Comparison of different PCR tests for detecting Shiga toxin-producing Escherichia coli O157 and development of an ELISA-PCR assay for specific identification of the bacteria

摘要: In an attempt to develop a standard for ELISA-PCR detection of Shiga toxin producing Escherichia coli (STEC) O157, six published PCR tests were tested in comparative study on panel 277 bacterial strains isolated from foods, animals and humans. These based the genes rfbE [J. Clin. Microbiol. 36 (1998) 1801] rfbB [Appl. Environ. 65 (1999) 2954], 3' end eae gene [Epidemiol. Infect. 112 (1994) 449], region immediately flanking 5' [Int. J. Food. 32 (1996) 103], flicH7 35 (1997) 656], or part recently described 2634-bp Small Inserted Locus (SILO(157) locus) STEC O157 Appl. 93 (2002) 250]. Unlike other assays, those amplifying rfb sequences unable distinguish toxigenic nontoxigenic O157. assays relatively specific giving essentially cross reaction with clonally related E. O55 lesser extent O145, O125, O126. They also detected (stx)-negative derivatives Based these results, assay consisting solution hybridization amplicons two probes that ensured specificity amplification was developed. The assay, which used internal control (IC) inhibition, able detect 1 10 copies tube. Adaptation into format facilitates sensitive products constitutes method choice screening