M. ARSHAD, G. MUHAMMAD¹, M. SIDDIQUE, M. ASHRAF AND H.A. KHAN

Abstract

    Milk samples of 100 clinically mastitic bovines (50 each from buffaloes and cows) were processed for bacterial isolation. A total of 90 bacterial isolates, including 33 of staphylococci and 57 of other bacterial species were recovered. Of the 33 staphylococcal isolates, 23 were identified as Staphylococcus aureus and 10 as Staphylococcus epidermidis. All Staphylococcus aureus isolates were positive for deoxyribonuclease and mannitol fermentation test and produced ß-haemolysis on blood agar. All Staphylococcus epidermidis isolates were negative to these tests and failed to produce ß-haemolysis on blood agar containing 5% sheep erythrocytes. Penicillin resistance was detected in 13(56.5%) isolates of Staphylococcus aureus and 8(80%) isolates of Staphylococcus epidermidis. Penicillinase was produced by 4 of the 13 penicillin resistant isolates of Staphylococcus aureus and 2 of the 8 penicillin resistant Staphylococcus epidermidis isolates.

Key words: Mastitis, staphylococci, biochemical properties.