Antimicrobial Resistance of Coagulase-positive Staphylococcus Isolated From Healthy Crioulo Horses and Associated Risk Factors.
Authors: Mota Sabrina Lopes, Dos Santos Lays Oliveira, Vidaletti Marina Roth, Rodrigues Rogério Oliveira, Coppola Mario de Menezes, Mayer Fabiana Quoos
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Antimicrobial resistance (AMR) in staphylococcal populations represents a genuine one-health concern, particularly given horses' close contact with humans and potential for bacterial transmission. Researchers in Brazil cultured coagulase-positive Staphylococcus from nasal and skin swabs of 107 healthy Crioulo horses, identifying 143 isolates across 79 animals (73.8% colonisation rate), of which eight were *Staphylococcus aureus*; notably, none of the *S. aureus* isolates displayed methicillin resistance. Resistance to at least one antimicrobial was documented in 38.5% of isolates (55/143), with activity demonstrated against seven of ten tested agents, though only one isolate (0.7%) met multidrug-resistant criteria. Stabling practices emerged as significant risk factors, with less frequent bedding changes (odds ratio 6.40) and failure to remove accumulated soiled material (odds ratio 3.47) both independently associated with increased resistance prevalence. These findings underscore that healthy equine populations harbour resistant bacteria within their normal microbiota, and suggest that pragmatic management interventions—particularly enhanced hygiene protocols around bedding disposal—may represent a straightforward strategy for reducing selective pressure favouring resistant organisms and mitigating zoonotic risk.
Read the full abstract on PubMed
Practical Takeaways
- •Implement frequent bed changing and proper bedding management protocols as cost-effective measures to reduce antimicrobial-resistant bacteria colonization in horse facilities
- •Recognize that healthy horses routinely carry resistant Staphylococcus species, emphasizing biosecurity importance when handling horses that may contact humans or other animal populations
- •Monitor for antimicrobial resistance patterns in your horse population, particularly in S. aureus, though methicillin resistance was not detected in this Brazilian cohort
Key Findings
- •73.8% of healthy Crioulo horses (79/107) carried coagulase-positive Staphylococcus, with 38.5% of isolates showing resistance to at least one antimicrobial
- •5.6% of isolates were S. aureus, of which 62.5% showed antimicrobial resistance but none were methicillin-resistant
- •Lower frequency of bed changing (OR=6.40, P=.001) and non-accumulation of bed materials (OR=3.47, P=.002) were significant risk factors for antimicrobial resistance
- •Only 0.7% of isolates were classified as multidrug-resistant, indicating limited but emerging resistance patterns in this population