Method for Detecting Virulent and Avirulent Escherichia Coli Strains
- patent application filed
Infection by Shiga toxin-producing E. Coli (STEC) strains results in bloody diarrhea, hemolytic uremic syndrome and renal failure. STECs are broadly divided into E. coli serotype O157 and non-O157 serogroups. In the last decade, the non-O157 serogroup has emerged as a major food-borne pathogen of concern worldwide. To date, a large number of STEC serogroups have been identified, but not all are pathogenic to humans. The frequency of infections of STEC serogroups is variable, with six non-O157 STEC serotypes being most commonly reported: O26 (26%), O103 (22%), O111 (19%), O121 (6%), O45 (5%), and O145 (4%), leading to their classification by the USDA as adulterants (zero tolerance) in non-intact raw beef products.
Previously, single nucleotide polymorphisms (SNPs) in the O-antigen gene has been identified and associated with virulent properties of STEC strains. Although commercial kits are presently available for identification of Shiga toxin genes, the high genetic diversity of the stx subtypes results in subtypes that may not necessarily be detected by the various assays The present invention provides methods for detecting and differentiating between virulent and non-virulent strains of Shiga-toxin producing Escherichia coli (STEC) O26 and O11 antigens in a biological sample.