Foodborne enterotoxigenic Escherichia coli: detection and enumeration by DNA colony hybridization.

Four methods were compared for detecting heat-labile toxin production by Escherichia coli: DNA colony hybridization, two enzyme-linked immunosorbent assays, and the mouse Y-1 adrenal cell reaction. Although results of the methods were in general agreement, there were some differences in specificity and sensitivity. DNA colony hybridization was used to detect and enumerate enterotoxigenic E. coli isolates in artificially contaminated food without enrichment. Sensitivity level was 100 cells per g.