Real-Time PCR as an Alternative Technique for Detection of Dermatophytes in Cattle Herds

SIMPLE SUMMARY: Fungal infections of the skin, hair, and nails in humans and animals are the most prevalent mycoses worldwide, with a high economic burden. The high degree of transmissibility poses an epidemiological threat and gives these infections a significant importance as zoonoses. Hence, the control of the presence of dermatophytes in herds of cattle and other species of farm animals should be routinely performed. The ongoing improvements in the field of fungal detection techniques give new scope for clinical implementations in specialized laboratories and hospitals or veterinary clinics, including the monitoring of disease and the detection of side effects of drugs and environmental risks. This study aimed to evaluate the analytical specificity and clinical application of direct sample real-time PCR by comparison with direct microscopy and culture methods. The pan-dermatophyte primers in the qPCR technique facilitated detection of the presence of the genetic material of dermatophytes with greater specificity than the microscopic examination. Moreover, this article describes an interesting case of the isolation of two different species of dermatophytes from the same clinical lesion, i.e., Trichophyton verrucosum and T. benhamiae. ABSTRACT: Dermatophytes are filamentous fungi with the ability to digest and grow on keratinized substrates. The ongoing improvements in fungal detection techniques give new scope for clinical implementations in laboratories and veterinary clinics, including the monitoring of the disease and carrier status. The technologically advanced methods for dermatophyte detection include molecular methods based on PCR. In this context, the aim of this study was to carry out tests on the occurrence of dermatophytes in cattle herds using qPCR methods and a comparative analysis with conventional methods. Each sample collected from ringworm cases and from asymptomatic cattle was divided into three parts and subjected to the real-time PCR technique, direct light microscopy analysis, and culture-based methods. The use of the real-time PCR technique with pan-dermatophyte primers detected the presence of dermatophytes in the sample with a 10.84% (45% vs. 34.17%) higher efficiency than direct analysis with light microscopy. Moreover, a dermatophyte culture was obtained from all samples with a positive qPCR result. In conclusion, it seems that this method can be used with success to detect dermatophytes and monitor cowsheds in ringworm cases and carriers in cattle.