New EHEC markers: toward an advanced STEC analytical approach
Introduction:
Standard molecular methods (without immunoconcentration step) of STEC detection in food matrices based on stx and eae genes co-detection and Top5/7 serogroup associated genes may lead to identify a significant number of false positives without detection of all enterohemorrhagic Escherichia coli (EHEC) potentially present. These major limits may cause either a substantial economic loss for food industry and a food safety risk for consumers.
In recent years, several studies highlighted the existence of three markers (espK, espV and
CRISPR_O26E) that can unequivocally identify 100% of EHEC of the Top7 and 93.7% of
new emerging EHEC (Delannoy et al., 2013, 2016).
The present study aimed at proposing and validating a new EHEC screening approach with
the objective to identify all EHEC strains and reduce the number of presumptive positives
samples subjected to a serogroup screening.