Print version ISSN 1813-5363
BONIFAZ PEREZ, Diego; SOSA TORDOYA, Luis Fernando and CHOQUEHUANCA QUISPE, José Luis. Diagnosis of cutaneous leishmaniasis by Polymerase Chain Reaction, using genetic material derived from smears of lesions stained with Giemsa. BIOFARBO [online]. 2011, vol.19, n.2, pp. 28-38. ISSN 1813-5363.
In Leishmaniasis pathogenicity, therapeutic approach and possible methods of control are largely determined by the infecting Leishmania species identified. The present study evaluates three methods for DNA isolation from Giemsa-stained smears of lesion. A smear from suspensions containing known concentration of Leishmania braziliensis promastigotes and Giemsa-Stained smears for lesion of patients with cutaneous leishmaniasis, was used to evaluate the analytical and diagnostic sensitivity methods based on K-Proteinase lysis solution (SLPK), Boiling and the commercial kit Promega Wizard Genomic DNA purification Kit, the obtained results from the PCR were compared against the results of conventional PCR and direct parasitological examination. From the three tested protocols, the SLPK method showed the best performance with range of DNA concentrations from 19.77 to 38.18 ng / uL and purity rates between 1.037 to 1.046, this method has a diagnostic sensitivity of 93% , specificity 45%, positive predictive value of 68% and negative predictive value of 84%. The degree of correlation measured by the Kappa index between SLPK and smears was moderate 0.403 (p <0.005) and between the two PCR methods was good 0.700 (p <0.005). The results show that DNA obtained from Giemsa-stained smears by the SLPK method is a good alternative for the molecular diagnosis of leishmaniasis and also be a useful tool for determining genetic polymorphisms of the parasite.
Keywords : Leishmania; Giemsa-stained smears; PCR; Diagnostic test.