Evaluation of meglumine antimonate therapy in cutaneous leishmaniasis: Comparison of in vitro sensitivity of Leishmania tropica isolates from patients treated with drug with clinical response

Basic treatment in Leishmaniasis consists of the administration of antimonial drugs, sodium stibogluconate (Pentostam) and meglumine antimonate (Glucantime). Unfortunately, treatment failure, especially in endemic areas, is becoming a common problem in this disease. This study was undertaken to evaluate the in vitro resistance or susceptibility of Leishmania tropica isolated from patients in endemic areas to tri- and pentavalent antimonial drugs and to compare them with the clinical response of the patients to antimonial therapy. The parasites were isolated from the patients in endemic area. These isolates were cultured using solid media (3N media) and liquid media (RPMI-1640). The in vitro intracellular amastigotes of the parasites were prepared by using of viable murine macrophages in three-chamber tissue plates. Then a dilution of the antimonial drug was added to each chamber. Drug efficacy was measured by counting the percent of infected macrophages and the number of intracellular amastigotes per one hundred of infected cells. The results showed that the minimum concentration of the trivalent antimony equal to 100 mg/ml was significantly effective to inhibit the growth of intracellular parasites (P<0.05). There was not significant correlation between the mean numbers of the intracellular amastigotes with the persistent of the lesions (P>0.05). Furthermore, there was not significant correlation between the percent of infected macrophages with the duration of the treatment in each patient. The present results suggest that the lack of relationship between the infectivity of the Leishmania isolated from patients with persistence lesions.