Diagnosis and identification of Leishmania spp. from Giemsa-stained slides, by real-time PCR and melting curve analysis in south-west of Iran

Abstract

Background: The aim of present study was describing a real-time PCR assay for the diagnosis and direct identification of Leishmania species on Giemsa-stained slides in south-west of Iran.

Materials and methods: Altogether, 102 Giemsa-stained slides were collected from different part of south-west of Iran between 2008 and 2011. All the Giemsa-stained slides were examined under light microscope. After DNA extraction, real-time PCR amplification and detection were conducted with fluorescent SYBR Green I. For identification, PCR products were analysed with melting curve analysis.

Results: One hundred and two archived slides from suspected lesion examined by microscopy and real-time PCR. The sensitivity of the real-time PCR on Giemsa-stained slid was 98% (96/102). The melting curve analysis (T_m) were 88·3±0·2°C for L. tropica (MHOM/IR/02/Mash10), 86·5±0·2°C for L. major (MHOM/IR/75/ER) and 89·4±0·3°C for L. infantum (MCAN/IR/97/LON 49), respectively.

Conclusion: This study is first report in use of real-time PCR for diagnosis and identification of Leishmania spp. in Iran. Up to now, in Iran, the majority of identification of Leishmania species is restriction fragment length polymorphism (PCR-RFLP) of ITS1 and kinetoplast DNA. Our data showed that Giemsa-stained slides that were stored more than 3 years, can be use for Leishmania DNA extraction and amplification by real-time PCR. Compared to conventional PCR-based methods, the real-time PCR is extremely rapid with results and more samples can be processed at one time.

This study is conducted and financially supported by grant no. 89104 from Ahvaz Jundishapur University of Medical Sciences. The authors would like to thank all staff of health centres of Ahvaz Jundishapur University of Medical Sciences. The authors declare no conflict of interests.