BackgroundThe understanding of the roles of gut bacteria in the fitness and vectorial capacity of mosquitoes that transmit malaria, is improving; however, the factors shaping the composition and structure of such bacterial communities remain elusive. In this study, a high-throughput 16S rRNA gene sequencing was conducted to understand the effect of developmental stage, feeding status, species, and geography on the composition of the gut bacterial microbiota of two main Colombian malaria vectors, Anopheles nuneztovari and Anopheles darlingi.ResultsThe results revealed that mosquito developmental stage, followed by geographical location, are more important determinants of the gut bacterial composition than mosquito species or adult feeding status. Further, they showed that mosquito gut is a major filter for environmental bacteria colonization.ConclusionsThe sampling design and analytical approach of this study allowed to untangle the influence of factors that are simultaneously shaping the microbiota composition of two Latin-American malaria vectors, essential aspect for the design of vector biocontrol strategies.Electronic supplementary materialThe online version of this article (10.1186/s40168-018-0528-y) contains supplementary material, which is available to authorized users.

No abstract

The understanding of factors affecting the gut bacterial communities in malaria vectors is essential for the design of vector control interventions, such as those based on a paratransgenic approach. One of the requirements of this method is the availability of bacteria from the mosquito susceptible to culture. Thus, the aim of this study was to evaluate the composition and structure of the culturable gut bacterial communities in field mosquitoes Anopheles albimanus from Colombia, in addition to generate a bacterial collection to further analyze microbial functional activity. Gut bacteria were isolated from An. albimanus larvae and adult mosquitoes collected in localities of the Atlantic and Pacific Coasts. The bacterial isolates were grouped in 28 morphospecies that corresponded to three phyla, three classes, nine families and 14 genera. The larvae guts from San Antero (Atlantic Coast) and Buenaventura (Pacific Coast) shared the genera Bacillus and Lysinibacillus and in adults, Bacillus and Bacillus cereus Group were registered in both localities. Gut bacterial richness was higher in adults from the Pacific with respect to the Atlantic Coast, while larval richness was similar in samples of both coasts. The Shannon index indicated uniformity in morphospecies abundances in both localities. Finally, the characterization of morphospecies from the gut of Anopheles albimanus mosquitoes from Colombia by culture-dependent methods complemented with 16S rRNA gene sequencing allowed the definition, at a finer resolution, of the composition and structure of these microbial communities. In addition, the obtained bacterial culture collection will allow further evaluation of the microorganisms for their potential as biocontrol agents.

Taxonomía y sistemática Distribución y parámetros entomológicos de Anopheles (Anopheles) calderoni (Diptera: Culicidae) de Colombia Distribution and entomological parameters of Anopheles (Anopheles) calderoni (Diptera: Culicidae) from Colombia