[Rates of resistance of mastitis pathogens from cows in Switzerland]

1215 strains of bacteria isolated from cows suffering from acute or chronic clinic mastitis were tested in the antibiogram according to the Kirby-Bauer method. The germ spectrum included: 304 DNase-positive strains of Staphylococci 304 DNase-negative strains of Staphylococci 304 CAMP-negative strains of Streptococci 303 Strains of Enterobacteriaceae The antibiotics selected were Penicillin, Cloxacillin, Neomycin und Gentamicin, then the combinations Penicillin/Neomycin, Cloxacillin/Gentamicin and Nafcillin/Penicillin/Dihydrostreptomycin. Gentamicin showed excellent action against Staphylococci and Enterobacteriaceae. Further on, the present investigations show, that the combination Cloxacillin/Gentamicin is fully effective in the gram-positive spectrum (against Streptococci and Staphylococci), as in the gram-negative spectrum (against E. coli).