Antimicrobial resistance in coagulase-positive staphylococci isolated from companion animals in Australia: A one year study.
Authors: Saputra Sugiyono, Jordan David, Worthing Kate A, Norris Jacqueline M, Wong Hui S, Abraham Rebecca, Trott Darren J, Abraham Sam
Journal: PloS one
Summary
# Editorial Summary Methicillin-resistant coagulase-positive staphylococci (CoPS) represent an emerging therapeutic challenge in companion animal medicine, yet their prevalence in Australia had not been systematically quantified. Between January 2013 and January 2014, researchers collated clinical Staphylococcus isolates (n = 888) from 22 veterinary diagnostic laboratories across Australia, identifying species through MALDI-TOF mass spectrometry and testing susceptibility to 16 antimicrobials across 12 drug classes; they subsequently analysed risk factors associated with methicillin resistance, particularly in *Staphylococcus pseudintermedius* from canine cases. Overall prevalence of methicillin resistance was moderate (11.8% for MRSP, 12.8% for MRSA), though critically, MRSP isolates demonstrated exceptionally strong associations with fluoroquinolone and clindamycin resistance (odds ratios of 287 and 105 respectively), whilst methicillin-resistant isolates from surgical and skin/soft tissue infections were significantly more common. Prior antimicrobial exposure emerged as a substantial risk factor, with surgically infected dogs previously treated with antimicrobials being three times more likely to harbour methicillin-resistant strains. For equine practitioners and small animal clinicians alike, these findings underscore the importance of judicious antimicrobial stewardship and rigorous infection control—the moderate current resistance rates could escalate rapidly without such measures, fundamentally constraining treatment options for staphylococcal infections in our patients.
Read the full abstract on PubMed
Practical Takeaways
- •Approximately 1 in 8-9 staphylococcal infections in companion animals are methicillin-resistant; culture and susceptibility testing should guide antimicrobial selection, particularly for surgical and skin infections
- •Avoid fluoroquinolones and clindamycin for presumptive MRSP treatment; enforce strict biosecurity and infection control in veterinary practices to prevent resistance spread
- •Prior antimicrobial exposure significantly increases methicillin resistance risk in surgical infections—use narrow-spectrum agents when possible and avoid unnecessary prophylactic antibiotics
Key Findings
- •Methicillin resistance frequency was 11.8% in S. pseudintermedius and 12.8% in S. aureus across Australian companion animals during 2013-2014
- •MRSP isolates showed strong association with fluoroquinolone resistance (OR 287) and clindamycin resistance (OR 105.2)
- •Surgical site infections and skin/soft tissue infections were significantly associated with MRSP status (OR 8.8 and 3.9 respectively)
- •Prior antimicrobial treatment increased likelihood of methicillin-resistant S. pseudintermedius in surgical site infections by threefold