FURTHER-STUDIES OF A NEW PATHOGENIC MYCOBACTERIUM (MYCOBACTERIUM-HAEMOPHILUM SP-NOV

M. haemophilum is an acid-fast rod-shaped organism, originally isolated from deep subcutaneous granulomata of a patient with Hodgkin's disease. Like the other 2 mycobacterial skin-pathogens, M. ulcerans and M. marinum, M. haemophilum has a maximum temperature for growth below 37°C. M. haemophilum is distinguished from all other species examined by its requirement of haemin for growth and its complete lack of catalase activity. Extraneous catalase cannot replace haemin as a growth factor for this organism. M. haemophilum can also be differentiated from other species by the patterns of electrophoresis of protein extracts and by gas-liquid chromatography of saponificated and methylated lipid extracts. A monospecific-agglutinating antiserum against M. haemophilum was obtained by adsorption of an immunoserum with M. intracellulare. A number of slow-growing mycobacterial species develop on monolayers of McCoy fibroblasts, and growth on these tissue cultures can be observed much earlier than on artificial media. M. haemophilum is characterized by exclusively intracellular development.