A new method to detect big six Shiga toxin-producing Escherichia coli in Apple Juice within one shift
The J Food Protection published an article describing a new method to detect Shiga toxin-producing Escherichia coli (STEC) in foods. The method is capable of detecting serotype O157:H7 one of six non-O157 serogroups, O26, O45, O103, O111, O121, and O145, termed “The Big Six.” The STEC bacteria were isolated from unclarified apple juice by a centrifugation step with the use of an immunocupture technique to minimize contaminants (such as pectin and polyphenols that may co-purify with DNA) that may interfere with DNA amplification efficiencies and limit sensitivity. The immunocupture method was followed by PCR of the Shiga toxin genes stx1a and stx2a. The new method did not involve any culture enrichment and allowed detection of <5 CFU Big Six STEC. The method could be completed in 6.5 h. Inclusivity and exclusivity were tested with 52 Big Six STECs and 30 unrelated strains. @ https://www.ncbi.nlm.nih.gov/pubmed/31414899
