RESUMO
To investigate the performance of "tofu-whey liquid medium" for the propagation of Mycobacterium tuberculosis [MTB] strain H37Rv. Two hundred micro liters [200 micro l] of 1 McFarland standard [1 mg/ml-bacillary suspension] were inoculated into different batches of tofu-whey liquid medium. Each series contained three trials of test [tofu-whey liquid medium] and control media [Middlebrook 7H9 medium]. Turbidity was measured within three weeks of inoculation using a nephelometer. The combinations of various tofu-whey liquid culture media were as follows; T1 [tofu-whey + ADC + glycerol + Potassium sulfate + Magnesium citrate + Sodium glutamate]; T2 [tofu-whey + ADC + glycerol + Potassium sulfate + Magnesium citrate]; T3 [tofu-whey + ADC + glycerol + Potassium sulfate]; T4 [tofu-whey + ADC + glycerol]; T5 [tofu-whey + ADC]; and T6 [tofu-whey only]. In all test and control liquid culture media, the multiplication of M. tuberculosis was documented under light and fluorescence microscopy. Of various tofu-whey medium used, T1 demonstrated the most potential for MTB propagation. The increased turbidity reading represented by the value in "unit drop of% transmittance" was higher [25 scores] in the T1 tofu-whey medium, compared with the T6 tofu-whey medium [8 scores]. The overall growth was significantly better in Middlebrook 7H9 culture media, although by the third day of incubation, the bacillary growth was superior in the T1 tofu-whey culture media. Sub-cultures in Lowenstein-Jensen [L-J] medium yielded between 87% [47 of 54] and 89% [48 of 54] recovery rate with between 7% and 13% contamination rate with coagulase-negative staphylococci. Tofu-whey media can be used as an economical alternative to Middlebrook 7H9 in resource-limited settings