Evaluation of Commercial Kits for a Rapid Detection of Escherichia coli O157 in Stool

Abstract

To introduce rapid detection of E. coli O157 in the stool without culturing, nine different commercial kits for detection of E. coli O157 were compared. VIP, Reveal, Path Stik, Quix, Now EH and EZ coli were found to detect E. coli O157 greater than 10⁶ CFU/ml. TECRA and Novapath could detect more than 10⁵ CFU/ml. VIDAS reacted positive with more than 10⁴CFU/ml.
TECRA, Novapath, Quix could detect 1: 4, 1: 4, 1: 9 dilution of stool specimen spiked with E. coli O157 respectively, but others could not detect with 1: 9 dilution of stool specimen.
When stool specimens spiked with E. coli O157 were diluted ten times, centrifuged slightly and supernatants were tested, Path Stik, Quix and EZ coli could detect 10⁷ CFU/ml. TECRA and Novapath could detect 10⁶ CFU/ml, whereas VIDAS could detect 10⁵ CFU/ml
Quix is therefore one of the most suitable kit for detection of E. coli O157 in the stool at the bedside, although some non-specific reactions were observed. Path Stik is also convenient kit at bedside. VIDAS, although it requires special equipment, is the most sensitive kit for detection E. coli O157 and is suitable for detection of low levels of E. coli O157 in the clinical laboratory.