Vaccination with the plasminogen activator from Streptococcus uberis induces an inhibitory response and protects against experimental infection in the dairy cow

Two antigens comprising either concentrated culture filtrate containing the plasminogen activator, PauA (total antigen) or the preparation from which PauA had been selectively removed by incubation with a PauA-specific monocl onal antibody and immobilisation on Protein-G agarose (depleted antigen) we re combined with either Freund's incomplete adjuvant (FIA) or a commerciall y used adjuvant (SB62) and used to vaccinate dairy cows by a subcutaneous r oute. Immunisation of four animals with depleted antigen combined with FLA conferred no protection to mastitis following intramammary challenge with S . uberis 0140J. However. immunisation of two groups of four animals with th e total antigen combined with either FIA or SB62 induced protection in 3 ou t of 8 and 5 out of 8 similarly challenged quarters, respectively. Protecti on corresponded to the production of an inhibitory antibody response to Pau A. (C) 1999 Elsevier Science Ltd. All rights reserved.