Experimental dermatophytosis in calves caused by Trichophyton verrucosum culture

Abstract

Microconidia suspension of Trichophyton verrucosum virulent culture isolated originally from the mycotic lesions of cattle was inoculated epicutaneously to calves in various doses. Four application methods were selected, namely, onto the sheared and gently scarified skin, onto the sheared and non-scarified skin, onto the non-sheared and gently scarified skin, and onto the non-sheared and non-scarified skin. The inoculated area was 10 x 10 cm for all cases mentioned. When the application was performed onto the sheared and scarified skin, at least 18,000 microconidia of T. verrucosum per one animal had to be used to induce the mycotic disease in 100% of animals. This value was 10 times higher when the application was performed onto the non-sheared and scarified skin, 100 times higher in the case of the sheared and non-scarified skin and 1,000 times higher in the case of the non-sheared and non-scarified skin. The minimum infectious dose still capable of inducing dermatophytosis was 180 microconidia per 100 cm(2) of the scarified skin, 18,000 microconidia per 100 cm(2) of the sheared and non-scarified skin, and 180,000 microconidia per 100 cm(2) of the non-sheared and non-scarified skin.

Clinical assessment of postinfection, postcontact and postvaccination immunity manifestation after experimental inoculation of calves with Trichophyton verrucosum culture

“…100 times up to 1000 times higher doses had to be used to induce the infection in cattle after application of the same culture of Trichophyton genus onto the non‐sheared and non‐scarified skin compared to the inoculation performed onto the sheared and scarified skin. This finding corresponds to the results of our study and previously published experiments 12,13 …”

“…The possibility of immunity development after an animal’s contact with the borderline doses of T. verrucosum culture capable of inducing clinical trichophytic changes in only some of the inoculated calves has been studied. The quantity of the doses was selected on the basis of the results of our previous study 13 . Protection against reinfection in calves showing no trichophytosis symptoms after the first inoculation with the T. verrucosum infectious culture depended on the method of the inoculum application.…”

Dermatophytes as a cause of epizoonoses in dairy cattle and humans in Iran: epidemiological and clinical aspects

“…In most cattle cases, T. verrucosum is the pathogen behind dermatophytosis in man 20 . In this study, T. verrucosum was the predominant dermatophytes causing dermatophytosis in humans.…”

Specific cell-mediated immune response in rabbits immunised and infected with Trichophyton mentagrophytes

“…Thus, spontaneous recovery from trichophytosis, i.e. complete regression of inflammatory and crusty lesions, as well as covering of the entire focus with healthy epidermis, and visible hair re-growth was attributed to the development of specific cell-mediated immunity, which is essential for elimination of infections caused by dermatophytes (7,8,14,15,17). The above data is consistent with the findings of other authors studying experimentally infected guinea pigs, mice, rats, foxes, and calves, which confirms that the extinction of the disease is associated with the development of specific antifungal cell immunity (9,11,(16)(17)(18).…”