title: Prevalence and risk factors for isolation of methicillin-resistant Staphylococcus in dogs with keratitis.
abstract: OBJECTIVE
  To determine the prevalence of, and risk factors for, methicillin-resistant Staphylococcus (MRS) isolation in dogs with naturally acquired bacterial keratitis.
  
  
  METHODS
  All Staphylococcus spp. isolated from corneal samples of dogs with keratitis during a 2-year period were evaluated for methicillin resistance by bacteriologic methods. Each MRS isolate was subjected to in vitro susceptibility testing for systemic and ocular antimicrobials. Nasal swabs for culture were collected from all dogs with MRS corneal isolation to evaluate for nasal carrier status. Potential risk factors for MRS isolation were investigated by medical record review and administration of an epidemiological survey to dog owners. Collected information characterizing animal, client, and environmental variables was analyzed for association with MRS isolation.
  
  
  RESULTS
  Seventy-one Staphylococcus spp. were isolated from seventy individual dogs with keratitis during the study period. Seventeen of the Staphylococcus isolates (23.9%) were methicillin resistant. The MRS isolates included Staphylococcus epidermidis (n = 10), Staphylococcus pseudintermedius (n = 6), and Staphylococcus aureus (n = 1). The MRS corneal isolates displayed extensive antimicrobial resistance. Four dogs (23.5%) with MRS corneal isolates had positive nasal cultures for MRS. Client occupation was significantly (P = 0.01) associated with MRS isolation, and dogs belonging to owners employed in veterinary or human healthcare fields were four times more likely to have MRS keratitis than dogs owned by clients with different professions. There were no significant associations between the other evaluated animal, client, and environmental factors.
  
  
  CONCLUSIONS
  Methicillin resistance is relatively common in Staphylococcus isolates from dogs with corneal infections, particularly among dogs belonging to healthcare workers.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: LoPinto
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Hussni O
authors.initials: HO
authors.lastname: Mohammed
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Ledbetter
mesh_terms: D000818:Animals; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D004283:Dog Diseases / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology*; D004285:Dogs; D007634:Keratitis / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology / Q000662:veterinary*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology / Q000662:veterinary*
keywords: Methicillin-resistant Staphylococcus aureus; cornea; dog; keratitis; methicillin-resistant Staphylococcus epidermidis; methicillin-resistant Staphylococcus pseudintermedius