Detection of non O157:H7 Shiga toxin-producing Escherichia coli (STEC) serogroups O26, O45, O103, O111, O121 and O145 from beef trim in Namibia

Molini, U., Khaiseb, S. and Kamwi, J.

Abstract: Many different serotypes of Shiga toxin-producing Escherichia coli (STEC) that cause disease in humans have been described. Illnesses range from mild diarrhea to bloody diarrhea to hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS). E. coli O157:H7 is the STEC strain most often associated with the most severe forms of disease. However, numerous non-O157 STEC isolates have also been linked to illnesses and outbreaks of disease. Several studies showed that majority of non O157:H7 STEC infections are caused by strains from one of six major serogroups, including O26, O45, O103, O111, O121 and O145. 771 Beef trim obtained from a local abattoir in Windhoek were tested for the presence of the top 6 non-O157 STEC serogroups using commercial BAX® System assays. All samples were screened for the presence of Shiga toxin (stx1 and stx2) and intimin (eae) virulence genes, which were both present in 136 (17.64%) out of 771 samples. Of the 136 positive samples for both stx and eae virulence genes, nine were positive for O26, one for O45, thirty-three for O103, one for O111, five for O121 and three for O145. There were also thirty-five samples positive for more than one STEC serogroup.The presence of virulent STEC in beef trim is a public health concern. The use of polymerase chain reaction assay should aid quick detection of this virulent serotypes and help to prevent severe epidemic of human diseases associated with STEC infections.

Keywords: E.coli, Beef, PCR, STEC.

Pages: 288 – 294 | Full PDF Paper