Australia and Singapore, as well as São Paulo State and Amazonas State.

The insects were macerated, and the total genomic DNA contained in the samples was extracted. Next, bioinformatics tools were used to select only the data referring to mitochondrial nucleotide sequences, which corresponded to between 1% and 5% of the total. Almost 100 mitochondrial genomes are detailed in the article published by Scientific Reports.

“Based on nucleotide diversity, it’s possible to estimate the time taken for each species or family to diverge during the geological timescale and to clarify phylogenetic relationships,” Junqueira said. “We used the few invertebrate fossils available as a benchmark. In the case of insects, fossils are dated according to the geological layer in which they were found. We added the molecular data to this information to estimate the period in which one species diverged from another.”

According to Azeredo-Espin, the analysis focused on flies that cause myiasis, the parasitic infestation of the body of a live mammal by fly larvae that grow inside the host while feeding on its tissue.

“Our line of research seeks to understand the evolution of parasitism in this group of flies, which are considered livestock pests and cause significant economic losses,” she said. “Additional knowledge can be useful for control strategies. The findings suggest ectoparasitism arose in flesh flies and blow flies between 2.3 million and 6.9 million years ago.”

The group’s hypothesis is that the Schizophora radiation began diversifying intensely after a period of severe worldwide drought gave rise to treeless dwarf vegetation and grasslands, to which herbivorous mammals adapted.

“At that time, the continents were closer together,” Junqueira said. “East Asia and North America were connected by the Bering land bridge, allowing animals and plants to disperse to the New World. There was an abundance of food, and they began to diversify. Herbivores became more common, increasing the diversification of carnivores. As a result, there was an increase in biomass, which was essential to the diversification of these species of sacrophagous insects that feed on dead or decaying organic matter.”

According to Azeredo-Espin, more generalist species emerged first, with habits that were not necessarily associated with the presence of other animals. After millions of years of coexistence with grazing mammals, insects with specialized habits appeared.

“Examples include the human botfly Dermatobia hominis and the secondary screw-worm Cochliomyia macellaria, which complete their reproductive cycle by laying eggs in a living warm-blooded host,” she said.

Population analysis

For two of the species included in the study – the Oriental latrine blow fly Chrysomya megacephala and the house fly Musca domestica – population analyses were also performed. These species are mechanical vectors of disease and hence are important to physicians and veterinarians.

Metagenomic datasets were generated for 64 specimens of these two species collected on three continents, with the aim of measuring genetic variability and gene flows from one location to another.

The results suggested that while house flies appeared to be grouped in distinct geographical zones with low levels of gene flow among the different populations, blow flies were practically uniform on all continents.

“The genetic variability observed in Chrysomya megacephala was very small, practically residual, on the scale expected only for species in extinction, yet this species displays significant invasive and adaptive capabilities,” Junqueira said.

To enhance their understanding of the phenomenon, the group plan to perform the same type of analysis using data from the nuclear genomes of the flies collected, according to Azeredo-Espin.

“We want to find out whether loss of genetic variation occurs only in the mitochondrial genome or is also present in the nuclear genome. Depending on what we discover, there could be a different explanation,” she said.

Given the impact of flies on environmental and human health, she added, this information could be highly strategic for the development of vector control programs in urban areas, where flies are major carriers of viruses and bacteria.

The article “Large-scale mitogenomics enables insights into Schizophora (Diptera) radiation and population diversity” (doi: 10.1038/srep21762) can be read at www.nature.com/articles/srep21762.

Source: Agência Fapesp

Karina Toledo  |  Agência FAPESP – Na mesma época em que os dinossauros começaram a desaparecer – durante a transição do período Cretáceo para o Paleoceno, há mais de 60 milhões de anos –, um grupo de insetos conhecido como Schizophora passou a florescer.

Pertencente à ordem Diptera e à subordem das moscas Brachycera, a radiação adaptativa Schizophora (termo usado para se referir a uma linhagem que se diversificou rapidamente em um determinado período) abrange milhares de espécies. Representam cerca de 3% de toda a diversidade animal na Terra, em uma variedade maior que a de todos os vertebrados somados.

Dentro desse grupo, há 22 milhões de anos surgiram as chamadas moscas- varejeiras, integrantes de famílias como Calliphoridae e Sarcophagidae. Seu aparecimento no planeta teria sido concomitante ao dos mamíferos pastadores, dos quais algumas espécies – como a mosca-da-bicheira (Cochliomyia hominivorax) – tornaram-se parasitas milhões de anos depois.

As conclusões são de um estudo publicado na Scientific Reports, do grupo Nature, por pesquisadores das universidades Estadual de Campinas (Unicamp), de São Paulo (USP) em Ribeirão Preto, Virginia (Estados Unidos) e Nanyang Technological (Cingapura).

Para desvendar a história evolutiva desses insetos, os cientistas adaptaram técnicas de mitogenômica em larga escala – que permitem sequenciar simultaneamente o DNA mitocondrial em centenas de amostras. O trabalho foi feito com apoio da FAPESP durante o pós-doutorado de Ana Carolina Martins Junqueira, sob a supervisão da professora Ana Maria Lima de Azeredo-Espin, da Unicamp.

“A mitogenômica é uma variação da genômica que, em vez de trabalhar com o DNA existente no núcleo celular, busca acessar as informações sobre as sequências de nucleotídeos contidas nas mitocôndrias”, explicou Junqueira, que atualmente é pesquisadora do Singapore Centre for Environmental Life Sciences Engineering, na Nanyang Technological University.

Por ser mais rápido de sequenciar, o genoma mitocondrial é o marcador mais usado em estudos evolutivos. “A tecnologia foi rapidamente desenvolvida para as pesquisas com vertebrados e amplamente empregada no estudo das migrações humanas. Mas havia ficado subdesenvolvida no caso dos insetos, apesar de eles representarem a maior diversidade de vida animal na Terra”, disse Junqueira.

Para desenvolver a mitogenômica de insetos em larga escala, o grupo elegeu como modelo a radiação Schizophora. Moscas de 32 espécies, de diferentes famílias, foram coletadas nos Estados Unidos, na Austrália e em Cingapura, além de em São Paulo e na região Amazônica.

Os insetos foram macerados e todo o DNA contido nas amostras, extraído. Em seguida, com auxílio de ferramentas de bioinformática, foram selecionados apenas os dados referentes às sequências de nucleotídeos da mitocôndria – algo entre 1% e 5% do total gerado. Quase uma centena de genomas mitocondriais foi divulgada no artigo publicado na Scientific Reports.

“Com base na diversidade dos nucleotídeos, é possível estimar o tempo de divergência de cada espécie ou família ao longo da escala geológica e esclarecer as relações filogenéticas. Usamos como referência os poucos dados fósseis existentes sobre invertebrados”, disse Junqueira.

“No caso dos insetos, os fósseis são datados de acordo com a camada geológica em que foram encontrados. Adicionamos os dados moleculares sobre essas informações para estimar o período em que uma espécie divergiu de outra”, disse.

Segundo Azeredo-Espin, o foco das análises foram as moscas causadoras de miíase, doença caracterizada pela infestação de larvas de moscas na pele ou outros tecidos.

“Nossa linha de pesquisa busca entender a evolução do hábito de parasitismo desse grupo de moscas, que são consideradas pragas da pecuária e causam grande perda econômica, pois o conhecimento pode ser útil em estratégias de controle. Os resultados sugerem que o ectoparasitismo de moscas-varejeiras teria surgido entre 2,3 e 6,9 milhões de anos atrás”, disse.

De acordo com a hipótese defendida pelo grupo, a radiação Schizophora começou a se diversificar intensamente após um período de forte seca no planeta, que deu origem a uma vegetação mais baixa, como gramíneas e tundra, à qual os mamíferos herbívoros se adaptaram.

“Nessa época, os continentes estavam mais próximos e o estreito de Bering era uma ponte terrestre, o que possibilitou aos mamíferos pastadores se dispersar pelo planeta. Havia abundância de alimento e eles começaram a se diversificar. Com a diversificação dos herbívoros, veio a diversificação dos carnívoros. Dessa forma, houve um aumento de biomassa, o que foi essencial para a diversificação dessas espécies de insetos saprófagos [que se alimentam de restos orgânicos em decomposição]”, disse Junqueira.

Azeredo-Espin conta que inicialmente surgiram espécies mais generalistas, cujos hábitos não estavam necessariamente associados à presença de outros animais. Após milhões de anos de convivência com mamíferos pastadores, entraram em cena insetos com hábitos especializados.

“É o caso da mosca-da-bicheira e da mosca-do-berne, que, para fechar seu ciclo reprodutivo, precisam depositar seus ovos em um hospedeiro vivo e de sangue quente”, disse a professora da Unicamp.

Estudo populacional

Para duas das espécies de moscas incluídas no estudo – a Chrysomya megacephala (um tipo de mosca-varejeira) e a Musca domestica (mosca-doméstica) – foi feito também um estudo populacional. Essas espécies são vetores mecânicos de patógenos e têm importância médica e veterinária.

Para o estudo, foram sequenciados 60 genomas de indivíduos das duas espécies, coletados em três diferentes continentes. O objetivo foi avaliar a variabilidade genética e o fluxo de genes de um local para outro.

Os resultados sugerem que, enquanto as moscas domésticas parecem estar agrupadas em zonas geográficas distintas, com baixo nível de fluxo gênico entre as diferentes populações, a espécie Chrysomya megacephala é praticamente igual nos diferentes continentes.

“A variabilidade genética observada na Chrysomya megacephala foi muito pequena, praticamente residual. Algo que seria esperado apenas para espécies em extinção. E, no entanto, a espécie demonstra grande poder de invasão e de adaptação”, disse Junqueira.

Para entender melhor o fenômeno, o grupo pretende fazer o mesmo tipo de análise usando como base os dados do genoma nuclear das moscas coletadas, contou Azeredo-Espin.

“Queremos descobrir se a perda de variação genética ocorre apenas no genoma mitocondrial ou se também está presente no genoma nuclear. Dependendo do que encontrarmos, haverá uma explicação diferente”, disse.

Segundo a pesquisadora, a informação será essencial para o desenvolvimento de programas de controle de vetores em áreas urbanas, onde a mosca é um importante carreador de vírus e bactérias.

O artigo Large-scale mitogenomics enables insights into Schizophora (Diptera) radiation and population diversity (doi: 10.1038/srep21762)pode ser lido em www.nature.com/articles/srep21762.

Source: Exame

Na mesma época em que os dinossauros começaram a desaparecer – durante a transição do período Cretáceo para o Paleoceno, há mais de 60 milhões de anos –, um grupo de insetos conhecido como Schizophora passou a florescer.

Pertencente à ordem Diptera e à subordem das moscas Brachycera, a radiação adaptativa Schizophora (termo usado para se referir a uma linhagem que se diversificou rapidamente em um determinado período) abrange milhares de espécies.

Representam cerca de 3% de toda a diversidade animal na Terra, em uma variedade maior que a de todos os vertebrados somados.

Dentro desse grupo, há 22 milhões de anos surgiram as chamadas moscas- varejeiras, integrantes de famílias como Calliphoridaee Sarcophagidae.

Seu aparecimento no planeta teria sido concomitante ao dos mamíferos pastadores, dos quais algumas espécies – como a mosca-da-bicheira (Cochliomyia hominivorax) – tornaram-se parasitas milhões de anos depois.

As conclusões são de um estudo publicado na Scientific Reports, do grupo Nature, por pesquisadores das universidades Estadual de Campinas (Unicamp), de São Paulo (USP) em Ribeirão Preto, Virginia (Estados Unidos) e Nanyang Technological (Cingapura).

Para desvendar a história evolutiva desses insetos, os cientistas adaptaram técnicas de mitogenômica em larga escala – que permitem sequenciar simultaneamente o DNA mitocondrial em centenas de amostras.

O trabalho foi feito com apoio da FAPESP durante o pós-doutorado de Ana Carolina Martins Junqueira, sob a supervisão da professora Ana Maria Lima de Azeredo-Espin, da Unicamp.

“A mitogenômica é uma variação da genômica que, em vez de trabalhar com o DNA existente no núcleo celular, busca acessar as informações sobre as sequências de nucleotídeos contidas nas mitocôndrias”, explicou Junqueira, que atualmente é pesquisadora do Singapore Centre for Environmental Life Sciences Engineering, na Nanyang Technological University.

Por ser mais rápido de sequenciar, o genoma mitocondrial é o marcador mais usado em estudos evolutivos.

“A tecnologia foi rapidamente desenvolvida para as pesquisas com vertebrados e amplamente empregada no estudo das migrações humanas. Mas havia ficado subdesenvolvida no caso dos insetos, apesar de eles representarem a maior diversidade de vida animal na Terra”, disse Junqueira.

Para desenvolver a mitogenômica de insetos em larga escala, o grupo elegeu como modelo a radiação Schizophora.

Moscas de 32 espécies, de diferentes famílias, foram coletadas nos Estados Unidos, na Austrália e em Cingapura, além de em São Paulo e na região Amazônica.

Os insetos foram macerados e todo o DNA contido nas amostras, extraído. Em seguida, com auxílio de ferramentas de bioinformática, foram selecionados apenas os dados referentes às sequências de nucleotídeos da mitocôndria – algo entre 1% e 5% do total gerado. Quase uma centena de genomas mitocondriais foi divulgada no artigo publicado na Scientific Reports.

“Com base na diversidade dos nucleotídeos, é possível estimar o tempo de divergência de cada espécie ou família ao longo da escala geológica e esclarecer as relações filogenéticas. Usamos como referência os poucos dados fósseis existentes sobre invertebrados”, disse Junqueira.

“No caso dos insetos, os fósseis são datados de acordo com a camada geológica em que foram encontrados. Adicionamos os dados moleculares sobre essas informações para estimar o período em que uma espécie divergiu de outra”, disse.

Segundo Azeredo-Espin, o foco das análises foram as moscas causadoras de miíase, doença caracterizada pela infestação de larvas de moscas na pele ou outros tecidos.

“Nossa linha de pesquisa busca entender a evolução do hábito de parasitismo desse grupo de moscas, que são consideradas pragas da pecuária e causam grande perda econômica, pois o conhecimento pode ser útil em estratégias de controle. Os resultados sugerem que o ectoparasitismo de moscas-varejeiras teria surgido entre 2,3 e 6,9 milhões de anos atrás”, disse.

De acordo com a hipótese defendida pelo grupo, a radiação Schizophora começou a se diversificar intensamente após um período de forte seca no planeta, que deu origem a uma vegetação mais baixa, como gramíneas e tundra, à qual os mamíferos herbívoros se adaptaram.

“Nessa época, os continentes estavam mais próximos e o estreito de Bering era uma ponte terrestre, o que possibilitou aos mamíferos pastadores se dispersar pelo planeta. Havia abundância de alimento e eles começaram a se diversificar. Com a diversificação dos herbívoros, veio a diversificação dos carnívoros. Dessa forma, houve um aumento de biomassa, o que foi essencial para a diversificação dessas espécies de insetos saprófagos [que se alimentam de restos orgânicos em decomposição]”, disse Junqueira.

Azeredo-Espin conta que inicialmente surgiram espécies mais generalistas, cujos hábitos não estavam necessariamente associados à presença de outros animais. Após milhões de anos de convivência com mamíferos pastadores, entraram em cena insetos com hábitos especializados.

“É o caso da mosca-da-bicheira e da mosca-do-berne, que, para fechar seu ciclo reprodutivo, precisam depositar seus ovos em um hospedeiro vivo e de sangue quente”, disse a professora da Unicamp.

Estudo populacional

Para duas das espécies de moscas incluídas no estudo – a Chrysomya megacephala (um tipo de mosca-varejeira) e a Musca domestica (mosca-doméstica) – foi feito também um estudo populacional.

Essas espécies são vetores mecânicos de patógenos e têm importância médica e veterinária.

Para o estudo, foram sequenciados 60 genomas de indivíduos das duas espécies, coletados em três diferentes continentes. O objetivo foi avaliar a variabilidade genética e o fluxo de genes de um local para outro.

Os resultados sugerem que, enquanto as moscas domésticas parecem estar agrupadas em zonas geográficas distintas, com baixo nível de fluxo gênico entre as diferentes populações, a espécie Chrysomya megacephala é praticamente igual nos diferentes continentes.

“A variabilidade genética observada na Chrysomya megacephala foi muito pequena, praticamente residual. Algo que seria esperado apenas para espécies em extinção. E, no entanto, a espécie demonstra grande poder de invasão e de adaptação”, disse Junqueira.

Para entender melhor o fenômeno, o grupo pretende fazer o mesmo tipo de análise usando como base os dados do genoma nuclear das moscas coletadas, contou Azeredo-Espin.

“Queremos descobrir se a perda de variação genética ocorre apenas no genoma mitocondrial ou se também está presente no genoma nuclear. Dependendo do que encontrarmos, haverá uma explicação diferente”, disse.

Segundo a pesquisadora, a informação será essencial para o desenvolvimento de programas de controle de vetores em áreas urbanas, onde a mosca é um importante carreador de vírus e bactérias.

O artigo Large-scale mitogenomics enables insights into Schizophora (Diptera) radiation and population diversity (doi: 10.1038/srep21762)pode ser lido em www.nature.com/articles/srep21762. 

Source: Agência Fapesp

No ano 2000, o grupo liderado pela professora da Unicamp Ana Maria Lima de Azeredo Espin foi o primeiro no país a sequenciar o DNA mitocondrial (encontrado no interior da mitocôndria) de uma espécie de inseto: a mosca-da-bicheira (Cochliomyia hominivorax), considerada uma das mais nocivas pragas da pecuária na América do Sul. Agora, passados 16 anos, a docente e sua equipe conseguem, pela primeira vez, sequenciar o DNA mitocondrial completo de diversas espécies do grupo Schizophora, que inclui 78 famílias da ordem Diptera (moscas e mosquitos), entre elas a mosca-varejeira (Chrysomya megacephala), a mosca-doméstica (Musca domestica), a mosca-das-frutas (Drosophila melanogaster) e a própria mosca-da-bicheira.

O estudo, que integrou parte do pósdoutorado da bióloga Ana Carolina Martins Junqueira, então sob a supervisão de Azeredo Espin, traz uma série de dados novos sobre a história evolutiva e populacional deste diverso grupo de insetos. Os resultados da pesquisa foram publicados no periódico de acesso livre Scientific Reports      (https://www.nature.com/articles/srep21762), pertencente ao grupo Nature.

Ana Junqueira desenvolveu seu pós-doutorado no Centro de Biologia Molecular e Engenharia Genética (CBMEG) da Unicamp. Atualmente, ela é pesquisadora do Singapore Centre for Environmental Life Sciences Engineering, da Nanyang Technological University, em Singapura.

Além de Ana Junqueira, também assinam o artigo a professora Ana Maria Azeredo Espin, que atua no CBMEG e no Departamento de Genética, Evolução e Bioagentes do Instituto de Biologia (IB); o doutorando da Unicamp Daniel Fernando Paulo; o pós-doutorando Marco Antonio Tonus Marinho, da Universidade de São Paulo (USP) em Ribeirão Preto; a pesquisadora Lynn Tomsho, da Universidade Estadual da Pensilvânia (Estados Unidos); Aakrosh Ratan, da Universidade de Virginia (Estados Unidos); e os pesquisadores Daniela Drautz-Moses, Rikky Purbojati e Stephan Schuster, da Nanyang Technological University (NTU). O estudo foi financiado pela Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp).

Utilizando diferentes estratégias de sequenciamento e análise, foi possível estimar que o grupo Schizophora surgiu entre 65 e 70 milhões de anos atrás, no mesmo período em que os dinossauros “não-avianos” desapareceram. Os pesquisadores acreditam que o surgimento desse grupo de insetos, concomitante ao desaparecimento dos dinossauros, não é mera coincidência.

“Toda vez que há uma extinção em massa, alguns grupos conseguem expandir a sua diversidade porque novos nichos ecológicos são abertos”, aponta Ana Carolina Junqueira. De acordo com ela, os resultados acerca do surgimento desse grupo corroboram os dados da literatura científica sobre o tema. “Nós conseguimos datar também o aparecimento da família Calliphoridae há 22 milhões de anos, do qual as moscas-varejeiras são integrantes”, revela.

A pesquisadora informa que o surgimento dessa família ocorreu após um período de seca que abateu o planeta, levando ao surgimento de um novo bioma, a tundra. Este novo ambiente possibilitou, por sua vez, o surgimento dos mamíferos pastadores, que são herbívoros. A mosca-da-bicheira (Cochliomyia hominivorax), que pertence à família Calliphoridae, tornou-se, milhões de anos depois (cerca de 7 milhões de anos atrás), um dos principais parasitas de mamíferos, causando severas infestações conhecidas como miíases.  

“Nós acreditamos que a evolução dessa família está muito relacionada a essa abertura de nicho, com uma nova vegetação que passou a existir. Foi a partir daí que surgiram os mamíferos pastadores que, por sua vez, deram origem aos carnívoros. Tudo isso gerou uma intensificação da produção de matéria orgânica, que é o principal alimento das moscas-varejeiras. É daí que essas moscas proliferaram e a evolução delas está muito ligada à própria diversificação de mamíferos”, sugere. 

A professora da Unicamp, Ana Maria Lima de Azeredo Espin, ressalta que foram empregadas diferentes técnicas da área conhecida como mitogenômica para sequenciar de modo simultâneo o DNA mitocondrial deste grupo de insetos. Segundo os pesquisadores, este é o estudo que mais descreve genomas mitocondriais completos de um grupo de insetos até o momento.

Ao todo foram sequenciados 91 genomas de 32 espécies diferentes. “Ao invés de trabalharmos com o DNA nuclear, nós utilizamos o DNA mitocondrial. A vantagem é que o genoma mitocondrial tem um tamanho menor em relação ao nuclear e isso possibilita que este genoma possa ser sequenciado completamente em menor tempo e a um custo relativamente baixo. O genoma mitocondrial tem sido muito utilizado para o entendimento da história evolutiva de grupos animais, inclusive de humanos”, explica a docente.

Com as técnicas empregadas, foi possível otimizar a escala de análise do genoma mitocondrial de insetos. “Isso é fundamental porque, com as novas plataformas de sequenciamento, nós conseguimos melhorar a escala de conhecimento desse grupo de insetos, do qual se tinha poucos dados disponíveis.” Os insetos foram coletados em diferentes regiões do mundo, incluindo Estados Unidos, Austrália, Cingapura, São Paulo e Amazônia.

Em relação ao aspecto populacional, Ana Junqueira destaca que há resultados importantes sobre a mosca-varejeira. Conforme a pesquisadora, a variabilidade genética desta espécie é muito reduzida, semelhante às encontradas em espécies em extinção. “Isso sugere que essa espécie é muito parecida no mundo inteiro, mas ao contrário de estar em extinção, ela é uma espécie em expansão, com grande poder de invasão e adaptação”, indica.

A mosca-varejeira é um vetor mecânico de patógenos, acrescenta a pesquisadora. “Ela se alimenta de matéria orgânica em decomposição, podendo carregar bactérias e vírus desses ambientes, facilitando a disseminação de doenças. Daí a importância de estudos como este. Sempre que existe a necessidade de desenvolver projetos ou programas de controle de vetores, como se faz para o Aedes aegypti (mosquito transmissor dos vírus da dengue, chikungunya e zika), por exemplo, são necessários dados populacionais. É preciso saber como a espécie está distribuída e estruturada para pensar nas estratégias que serão utilizadas como controle”, exemplifica.

Pesquisas em andamento já estão sendo conduzidas para sequenciar também o DNA nuclear da mosca-varejeira, informa a bióloga. A perspectiva é ter o chamado ‘genoma de referência’. “Com o genoma nuclear vamos tentar entender, por exemplo, porque essas moscas não ficam doentes, apesar do ambiente extremamente patogênico em que elas vivem. Será que existe algo do sistema imune que as protejam contra essa quantidade de bactérias?”, indaga a pesquisadora Ana Junqueira.

Neste ponto, a professora da Unicamp informa que o grupo também aprovou um projeto em colaboração entre a Unicamp e NTU para o sequenciamento do genoma nuclear da mosca-da-bicheira. A pesquisa, de acordo com ela, será fundamental para o desenvolvimento de estratégias de controle na agropecuária nacional, já que esta mosca tem se mostrado muito resistente a inseticidas. “O estudo buscará compreender também quais são as diferenças entre as duas moscas da mesma família, a da bicheira e a varejeira, já que uma é parasita de animais e a outra é um vetor de patógenos.”

O aluno Daniel Fernando Paulo, que desenvolve doutorado sob a orientação de Azeredo Espin, acrescenta que a diferença de hábitos alimentares entre essas duas espécies é respaldada pelas análises evolutivas. “Utilizando os dados deste estudo em conjunto com as informações funcionais e regulatórias do genoma nuclear dessas espécies, nós poderemos inferir como estes hábitos alimentares surgiram, como eles evoluíram e como podemos ‘controlá-los’. Este estudo abre uma série de outras linhas de pesquisa que poderão ser exploradas no futuro”, prevê.

Publicação

Junqueira, A. C. M. et al. Large-scale mitogenomics enables insights into Schizophora (Diptera) radiation and population diversity. Sci. Rep. 6, 21762; doi: 10.1038/srep21762 (2016).

Source: Jornal da Unicamp

Agência FAPESP – Nearly 30% of the microorganisms found in blowflies are capable of causing diseases in humans says a study carried out by researchers at the University of Campinas (Unicamp), Pennsylvania State University in the United States and Nanyang Technological University in Singapore.

Among the bacteria found in the bodies of the insects were Yersinia pestis, which causes bubonic plague, Helicobacter pylori, which is associated with gastritis, ulcers and stomach cancer, and several species that can cause gastroenteritis, pneumonia and urinary infections.

The data were presented by Ana Carolina Martins Junqueira, a researcher at the Singapore Center on Environmental Life Sciences Engineering (Scelse) in Singapore, during the event “Advanced Topics in Genomics and Cell Biology,” held August 4-6, 2014, at Unicamp.

“Everyone knows that flies are dirty insects, but the rate of pathogenic bacteria was so high that we were stunned. It’s the most pathogenic microbiome ever described. We’re going to now begin some experiments to determine whether flies merely transport the microorganisms or whether they in fact transmit these diseases to people by landing on food, for example,” Junqueira explained.

The scientists analyzed the microbiota found in the bodies of 127 flies from 19 species that are usually attracted to decomposing organic matter. The insects were collected in 12 different locations in the U.S. and Brazil during Junqueira’s post-doctoral studies, sponsored by FAPESP and carried out at Unicamp.

In the areas around Campinas, collections were performed at a public hospital, a food market, a city park and a rubbish dump. Collections were also made at a nature reserve in the Amazon Forest and in six stalls of different species of animals raised on the Penn State University Park campus, in State College, Pennsylvania. A control lineage was maintained in a laboratory at the Center for Molecular Biology and Genetic Engineering (CBMEG/Unicamp).

Junqueira remarked that the original project goal had been to sequence the mitochondrial genome of 20 species of flies belonging to the order Diptera as well as to study the evolution of these insects with the help of next-generation sequencing platforms.

“In the beginning, I had some trouble sequencing certain fragments of the genome. Then, I met Stephan Schuster, at the time a professor at Penn State University, who became interested in the work and decided to collaborate,” said Junqueira.

Schuster suggested that the best way to map the mitochondrial genome would be to sequence everything from the collected flies, including the microbiota they carried, and then to filter the associated genomes (metagenome) during the data analysis step. “First we sequenced only the head, then the thorax and abdomen and, finally, the feet and wings,” the researcher explained.

After completing her post-doctorate, Junqueira worked with Schuster in the United States to analyze the metagenome. To do that, they needed to develop new techniques to optimize the treatment and categorization of the immense volume of data generated by next-generation sequencing methods.

“By using statistical analyses on the microorganisms collected, it was possible to separate the flies according to where they were found: urban environments, the Amazon, rural environments and the laboratory. This shows that the environment has much more impact on modulating the microbiome than the species itself,” Junqueira said.

According to the researcher, the number of pathogens found in the flies from urban environments was much larger than from the other environments, likely because there is more trash and decomposing organic matter available in that environment.

“The real problem is that these insects easily go back and forth between a filthy environment such as a dump and, for example, our backyard barbeques. In the flies collected inside the hospital, we found bacteria responsible for two-thirds of the world’s hospital infections,” Junqueira commented.

In addition to the fact that the bacteria are pathogenic to humans, the researcher added, species that can cause diseases in plants and animals were also found.

“We defended the hypothesis that this type of insect can be used as an environmental sensor to help predict outbreaks, mainly in border areas, ports and airports. We could monitor contamination by analyzing the microbiome of these flies,” the researcher said.

Aedes

At the Singapore Center on Environmental Life Sciences Engineering, Schuster and Junqueira are currently using the same approach created in the study of blowflies to investigate the microbiome of Aedes aegypti, the mosquito that can transmit dengue.

“The goal is to see whether there is a difference between the microorganisms found in mosquitoes infected by the dengue virus and those not infected. The study is still in its early stages and, for now, we’ve only worked with laboratory specimens. However, we have already observed differences between the bacteria found in these two groups,” Junqueira explained.

In the future, the scientists are planning to investigate the possibility of preventing the mosquitoes from being infected with the virus through modulation of the microbiome found in their bodies.

At the same time, Junqueira is also working with researchers from the Center for Molecular Biology and Genetic Engineering (CBMEG/Unicamp) led by professor Ana Maria Lima de Azeredo-Espin. With support from FAPESP, the group is analyzing microRNAs of different species of blowflies and livestock pests to attempt to understand the regulation of genes involved in the feeding habits of these insects.

“The study could generate data on the genetic factors of flies that are associated with their attraction to decomposing organic matter or live tissue, in addition to providing essential data for the study of the host-microbiome interaction,” Junqueira explained.

Source: Agência FAPESP

Agência FAPESP – Cerca de 30% dos microrganismos encontrados em moscas varejeiras são capazes de causar doenças em seres humanos, revelou um estudo feito por pesquisadores da Universidade Estadual de Campinas (Unicamp), da PennState University, dos Estados Unidos, e da Nanyang Technological University, de Cingapura.

Entre as bactérias encontradas nos corpos dos insetos estavam a Yersinia pestis, causadora da peste bubônica, a Helicobacter pylori, associada ao surgimento de gastrite, úlcera e câncer de estômago, e diversas espécies que podem provocar gastroenterite, pneumonia e infecções urinárias.

Os dados foram apresentados por Ana Carolina Martins Junqueira, pesquisadora do Singapore Centre on Environmental Life Sciences Engineering (Scelse), de Cingapura, durante o evento “Advanced Topics in Genomics and Cell Biology”, realizado entre os dias 4 e 6 de agosto na Unicamp.

“Todo mundo sabe que moscas são insetos sujos, mas o índice de bactérias patogênicas foi tão alto que ficamos assustados. É o microbioma mais patogênico já descrito. Vamos iniciar agora alguns experimentos para descobrir se elas apenas transportam os microrganismos ou se podem, de fato, transmitir essas doenças para as pessoas ao pousar na comida, por exemplo”, contou Junqueira.

Os cientistas analisaram a microbiota encontrada no corpo de 127 moscas, de 19 espécies que costumam ser atraídas por matéria orgânica em decomposição. Os insetos foram coletados em 12 locais diferentes do Brasil e dos Estados Unidos durante o pós-doutorado de Junqueira – realizado na Unicamp com apoio da FAPESP.

Nos arredores de Campinas, a coleta foi feita em um hospital público, um mercado de comidas, um parque de área urbana e um lixão. Também foram realizadas coletas em uma reserva natural da Floresta Amazônica e em seis estábulos de diferentes espécies de animais criados no campus da PennState University, em University Park, Pennsylvania. Uma linhagem foi mantida em um laboratório do Centro de Biologia Molecular e Engenharia Genética (CBMEG/Unicamp) como controle.

Originalmente, contou Junqueira, o objetivo do projeto era sequenciar o genoma mitocondrial de 20 espécies de moscas pertencentes à ordem Diptera, bem como estudar a evolução desses insetos com auxílio de plataformas de sequenciamento de nova geração.

“No início, tive certa dificuldade para sequenciar determinados fragmentos do genoma. Posteriormente, conheci Stephan Schuster, na época professor da PennState University, que se interessou pelo trabalho e decidiu colaborar”, contou Junqueira.

Schuster propôs que a melhor maneira de mapear o genoma mitocondrial seria sequenciar tudo que havia nas moscas coletadas, inclusive a microbiota por elas transportada, e depois filtrar os genomas associados (metagenoma) durante a etapa de análise dos dados. “Primeiro sequenciamos apenas a cabeça, depois o tórax, o abdômen e, por último, patas e asas”, contou a pesquisadora.

Após terminar o pós-doutorado, Junqueira trabalhou com Schuster nos Estados Unidos para fazer a análise do metagenoma. Para isso, foi necessário desenvolver novas técnicas, de modo a otimizar o tratamento e a categorização do imenso volume de dados gerados pelos métodos de sequenciamento de nova geração.

“Por meio de análises estatísticas dos microrganismos encontrados, foi possível separar as moscas de ambiente urbano, as da Amazônia, as de ambiente rural e as de laboratório. Isso mostra que o ambiente tem um peso muito maior na modulação do microbioma do que a espécie em si”, disse Junqueira.

De acordo com a pesquisadora, o número de patógenos encontrados nas moscas de ambientes urbanos foi muito maior que nas demais, provavelmente porque nesse ambiente há maior quantidade disponível de lixo e de matéria orgânica em decomposição.

“O grande problema é que esses insetos comutam facilmente entre um ambiente sujo, como um lixão, e o churrasco das nossas casas. Nas moscas coletadas dentro do hospital, por exemplo, encontramos bactérias responsáveis por dois terços das infecções hospitalares do mundo”, disse Junqueira.

Além das bactérias patogênicas para humanos, acrescentou a pesquisadora, também foram encontradas espécies que podem causar doenças em animais e em plantas.

“Defendemos a hipótese de que esse tipo de inseto pode ser usado como sensor ambiental e ajudar a predizer surtos, principalmente em regiões de fronteira, portos, aeroportos. Poderíamos monitorar a contaminação dos ambientes por meio da análise do microbioma das moscas”, afirmou a pesquisadora.

Aedes

Atualmente no Singapore Centre on Environmental Life Sciences Engineering, Schuster e Junqueira estão usando a mesma abordagem criada no estudo com moscas varejeiras para investigar o microbioma do Aedes aegypti, mosquito transmissor da dengue.

“O objetivo é ver se há diferença entre os microrganismos encontrados em mosquitos infectados pelo vírus da dengue e os não infectados. O estudo ainda está no começo e, por enquanto, só trabalhamos com espécimes de laboratório. Mas já vimos diferenças entre as bactérias existentes nesses dois grupos”, explicou a pesquisadora.

No futuro, os cientistas pretendem investigar a possibilidade de inibir a infecção do mosquito pelo vírus por meio da modulação do microbioma existente em seu corpo.

Paralalelamente, Junqueira também colabora com pesquisadores do Laboratório de Genética e Evolução Animal do CBMEG/Unicamp, liderado pela professora Ana Maria Lima de Azeredo-Espin. O grupo analisa microRNAs de diferentes espécies de moscas varejeiras e pragas da pecuária para tentar entender a regulação de genes envolvidos no hábito alimentar desses insetos, com o apoio da FAPESP.

“O estudo poderá gerar dados a respeito de fatores genéticos das moscas que estão associados à atração por matéria orgânica em decomposição ou tecidos vivos, além de proporcionar dados fundamentais para o estudo da interação hospedeiro-microbioma”, contou Junqueira.

Source: Agencia FAPESP

Na tarde da última sexta-feira (19/7), o pátio do Centro de Ciências da Saúde (CCS) virou palco de aprendizado e troca de experiências. De férias de suas agendas escolares, cerca de 100 estudantes, vindos de diversas regiões do país e interessados em expor o que aprenderam sobre Paleontologia, Biologia, Astronomia e Farmácia, estavam reunidos para a culminância do projeto Clubes de Ciência.

Entre 15 e 19 de julho, a UFRJ recebeu a terceira edição do evento, que teve como ponto de partida, no Brasil, a Universidade Federal de Minas Gerais (UFMG) e, no mundo, o Instituto de Tecnologia de Massachusetts (MIT) e a Universidade de Harvard. A ideia do Clubes de Ciência é aproximar jovens interessados em pesquisa científica e profissionais já inseridos ou experientes neste fazer. Com isso, cria-se um ambiente de partilha de conhecimento, inovação e prospecção para o futuro.

Durante uma semana, o CCS abrigou palestras, desafios e experimentos coletivos em torno de cinco grupos temáticos – ou Clubes – diferentes: Astrobiologia – a Busca de Vida no Universo; Combatendo Epidemias; Detetives do Passado – as Lições da Paleontologia; Descobrindo Novos Fármacos com Ambiente Virtual; e Entendendo a Vida Através da Genômica. Com isso, os estudantes tiveram acesso a debates que, pela complexidade, não estão na escola.

Olhos brilhantes

Selecionado entre 400 inscritos, Gabriel Balbino, do Rio de Janeiro, nunca havia visitado a UFRJ. Para ele, foi uma surpresa. “Ouvia falar que o Fundão era perigoso, mas não senti isso. Este lugar [CCS] foi bem propício para os nossos estudos”, declarou. Ele foi informado do evento pela direção do Colégio Fator, onde estuda, e não teve dúvidas sobre qual área escolheria: “Eu me inscrevi para participar do Clube sobre Astrobiologia, pois nasci para fazer coisas de natureza”.

Durante a semana, Gabriel aprendeu a identificar se há planetas orbitando estrelas e, também, a investigar a presença de organismos no solo. Entre aulas teóricas e práticas, ele ainda participou da primeira observação aos astros da história da UFRJ feita fora do Observatório do Valongo, no terraço do novo prédio da Faculdade de Farmácia. “Entrei com uma mentalidade e estou saindo com outra. Esse foi o meu primeiro evento acadêmico e não será o único”, concluiu.

Com os olhos brilhantes, Clarissa Souza, do Instituto Federal de Minas Gerais (IFMG), afirmou que este foi um “divisor de águas” em sua vida. “Visitamos o Museu de Geociências, participamos de oficinas, convivemos com muitas pessoas inteligentes, aprendemos a fundo vários assuntos. Quero voltar”, resumiu. Na bagagem, ela levou para Belo Horizonte réplicas de fósseis que modelou com seus colegas e instrutores, bem como o sentimento de estar próxima a uma carreira. “Quero cursar Paleontologia, Geologia ou Geografia”, apontou.

Decisão e foco

Também de Belo Horizonte, Rafaela Boaventura, do Colégio Claretiano, acompanhou as dinâmicas do Clube Entendendo a Vida Através da Genômica. Ela disse optar pela ciência que estuda os genes dos seres vivos por entendê-la como mais próxima da Medicina – o que pretende cursar na graduação. Rafaela esperou um ano para participar do evento e, uma vez  na UFRJ, aproveitou para estabelecer contatos visando a uma possível iniciação científica. “Queria me inscrever no 9° ano [do Ensino Fundamental], mas só podia a partir do Ensino Médio. Então, tive que esperar. Agora, não quero mais parar. Aqui pudemos sair de nossas bolhas, conhecer pessoas diferentes, quebrar tabus”, avaliou.

Veterano entre os colegas, Arthur Borges Cantanzaro, da Escola Estadual Zacarias Antônio da Silva, situada em Cotia, São Paulo, se considera um “neurocientista” e “divulgador científico” desde os 14 anos. Há dois na iniciação científica, ele também optou pelo Clube sobre Genômica por querer “entender mais sobre alinhamento e sequenciamento genético”.

Em sua opinião, outras pessoas poderiam ter a mesma oportunidade. “Tivemos uma palestra essencial sobre como fazer a própria pesquisa: como se elabora uma hipótese? Como você começa a estudar? Isso é fundamental para quem quer começar. Seria interessante se surgissem mais programas como esse para os jovens se aproximarem das ciências o quanto antes. Não só os jovens das capitais, mas também do interior, das periferias”.

Transformação

Professora da Faculdade de Farmácia da UFRJ e anfitriã do evento Clubes de Ciência no Rio de Janeiro, Alessandra Souza considerou o projeto uma oportunidade para abrir as portas da Universidade e estimular a juventude a estudar, mesmo nas férias. “Fui convidada a participar no ano passado, em Belo Horizonte. Trouxe o evento para UFRJ neste ano e, em 2020, já combinamos que o realizaremos aqui novamente”, anunciou.

Para ela, a iniciativa tem um potencial transformador. “A ideia é fazer com que os alunos vivenciem a vida científica conosco. É bom para eles e para nós. No início, achei exagerado dizer que os Clubes mudam a vida das pessoas. Hoje, concordo: mudam mesmo”, observou.

Rede

“Clubes de Ciência” é também o nome de uma organização fundada em 2014 por pesquisadores mexicanos que frequentavam universidades estadunidenses (MIT e Harvard). Em um ano, o projeto alcançou mais de quatro mil estudantes bolivianos e colombianos. Em 2017, chegou ao Brasil. Atualmente, é realizado também no Paraguai e no Peru.

Conforme o site oficial, o propósito do grupo é “expandir o acesso ao ensino de ciências de alta qualidade” e inspirar “as futuras gerações de pesquisadores por meio de uma rede de colaboração científica”. Assim, à medida que os Clubes vão sendo realizados, mais instituições podem aderir e oferecer novos cursos.

A rede em formação tem como meta, até o próximo ano, incorporar mais cinco países e alcançar até 40 mil estudantes. Além da UFMG e da UFRJ, a Fundação Oswaldo Cruz (Fiocruz) também integra a iniciativa.

Source: UFRJ

Scientists from the Singapore Centre for Environmental Life Sciences Engineering (SCELSE) at Nanyang Technological University, Singapore (NTU Singapore) have found that the air in the tropics is teeming with a rich and diverse range of at least 725 different microorganisms.

The NTU scientists used a new sampling and DNA sequencing protocol of microbial communities in Singapore’s air. They found that the composition of the microbial community in the tropical air changes predictably, with bacteria dominating in the day and fungi at night.

This day-night pattern and the diversity of airborne microorganisms in the near-surface atmosphere was previously unknown, as the atmosphere is technologically challenging to study, making it the most underexplored ecosystem on a planetary scale, compared to land and sea ecosystems.

The new knowledge on tropical bioaerosols – tiny airborne particles comprising fungi, bacteria and plant material – is reported this week in the Proceedings of the National Academy of Sciences.

In the research paper led by NTU genomics professor Stephan Schuster, the team reported that tropical air had a microbial diversity with similar complexity to other well-studied ecosystems, such as seawater, soil, and the human gut.

These bioaerosol communities (airborne particles of biological origin) have an unexpectedly high number of bacterial and fungal species, and they follow a diel cycle (a 24-hour day and night cycle) which scientists believe is driven by environmental conditions such as humidity, rain, solar irradiance and carbon dioxide levels.

They also demonstrate a greater variation in composition within a day than between days or even months. This robust community structure maintains long-term predictability, despite variations in airflow and monsoonal winds across the tropical seasons.

Impact on human health

Professor Schuster, who is a research director at SCELSE, said having the ability to analyse bioaerosols provides insights into many aspects of urban life that affect our daily living and human well-being. It also provides an understanding of the interactions between atmospheric, terrestrial and aquatic planetary ecosystems, which is particularly valuable during climate change.

“Our current study suggests that temperature is also a global driver of microbial community dynamics for the atmosphere near the surface. Such understanding is fundamental to ensuring ecosystem sustainability in urban settings and beyond,” Prof Schuster added.

“Locally, understanding bioaerosol dynamics will also inform the way we are managing our surrounding atmosphere, such as the effect of indoor air quality, mechanical ventilation and pollution on the air microbiomes that surround us. Further, our study provides important and much-needed insights into bioaerosols in a tropical setting, given that existing studies have exclusively involved temperate climates.”

On average, humans breathe in 11 cubic metres of air daily (11 thousand litres), which could contain some 50 thousand organism cells in the tropics during the day time, but 30 to 100 times that amount at night.

The scientists say they are beginning to understand the effect of air microbial communities on the environment and human health, with the most immediate impact on patients with respiratory illnesses. Further, damage to agricultural crops could be avoided long term, as many of the detected organisms are plant pathogens or wood rotting fungi.

The findings have led the research team to initiate an ongoing interdisciplinary research project between SCELSE and NTU’s Lee Kong Chian School of Medicine in the area of respiratory health.

Together with clinical experts led by respiratory physician Assistant Professor Sanjay Chotirmall, Provost’s Chair in Molecular Medicine, the joint team is assessing how bioaerosols affect patients with bronchitis, chronic obstructive pulmonary disease and severe asthma.

Novel method of sequencing bioaerosols

The research team set up a series of air sample collectors on a rooftop at the NTU campus, which collected samples every two hours over the course of five days (180 samples per time series). This same experiment was repeated every three months for 13 months, which included Singapore’s two monsoon seasons.

Airborne biomass was collected by pumping air through an electrostatic filter retaining particles from 0.5 to 10 micrometre range (about 50 times to 10 times smaller than the average thickness of a human hair respectively). Previously, air samples had to aggregate for weeks or months in order to amass sufficient material for analysis.

Through the new ultra-low biomass DNA sequencing protocol developed by the NTU research team, much smaller volumes of air could be analysed, enabling for the first time the ability to study hourly changes in the air microbiome composition.

All bioaerosols were classified according to their DNA similarities and differences, which allowed for species-level identification of airborne organisms after comparison with existing DNA sequence databases.

The researchers surpassed the level of identification of bioaerosols previously achieved by scientists, without the need to amplify DNA or using long-term sampling periods that do not provide sufficiently detailed information at short time intervals.

Previous studies by other research groups have reported bioaerosol communities based on either cultivation or gene amplification, both of which incur substantial biases and aggregates of time, without however achieving a temporal resolution that would have allowed for observing the daily cycling of airborne microorganisms.

Team member Dr Elena Gusareva, a postdoctoral research fellow at NTU said the unprecedented scale and depth of analysis and classification, allowed the team to identify more than 1,200 bacterial and fungal species that perform a changing pattern of microbial community composition.

Ongoing research at NTU is now looking at using the same method to analyse bioaerosols globally at other sites, which could yield similar trends in terms of following the diel cycle.

###

This five-year Singapore study, supported by Singapore’s Ministry of Education Tier 3 Academic Research Fund, involved over 25 NTU scientists and researchers.

Notes to Editor:

Paper titled “Microbial communities in the tropical air ecosystem follow a precise diel cycle”, published in PNAS, 29 Oct 2019.

Media contact:

Lester Kok
Assistant Director
Corporate Communications Office
Nanyang Technological University
Email: lesterkok@ntu.edu.sg

About Nanyang Technological University, Singapore

A research-intensive public university, Nanyang Technological University, Singapore (NTU Singapore) has 33,000 undergraduate and postgraduate students in the Engineering, Business, Science, Humanities, Arts, & Social Sciences, and Graduate colleges. It also has a medical school, the Lee Kong Chian School of Medicine, set up jointly with Imperial College London.

NTU is also home to world-class autonomous institutes – the National Institute of Education, S Rajaratnam School of International Studies, Earth Observatory of Singapore, and Singapore Centre for Environmental Life Sciences Engineering – and various leading research centres such as the Nanyang Environment & Water Research Institute (NEWRI) and Energy Research Institute @ NTU (ERI@N).

Ranked 11th in the world, NTU has been placed the world’s top young university for the past six years. The NTU Smart Campus is frequently listed among the Top 15 most beautiful university campuses in the world and it has 57 Green Mark-certified (equivalent to LEED-certified) building projects, of which 95% are certified Green Mark Platinum. Apart from its main campus, NTU also has a campus in Novena, Singapore’s healthcare district.

For more information, visit http://www.ntu.edu.sg.

Source: EurekAlert

Organisms across the tree of life, from plankton to humans, follow day-night cycles. New research shows that the airborne microbiome cycles through day-night cycles as well.

Researchers in Brazil and Singapore captured the microbes present in the air of a tropical environment using air samplers located at Nanyang Technical University. Considering the popularity of microbiome studies in both humans and ecosystems, the microbiomes in the atmosphere are incredibly understudied, especialy compared to human-, water- or soil-based microbiomes.

The study sampled every two hours each day, which is high resolution for experiments collecting air samples. The researchers took almost 800 samples that spanned over a year, which covered Singapore’s wet and dry seasons. This dataset includes two monsoon seasons and microbes that dispersed from different directions (generally the northeast and southwest).

The atmospheric microbiome is challenging to study. Often, a low amount of biological material is typically collected, which can hinder next-generation sequencing methods identifying microbial species. The researchers developed a method to collect enough biological material that allowed them to look at which species and how many of each across fungi, bacteria, virus and plants.

The air sampling site in Singapore was ideal for this type of study because it’s so close to the equator that there is little variation in daylight hours throughout the year, as well as minimal variability in temperature and relative humidity, all of which remove sources of noise in the data.

The air microbiome followed a clear day-night cycle that was regulated by environmental conditions, particularly temperature. This pattern was stronger than variation over days, weeks or months.

O que existe no ar que respiramos? A verdade é que há até bem pouco tempo, ninguém sabia. Embora os microorganismos presentes no solo e nos oceanos estejam bem mapeados, o bioma do ar nunca tinha sido estudado em larga escala. Agora, pela primeira vez, cientistas da Universidade Federal do Rio de Janeiro (UFRJ) e da Universidade Tecnológica de Nanyang, em Cingapura, conseguiram fazer esse levantamento. E a resposta é inquietante: são mais de mil espécies de micróbios diferentes, muitas delas totalmente desconhecidas.

Segundo os pesquisadores, esse detalhamento inédito pode ajudar a criar ambientes com determinadas características, como o de hospitais por exemplo. Conhecendo os microorganismos presentes no ar também será possível estimar os efeitos do aquecimento global sobre esse bioma. O trabalho foi publicado no mês passado na Proceedings of the National Academy of Sciences (PNAS)

“A gente se preocupa muito com a água que bebe e muito pouco com o ar que respira”, alertou Ana Carolina Junqueira, professora do Departamento de Genética do Instituto de Biologia da UFRJ, uma das autoras do estudo.”

Estudar o ecossistema do ar sempre foi um desafio para os cientistas por conta das baixas quantidades de material genético – o que dificulta a aquisição de DNA em quantidades suficientes para serem testadas. Por isso, o microbioma da atmosfera era o menos estudado em escala global, sobretudo quando comparado à hidrosfera e à litosfera.

O mapeamento foi possível agora por conta da descoberta de um novo método de coleta do ar e análise genética em amostras mínimas, até 50 vezes menores que um fio de cabelo. Os poucos estudos disponíveis até hoje tinham sido feitos em países de clima temperado. O novo levantamento foi realizado em Cingapura, um país de clima tropical como o Brasil.

Os pesquisadores concluíram que existem mais de mil espécies de micróbios no ar e, ainda, que essa diversidade responde a padrões específicos nos trópicos: o ar diurno é dominado por bactérias, enquanto o noturno é predominantemente constituído por fungos.

“Grande parte da população é alérgica”, lembra Ana Carolina. “Com essas informações, podemos determinar padrões de incidência de alergias em diferentes regiões, por exemplo. Também podemos orientar para que deixem a janela aberta à noite ou de dia, dependendo da alergia. Usar filtros de ar para não permitir a proliferação de determinados fungos.”

O novo estudo revela que o ar tropical apresenta uma complexidade microbiana semelhante à dos oceanos, solos e trato gastrointestinal humano – para citar os três microbiomas mais bem estudados até hoje. Fatores ambientais como a temperatura, umidade, irradiação solar e níveis de dióxido influenciam a composição e abundância das comunidades microbianas.

Por isso, o trabalho também é importante para o entendimento de processos relacionados às mudanças climáticas globais e à qualidade do ar.

“Estes resultados indicam que subestimamos a diversidade de microrganismos presentes na atmosfera e que mudanças climáticas podem alterar a composição do microbioma do ar”, sustenta Ana Junqueira.

Source: UOL Noticias

Airborne transport of microorganisms is assumed to occur over vast global scales, but we know little about it. Gusareva et al. undertook a year-long metagenomic study of atmospheric organisms above Singapore. Daily patterns were seen in more than 700 taxa, dominated by eukaryotes. At night, spores of basidiomycete fungi formed the greatest airborne biomass. Ascomycete fungal spores prevailed during daytime and correlated with rainfall. The richness of the bacterial groups Firmicutes and Proteobacteria peaked at noon, whereas Cyanobacteria and Actinobacteria abundances stayed uniform over 24 hours. The chief variable was the shift between temperatures at night (26°C) and day (35°C at noon), which presumably drives lift-off.

Proc. Natl. Acad. Sci. U.S.A. 116, 23299 (2019).

Source: Science

Pesquisadores processam montanha de dados de mais de 300 espécies de tartarugas viventes e extintas para identificar onde e quando evoluíram os ancestrais comuns das tartarugas modernas

Sequenciadores de DNA, gravadores, drones e outros aparelhos de uso crescente permitem imensos ganhos de tempo e impõem uma reviravolta metodológica.

Há diversos microrganismos habitando a atmosfera do nosso planeta, e não só aqui embaixo, pertinho de nós.

Interactions between hosts and microorganisms are ubiquitous in nature, capable of modulating animal physiology, fitness, protection against infections, and host behavior. We are using whole shotgun metagenomics to study the microbial communities associated with biological (mosquitoes and kissing bugs) and mechanical insect vectors (houseflies and blowflies). Insects are major agents of infectious diseases, often inhabiting densely populated areas where their propagation is increased. Switches in microbial communities could lead us to a set of naturally occurring microbes that respond to metabolic pathways that could help us to assemble a microbiome-based strategy to control vectors of diseases in urban and rural areas.

Junqueira et al., 2017. https://www.nature.com/articles/s41598-017-16353-x

Recent developments in comparative genomics allow us to analyze features that help us understand how genomes evolved, giving rise to various insect habits. In flies (Diptera), different feeding strategies are also associated with the evolution of parasitism and adaptation to living hosts. We are currently working with two genomes of flies generated: the blowfly Chrysomya megacephala and the New World screwworm (NWS) fly Cochliomyia hominivorax. While the blowfly has a necrophagous habit and acts as a vector of diseases, the NWS fly feeds on the living tissues of vertebrate hosts, being one of the most important livestock pests in the New World. Genomic resources generated are also helpful in assisting future developments in vector and pest control based on targeted genome editing using CRISPR/Cas9.

Paulo et al., 2021. https://www.nature.com/articles/s41598-021-90649-x

With the onset of new sequencing platforms, an increasing number of genomes became available in public databases and can now be analyzed with methods that deal with the intersection of phylogenetics and genomics. Our research conciliates molecular data with fossil records, geological events, and cutting-edge bioinformatics to estimate the time tree of species in different groups, such as flies and turtles.

Junqueira et al., 2016. https://www.nature.com/articles/srep21762.

Selvatti et al., 2023. https://doi.org/10.1016/j.ympev.2023.107773.

The World Health Organization has listed air pollution, climate change, and the emergence of antimicrobial resistance as the main threats to global health in the future. We use breakthrough methods in ultra-low biomass sequencing to analyze the urban microbiome from surfaces swabbed in Rio de Janeiro to uncover the microorganisms circulating in populated areas and their public health impact on future outbreaks. Likewise, we are involved in an integrated analysis of air microbiomes sampled in different locations on the planet, together with extensive meteorological and physicochemical records, which will give insights into the airborne ecosystem.

Gusareva et a., 2019. https://www.pnas.org/doi/10.1073/pnas.1908493116