A study on antibiotic sensitivity test of methicillin resistant and non methicillin resistant Staphylococcus aureus from mastitic milk

Abstract

The current investigation was planned to evaluate the incidence of “Methicillin resistant Staphylococcus aureus” (MRSA) and “Non-Methicillin resistant Staphylococcus aureus” (Non- MRSA) from clinical mastitis milk samples and their antibiotic resistance profile. From acute clinical mastitic samples isolation and identification of MRSA and Non- MRSA were executed. The isolates were tested using agar disc diffusion method for their antimicrobial susceptibility for eight (8) different antimicrobial drugs. A total of 167 clinical samples of mastitic milk from milching cows were cultured for incidence of S. aureus. MRSA and non MRSA were isolated in 11 (22%) and 39 (78%) from the total of fifty (50) S. aureus positive samples respectively. Based on the antimicrobial sensitivity test results, MRSA isolates were found 100%, 36.36% and 27.27% sensitive to vancomycin, cefazolin and cefotaxime respectively & found 100%, 100%, 100%, 90.90% resistant to, cloxacillin, penicillin, methicillin and oxacillin respectively. Similarly, non MRSA isolates were found 100%, 97.43%, 94.87%, 89.74%, 84.61%, sensitive to vancomycin, methicillin, cefoxitin, oxacillin, cefotaxime respectively & found 20.5%, 15.3%, 10.25% resistant to penicillin, cloxacillin and cefazolin respectively.