title: Immunogenicity in calves of a crude ribosomal fraction of Trichophyton verrucosum: a field trial.
abstract: This paper describes a field trial involving 13 calves raised on a farm known to be endemic for Trichophyton verrucosum infection. Seven calves were immunized by subcutaneous inoculations with a crude ribosomal fraction (CRF) of T. verrucosum suspended in aluminium hydroxide as adjuvant. Six animals were sham-immunized with buffer suspended in the adjuvant and served as controls. Two injections were given: one at the age of 2 weeks and a second 2 weeks later. CRF was prepared from T. verrucosum cultures grown in a vitamin-enriched liquid medium. The fungal mat was disrupted mechanically and CRF was separated from the cell-free extract by differential ultracentrifugation. The CRF was characterized biochemically (RNA and protein content) and physically (electron microscopy). The protection induced by vaccination was assessed through a clinical follow-up of the animals to determine the presence and duration of dermatophyte infection following their exposure to a T. verrucosum-contaminated environment. Vaccination with the CRF resulted in a statistically significant decrease in the period during which clinical signs of dermatophytosis were observed (from a mean of 9.5 weeks to 3.7 weeks). To assess the humoral response, serum samples were taken before each vaccination and 2 weeks after the second inoculation. For the cell-mediated immune (CMI) response assessment, whole-blood samples were taken 2 weeks after the second vaccination. The presence of anti-T. verrucosum antibodies in the sera was determined by ELISA and the CMI response was assessed in vitro by the lymphocyte stimulation test.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Bacteriology, Kimron Veterinary Institute, Bet-Dagan, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Elad
authors.forename: E
authors.initials: E
authors.lastname: Segal
mesh_terms: D000818:Animals; D000917:Antibody Formation; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology*; D005260:Female; D007114:Immunization; D012270:Ribosomes / Q000276:immunology*; D013347:Subcellular Fractions / Q000276:immunology*; D014005:Tinea / Q000276:immunology / Q000662:veterinary*