Rapid and quantitative detection of Salmonella harboring the invA gene in Indian Chironomid larvae (Diptera: Chironomidae), using Real–time PCR

Ramprasad Kuncham; Tha. Thayumanavan; Gopireddy V. Subba Reddy

Volume : IV, Issue : XII, December - 2015

Rapid and quantitative detection of Salmonella harboring the invA gene in Indian Chironomid larvae (Diptera: Chironomidae), using Real–time PCR

Ramprasad Kuncham, Tha. Thayumanavan, Gopireddy V. Subba Reddy

Abstract :

The chironomid larvae inhabited in aquatic sediments act as potential vectors for pathogenic bacteria present in aquatic sediments. In our study, we identified the Salmonella species present in the gut of thirty south indian chironomids collected from randomly selected rural and urban aquatic habitats with Real–time PCR approach using fast SYBR green chemistry. We used specific primer for target gene invA located on the Salmonella pathogenecity island–1 (SPI–1), that encodes an inner memane protein and provides the bacteria with the capability to invade epithelial cells. The detection assayed in 3 hours, the CT Values were used to determine the concentration of bacterial load in the larval gut. The CT value of samples inhabiting rural sites is 33.06±0.96 and of urban sites is 28.81±0.51 against the positive control 13.89. Our results show that the Rt–PCR assay was rapid, and could sensitively detect even a single copy of Salmonella in the samples studied.