Lack of MRSP detection in healthy dogs attending a Danish referral hospital

Research output: Contribution to conferencePosterResearchpeer-review

Paul NC, Bärgman SC, Moodley A, Guardabassi L.

Introduction: Methicillin-resistant S. pseudintermedius (MRSP) is an emerging threat to pet animals due to its characteristic multidrug resistance profile. The current knowledge of the frequency of MRSP in the dog population is limited to few countries. Prior to this study, no information was available about the frequency of MRSP healthy dog carriers in Denmark.

Objectives: The objectives of this study were i) to estimate the prevalence of MRSP and methicillin-susceptible S. pseudintermedius (MSSP) among healthy dogs in the area of Copenhagen, and ii) to compare the carriage rates at different body sites.

Methods: A total 476 swabs were collected from perineum, groin, mouth and nasal vestibulum of 119 healthy dogs attending the Copenhagen University small animal hospital between October and December 2010. The dogs were defined as healthy and included in the study on the basis of veterinary records (no skin or wound infection and no antibiotic therapy in last 6 months) and clinical examination. Each swab was enriched in Mueller Hinton Broth with 6.5% NaCl and subcultured on both blood agar and MRSA brilliance agar (Oxoid, Deutschland GmbH, Wesel, Germany). The species of presumptive S. pseudintermedius colonies from blood agar was confirmed by nuc PCR. Any light blue/blue colonies growing on Brilliance agar were subjected to mecA PCR for confirmation of methicillin resistance.

Results: Despite the use of a selective isolation method, no MRSP-positive dogs were detected.
MSSP were isolated from 82 (69%) of the 119 healthy dogs sampled. The perineum (66%) and mouth (65%) were the most frequent colonization sites followed by nasal vestibulum (26.9%) and groin (23%). Most dog carriers were positive at only one body site (39/119; 33%). Carriage at two (25/119; 21%), three (13/129; 11%) and four body sites (5/129; 4%) was less frequent. Among dogs carrying S. pseudintermedius at multiple sites, positive culture of perineum and mouth samples was the most frequent combination and accounted for 90% (74/82) of the dogs.

Discussion/conclusion: The study indicates that the prevalence of MRSP is very low in the Copenhagen area. This finding may explain why MRSP is rarely isolated from canine clinical at our diagnostic laboratory. Differently from S. aureus in humans, the perineum and the mouth are the body sites most frequently colonized with S. pseudintermedius in dogs. This information is highly relevant for the design of MRSP screening studies in dogs. Based on our data, both sampling sites should be analyzed since the combination of the two samples increase the sensitivity of the screening by 25% and 26% in comparison to perineum or mouth samples alone, respectively.
Original languageEnglish
Publication date2011
Publication statusPublished - 2011
EventASM-ESCMID Conference on Methicillin-resistant Staphylococci in Animals: Veterinary and Public Health Implications - Washington DC, United States
Duration: 8 Sep 201111 Sep 2011
Conference number: 2

Conference

ConferenceASM-ESCMID Conference on Methicillin-resistant Staphylococci in Animals
Number2
CountryUnited States
CityWashington DC
Period08/09/201111/09/2011

ID: 35360757