Characterization of leishmania parasites from archived geimsa-stained slides using nested polymerase chain reaction

ABSTRACT

In Iran, the clinical presentation of cutaneous leishmaniasis is mainly in the form of dry type [urban form] or wet type [rural form]. The microscopic finding of amastigotes in Giemsa-stained smears is the most practical laboratory test for the diagnosis of cutaneous leishmaniasis. However, determination of parasite species is not possible when using this method. Parasite characterization is made by various biochemical, immunological and molecular methods based on massive culture of the parasites. In this study nested PCR was used both for diagnosis as well as species identification. Giemsa-stained slides from forty-nine patients, that had been included in a drug resistance survey, were used in this study. From the available slides, forty-seven were diagnosed as having leishmaniasis using the nested PCR technique. Twenty of these were Leishmania tropica [L. tropica] and the remaining were Leishmania major [L. major]. Amastigotes were recovered from twenty-nine of these patients after standard treatment. This study revealed that clinically drug-resistant cases are more likely to be infected with L. tropica than with L. major, although this difference was not statistically significant. L. tropica was mostly present in facial lesions while L. major was mostly detected in hand and foot lesions. In patients with more than two lesions, L major was the predominant cause. L tropica was the cause of a more prolonged duration of disease. None of the above findings were, however, statistically significant. It can be concluded that nested PCR is a useful technique for studying the molecular epidemiology of leishmaniasis in the field