Abstract

To investigate the occurrence and determine the prevalence of Escherichia coli O157 in Traditional cattle herds in Sokoto State Nigeria, rectal swab samples were collected from 402 cattle in 36 randomly selected herds, from the period May 2013 to April 2014. The faecal samples were subjected to selective-culture on SMAC and E. coli O157:H7 was confirmed using E. coli O157 and H7 antisera respectively. The E. coli O157 isolates were assessed for phenotypic expression of enterohemolysis and verotoxin-production as virulence properties, by standard methods (what is the name of the standard method). Of the herds surveyed, 10 (27.8%) were found to have at least one positive isolation of E. coli O157:H7 in feacal samples examined. Within-herd prevalence ranged from 6.7 to 20.0%, with an average of 12.9 +/- 5% SD, and the individual-animal prevalence was 4.0% of the 402 rectal swab samples examined. The prevalence was highest among female (4.5%) than male (3.2%) cattle respectively, and also among weaned calves (7.0%) and yearling heifers. Eleven (68.8%) of the E. coli O157:H7 isolates were positive for enterohemolysis, while verotoxin assay showed 4 (25%) as verotoxin-producers. No significant association was observed between verotoxin-production and enterohemolysin expression among the isolates tested (p > 0.05). This study confirmed the presence of E. coli O157:H7, including the potential pathogenic strains in cattle managed under traditional-herding system in Sokoto state. This is potential public health threat for human infection in the state, which needs to be controlled.