DIFFERENTIAL MOLECULAR DETECTION OF DERMATOPHYTES IN DOGS USING COMMON PAIR OF OLIGOS IN A UNIPLEX POLYMERASE CHAIN REACTION

Abstract

Dermatophytes are common pathogenic fungi of fundamental importance in small animal practice and are given due consideration due to their zoonotic potential. A number of techniques are available to diagnose dermatophytosis and differentiate among the genera that cause it, but most of these techniques are either laborious, time consuming or lack cost effectiveness. The current study was designed to develop and validate a rapid and accurate diagnostic assay to detect two important genera of dermatophytes in dogs, Microsporum and Trichophyton differentially by a uniplex PCR reaction.18S ribosomal RNA gene of both the genera was used to design common forward and reverse primers. Genome specific product sizes were detected in clinically positive samples. Out of 52 clinically positive dogs based on clinical signs, direct microscopy of skin or hair and wood’s lamp technique, 46 samples (88.46%) were positive for dermatophytosis through the uniplex PCR out of which 38 samples (82.6%) were positive for Microsporum, 6 samples (13.04%) for Trichophyton and two samples (4.34%) were positive for mixed infection of Microsporum and Trichophyton. The sensitivity of the test was 88.46%. The uniplex PCR was also applied to 20 clinically negative samples. Four clinically negative samples were identified as false positives and 16 samples were true negatives by the uniplex PCR. The specificity of the test was 80.0%. It was concluded that uniplex PCR can be used for accurate diagnosis of dermatophytes in dogs.