Usefulness of a commercially available enzyme immunoassay for Shiga-like toxins I and II as a presumptive test for the detection of Escherichia coli O157:H7 in cattle feces.
The performance of a commercially available enzyme immunoassay (EIA) for determining the presence of Shiga toxin I and II in human diarrheal stool samples was evaluated for use as a presumptive test for the presence of Escherichia coli O157:H7 in nondiarrheal bovine fecal samples collected from 10 Kansas cow-calf ranches. The prevalence of E. coli O157:H7 in 2,297 samples, as determined by selective bacterial culture, was 1.6%. The sample prevalence of non-E. coli O157:H7 Shiga toxin-producing bacteria, as detected by the Shiga toxin EIA, was 5.8%. Only 2 of 136 samples that tested positive with the Shiga toxin EIA were positive for E. coli O157:H7 by culture. Compared with bacterial culture, the sensitivity of the Shiga toxin EIA was 5.5% and the specificity was 94.1%. Agreement between the 2 tests, as measured by the kappa statistic, was poor (kappa = -0.002). Although the Shiga toxin EIA was not a good presumptive test for the determination of E. coli O157:H7 in bovine fecal samples because of its low sensitivity (5.5%), it might be a useful test for the detection of Shiga toxin producing non-E. coli O157:H7 organisms in bovine feces.
Food Animal Health and Management Center, College of Veterinary Medicine, Kansas State University, Manhattan 66502, USA.
D R
DR
Hyatt
J C
JC
Galland
J R
JR
Gillespie
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000821:virology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000662:veterinary*; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D005243:Feces / Q000821:virology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D022622:Shiga Toxin 1 / Q000032:analysis* / Q000276:immunology; D022641:Shiga Toxin 2 / Q000032:analysis* / Q000276:immunology
D022622:Shiga Toxin 1; D022641:Shiga Toxin 2