Skin granulomata caused by a new microorganism (Mycobacterium haemophilum sp. nov.)

In a patient receiving chemoprophylaxis (INH) because of steroid treatment, a number of intra- and subcutaneous noduli were found. Cutaneous tuberculosis was suspected and anti-tuberculosis treatment was started. The skin lesions healed after 8 months. Histological examination showed a necrotic granulomatous picture. From 4 samples of aspirated pus pure cultures of an unusual microorganism were obtained. The main properties of the isolates included: a short nonmotile and nonsporulating rod, not stained by Gram's method, acid- and alcohol-fast and stained homogeneously after Ziehl-Neelsen, growth on solid and liquid media at 30° in 3-4 weeks but no growth at 37°, hemoglobin or hemin required for growth, synthesis of pyrazinamidase and nicotinamidase but not of catalase nor urease, neutral red positive. From these data and from serological examinations it was concluded that this organism is a new species of mycobacterium. It was designated Mycobacterium haemophylum sp. nov. and the type strain of the species was disposed at the American Type Culture Collection (number ATCC 29548).