Molecular analysis of tetracycline resistant gene in gram-negative bacteria isolated from dairy farms

The present study was conducted from April 2019 to June 2019 in order to detect the tetracycline A resistant Gene in gram negative bacteria. A total of 40 buffalo's milk samples were collected randomly by aseptic technique, brought to laboratory. They were inoculated on Blood and MacConkey agars and then incubated at 37°C for 24 hours whereby growth of colonies were further confirmed with catalase test, Coagulase test, Oxidase test, Gram staining and API 20 E kit. Bacterial DNA was isolated using the boiling method. The Tet A gene (210 bp) was amplified in thermal cycler and run on 1.8-gram agarose gel with 50 kb ladder. The most predominant bacterial colonies observed were of Escherichia coli (10 (33.3%) followed by Klebsiella pneumonia 5 (16.7%), Klebsiella spp. 5 (16.7 %), Pseudomonas spp. 10 (33.3%) and prevalence of tetracycline A gene was 8 (26.7%).