DETECTION OF ENTEROTOXIGENIC ESCHERICHIA-COLI IN WATER BY POLYMERASE CHAIN-REACTION AMPLIFICATION AND HYBRIDIZATION

Enterotoxigenic Escherichia coli was studied in waste water, river wat er, and seawater from six locations along the west coast of Normandy b y using the polymerase chain reaction (PCR) to amplify the heat labile (LT) gene. Cellular DNA was extracted from centrifugation pellets and amplified using PCR. The PCR products were detected by gel electropho resis and confirmed by hybridization assay, using an 850 base pair Hin dIII DNA fragment probe from pEWD299 conjugated to digoxigenin and spe cific for the LT gene. Results of the PCR amplification were compared with those of GM1 enzyme-linked immunosorbent assay, latex agglutinati on, and colony hybridization. The PCR method was found to be more prec ise and less time consuming, especially when compared with methods req uiring culture of isolates for enumeration of enterotoxigenic E. coli in water.