Multi-drug and methicillin resistance of staphylococci from canine patients at a veterinary teaching hospital (2006–2011)

摘要

Background: Over the past 10?years, an increase in methicillin and multi-drug resistant staphylococcal species has been identified worldwide and anecdotally reported within our veterinary teaching hospital.Objective: To determine the methicillin resistance (MR) and multi-drug resistance (MDR) patterns of staphylococcal species isolated from canine patients between 2006 and 2011.Animals and Methods: Staphylococcal isolates (n = 1069) were cultured from the canine patient population of the veterinary teaching hospital. The susceptibility reports of Staphylococcus pseudintermedius , S. aureus, S. schleiferi v. coagulans , S. schleiferi v. schleiferi , and other coagulase-negative staphylococci (CoNS) were assessed. Isolates were organized into five site categories. Isolates were scored on a 0–10 scale based on resistance to antimicrobial classes, with MDR classified as an isolate scoring a value ≥3. Statistical analysis included χ~(2), Fisher's exact test, and ANOVA with mean square and post hoc analysis; p 0.05 was significant.Results: S. pseudintermedius (76.6%), S. aureus (15.5%), S. schleiferi v. coagulans (5.7%), S. schleiferi v. schleiferi (1.2%), and CoNS (0.9%) isolation was observed. MR occurred in 11.4% of all combined isolates, with no difference between sites and years. Of the S. pseudintermedius isolates, 4.5% were methicillin resistant. Of all the isolates, 27.5% were MDR. The mean resistance score of S. pseudintermedius isolates increased significantly comparing 2006 and 2008 (p = 0.0006) and 2006 and 2009 (p = 0.0009). The mean score of all combined isolates increased significantly comparing 2006 and 2008 (p = 0.001).Conclusion: MR staphylococci isolation is similar when compared to other studies. However, increased MDR isolation is of greater concern and high-scoring MDR staphylococci will limit our future antimicrobial choices.