Comparison of enterotoxic activities of heat-stable enterotoxins from class 1 and class 2 Escherichia coli of swine origin.

摘要: Pig small intestine develops age-dependent resistance to some (class 2 strains) enterotoxigenic Escherichia coli while remaining susceptible others 1 strains). This study tested the hypothesis that class and strains produce different subtypes of heat-stable enterotoxin (ST). The dose-response curves crude ST preparations from a strain were compared in several species. In infant mice, preparation was less active than preparation, whereas rabbits equally potent. However, 1-, 7-, 14-week-old pigs, more preparation. At low doses, both caused reduced absorption pigs all three age groups, at high doses secretion groups. contrast, 1-week-old but only older pigs. when fractionated by methanol extraction, cases mouse-negative, pig-positive activity associated with methanol-insoluble fraction mouse-positive, methanol-soluble fraction. results are consistent E. response pig varies toxin subtype.