Infection of Trichophyton verrucosum in cattle breeders, Poland: A 40‐year retrospective study on the genomic variability of strains

Abstract

Trichophyton verrucosum is a zoophilic fungus that is the most frequent aetiological agent of dermatophytosis in cattle. During the last few years, the number of cases of T. verrucosum from humans has been increasing constantly, which is correlated with the presence of cattle-rearing farms. We identified and analysed T. verrucosum strains isolated from humans and cattle. Identification was carried out traditionally by correlating both the clinical manifestations with a micro- and macroscopic examination. To confirm the species affiliation fully, molecular differentiation methods were used. Direct analysis revealed the presence of arthrospores. The macro- and micromorphology of the isolates obtained from material sampled was homogeneous, and characterised for T. verrucosum. The phylogenetic analysis based on the ITS sequences demonstrated that the strains formed a monophyletic group with T. verrucosum ATCC10 695 with a support of 99%. The MP-PCR analysis indicates high invariability of genomes of strains from humans and animals. MSP-fingerprinting analysis gives the same results as the MP-PCR analysis. To sum up, the rDNA ITS sequence analysis in combination with macro- and micro-morphology only facilitated T. verrucosum species identification without the possibility of intraspecific differentiation. Finding and testing methods, especially molecular technique, with sufficient discriminatory power, is the present challenge for mycologists.

The host range of dermatophytes, it is at all possible? Phenotypic evaluation of the keratinolytic activity of Trichophyton verrucosum clinical isolates

“…It is puzzling whether isolates from other regions can be adapted to a different range of hosts. This hypothesis is even more interesting considering the high genetic preservation of T. verrucosum strains; in a particular geographical region, clinical isolates show only little genetic diversity and, at the same time, remain morphologically indistinguishable . Sharma et al analysed the degree of keratin degradation with fungi isolated from dermatophytosis patients in Jaipur (India) and revealed different efficiencies of T. verrucosum to degrade hair, that is, higher in the medium with animal keratin and weaker for human keratin.…”

“…The material for the analysis was collected from the lesion margins. Isolates were identified at the species level on the basis on the morphology of the colony texture, by microscopic examination of the production of typical spores and molecularly by ITS sequencing at the Sub‐Department of Veterinary Microbiology, University of Life Sciences in Lublin, Poland …”

“…What is more, traditional outdoor breeding methods with freely wandering and gathering animals, which allows direct contact between animals and between animals and humans, are still predominant . Trichophyton verrucosum infections and carriers are less frequent in domestic animals other than cattle . In the literature, there are no reports of any T. verrucosum infections in wild animals.…”

Comparison of in vitro activities of 11 antifungal agents against Trichophyton verrucosum isolates associated with a variety hosts and geographical origin

“…The frequency of T. verrucosum isolation among other dermatophyte species is relatively high . Interestingly, nearly half of the human patients have acquired the T. verrucosum infection indirectly, without exposure to cattle as a main fungal reservoir .…”

“…Dermatophytes are repeatedly mentioned among the most frequent causes of dermatological problems in animals . The high prevalence of dermatophytosis in animals is usually associated with extra expenditure on prevention, diagnosis and long‐term treatment .…”