FIG 4.

In vitro susceptibility of PMM-R isolates to nitrosative and oxidative stress. (A to C) The susceptibility of PMM-R and PMM-S parasites to 3-morpholinosydnonimine (SIN-1) (A), S-nitroso-N-acetyl-dl-penicillamine (SNAP) (B), and hydrogen peroxide (H₂O₂) (C) at the promastigote stage was determined using the resazurin assay. (D) The susceptibility at the intracellular amastigote stage was determined after incubation with different concentrations of SNAP, using peritoneal macrophages. Each bar represents the mean ± SD IC₅₀ of two independent experiments. *, P < 0.05.