Detection of Shiga toxin-producing Escherichia coli and enteropathogenic Escherichia coli in faecal samples of healthy mithun (Bos frontalis) by multiplex polymerase chain reaction.

Faecal samples obtained from 190 healthy mithuns were examined for the presence of Escherichia coli. Total one-hundred and five E. coli isolates were obtained from these samples, which belonged to 55 different serogroups. These isolates were subjected to multiplex polymerase chain reaction (m-PCR) for detection of stx1, stx2, eaeA and hlyA genes. Twenty-three (21.90%) E. coli isolates belonging to 14 serogroups revealed the presence of at least one virulence gene when examined by m-PCR. Nineteen percent and 2.85% of the mithuns were found to carry Shiga toxin-producing E. coli (STEC) and enteropathogenic E. coli, respectively. stx1 and stx2 genes were found to be prevalent in 7 (6.67%) and 18 (17.14%) of the isolates respectively, whereas eaeA and hlyA genes were found to be carried by three (2.85% each) isolates. Interestingly, none of the STEC isolates belonged to serogroup O157.