Shiga Toxin Producing Strains of Escherichia coli (STEC) Associated with Beef Products and Its Potential Pathogenic Effect

Background: Contaminated beef products sold in Nigeria are widely consumed by all with little or no knowledge of the presence or occurrence of possible pathogen.

Methods: The current study investigated the presence of shiga toxin producing strains of E. coli (STEC) in beef products using selective and chromogenic media. Furthermore, the pathogenicity of STEC was determined in vivo using established methods.

Results: E. coli was isolated from all beef samples while 30 % (mean) were reported to be STEC. There was a dose-dependent increase in the levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase observed in the serum of all mice exposed to STEC. This was also confirmed by an obvious damage in the livers and kidneys of the affected mice.

Conclusion: By and large, the result of this study shows that beef products sold in Benin City, Edo State, Nigeria are loaded with STEC, which could pose grave problem for consumers. Hence, effort should be made to minimize their presence in beef, and to prevent possible outbreaks.