title: Lincosamide resistance is less frequent in Denmark in Staphylococcus pseudintermedius from first-time canine superficial pyoderma compared with skin isolates from clinical samples with unknown clinical background.
abstract: BACKGROUND
  Antimicrobial resistance may be overestimated in bacterial isolates from clinical samples because veterinarians often submit samples in cases of treatment failure or recurrent cases, which are more frequently associated with resistant strains.
  
  
  OBJECTIVE
  To assess to what extent the prevalence of antimicrobial resistance in Staphylococcus pseudintermedius isolated from first-time superficial pyoderma differs from canine skin isolates from clinical samples with unknown clinical background.
  
  
  METHODS
  Two study groups were enrolled in Denmark between March 2012 and October 2013: 57 dogs with first-time superficial pyoderma and no prior antimicrobial treatment (Group A); and 289 different dogs for which skin specimens were submitted for culture during the study (Group B).
  
  
  METHODS
  One S. pseudintermedius isolate from each dog was confirmed by MALDI-TOF mass spectrometry and tested for antimicrobial susceptibility by broth microdilution. Resistance levels in the two groups were compared by Fisher's exact test.
  
  
  RESULTS
  Clindamycin resistance was less frequent in Group A (14%) than in Group B (27%) (P = 0.02). Similar trends were observed for amoxicillin-clavulanic acid (1.8 versus 4.8%), chloramphenicol (8.8 versus 14.5%), enrofloxacin (1.8 versus 3.5%), oxacillin (1.8 versus 4.8%) and trimethoprim/sulfamethoxazole (3.5 versus 5.9%). Oxacillin resistance was significantly associated with resistance to six of seven non-β-lactams.
  
  
  CONCLUSIONS
  The prevalence of lincosamide resistance is markedly influenced by patients' clinical and antimicrobial treatment history. To limit selection of multidrug-resistant bacteria, lincosamides are appropriate empirical choices for treatment of first-time superficial pyoderma even though resistance is not infrequent. Culture and susceptibility testing are, however, recommended for all pyoderma patients.
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1-20, 1870, Frederiksberg C, Denmark.
authors.forename: Rikke
authors.initials: R
authors.lastname: Larsen
authors.affiliation: Veterinary Dermatology Clinic, Rudemarken 37, 2840, Holte, Denmark.
authors.forename: Lene
authors.initials: L
authors.lastname: Boysen
authors.affiliation: Veterinary Dermatology Clinic, Rudemarken 37, 2840, Holte, Denmark.
authors.forename: June
authors.initials: J
authors.lastname: Berg
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1-20, 1870, Frederiksberg C, Denmark.
authors.forename: Luca
authors.initials: L
authors.lastname: Guardabassi
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1-20, 1870, Frederiksberg C, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Damborg
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D003718:Denmark / Q000453:epidemiology; D004283:Dog Diseases / Q000188:drug therapy* / Q000382:microbiology; D004285:Dogs; D024881:Drug Resistance, Bacterial; D055231:Lincosamides / Q000627:therapeutic use*; D015995:Prevalence; D011711:Pyoderma / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D012867:Skin / Q000382:microbiology; D013207:Staphylococcal Skin Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D013210:Staphylococcus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D055231:Lincosamides