Abstract

Background & objectives: The mechanism of antimony resistance in Leishmania has been studied extensively, in connection with decreased influx and/or increased eflux of the drug. Aquaporin 1 (AQP1) protein has been shown to mediate the uptake of trivalent antimony. This study was aimed to find the expression level of AQP1 gene in resistant versus non-resistant clinical isolates of Leishmania major in Iranian patients. Methods: Clinical isolates were obtained from 16 considered patients referred to Navab Safavi Clinical Center, Isfahan, Iran from October 2014 to December 2015. After diagnosis of cutaneous leishmaniasis using microscopic observation, biopsy was performed from lesion(s) of each patient and stored inside RNAlater solution at -20 degrees C. Written informed consent was obtained from all the patients to participate in the study before recording their information and sampling based on Helsinki declaration. Each patient was treated with Glucantime and followed for three months. All sensitive and resistance isolates were considered and compared with AQP1 gene expression using real time PCR that was analyzed with delta-delta Ct. Results: Out of 16 clinical isolates, four patients were resistant and 12 were non-resistant. The AQP1 gene expression in resistant isolates was significantly higher than the one in response failure isolates (p = 0.001). Interpretation & conclusion: The significant over expression (0.5 fold) of AQP1 gene in resistant versus nonresistant isolates suggests different mechanism of drug resistance such as mutations. Mutations may change the physiological function of the Aquaporin 1 protein that might affect its expression level.