A disc growth-inhibition test for differentiating Treponema hyodysenteriae from other intestinal spirochaetes.

A disc growth-INHIBITION (GI) test was developed for differentiating Treponema hyodysenteriae from other intestinal spirochaetes. Tests with antisera against six spirochaetes, including two strains of T hyodysenteriae revealed four serological types among the six strains. The two strains of T hyodysenteriae represented one type. The test was specific in that there were no cross-reactions between the four types. Using antisera to two strains of T hyodysenteriae, it was possible to distinguish 11 strains isolated from cases of swine dysentery from nine other intestinal spirochaetes, seven from pigs, one from a cat and one from a chicken. The GI test seems to have potential as a simple, specific screening test for T hyodysenteriae.