Studies on the penicillin- resistance with same enzyme characteristics and biochemicaı tests of staph. aureus isolated from cows milk with mastitis

Abstract

Nineteen strains of Staph. aureus isolated from cows milk with mastitis were tested for their ability to produce coagulase, phosphatase, catalase, B-lactamase, clumping factor, oxydation/fermentcı. tion (O/F) and resistance of penicillin and ampicillin. All of the strains have produced B-lactamase and their resistance rates to penicillin and ampicillin were 94.9%, 47.9% respectively. Catalase, ı;ıhosphatase and 0/l<., producing rate of all Staph. aureus were positive 100%. The Coagulase tests found to be positive at the rate of 89.8% with rabbit plasma, 73.7% with cow plasma, 100% with mixture of rabbit-cow piasma. The rate of positive clumping factors was also found to be 89.8%, 94.9%, 100% with rabbit, cow and mix plasma, respectively. 73.7% of all strains have grown on Mannitol Salt Agar plates. 12 strains producedgolden cooured colonies. All of the 6 strains were intracutaneously inoculated to rabbits reduced necrosis.