Cross-Immunity in Calves after Vaccination against Trichophytosis

Abstract

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, challenge Immune 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 pre­ paration 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 stu­ died 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. ver­ rucosum 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 ex­ periments.