Public health risk of O157 and Non-O157 Shiga toxin producing Escherichia coli strains in a semi-urban environment in Nigeria

Abstract

Vehicles of shiga toxin producing Escherichia coli (STEC) infections can be quite broad and under reported especially in the rural and semi-urban communities in the developing countries, suggestive of silent and high prevalence which is a public health risk. This may not be unconnected with acute renal failure cases in children and adolescents in the developing countries as STEC related infections have been associated with the few investigated among many un-investigated cases. In this study, multiplex PCR molecular profiling showed high prevalence (27.9%) of STEC strains in the environment studied, majority of which were the non-O157: H serotypes. Sixty-two (86%) of the E. coli 16SrRNA gene positive isolates were positive for stx1, stx2 or both. Two O157: H serotypes were identified, twenty-five (40%) as non-O157: H⁺ (motile) and 34 (54%) classified as non-O157: H^- (non-motile) serotypes. There was a marked heterogeneity in the STEC strains identified in this study, suggesting that the ecology of STEC seems more complex in the environment studied than elsewhere likely enhanced by commercial, social and cultural practices. The results of this study revealed an alarming prevalence of non-O157 serotypes and a few O157 serotypes in the environment studied which is a public health risk and could serve as a point of outbreak or sporadic cases globally as the world today is a global village.