Enteropathogenicity of various isolates of Treponema hyodysenteriae

Abstract

Isolates of Treponema hyodysenteriae from 25 geographically separated outbreaks of swine dysentery, which is a mucohemorrhagic diarrheal disease, were tested for their ability to produce the disease. Clinical signs and lesions typical of acute swine dysentery were produced in 52 of 68 (75%) susceptible specific pathogen-free pigs that had been orally inoculated with pure cultures of 23 of 25 beta-hemolytic isolates. In addition, 13 weakly beta-hemolytic isolates of nondysentery origin with morphology similar to T. hyodysenteriae did not produce disease when orally inoculated into susceptible specific pathogen- free pigs. Two of these latter isolates, Puppy and B296, and one pathogenic, beta-hemolytic isolate failed to produce disease when orally inoculated into puppies.