Bacterial diversity associated with the abdomens of naturally Plasmodium-infected and non-infected Nyssorhynchus darlingi.

Background: The bacterial community present in the abdomen in Anophelinae mosquitoes can influence mosquito susceptibility to Plasmodium infection. Little is known about the bacteria associated with Nyssorhynchus darlingi, a primary malaria vector in the Amazon basin. We investigated the abdominal bacterial community compositions of naturally Plasmodium-infected (P-positive, n = 9) and non-infected (P-negative, n = 7) Ny. darlingi from the Brazilian Amazon region through massive parallel sequencing of the bacterial V4 variable region of the 16S rRNA gene.

Results: Bacterial richness of Ny. darlingi encompassed 379 operational taxonomic units (OTUs), the majority of them belonging to the Proteobacteria, Firmicutes and Bacteroides phyla. Escherichia/Shigella and Pseudomonas were more abundant in the P-positive and P-negative groups, respectively, than in the opposite groups. Enterobacter was found only in the P-negative group. The results of statistical analyses conducted to compare bacterial abundance and diversity between Plasmodium-infected and Plasmodium-non-infected mosquitoes were not significant.

Conclusions: This study increased knowledge about bacterial composition in Ny. darlingi and revealed that Plasmodium-positive and Plasmodium-negative groups share a common core of bacteria. The genera Prevotella 9, Sphingomonas, Bacteroides, and Bacillus were reported for the first time in Ny. darlingi.