Evaluation of the colilert® test for detection of verotoxin-producing escherichia coli in water: A tool for on-farm food safety

The objective of this study was to estimate the sensitivity of the Colilert® test for detection of different isolates of Escherichia coli (E. coli) O157:H7 and other verotoxin-producing E. coli (VTEC) serotypes from water for potential on-farm food safety application. E. coli isolates evaluated were of human, bovine, porcine, or food origin. The sensitivity of the Colilert® test was 92% overall for the verotoxin-producing serotypes of E. coli. However, none of the E. coli O157:H7 isolates were identified as E. coli. No false-positive results for E. coli were detected. The Colilert® test could be used to screen water supplies for E. coli on the farm, however, an important pathogenic E. coli sero-type is not detected by the Colilert® test.