A New Screen for Tuberculosis Drug Candidates Utilizing a Luciferase-Expressing Recombinant Mycobacterium bovis Bacillus Calmette-Guéren
Fig 2
TB drugs abrogate the increase of both luciferase activity and the CFU of rBCG-MDP1-luc.
TB drugs, such as INH, RFP, LVFX, and SM, were added to the bacterial suspension at a concentration of 0.5 μg/ml, 8 μg/ml, 1 μg/ml, and 4 μg/ml, respectively (10 fold concentration of the MIC of each drug). At each time point, 50 μl of bacterial suspension was mixed with the same volume of the luciferin-ATP mixture (Promega) and then the luciferase activity was determined immediately as the RLU. At the same time, each bacterial culture was serially diluted and inoculated on 7H11-OADC agar containing 10 μg/ml of Km. Three weeks after cultivation at 37°C, the CFU were counted and compared with the RLU. The representative data of two independent experiments are presented as the means ± SD.