Molecular detection, antibiogram, and risk factor analysis of Staphylococcus aureus from subclinical mastitis of goats in conventional and organized farms

Abstract

Objectives: The goal of this study was to isolate, molecularly identify, and antibiogram of Staphylococcus aureus, as well as to investigate risk factors for subclinical mastitis in the Jhenaidah and Chuadanga districts of Bangladesh. Materials and Methods: A total of 100 milk samples were collected from apparently healthy goats at various farms in the Jhenaidah and Chuadanga districts. To detect samples with subclinical mastitis (SCM), the California Mastitis Test (CMT) was done. S. aureus was isolated and identified from milk samples that tested positive for CMT using a combination of standard bacteriological examinations, biochemical tests, and PCR confirmation. The disc diffusion test was used to determine the antibiogram status of the isolates. The risk factors for SCM in goats were analyzed using a semi-structured questionnaire with thirteen variables. Results: Some characteristics were significantly associated with goat mastitis, including farm, breed, shed construction, floor surface condition, and farm adviser. The CMT identified 52 positive samples for SCM, with 73.07% (n = 38/52) suggesting the presence of the nuc gene. Antibiotic susceptibility testing revealed that the isolated S. aureus was totally resistant to the antibiotics Penicillin, Oxacillin, and Vancomycin (21%). On the other hand, Tetracycline, Gentamycin, Norfloxacin, and Levofloxacin were all susceptible to all isolates. Conclusion: SCM is a severe problem in goats in Jhenaidah and Chuadanga districts. To minimize the risk of SCM infection in goats, hygiene precautions can be followed, and education among goat farm owners and farmers can be improved.