Antimicrobial Resistance of Coagulase-positive Staphylococcus Isolated From Healthy Crioulo Horses and Associated Risk Factors.

The research study investigates the antimicrobial resistance of coagulase-positive Staphylococcus, including Staphylococcus aureus, found in healthy Crioulo horses. It was found that both resistant bacteria exist in the horses’ microbiota and that the frequency of changing bedding and the nonaccumulation of bed materials are risk factors.

Objective of the Study

• This study was undertaken to investigate the antimicrobial resistance (AMR) of a specific type of bacteria, called coagulase-positive Staphylococcus (CoPS), that also includes Staphylococcus aureus and is found in healthy Crioulo horses.
• Understanding the presence of these bacteria in horses is important due to the potential for these animals to transmit resistant strains of the bacteria to humans.

Methods Used in the Study

• The researchers obtained swab samples from the nostrils and skin of 107 horses from Porto Alegre, South Brazil, which were utilized to isolate CoPS.
• The isolated bacteria were then evaluated for their resistance to antimicrobials.
• A multivariate logistic regression analysis was used to identify any potential risk factors associated with AMR.
• Data on the management of the horses and the conditions of their environments, more specifically their bedding, were used in this analysis.

Key Findings

• Out of 107 horses, 143 CoPS were isolated from 79 horses (73.8%), of which 5.6% were confirmed as S. aureus.
• The isolated bacteria showed resistance to seven out of the ten tested antimicrobials, with 38.5% of them resistant to at least one antimicrobial. Additionally, 0.7% were classified as multidrug-resistant.
• For S. aureus specifically, 62.5% displayed AMR, though none were methicillin-resistant.
• Based on the analysis, risk factors associated with CoPS’ antimicrobial resistance were a low frequency of changing beds and non-accumulation of bed materials. These elements were associated with higher rates of AMR.

Conclusion

• The study concludes that healthy horses harbor antimicrobial-resistant CoPS and S. aureus in their microbiota. This can pose a concern for both animal and human health due to the potential for transmission.
• It is also highlighted that proper bed management is correlated with lower AMR, thereby suggesting it as an effective focus for best practices to prevent the occurrence of resistant bacteria in these animals.