Figure 1.

(A) Flow cytometric detection of intracellular thiol content in both SSG-R and SSG-S isolates using the fluorescence probe 5-chloromethylfluorescein-diacetate (CMFDA). Two million stationary-phase parasites were incubated in 5 μM of CMFDA in phosphate-buffered saline (PBS) at 37°C for 15 min. Fluorescence was measured in log mode and expressed as mean fluorescence intensity (MFI). Data are expressed as MFI ± SD for three independent experiments. ****p < 0.0001, ***p < 0.001, **p = 0.001–0.01, *p = 0.01–0.05; ns, non-significance. (B) Electrical equivalent circuit model for Leishmania donovani (LD) promastigotes suspended in media. R_i and C _mem denote cytoplasm resistance and membrane capacitance, respectively, which may vary depending upon cell types. Solution resistance (R _sol) and capacitance (C _sol) are present due to the ionic conductivity of PBS and electrode–electrolyte interface. (C) Impedance spectrum showing the magnitude of impedance vs. frequency (Hz) for LD isolates. The magnitude of impedance was recorded against a frequency range of 40 Hz to 100 MHz, with a sinusoidal excitation voltage of 10 mV. A significant change is visible within the frequency range of 40 Hz to 10 kHz as depicted in the figure. Representative figure is presented from three independent experiment. (D) Splenic and hepatic parasite burden of hamsters infected with either BHU782 and BHU814 isolates (showing low susceptibility towards Mil) or BHU816 and BHU777 (showing high susceptibility towards Mil) and either treated with 17.5 mg/kg Mil or left untreated was expressed as Leishman Donovan units, calculated as the number of parasites per 1,000 nucleated cells  ×  weight of the organ (in mg). Data are expressed as means ± SD, with statistical significance being determined for parasite clearance after Mil treatment comparing Mil less susceptible strains (BHU 782 and BHU 814) with highly susceptible strains (BHU 816 and BHU 777). **p = 0.001–0.01; ns, non-significance.