DETECTION OF ENTEROTOXIGENIC ESCHERICHIA-COLI IN STOOL SPECIMENS BY POLYMERASE-CHAIN-REACTION

A polymerase chain reaction (PCR) protocol for rapid (7 h) detection o f enterotoxigenic Escherichia coli (ETEC) is described. This protocol has been validated on 57 stool samples fi om young children by compari ng it with the colony hybridization technique. A good agreement was fo und between the two methods with Cohen's kappa statistics of 0.87 and 0.79 for the detection of the heat-stable toxin (ST) and heat-labile t oxin (LT), respectively Of 26 samples positive for LT and 15 samples p ositive for ST by colony hybridization, 21 (81%) and 15 (100%) were al so found to be positive for LT and ST by PCR respectively Only one sam ple identified as LT-negative by colony hybridization was found to be positive by PCR. However, 3 of 42 samples of ST-negative by colony hyb ridization were detected as positive by PCR. A reconstruction experime nt revealed that PCR could detect LT-producing and ST-producing ETEC a t minimal concentrations of 2.5 x 10(3) cfu and 2.5 x 10(2) cfu per gr am of feces, respectively. These data indicate the possible use of thi s method for rapid identification of ETEC-associated diarrhea in clini cal and epidemiological settings. (C) 1998 Elsevier Science Inc.