Cultivable bacterial communities associated with the salivary gland of Aedes aegypti

Abstract

Rapid spread of vector borne diseases, especially through mosquitoes is in alarming rise worldwide. Among mosquitoes, Aedes aegypti is a major vector transmitting arboviruses such as dengue and zika to human population. The ineffectiveness of control measures against these arboviruses has necessitated alternate strategies to curb disease transmission. Recent studies show that symbiotic bacteria from insects hinder pathogen transmission by altering vector competence. Therefore, analyzing the bacterial communities of mosquitoes is essential to identify potential bacteria that play a critical role in vector competence. Salivary gland, a key organ in viral transmission however, is minimally explored towards their microbiota. In this study, we have screened 28 bacterial isolates from salivary glands of non-blood fed (NBF) and blood fed (BF) female Ae. aegypti, collected from the field population of Coimbatore, India. Among them, 11 bacterial species from distinct genera belonging to three major phyla; Proteobacteria, Firmicutes and Actinobacteria were identified through 16S rRNA gene sequencing. Interestingly, the differences in bacterial species associated with salivary glands were clearly discernible. This suggests that the dynamics of bacterial population after blood feeding is not restricted to the mosquito gut, but envisioned in the salivary glands as well. Overall, the results shed more light into the understating on salivary glands microbiota of dreadful vector Ae. aegypti.