Repeated isolation of chemoautotrophic nocardioform bacteria from fish epizootic ulcerative syndrome.

Nocardioform actinomycetic organisms were present regularly in, and isolated repeatedly from, different varieties of fish affected with epizootic ulcerative syndrome lesions of dermis, muscle, subcutaneous tissues and internal organs. These acid-fast bacilli, resembling human and rat leprosy bacilli, together with other actinomycotic bodies, appeared to explain the characteristic macrophage granuloma observed in such lesions, similar to those of humans. These isolates possessed fundamental similarities to the human isolates of chemoautotrophic nocardioform bacteria reported earlier.