Characterization of Penicillinase Inhibitor in Bovine Serum

Bovine serum containing penicillinase inhibitor activity was fractioned by gel filtration chromatography and ion exchange chromatography. The penicillinase inhibitor was principally located in the IgG-fraction and therefore appears to be an antibody.When serum antipenicillinase activity was screened in material consisting of 54 animals, mastitis cows showed higher incidence of penicillinase inhibitor than healthy animals.Serum penicillinase inhibitor had a slight effect on the MIC-value of penicillin against penicillinase producing staphylococci which indicates that this inhibitor could have some clinical influence in increasing bacterial sensitivity to penicillin.