Incidence of Shiga toxin gene (STX) bearing escherichia coli in bovines in Jammu Region, India

Shiga toxin-producing Escherichia coli (STEC) are capable of causing diarrhoea in calves. Ruminants, particularly cattle and sheep are considered as the major reservoirs of STEC and lead to gastro-intestinal infections and life threatening diseases in humans by the consumption of food contaminated with faeces. The present study was based on detection and molecular characterization of STEC in bovines. Isolates of E. coli were characterized by multiplex Polymerase Chain Reaction (PCR) using four primers stxl, stx2, eaeand hlyA. On the basis of gene profile, a total of 19 STEC isolates were detected from faecal samples of diarrhoeic calves while 24 STEC isolates were identified from healthy calves. stxl, stx2 and hlyA was the most common gene combination found in STEC strains from both healthy and diarrhoeic calves. All STEC isolates from diarrhoeic and healthy calves produced haemolysin that produced turbid zones of haemolysis around bacterial colonies on Soyabean casein digest agar supplemented with 5% sheep erythrocytes and 10mM CaCl₂.