A PCR test for detecting Escherichia coli O157:H7 based on the identification of the small inserted locus (SILO157)

AIMS: This paper provides identification of a DNA sequence derived from Shiga toxin-producing Escherichia coli (STEC) O157:H7 and information on its utilization for detecting STEC O157 by PCR. METHODS AND RESULTS: Random Amplified Polymorphic DNA and DNA library were used to identify in STEC O157:H7 (strain EDL 933) a 2634-bp Small Inserted Locus, designated SILO157. Analysis of 211 bacterial strains showed that the PCR assays amplifying the SILO157 region could be used to detect STEC O157 with a good specificity. CONCLUSIONS: Characterization of a novel locus in STEC O157 is attractive since the serotype O157:H7 of STEC is still by far the most important serotype associated with more serious diseases. This island encodes putative proteins and especially one that is predicted to be an outer membrane protein designated IHP1. SIGNIFICANCE AND IMPACT OF THE STUDY: Further investigations could now be developed to appreciate the role of the SILO157 in pathogenicity.