Pathogenic synergism between Treponema hyodysenteriae and other selected anaerobes in gnotobiotic pigs

Abstract

Gnotobiotic pigs were orally exposed to various anaerobes at 6-9 days of age and similarly inoculated with T. hyodysenteriae B204 3-6 days later. Watery diarrhea and fecal excretion of large quantities of mucus and some fibrin clots were observed 4-20 days after inoculation with B204 if other anaerobes were present. Colonic lesions characteristic of swine dysentery were observed when B204 was present with Fusobacterium necrophorum, 3 strains of Bacteroides vulgatus [B. fragilis ssp. vulgatus], a Clostridium sp. and Listeria denitrificans individually and when some of these microbes were present in various combinations, but not when B204 was present alone. T. hyodysenteria is the primary pathogen in the etiology of swine dysentery. Presence of 1 or more other anaerobes is a prerequisite for expression of pathogenicity of T. hyodysenteriae. This prerequisite can be met by a variety of anaerobes.