P. falciparum traverses the intestinal epithelium within 24 h after blood meal, at the peak of the digestion process; and whether parasites take advantage of intense competitive interactions for nutrient resources between bacteria to thwart the immune surveillance has to be investigated. Indeed, www.selleckchem.com/products/ganetespib-sta-9090.html the gut microbiota is known to play an important role in protecting the host from potentially pathogenic microbes [64], [65]. Protection occurs through different processes: stimulation of the mosquito immune response, competition for binding sites or nutrients and production of toxins [65]�C[67]. However, despite the beneficial role of the microbiota, pathogens, such as helminthes and viruses have developed strategies for exploiting the gut microbiota to promote their transmission [68], [69], [70].

For the mosquito vector, our understanding is still at an early stage for how the natural resident microbial flora of the mosquito midgut contributes to its resistance to the Plasmodium [15], [17], [18], [24]. In this study, we found that the abundance of Enterobacteriaceae is higher in P. falciparum-infected mosquitoes, suggesting that some microbe-parasite interactions may contribute to the successful development of the malaria parasite. However, whether Enterobacteriaceae have an effect on parasite survival or whether the increased level of Enterobacteriaceae is a consequence of Plasmodium development remains elusive. Alternatively, genetic factors, such as allelic polymorphism of immune genes, could regulate the variable levels of permissiveness of the mosquitoes as has been previously shown [71].

In contrast to our findings, previous studies reported the deleterious effect of bacterial infections on Plasmodium development in the mosquito [19], [23]�C[25]. Of interest in this context, several Enterobacteriaceae strains were able to inhibit the development of Plasmodium species in the mosquito midgut, among them Cedecea spp., Serratia spp., and Enterobacter spp. isolated from A. albimanus, A. stephensi, or A. arabiensis [19], [22]�C[24]. The Esp_Z Enterobacter strain isolated from A. arabiensis caught in Zambia [24] was not identified in any of the reads we analyzed. The possibility that this Enterobacter strain would have been absent from the PCR products because of competition with a different clade is unlikely as we used three different sets of primers.

Therefore, we expect that in the gut of A. gambiae mosquitoes in Cameroon, the Esp_Z Enterobacter strain was below Batimastat the 0.1% abundance threshold or absent. This Enterobacter strain was isolated in Zambia from wild-caught A. arabiensis mosquitoes, and differences in the mosquito species, as well as differences between the study areas, may explain why we did not find this bacterium in our material.