Occurrence of Hybrid Escherichia coli Strains Carrying Shiga Toxin and Heat-Stable Toxin in Livestock of Bangladesh

Shiga-toxin producing Escherichia coli (STEC) and enterotoxigenic E. coli (ETEC) are important causes of diarrhea in humans and animals worldwide. Although ruminant animals are the main source of STEC, diarrhea due to this pathotype is very low in Bangladesh where ETEC remains the predominant group associated with childhood diarrhea. In the present study, E. coli strains (n=35) isolated from Bangladesh livestock (goats, sheep and cattle) and poultry (chicken and ducks) were analyzed for the presence of major virulence factors such as Shiga toxins (STX-1 and STX-2), heat-labile toxin (LT), and heat-stable toxins (STa and STb). Multiplex polymerase chain reaction (PCR) results revealed 23 (66%) E. coli strains to be virulent possessing either sta (n=5), stx (stx1, n=8; stx2, n=2), or…