Culex quinquefasciatus mosquitoes were collected from the field and microbial flora was isolated from their midgut. Isolates belonging to 13 different genera were obtained. Four most abundant isolates viz. Pseudomonas sp., Acinetobacterjunii, Staphylococcus epidermis and Aeromonas culicicola were used to study their effect on the susceptibility of mosquitoes to Japanese encephalitis virus (JEV). Incorporation of individual isolates in the mosquito bloodmeal resulted in an increased susceptibility of mosquitoes to the virus. However, only the effects of Pseudomonas sp. and Acinetobacterjunii could be statistically evaluated but they were found insignificant.