Mycobacterium tuberculosis transcriptional response to Pyrazinoic acid

The ability of Mycobacterium tuberculosis (Mtb) to adopt heterogeneous physiological states, underlies it’s success in evading the immune system and tolerating antibiotic killing. Drug tolerant phenotypes are a major reason why the tuberculosis (TB) mortality rate is so high, with over 1.8 million deaths annually. To develop new TB therapeutics that better treat the infection (faster and more completely), a systems-level approach is needed to reveal the complexity of network-based adaptations of Mtb. Here, we report the transcriptional response of Mtb to the drug Pyrazinoic acid . We performed transcriptomic sequencing (RNA-seq) on Mtb bacilli at 4, 24, 72 h following exposure to the drug. Cultures of Mycobacterium tuberculosis were grown in 7H9 media supplemented with ADC, 0.2% glycerol and 0.05% tyloxapol in a 37 degrees C incubator with shaking until mid log phase. Frozen 1 mL stocks of Mtb cells were added to 7H9-rich media and grown until the culture reached an OD600 of ~0.4-0.8. The cells were then diluted to OD600 of 0.05 and added to 7H9-rich media containing Pyrazinoic acid at the predetermined amounts (0 or 3100 μg/mL, as indicated in each sample title). Samples were collected at 4 h, 24 h, and 72 h from three biological replicates. The sequence reads that passed quality filters were aligned with Bowtie2 and processed using the R package DuffyNGS.