Comparative assessment of the bacterial communities associated with Anopheles darlingi immature stages and their breeding sites in the Brazilian Amazon

Abstract

Background The neotropical anopheline mosquito Anopheles darlingi is a major malaria vector in the Americas. Studies on mosquito-associated microbiota have shown that symbiotic bacteria play a major role in host biology. Mosquitoes acquire and transmit microorganisms over their life cycle. Specifically, the microbiota of immature forms is largely acquired from their aquatic environment. Therefore, our study aimed to describe the microbial communities associated with An. darlingi immature forms and their breeding sites in the Coari municipality, Brazilian Amazon. Methods Larvae, pupae, and breeding water were collected in two different geographical locations. Samples were submitted for DNA extraction and high-throughput 16S rRNA gene sequencing was conducted. Microbial ecology analyses were performed to explore and compare the bacterial profiles of An. darlingi and their aquatic habitats. Results We found lower richness and diversity in An. darlingi microbiota than in water samples, which suggests that larvae are colonized by a subset of the bacterial community present in their breeding sites. Moreover, the bacterial community composition of the immature mosquitoes and their breeding water differed according to their collection sites, i.e., the microbiota associated with An. darlingi reflected that in the aquatic habitats where they developed. The three most abundant bacterial classes across the An. darlingi samples were Betaproteobacteria, Clostridia, and Gammaproteobacteria, while across the water samples they were Gammaproteobacteria, Bacilli, and Alphaproteobacteria. Conclusions Our findings reinforce the current evidence that the environment strongly shapes the composition and diversity of mosquito microbiota. A better understanding of mosquito–microbe interactions will contribute to identifying microbial candidates impacting host fitness and disease transmission. Graphical Abstract

Limnological variables associated with the presence of Anopheles Meigen, 1818 (Diptera: Culicidae) larvae in breeding sites in Amazonas, Brazil

“…A recent study with An. darlingi collected from ponds and dams in the middle Solimões region of Amazonas, sought to identify the microbiota associated with the mosquito and the aquatic environment of the breeding sites, in an attempt to understand their interactions and potential uses (Mosquera et al 2023). Another region affected by the proliferation of the malaria vector is in indigenous areas of the State, with few studies on the larval bionomics of anophelines.…”

Oviposition site selection in mosquitoes : the role of conspecific larvae, heterospecific larvae and microbes

“…The diversity of microbiota at a breeding site varies considerably between sites, habitats and geographical locations (Bennett et al, 2019;Caragata et al, 2021;Mosquera et al, 2023b;, with Proteobacteria and Firmicutes dominating the sites (Mosquera et al, 2023b;. Mosquito larvae feed on this microbiota, as demonstrated using 16S ribosomal RNA sequencing, identifying Proteobacteria and Firmicutes as the most abundant bacterial phyla, but also Bacteroidetes, and Actinobacteria (Boissière et al, 2012;Mancini et al, 2018;Terenius et al, 2012).…”

Biotechnological Potential of Microorganisms for Mosquito Population Control and Reduction in Vector Competence

“…The mosquito microbiota influences host development, nutrition, reproduction, and immune responses to invading organisms [ 211 , 212 , 213 , 214 ]. While the composition of the mosquito microbiota is largely defined by the environment in which they live [ 215 , 216 , 217 ], resident bacteria can modulate the development and replication of parasites and viruses within their vectors [ 218 , 219 , 220 , 221 , 222 , 223 , 224 , 225 ]. Although this modulation can enhance or reduce the survival and replication of pathogens within mosquitoes, those mosquito–microbiota interactions that negatively affect pathogens offer possibilities to control arthropod-borne diseases.…”