Standardization of a PCR for molecular diagnosis of microsporum canis in samples of fur and crusts of dogs and cats

Abstract

The aim of this study was to standardize a Polymerase Chain Reaction protocol (PCR) for the detection of Microsporum canis in fur and/or crusts of dogs and cats. 48 samples previously identified by culture were selected. Of these, 23 were positive for dermatophytes in culture. PCR was standardized from drawn primers whose target is M. canis. A total of 61% (14/23) of the dermatophyte positive samples were identified as M. canis in culture. Of this total, 71.4% (10/14) presented a fragment of 218bp compatible with that expected for the fungal species target of the reaction. A sensitivity of 71.4% and specificity of 100% in the PCR were observed, in addition to a good agreement between the techniques (Kappa: 0.78; P < 0.0001). The protocol used in this study showed high specificity in the detection of M. canis directly from fur and/or crusts of dogs and cats, making possible a faster and more specific diagnosis. This protocol could be used as a confirmatory method, speeding the detection of M. canis.