According to the most recent EFSA opinion published on EFSA Journal 2020;18(1):5967 all Shiga toxin-producing E. coli strains are pathogenic and potentially associated with severe illness such as hemolytic uremic syndrome (HUS), bloody diarrhea and hospitalization.
Although stx2a had the highest rates of these, all other Shiga toxin (stx) subtypes were associated with at least one of these severe illness outcomes.
Presence of intimin (eae gene) was an aggravating factor, but this virulence marker was not always essential for severe illness. The minimum combination of genes required to cause severe illness is unknown.
There are four stx1 and twelve stx2 subtypes. As stated in the latest edition of ISO13136 the Real-Time PCR assay design for stx2 detects all the subtypes but 2f.
Two new PATHfinder kits detecting stx2f are now available in Generon portfolio:
- PMB10A-V2F-50 – PATHfinder Real-Time PCR kit for the detection of foodborne E.coli STEC
- PMB10A-F-50 – PATHfinder 2×2-Plex Real-Time PCR kit for the detection of foodborne STEC stx1+stx2/stx2f & eae/IAC
The latter offers a complete screening for the virulence factors according to both ISO13136 and EFSA indications. Both the kit are 2-plex kit and can be ran on the majority of Real-Time PCR instruments including Bio-Rad systems and Hyris bCube.