Detection of methicillin resistance and antimicrobial sensitivity of Staphylococcus Aureus from domestic animals

Staphylococcus aureus is a fascinating pathogen residing on skin and mucous membrane of domestic animals and man. A total of 92 clinical samples (milk, nasal swab, wound swab) from cattle (n = 36), goat (n = 29) and dog (n = 27) of West Bengal, India were examined by conventional and molecular methods for S. aureus. Screening for methicillin resistance was determined phenotypically by cefoxitin disc diffusion and genotypically by mecA PCR. A total of 41 isolates of S. aureus from cattle (n = 20), goat (n = 13) and dog (n = 8) were confirmed by S. aureusspecific thermonuclease (nuc) gene polymerase chain reaction (PCR). Out of 41, two (4.88%) isolates, one each of cattle and goat, were found to be methicillin-resistant S. aureus (MRSA). Antimicrobial susceptibility of all the 41 isolates of S. aureus was determined in Bauer-Kirby disc diffusion tests. They were found to be highly sensitive to amikacin (95.12%), linezolid (100%), vancomycin (100%) and highly resistant to ampicillin (39.02%) followed by tetracycline (24.39%), azithromycin (17.07%), ciprofloxacin (17.07%) and sparfloxacin (17.07%). Prevalence of MRSA was found to be low in clinical isolates of S. aureus from domestic animals and isolates were resistant to several classes of antimicrobials.