Isolation, characterization and antibiotic susceptibility profile of Staphylococcus aureus from raw milk samples in Nagpur district, India

The study was carried out from July 2010 to June 2011. The aim of the present investigation was to isolate Staphylococcus aureus from raw milk obtained from cow from different parts of Nagpur district, India and to determine their antibiotic susceptibility profile. General biochemical tests along with the MASTASTAPHTM rapid agglutination tests were employed for bacterial identification. All the well characterized isolates were further confirmed by amplifying coa gene by PCR. A total 95 S. aureus isolates were obtained during this study from 50 raw milk samples. When all the well characterized isolates were subjected to antibiotic susceptibility testing, erythromycin and chloramphenicol were the most effective antibiotics. A large proportion of isolates were found to be resistant to Co-trimoxazole (89%) followed by Linomycin (81%) and Penicillin (35%) It was concluded from the current study that the hygiene of the milk was poor and resistant strains contaminated the milk probably during the process of transportation