| dc.description.abstract | Symbiotic bacteria established in mosquito gut significantly influence disease transmission, host-parasites interaction, and determination of vectorial capacity. The present
study focused on screening of midgut microbial diversity of adult Culex quinquefasciatus
as a fundamental pre-requirement to support the paratransgenesis process, which is
progressing in Sri Lanka. Mosquito surveys were conducted from September 2022 to
December 2022 at 3 sites (Kelaniya, Gampaha, and Meerigama) in the Gampaha Medical
Office of Health area of Sri Lanka. Unfed adults were sacrificed using a cold shock and
surface sterilization was performed using 70% ethanol followed by rinsing with Phosphate
Buffer Saline (PBS). The midgut of adults was dissected and the midgut of ten individuals
was pooled in sterile PBS (250 µl) to make a homogenized lysate. A dilution series (100−
10−7
) was made from lysate and 100 µl from each dilution was plated on Plate Count
Agar and pure cultures for each microbe were obtained. Isolated bacteria were subjected
to 16S rRNA amplification. A total number of 4 bacterial families Staphylococcaceae,
Streptococcaceae, Bacillaceae, and Moraxellaceae were identified. Family Bacillaceae
(43%) and Moraxellaceae (4%) were found as the highest and least abundant bacterial
families respectively. Better separation of colonies was observed at 10−3
, 10−4
, and
10−5 dilutions. Species composition was dominated by 5 major genera; Staphylococcus,
Streptococcus, Lysinibacillus, Acinetobacter and Pseudomonas. Lysinibacillus sphaericus
was identified as the most abundant microbial species isolated from the midgut. The
relative distribution of midgut bacteria differed significantly among field-caught adult
strains, collected from three different study areas. The present data strongly encourage
further investigations to explore the potential usage of the microbes in paratransgenesis
control approaches. | |
