Background and aims: Regarding the increasing numbers of clinical antimonial-resistant Leishmaniasis, understanding the reasons for drug resistance is helpful. This study aimed to find the expression level of the genes related to resistance, P-glycoprotein A (PgpA), G-glutamylcysteine synthetase 1 (Gsh1), and aquaglyceroporin 1 (Aqp1) in antimonial-resistant clinical isolates.
Methods: Samples were isolated from leishmaniasis ulcers of 10 non-healing patients and the species were identified by the nested-polymerase chain reaction (PCR) method. In vitro experiments were performed using the amastigote-macrophage model by J774 cell line, and in vivo studies were conducted by animal model, the Balb/c mice. Finally, the values of genes expression were determined by quantitative-reverse transcription (q-RT) real-time PCR method and then compared with non-resistant Leishmania major (MRHO/IR/75/ER).
Results: Molecular identification showed that all isolated protozoa were L. major. The isolated samples from clinical resistant patients represented no increase in expression in the tested resistance genes (P>0.05). Finally, it was found that the lack of improvements in patients was not associated with the increased expression of resistance genes.
Conclusion: In general, no inherent resistance was observed in the tested samples neither a correlation between the healing of lesions and the level of genes expression.