Detection of Altered Pattern of Antibiogram and Biofilm Character in Staphylococcus aureus Isolated From Dairy Milk

Dairy milk is overwhelming with biofilm producing Staphylococcus aureus (bpSA), whereas response to commonly used antibiotics is not only becoming worrisome in bpSA but also in non-biofilm producing S. aureus (nbpSA). Current study was planned to detect bpSA from dairy milk, confirmation of presumed risk factors, and comparative analysis of antibiogram of bpSA and nbpSA at various cadre. Milk samples (n=250) from cattle (n=90) and buffalo (n=160) were aseptically collected from various dairy farms and put to biofilm detection and antibiogram. Based on collected data with statistical inferences, the study found 61.60% of S. aureus from subclinical samples, while 72.73% of S. aureus were positive for biofilm with uniform hike in samples from cattle (77.55% bpSA) and buffalo (70.48% bpSA). Udder condition/consistency, teat dip, teat abnormality, tick infestation, body condition, mastitis knowledge, treatment approach, and therapeutic drug use were significantly (p<0.05) associated with rise in S. aureus in dairy milk. All the tested isolates were found 100% resistant to Cefotaxime, Fusidic acid, and Ampicillin while 60-80% of these isolates were found sensitive to Cefoxitin, Gentamicin, Trimethoprim + Sulphamethoxazole, and Oxytetracycline. Except Trimethoprim + Sulphamethoxazole, non-significant differences (p>0.05) of isolates at resistant, intermediate, and sensitive cadre were noted against Vancomycin, Oxacillin, Amoxy clavulanate, and Linezolid. Same pattern was observed when tested against Oxytetracycline, Gentamicin, Cefotaxime, Fusidic acid, and Ampicillin. The study concluded hiked biofilm character in S. aureus with prevailing significant risk factors and heightened change in antimicrobial resistance by all isolates which demands immediate action plans to be taken.