Figure 6. Effect of NO inhibitor, aminoguanidine (AG) and NO donor sodium nitroprusside (SNP) on survival of M. smegmatis harbouring either backbone vector (Msmeg-pVV16), or expressing PPE2 (Msmeg-PPE2) or ΔNLS-PPE2 (Msmeg-ΔNLS-PPE2).

Murine peritoneal macrophages (0.5 × 10⁶) were either cultured in medium alone or pre-treated with either AG (300 μg/ml) or SNP (100 μM) followed by infection with either Msmeg-pVV16, or Msmeg-PPE2 or Msmeg-ΔNLS-PPE2 at 1:10 multiplicities of infection (MOI). Twenty four hours after infection, supernatants were removed for nitrite determination and the cells were lysed for CFU assay. The cell lysates were plated on 7H10 plates supplemented with 10% ADC, Kanamycin (25 μg/ml), Hygromycin B (50 μg/ml) and 0.05% of Tween 80 and incubated for 4 days for counting the number of colony forming units (CFUs). Data were expressed as mean ± SD of 3 independent experiments.