Typing of Leishmania Species Causing Cutaneous Leishmaniasis by Sybr Green Based ITS-1 Real Time Polymerase Chain Reaction Method

Cutaneous leishmaniasis (CL) is an important public health problem, most frequently seen in Sanliurfa in Turkey. It is important to determine the species in regions where infection occurs with different Leishmania species, as in our province. In this study, it was aimed to genotype 136 samples with suspected Leishmania from Sanliurfa using the Sybr Green-based ITS-1 real time polymerase chain reaction (Rt-PCR) method and then to compare them with ITS-1 PCR RFLP and direct microscopy methods. Wound fluid samples from patient lesions suspected of leishmaniasis were mounted on a slide, fixed, and stained with Giemsa dye. The preparations were examined under the microscope and evaluated for the presence of amastigote. After the extraction of DNA from Giemsa stained preparations by using the QIAmp DNA Mini Kit (Qiagen, Germany), the samples were studied with the Sybr Green based ITS-1 Rt-PCR method using LITSR and L5.8S primers. As a result of the PCR study, melting curve analysis was determined and the melting curves were compared with the reference strains. Then, PCR was performed in 136 samples for ITS1 region amplification using primers LITSR and L5.8S. PCR products were digested with Hae III restriction enzyme and RFLP process was performed. The products were run on metaphor agarose gel than the gels were stained with ethidium bromide for 15 min and visualized in a UV transilluminator In our study, the results of Sybr Green-based ITS-1 Rt-PCR, ITS-1 PCR-RFLP and direct microscopy methods were compared. The highest positivity rate was determined as 97% (136/132) in ITS-1 Rt-PCR method. With ITS-1 PCR-RFLP method 95.5% (136/130) positivity and with direct microscopy 94.1% (136/128) positivity were obtained, respectively. Of 132 samples, which were studied with the Sybr Green-based ITS-1 Rt-PCR method and found as positive, 121 were genotyped as L.tropica and 11 were genotyped as L.major by melting curve analysis. It was determined that, of 130 samples studied with ITS-1 PCR RFLP method 119 (91.5%) were detected as L.tropica and 11 (8.5%) were detected as L.major. The ITS-1 Rt-PCR method we used in our study was the method that detected the most positivity rate. With this method, Leishmania specimens were typed as L.tropica and L.major. It is thought that this method may be useful for the detection of the presence of Leishmania parasite and in the rapid identification of Leishmania species, as it does not require extra processes such as cutting and staining after PCR and results in a short time, but new studies are needed to observe its effectiveness in detecting other species other than L.tropica and L.major.