Figure 7.

Effect of PezT^Mtb overexpression on cell length and drug tolerance of M. smegmatis. (A) DAPI stained fixed images of M. smegmatis harbouring vector or expressing PezT^Mtb in the absence or presence of PezA^Mtb after 3 hrs of induction. (B,C) The panel depicts cell length of M. smegmatis harbouring either pTetR-Int or pTetR-Int-PezT^Mtb or pTetR-Int-PezT_Mtb and pLam12-PezA^Mtb. The cultures were induced for either 3 hrs (B) or 6 hrs (C) and bacilli length was measured using Fluoview FV1000 software. The y-axis represents mean ± S.E. of cell length for bacilli per strain. The data shown in this panel is representative of three independent experiments. (D,E) Induced M. smegmatis cultures harbouring either pTetR-Int or pTetR-Int-PezT^Mtb were exposed to either 15.6 μM ethambutol or 2.0 μM levofloxacin. For bacterial enumeration, 12 hrs post-exposure, cultures were harvested, washed and 100 μl of 10.0-fold serial dilutions were plated on MB7H11 plates at 37 °C for 2–3 days. Significant differences were observed for the indicated groups (paired, two-tailed, t-test, *P < 0.05, ***P < 0.001).