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.

The protective efficacy of two Czech vaccines against bovine Trichophyton verrucosum infection after double vaccination of calves in prophylactic doses, with an interval of 13 days between vaccination and revaccination, was very good. When these preparations were applied in a double dose only once, less protective effect was produced. The use of 0.5% aluminium hydroxide to dilute the vaccines had no influence on the effect of single vaccination.

Rybnikar A., V. Vrzal, J. Chumela: Vaccination oj Young Calves against Trichophytosis. Acta vet. Brno, 62, 1993: 55-61. .• . Calves vaccinated against trichophytosis at 1 to 7 days of age and revaccinated 10 days later showed a satisfactory degree of protection against experimental infection . with a virulent strain of Trichephyton verrucosum. The same results were obtained after immunization of calves in groups of older animals (aged 8 to 42 days). All non-vaccinated controls given the same challenge dose showed extensive trichophYrlc crusts that persisted throughout the observation period. A field experiment with the same vaccine was conducted in a herd where 50% of the calves were affected with trichophytosis. New arrivals in the calf-house were vaccinated at 3 to 6 days of age and revaccinated 10 days later. Of 179 vaccinated animals, 4 (2.2%) developed trichophytosis.

Rybnikar A.: Cross-Imunity in Calves after Vaccination against Trichophytosis. Acta vet. Bmo, 61, 1992: 189-194.Calves vaccinated against Trichophyton verrucosum were resistant to experimental infection with T. verrucosum strain and T. mentagrophytes strain. Immunization with a vaccine containing T. mentagrophytes produced reliable immunity against the homologous strain but failed to confer a satisfactory degree of protection against the heterologous dermatophyte T. verrucosum. Four out of 12 calves of this group reacted to challenge by development of mycotic changes persisting throughout the observation period. All non-vaccinated controls inoculated with one or the other of the two challenge cultures showed a similar clinical picture of trichophytosis. Trichophyton mentagrophytes, Trichophyton verrucosum, immunization, challengeImmune cross-reactions in dermatophytes have been studied both in vitro and in vivo with frequently conflicting results. The differences have been explained particularly by different preparation and composition of antigens and by the use of qualitatively and quantitatively different methods (Kaaman and Wasserman 1981). In in-vivo experiments the immune response was studied in animals and humans sensibilized, infected or immunized with dermatophytic antigens.Foals injected i. m. with living Trichophyton equinum antigen developed immunity not only to the homologous species but also to Trichophyton mentagrophytes (petrovich and Sarkisov 1981). However, from the observations reported by Petrovich (1985) it appears that horses that recovered from trichophytosis lacked cross-immunity to subsequent infection with the causative agent-of microsporidia and vice versa. Woloszyn (1987) reported that cattle infected with T. verrucosum cross-reacted with trichophytin prepared from T. mentagrophytes. Wawrzkiewicz and Rzechowski (1983) who vaccinated guinea-pigs with living and inactivated vaccine against trichophytosis found immune cross-reactions between T. verrucosum and T. mentagrophytes strains. Petrovich et a!. (1972) and Rasulev and Turdiev (1975), on the other hand, found no cross--immunity between T. verrucosum and T. mentagrophytes in calves.The present study was designed to assess the development of post-vaccination immunity against homologous and heterologous dermatophyte species in 69 calves on the basis of challenge experiments. Materials and MethodsThe experimental animals were calves of the Bohemian Pied breed from herds without a history of trichophytosis, aged 4 to 6 weeks at the beginning of the experiments.The following two vaccines were used: (a) a commercial vaccine against bovine trichophytosis containing living T. verrucosum strain TV-M-310 attenuated by ultra-violet radiation (manufacturer~ Bioveta, Ivanovice na Hane, Czechoslovakia) and (b) an experimental living vaccine prepared from microconidia of a T. mentagrophytes strain.Each vaccine was injected i. m. into the gluteal muscle in two doses of2.5 mI. Each vaccination dose contained approximately 15 million CFU. The...

Twenty-six sporulating strains of lyophilized microscopic fungi of the genera Epidermophyton, Microsporum, Paecilomyces and Trichophyton have been maintained at 2-8 degrees C for 8-14 years. In 23 strains the number of viable particles reduced less than 10-fold during this period compared with immediately after lyophilization. The viability of other three investigated strains ranged from 3.4% to 7.1% in comparison with the original values.