Comparison of Vero cell assay and PCR as indicators of the presence of verocytotoxigenic Escherichia coli in bovine and human fecal samples

• Published in: Applied and Environmental Microbiology 1996-12, Vol.62 (12), p.4314-4317
• Main Authors: Rahn, K. (Agriculture and Agri-Food Canada, Guelph, Ontario, Canada.), Wilson, J.B, McFadden, K.A, Read, S.C, Ellis, A.G, Renwick, S.A, Clarke, R.C, Johnson, R.P
• Format: Article
• Language: English
• Subjects: Animals; Bacteria; Bacteriological methods and techniques used in bacteriology; Bacteriology; Biological and medical sciences; BIOSINTESIS; BIOSYNTHESE; BOVIN LAITIER; Cattle; Cells; Cercopithecus aethiops; CULTIVO DE CELULAS; CULTURE DE CELLULE; DOSAGE BIOLOGIQUE; ENSAYO BIOLOGICO; ESCHERICHIA COLI; Escherichia coli - isolation & purification; Escherichia coli - pathogenicity; ESTIERCOL; EXPLOITATION AGRICOLE FAMILIALE; EXPLOITATION LAITIERE; EXPLOTACION AGRICOLA FAMILIAR; FAMILIA; FAMILLE; FECES; Feces - microbiology; FUMIER; Fundamental and applied biological sciences. Psychology; GANADO DE LECHE; GENERO HUMANO; GENRE HUMAIN; GRANJAS LECHERAS; HECES; HOGARES; Humans; MENAGE; Microbiology; MONO; ONTARIO; PCR; Polymerase Chain Reaction; REIN; RINONES; SINGE; TOXICIDAD; TOXICITE; TOXINAS; TOXINAS BACTERIANAS; TOXINE; TOXINE BACTERIENNE; Vero Cells
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.62.12.4314-4317.1996

Comparisons were made between Vero cell assay (VCA) and PCR as indicators for the detection of verocytotoxigenic Escherichia coli (VTEC; also known as Shiga-like toxin-producing E. coli) and as predictors of VTEC isolation from bovine and human fecal samples. Fecal samples were collected as part of a survey on the prevalence of VTEC on dairy farms in southern Ontario (J. B. Wilson et al., J. Infect. Dis., 174:1021-1027, 1996). A total of 2,655 samples were examined by VCA and PCR, 2,153 originating from cattle and 502 originating from humans. Overall, 36.2% of the samples were positive in the VCA and 38.7% were positive by PCR. Of the VCA-positive samples screened, 41.6% yielded a VTEC isolate. For both human and bovine samples, a significant positive association between PCR result and VCA titer (P = 0.0001) was found. In addition, there was a significant positive association between the PCR result and VTEC isolation from VCA-positive samples for cattle (odds ratio = 9.1, P 0.0001). For bovine samples positive in the VCA, VCA titer was significantly associated with the probability of obtaining a VTEC isolate. Agreement between VCA and PCR was good for both bovine and human samples (kappa