Comparação de nested PCR e PCR em tempo real para diagnóstico de Trypanosoma caninum em pele de cães

Abstract

Trypanosomatidae family encompasses several species of parasites from different hosts and in 2009 a new species, Trypanosoma caninum, was isolated from the skin of a dog coinfected with Leishmania braziliensis. Since then, this parasite has been detected in overlapping areas with other trypanosomatids, such as L. infantum, T. cruzi, raising questions about the possibility of cross-reaction in serological tests and reinforcing the importance of more sensitive and specific diagnostic methods, such as molecular techniques. In this context, the present study aimed to compare two variations of polymerase chain reaction (PCR), nested PCR and real-time PCR (qPCR), in detecting T. caninum infection in skin dogs attended at the Veterinary Hospital of the Federal University of Mato Grosso (HOVET-UFMT). Skin samples from 150 dogs treated at this location were used for molecular analyses. The occurrence of infection by this trypanosomatid was 8% (12/150), regardless of the molecular method used. nPCR detected the infection in 2% (3/150) of the dogs, and qPCR in 7.3% (11/150). There was no statistically significant association observed between T. caninum infection and the variables of breed, gender, and age. However, an association was found between infection and the absence of dermatopathies, indicating a higher likelihood that the infection does not induce dermatological changes. Real-time PCR associated with the use of specific primers for T. caninum allowed a greater detection and understanding of the true occurrence of the agent in comparison to nPCR.