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Shiga toxin-producing Escherichia coli (STEC) are receiving more attention mainly because they are zoonotic and food borne in nature. The objectives of the present study were to determine the occurrence of non-O157 Shiga toxin producing E. coli in cattle and goats and distribution of the virulence genes in the isolates. The overall isolation rates of non-O157 STEC was 15.27% (7/87) in cattle and 8.14% (22/144) in goats. Four serogroups namely O8, O26, O103 and O128 were detected. Of these serogroups, O8, O26 and O103 were common in both, cattle and goats, whereas O128 was carried by goats only. Using Duopath Verotoxin (DV) test, 52.63% of sero-positive E. coli isolates from cattle were positive for Stx1 shiga toxin whereas none of the isolates was positive for Stx2. Similarly, 42.9% (3/7) of sero-positive E. coli isolates from goats produced Stx1 and 14.3% (1/7) were positive for both, Stx1 and Stx2. The study on virulence genes showed that stx1 was commonly distributed among non-O157 STEC isolates of cattle (57.9%) and goats (57.1%). Key words: Non-O157 STEC, cattle, goats, virulence genes.

Hamuel JD, Ndakidemi PA, Human IS & Benade S Virulence factors and antibiotic susceptibility among verotoxic non-O157: H7 Escherichia coli isolates obtained from water and wastewater samples in Cape Town, Joint Workshop on Food Security & Environmental Sustainability in a World of Changing Climates Conference Bondo, Kenya, 20-23 February 2011

Cape Peninsula University of Technology, Cape Town South Africa through the University Research Fund RP03

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. coli16SrRNA 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. Key words: Multiplex polymerase chian reaction (PCR), Escherichia coli.