Prevalence of heat-stable II enterotoxigenic Escherichia coli in pigs, water, and people at farms in Thailand as determined by DNA hybridization

Abstract

The DNA hybridization assay employing a 460 base pair fragment of DNA encoding for the methanol-insoluble form of heat-stable toxin (ST-II) was used to determine the prevalence of ST-II enterotoxigenic E. coli (ETEC) in pigs, people and water at 57 farms in Sri Racha, Thailand. ST-II ETEC was found in 62 (3%) of 2110 suckling, 181 (32%) of 560 weaned and 4 (1%) of 457 adult pigs examined. Of 62 suckling pigs with ST-II ETEC infections, 21% had diarrhea; none of 185 infected older pigs had diarrhea. ST-II ETEC was found more frequently in suckling pigs with diarrhea than without diarrhea (13 of 146 vs. 49 of 1964) (P < 0.001). ST-II ETEC was detected in water collected from 3 of 57 clay jars containing water used to bathe at 3 pig farms, in 1 jar used to bathe immediately after working in the barn and from 1 farmer who did not have a recent history of diarrhea. Evidence of this organism was not found in 245 other individuals living on the pig farms or in 220 inhabitants and 114 water specimens collected at tapioca farms nearby. In Thailand ST-II ETEC was found in suckling pigs with diarrhea but was infrequently found in humans.