Comparative assessment of regulated methods and PCR in the diagnosis of trichophytosis in veterinary mycology

Abstract

Background: There is an increase in the incidence of human and animal infectious skin diseases of fungal aetiology in the world. The main source of infecting the population has become agricultural and stray animals. Aim: The objective of this study was to examine the morphophysiological and microbiological characteristics of pathogenic fungi belonging to the species Trichophyton verrucosum. This species is known to cause diseases in both humans and livestock in Kazakhstan. Additionally, the study aimed to assess the feasibility of using the polymerase chain reaction (PCR) method for detecting T. verrucosum. This assessment was conducted in comparison to the outcomes of conventional laboratory diagnostic tests commonly employed for trichophytosis. Methods: The research focused on analyzing 141 samples of pathological material obtained from calves in Almaty, Turkestan, and Kyzylorda regions. These calves exhibited clinical symptoms of skin disease. The study aimed to identify the causative agent using various techniques, including microscopic examination, microbiological methods involving the isolation of pure cultures, and polymerase chain reaction. Results: The detection of the causative agent of dermatophytosis using conventional methods was relatively low, 86% for the microscopic method and 79% for the microbiological method with the isolation of the culture of the pathogen. Extraction and detection of the genetic material of the causative agent of the disease for polymerase chain reaction was carried out according to the method developed by the authors. The effectiveness of the polymerase chain reaction (PCR) method was 97.9%, which is significantly higher (p<0.05) compared with the diagnostic effectiveness of conventional methods. The polymerase chain reaction method using specific primers identified the causative agent in 98% of cases, which significantly (p<0.05) exceeded the results obtained using conventional diagnostic methods. Accordingly, the PCR method had better sensitivity and specificity indicators. Conclusion: The conducted study allowed recommending the method of PCR diagnosis of dermatophytosis for fast and reliable confirmation of the diagnosis of dermatophytosis in humans and animals in Kazakhstan.