The prevalence, genetic diversity and antibiotic resistance of Staphylococcus aureus associated with subclinical bovine mastitis in Balikesir, Turkey


Tavsanli H., Cibik R.

VETERINARSKI ARHIV, vol.92, no.1, pp.17-25, 2022 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 92 Issue: 1
  • Publication Date: 2022
  • Doi Number: 10.24099/vet.arhiv.1315
  • Journal Name: VETERINARSKI ARHIV
  • Journal Indexes: Science Citation Index Expanded, Scopus, BIOSIS, CAB Abstracts, EMBASE, Veterinary Science Database
  • Page Numbers: pp.17-25
  • Keywords: SCCmec types MRSA, somatic cell count, spa types of MRSA, subclinical mastitis, SOMATIC-CELL COUNT, COAGULASE-NEGATIVE STAPHYLOCOCCI, ANTIMICROBIAL RESISTANCE, METHICILLIN RESISTANCE, PCR ASSAY, MILK, STRAINS, UDDER

Abstract

Subclinical mastitis caused by Staphylococcus aureus is very common in dairy cows and creates serious problems on dairy farms. In this study, we investigated the prevalence, genetic diversity and antimicrobial resistance of S. aureus from subclinical bovine mastitis on 12 dairy herds in Balikesir province of Turkey, by SCCmec and spa typing. Ninety-five isolates of S. aureus were isolated from 725 subclinical mastitic milk samples that exceeded the somatic cell count (SCC) limit of 4 x 10(5) cell/mL. The frequency of MRSA (methicillin-resistant Staphylococcus aureus) and MSSA (methicillin-sensitive S. aureus) was 6.3% (6 isolates) and 93.68% (89 isolates) respectively. SCCmec types of MRSA isolates were community-associated CA-MRSA type IVb (4 isolates) and type IVd (two isolates), while the spa types were T 005 and T 5163 (three isolates from each). The resistance rate of MRSA isolates was 100% for oxacillin and cefoxitin, 83% for penicillin, ampicillin, clindamycin, erythromycin and 66% for gentamicin and trimethoprim/sulfamethoxazole. However, compared to MRSA, the resistance of MSSA isolates was relatively lower. This study supported the scientific data on the occurrence of MRSA and MSSA in subclinical mastitis, and highlighted the need for preventive measures to eliminate or decrease S. aureus contamination of milk in dairy herds.