title: Managemental influences on the selective proliferation of two strains of haemolytic Escherichia coli in weaned pigs.
abstract: In an experimental study on a piggery it was found that haemolytic Escherichia coli of O-serotypes 138 or 139 proliferated in the intestinal tracts of pigs following weaning, with E. coli of the O-138 type also being occasionally recovered from unweaned pigs, and once from a sow. Organisms of the O-138 type produced heat labile enterotoxin and their presence in weaned pigs was associated with the development of severe post-weaning diarrhoea. E. coli of O-139 type produced a vero cell cytotoxin and were associated with a milder diarrhoea in weaned pigs. Under various managemental circumstances the O-138 type E. coli almost invariably proliferated after weaning. The O-139 strain of E. coli did however proliferate rather than the O-138 strain following the movement of weaned pigs to new accommodation, after weaned pigs were returned to their sow and then weaning again 5 days later, and very occasionally in pigs weaned at 5 weeks of age. In all these cases earlier proliferation of the O-138 E. coli had been detected, suggesting that this may be a prerequisite for proliferation of the O-139 strain.
authors.affiliation: Department of Veterinary Pathology, Massey University, Palmerston North, New Zealand.
authors.forename: D J
authors.initials: DJ
authors.lastname: Hampson
authors.forename: Z F
authors.initials: ZF
authors.lastname: Fu
authors.forename: K A
authors.initials: KA
authors.lastname: Bettleheim
authors.forename: M W
authors.initials: MW
authors.lastname: Wilson
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis; D003603:Cytotoxins / Q000096:biosynthesis; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary*; D004768:Enterotoxins / Q000096:biosynthesis; D004926:Escherichia coli / Q000145:classification / Q000254:growth & development* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000662:veterinary*; D029968:Escherichia coli Proteins; D007422:Intestines / Q000382:microbiology*; D012703:Serotyping; D022622:Shiga Toxin 1; D013552:Swine / Q000382:microbiology; D013553:Swine Diseases / Q000382:microbiology*; D014886:Weaning
chemical_list: D001427:Bacterial Toxins; D003603:Cytotoxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; C027538:heat-labile enterotoxin, E coli