Branched Mycobacterium-like organisms from swine lymph nodes

Branched, weakly acid fast organisms were isolated from 5 of 112 caseous lymph nodes derived from slaughter-house pigs. In two cases they were associated with typical Mycobacterium avium strains. The bacteria differed from all other mycobacteria known at present. Limited experiments in pigs with one strain failed to disclose a possible pathogenic role in the host species although this strain was pathogenic for mice. Tests with this and three other strains showed that all four were apathogenic for chickens.