PREVALENCE OF PENICILLINASE-FARMING STRAINS OF STAPHYLOCOCCI MASTITIS

The results of an investigation of the prevalence of resistant staphyl ococci isolated from quarter milk samples during the period 1992 to 19 96 from Styria, Austria are described. This involved the examination o f 13,868 strains of Staphylococcus aureus and 3,658 strains of staphlo coccal species. A significant decrease, from 35.2 to 15.4%, in the pre valence of penicillinase-forming strains occurred during this period T his decrease is discussed in relation to regional differences in agric ultural structure, the antibiotic doses used in mastitis therapy, the various therapeutic and prophylactic measures and the possible transfe r of resistant strains from swine poultry to cattle.