More than 96% of tags corresponding to bacteria in the midguts of mosquitoes from the Ngousso colony were assigned to Flavobacteria, although this class accounted for only 0.38% selleck chem (��0.24) of the sequence tags in field mosquitoes. Similarity searches against the SSU SILVA database (release 108) identified Flavobacteria tags as belonging to Elizabethkingia sp., which already has been isolated from A. gambiae midguts from different insectaries [15], [35], [36]. The guts of Ngousso mosquitoes also contained, to a lower extent, Gammaproteobacteria (Pseudomonas sp.) and Alphaproteobacteria (Asaia sp.). Figure 2 Relative abundance of the different bacterial classes within each mosquito midgut sample.

In mosquitoes from natural habitats, midguts were mainly colonized by Proteobacteria (94%), and the most prominent classes were Gammaproteobacteria, Alphaproteobacteria and Betaproteobacteria (Figure 2). Figure 1 clearly shows the difference in bacterial composition between mosquitoes from the 2 breeding sites used in this study. In mosquitoes originating from Nkolondom, the intestinal bacterial flora is dominated by Alphaproteobacteria (68.65��7.38%), mainly of the genus Asaia sp. By contrast, the three major classes are almost equally represented in the midgut of mosquitoes from Mvan, although with large individual variability. The main taxa in this locality were Asaia, Sphingomonas, Burkholderia, Ralstonia, and Enterobacteriaceae. Enterobacteriaceae could not be assigned to more precise taxonomic ranks. Midgut bacteria were unevenly distributed among individual mosquitoes and between the different sampled localities.

Several genera were found in all, or at least in a large majority, of the mosquitoes possibly representing the ��mosquito midgut core microbiota�� (Table S3). They included members of the genera Asaia, Burkholderia, Serratia, Ralstonia, Acinetobacter, Pseudomonas, Sphingomonas, Staphylococcus, Streptococcus, and Escherichia/Shigella. Of note, Asaia sp. was found in all samples, and its relative abundance showed great variation from one midgut to another, ranging from 1.49 to 98.95% in mosquitoes from Nkolondom and from 0.04 to 49.66% in those from Mvan. The group of unassigned Enterobacteriaceae also was identified in all field samples, with relative abundance ranging from 0.01 to 1.03% and from 0.04 to 71.51% in Nkolondom and Mvan, respectively.

Other specific members of Enterobacteriaceae were frequent and represent a large proportion of the midgut bacterial communities: Serratia spp. accounted for 96.93% of the midgut bacteria in a mosquito (NKD97) from Nkolondom, and Cedecea spp. encompassed 12% of the gut bacterial content in 2 mosquitoes from Mvan. Escherichia/Shigella was found in more AV-951 than 85% of the mosquitoes, at low densities.