Molecular diagnosis of leishmaniosis in the Paraná state of southern Brazil

Abstract: The objective of the present study was to establish a polymerase chain reaction (PCR) technique for the diagnosis of cutaneous and mucocutaneous leishmaniosis from autochthonous cases in the state of Paraná in southern Brazil as well as imported cases. We sought to determine its utility and accuracy compared with smears and present culture methods. To standardize PCR samples, skin and mucosal punch biopsies from human lesions were performed on patients living in different regions of the Paraná state (76 cases) and other endemic areas of Brazil and Argentina (7 cases). For PCR standardization, two pairs of primers (MP1L/MP3H and B1/B2) were utilized for amplification of the conserved sequences in the minicircle of kinetoplast DNA (kDNA) for the Leishmania braziliensis complex. Two other primer pairs (b1/b2 and a1/a2) were species-specific for L. (V.) braziliensis and L. (V.) amazonensis, respectively. After differential diagnosis, eight patients had clinical diagnosis of the cutaneous ulcer changed to others pathologies such as syphilis, baso-cellular carcinoma, varicose ulcer, ecthyma and paracoccidioidomycosis. Of the 75 patients with cutaneous (CL) and mucocutaneous (MCL) lesions who provided samples, 47 (46 CL + 1 MCL) were diagnosed with leishmaniosis by smear and 57 (52 LC + 5 MCL) were diagnosed by culture methods. In contrast, our PCR technique presented higher accuracy when compared to the direct examination and culture of parasites. PCR is applicable both for CL where all 61 lesions were diagnosed, and MCL where 12 of 14 lesions were diagnosed. This molecular biology technique is also a faster and more specific diagnostic method compared with present parasitological procedures.