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Updated: Jan 25, 2026

Foodborne Pathogen Screening Using Magneto-fluorescent Nanosensor: Rapid Detection of E. Coli O157:H7
Published on: September 17, 2017
Low Specificity of the HEC O157™ ELISA in Screening Ground Beef for Escherichia coli O157:H7
Loreen P Sernowski1, Steven C Ingham1
1Department of Applied Microbiology and Food Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 0W0.
Abstract:
During January-August, 1991, 74 retail ground beef samples were tested for the presence of Escherichia coli O157:H7 using the commercial HEC O157™ ELISA kit. A total of 17 samples (23%) were presumptively positive for E. coli O157:H7. Twenty-nine isolates were taken from colonies corresponding to positive spots on the immunoreactive discs and 13 from colonies on sorbitol MacConkey agar No. 3 plates. Of these isolates, 30 were positive when retested as pure cultures with the ELISA (enzyme-linked immunoabsorbent assay). Only 15 of these 30 isolates were E. coli , 6 were identified as Hafnia alvei , and 9 were not identifiable. None of the E. coli isolates were serotype O157:H7. These results confirm that: a) the HEC O157™ ELISA method for detecting E. coli O157:H7 has low specificity, and b) use of the HEC O157™ ELISA necessitates thorough confirmatory testing.
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