Comparison of polymerase chain reaction using kinetoplast DNA specific primers and other parasitological methods in the diagnosis of clinical samples of suspected patients with cutaneous leishmaniasis in Şanlıurfa

Abstract

Visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) are seen endemically in Turkey and CL caused by Leishmania tropica is an important public health problem in southeastern as well as other regions of Turkey. The diagnosis has been usually made by clinical view of lesion and/or parasitologically using lesion aspiration smears. Histological examination does not, always reveal the parasite in the skin biopsy, particularly in chronic lesions. Besides this, due to CL infections caused by different species in endemic areas, diagnostic methods enabling species identification are in great need. Species identification, in the time of diagnosis, is an important procedure for helping the clinicians in the planning of treatment as well as control measures. Polymerase chain reaction (PCR) is a specific and sensitive diagnostic tool that can also identify the parasite at species level. Kinetoplast DNA (kDNA) is one of the genetic regions that can be used for the detection of Leishmania parasites in clinical specimens, kDNA PCR is reported as one of the most sensitive methods related to species-specific variable regions in mini-circle long time ago. It has been considered as one of the most ideal targets for the diagnosis of leishmaniasis. The aim of the study was to perform PCR targeting kDNA by using the primers of Uni21/Lmj4 in clinical samples and compare the results with other parasitological methods like smear and culture, for the diagnosis of CL. The kDNA PCR, parasite culture and microscopical evaluation of stained smears of 62 specimens from suspected CL cases who have referred to Cutaneous Leishmaniasis Diagnosis and Treatment Center in Sanliurfa, Turkey were included in the study. The kDNA PCR showed the highest sensitivity 100% of the samples (35/35) among all diagnostic assays, followed by the microscopy (25/35 positive, 71.4% sensitivity) and culture (19/35 positive, 54.3% sensitivity). The sensitivity of combination of culture and microscopy was 88.6% (31/35 positive). These results suggested that performing kDNA PCR in addition to conventional techniques is important for improving the true diagnosis of CL to the species level and also important for establishing treatment regimens and designing appropriate precautions in highly endemic area like the southeastern region of Turkey.