VACCINATION AGAINST STAPHYLOCOCCUS-AUREUS MASTITIS - IMMUNOLOGICAL RESPONSE OF MICE VACCINATED WITH FIBRONECTIN-BINDING PROTEIN (FNBP-A) TOCHALLENGE WITH STAPHYLOCOCCUS-AUREUS

Mice were immunized with fusion proteins encompassing the fibronectin- binning domain of a staphylococcal fibronectin-binding protein (FnBP-A ). A specific antibody response against the fibronectin-binding part o f the fusion proteins was detected in the serum of all vaccinated anim als. The protective potential of these vaccinations was evaluated in a mouse mastitis model, using Staphylococcus aureus, strain SA113, for challenge. The mice vaccinated with FnBP fusion proteins showed a decr eased number of bacteria recovered from the mammary glands and signifi cantly reduced cases of severe mastitis. Histopathological examination of tissue from challenged glands of vaccinated mice revealed either n o pathological reactions or disseminated inflammatory reactions with f ocal necrosis whereas four of six examined tissues from challenged gla nds of non-vaccinated animals showed total necrosis. A combination of FnBP fusion protein with staphylococcal alpha-toxoid did not increase the efficacy of the vaccination and animals vaccinated with alpha-toxo id alone were as sensitive to challenge as those from the non-vaccinat ed control group. Thus vaccination of mice with recombinant FnBP resul ted in significant protection against challenge with S. aureus.