Isolation and identification of Staphylococcus aureus from milk and milk products and their drug resistance patterns in Anand, Gujarat

Aim: The study was carried out with aim to isolate Staphylococcus aureus from milk and milk products (pedha and curd) and determine antibiogram pattern of S. aureus isolates. Materials and Methods: During 9 months duration of study a total of 160 milk and milk product samples (pedha and curd) were collected from different places in and around Anand city such as milk collection centre of Co-operative milk dairies, cattle farms, individual household, milk vendors and sweet shops. The samples were collected under aseptic precautions and were enriched in Peptone Water (PW) followed by direct plating on selective media viz. Baird-Parker Agar. The presumptive S. aureus isolates were identified by biochemical tests. Antibiogram pattern of S. aureus to antimicrobial agents were evaluated by disk diffusion method. Results: Analysis of result revealed that out of total 160 samples of milk (100) and milk products i.e. curd (30) and pedha (30) resulted in the isolation of 10 isolates (6.25 %) of S. aureus. In the present study S. aureus isolates were found variably resistant to the antibiotics tested. The S. aureus isolates showed highest sensitivity towards cephalothin (100.00 %), co-trimoxazole (100.00 %), cephalexin (100.00 %) and methicillin (100.00 %) followed by gentamicin (90.00 %), ciprofloxacin (80.00 %), oxacillin (70.00 %), streptomycin (60.00 %) and ampicillin (60.00 %). The pattern clearly indicated that the overall high percent of S. aureus isolates were resistant to Penicillin-G (100.00 %) followed by ampicillin (40.00 %), oxytetracycline and oxacillin (20.00 %) and streptomycin and gentamicin (10.00 %) Conclusions: Results clearly suggested a possibility of potential public health threat of S. aureus resulting from contamination of milk and milk products with pathogenic bacteria is mainly due to unhygienic processing, handling and unhygienic environment. [Vet World 2013; 6(1.000): 10-13]