Human infections with Mycobacterium bovis.

Two patients with tuberculosis due to Mycobacterium bovis were identified at The Mount Sinai Hospital from 1970 through 1973. In addition, 2 isolates of M. bovis-BCG were recovered from abscesses at vaccination sites of nontuberculous patients. All 4 strains were slow growers, produced nonpigmented, rough colonies, and demonstrated cording. Initial isolation was best achieved in media devoid of glycerol. The 2 wild M. bovis strains were dysgonic, inhibited by glycerol, niacin and nitrate negative, and susceptible to the action of thiophene-2-carboxylic acid hydrazide (TCH). One of them was found to be pathogenic for rabbits. After rabbit passage, this strain became eugonic, producing luxuriant growth of larger, smoother colonies on Lowenstein-Jensen (L-J) and Middlebrook 7H11 agars, and inconsistently niacin positive. The 2 isolates of M. bovis-BCG were not inhibited by glycerol, as evidenced by eugonic growth on L-J and 7H11, but were niacin and nitrate negative and susceptible to TCH.