Postweaning diarrhea in swine: experimental model of enterotoxigenic Escherichia coli infection.
A reproducible model of postweaning colibacillosis was obtained by controlling management and environmental variables to simulate conditions often seen at weaning. Suckling pigs were exposed briefly to starter diet at 1 week of age, weaned at 3 weeks of age, held at an ambient temperature of 20 +/- 2 C, and again given the starter diet. One day after weaning, each pig was given 10(10) colony-forming units of enterotoxigenic Escherichia coli strain M1823B (O157:K88ac:H43-LT+ STb+) in broth containing 1.2% sodium bicarbonate via stomach tube. In vitro adhesion by strain M1823B to isolated intestinal branch borders was used to test pigs for susceptibility to K88. In this model, 3 syndromes were induced in susceptible pigs: (1) peracute fatal diarrhea; (2) moderate diarrhea, weight loss, and fecal shedding of the inoculum strain; and (3) no diarrhea, weight loss, and fecal shedding of the inoculum strain. Rotavirus particles were not found in fecal specimens of pigs with diarrhea. The K88-susceptible, noninoculated control pigs remained clinically normal. It was concluded that susceptibility to adhesion by K88+ enterotoxigenic Escherichia coli was a requirement for the production of disease in this model; inoculation with rotavirus was not necessary.
D000818:Animals; D000831:Animals, Newborn; D001422:Bacterial Adhesion; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary*; D004195:Disease Models, Animal; D004926:Escherichia coli / Q000502:physiology*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D005260:Female; D007413:Intestinal Mucosa / Q000382:microbiology; D007583:Jejunum / Q000382:microbiology; D008871:Microvilli / Q000382:microbiology; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*; D013997:Time Factors; D014886:Weaning