ABSTRACT
Aims
To investigate the frequency of carriage of methicillin-susceptible and methicillin-resistant Staphylococcus pseudintermedius (MRSP) in a population of clinically normal dogs within the Christchurch and wider Canterbury region, an area in which MRSP has been detected.
Methods
Buccal and perianal swabs were collected from 126 clinically normal dogs presenting at veterinary clinics in the Christchurch/Canterbury region for de-sexing or routine vaccination. S. pseudintermedius was isolated by selective culture. Isolates were tested for susceptibility to 12 antimicrobials by disc diffusion.
Results
S. pseudintermedius was isolated from 92/126 (73.0 (95% CI = 64.4–80.5)%) dogs, with 38/126 (30.2 (95% CI = 22.3–39.0)%) positive dogs carrying S. pseudintermedius at both sampled sites. More animals (78/126; 61.9 (95% CI = 52.8–70.4)%) had positive mouth cultures than positive perianal region cultures (52/126; 41.3 (95% CI = 32.6–50.4)%). No MRSP was isolated from clinically normal dogs. However, resistance to penicillin (106/130 (85.1%) swabs) and tetracycline (33/130 (25.4%) swabs) was seen.
Conclusions
The majority of the dogs in this sample were carriers of S. pseudintermedius. However, none of these isolates were MRSP.
Clinical relevance
While most clinically normal dogs in the studied region are likely to be carriers of S. pseudintermedius, only a small proportion, if any, are likely to be carriers of MRSP. Antibiotic stewardship practices may be important to maintain low-level circulation of drug-resistant bacterial lineages.
Acknowledgements
We thank all the owners who allowed their dogs to be sampled and all the dogs who cooperated with the swabbing. We would like to thank the numerous staff of Harewood Veterinary Hospital, Pet Doctors (Marshall and Pringle, Templeton and Barrington), the Hornby Veterinary Centre, OurVets (Riccarton and Halswell), McMaster and Heap Veterinary Practice, and Rangiora Vet Centre, who all participated in this project by providing swab samples. We are grateful to Sylvia McLean and Lee Williams for helpful discussions. This study was funded by Healthy Pets NZ (formerly the New Zealand Companion Animal Health Foundation) [grant number HPNZ 17-03].