Accuracy of quantitative polymerase chain reaction in samples of frozen and paraffin-embedded healthy skin for the diagnosis of canine visceral leishmaniasis

Acurácia da reação em cadeia da polimerase quantitativa em amostras de pele íntegra congelada e parafinada no diagnóstico da leishmaniose visceral canina

M.P. Campos M.F. Madeira D.A. Silva M.S. Solcà O.M. Espíndola A.A.V. Mendes Júnior F.B. Figueiredo About the authors

ABSTRACT

The purpose of the present work was to evaluate the accuracy of quantitative polymerase chain reaction (qPCR) performed on samples of fresh frozen tissue (FT) and formalin-fixed, paraffin-embedded (FFPE) healthy skin. This is a validation study conducted with samples from 46 dogs from an endemic area in Brazil. After sample collection, DNA extractions were conducted using commercial kits and qPCR was oriented to kinetoplast DNA (kDNA) targets of the Leishmania infantum species. The results obtained for the FFPE samples showed 63.6% sensitivity and 77.1% specificity, whereas those obtained for the FT samples showed 100% and 48.6%, respectively. Poor agreement was observed for the results of the qPCR technique with FT and FFPE samples. Our results suggest freezing as the most suitable conservation method for the formation of sample databases considering DNA recovery

Keywords:
diagnosis; qPCR; canine visceral leishmaniasis

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