Diversity of the Bacterial Microbiota of Anopheles Mosquitoes from Binh Phuoc Province, Vietnam.

Chung T Ngo,Sara Romano-Bertrand,Sylvie Manguin,Estelle Jumas-Bilak

doi:10.3389/fmicb.2016.02095

Abstract

The naturally acquired microbiota of Anopheles can influence vector’s susceptibility to Plasmodium and its capacity to transmit them. Microbiota modification is a new challenge to limit disease transmission but it still needs advanced knowledges on bacterial community in Anopheles, especially in wild and infected specimens from diverse origin and species. Bacterial culture and 16S rRNA gene-PCR associated to Temporal Temperature Gradient Electrophoresis (TTGE) were applied to explore the bacterial diversity in the abdomen of 100 wild specimens (eight Anopheles species) collected in the Binh Phuoc Province, Vietnam. Culture and PCR-TTGE were complementary. The bacterial richness of the mosquito collection encompassed 105 genera belonging to seven phyla, mostly Proteobacteria, Firmicutes, and Actinobacteria. Staphylococcus, Clostridium, and Bacillus in Firmicutes were the most prevalent genera. However, Proteobacteria represented by 57 genera was the most diversified phylum in Anopheles microbiota. The high overall of Anopheles-associated bacteria is confirmed with, to our knowledge, 51 genera described for the first time in Anopheles microbiota. However, the diversity per specimen was low with average diversity index and the average Shannon–Wiener score (H) of 4.843 and 5.569, respectively. The most represented bacterial genera were present in <30% of the specimens. Consequently, the core microbiota share by Anopheles from Binh Phuoc was very narrow, suggesting that Anopheles microbiota was greatly influenced by local environments. The repertory of bacterial genera in two specimens of An. dirus and An. pampanai naturally infected by Plasmodium vivax was also described as preliminary results. Finally, this study completed the repertory of bacteria associated to wild Anopheles. Anopheles associated-bacteria appeared specimen-dependent rather than mosquitoe species- or group-dependent. Their origin and the existence of Anopheles-specific bacterial taxa are discussed.

Highlights

MATERIALS AND METHODSDespite some success in controlling malaria, this disease continues to be a major health burden in many countries around the world with 438,000 deaths reported in 2015, in sub-Saharan Africa recording 395,000 deaths (90%), and in forested regions of Southeast Asia with 32,000 deaths (7%; WHO, 2015)
Protective role of Anopheles bacterial microbiota against Plasmodium infections has been demonstrated because clearing midgut microbiota by antibiotic treatment resulted in enhanced Plasmodium infections rate (Beier et al, 1994; Favia et al, 2007; Dong et al, 2009; Rodrigues et al, 2010)
But in semi-natural settings, antibiotics in ingested blood enhanced the susceptibility of An. gambiae to Plasmodium infection and increasing mosquito fitness through higher survival and fecundity

Summary

Introduction

MATERIALS AND METHODSDespite some success in controlling malaria, this disease continues to be a major health burden in many countries around the world with 438,000 deaths reported in 2015, in sub-Saharan Africa recording 395,000 deaths (90%), and in forested regions of Southeast Asia with 32,000 deaths (7%; WHO, 2015). A previous report on the biodiversity of the abdomen microbiota of 100 wild Anopheles specimens (five species) from Dak Nong Province showed a high taxonomic diversity, including species reported as implicated in the mosquito resistance to Plasmodium infection (Ngo et al, 2015).

Results

Conclusion