TABLE 1.

Biochemical characteristics of type strains M. tuberculosis H37 (ATCC 27294), M. bovis (ATCC 19210), and M. africanum (ATCC 25420) and the strains analyzeda

Organism and group (no. of strains)Test result (% of isolates)
Niacin accumulationNitrate reductionGrowth in presence of:Colony morphologyChange of color of bromocresol mediumGrowth on Lebek mediumMean catalase activityb ± SD
TCHPZA
M. tuberculosis H37 (ATCC 27294)+++Eugonic+Aerophilic6.0
M. bovis (ATCC 19210)+DysgonicMicroaerophilic0.1
M. africanum (ATCC 25420)±DysgonicMicroaerophilic0.2
M. tuberculosis (76)+ (100)+ (100)+ (100)− (97), + (3)cEugonic (100)+ (100)Aerophilic (100)3.0 ± 1.2
M. bovis (1)+DysgonicMircroaerophilic0.1
M. africanum subtype II Uganda I (55)+ (7), ± (87), − (6)+ (100)+ (100)− (100)Dysgonic (100)− (100)Microaerophilic (100)0.5 ± 0.2
M. africanum subtype II Uganda II (102)+ (5), ± (91), − (4)+ (100)+ (100)− (100)Dysgonic (100)− (100)Mircroaerophilic (100)0.5 ± 0.2
  • a Abbreviations and symbols: +, positive test result; −, negative test result; ±, weakly positive; PZA, pyrazinamide. One M. tuberculosis isolate, three M. africanum subtype II Uganda I, and two Uganda II isolates were resistant to isoniazid and cross-resistant to TCH.

  • b Centimeters of foam production at room temperature.

  • c Strains were resistant to isoniazid, streptomycin, and pyrazinamide.