title: Prevalence of methicillin-resistant Staphylococcus haemolyticus in companion animals: a cross-sectional study.
abstract: BACKGROUND
  Among coagulase-negative staphylococci, Staphylococcus haemolyticus is the second most frequently isolated species from human blood cultures and has the highest level of antimicrobial resistance. This species has zoonotic character and is prevalent both in humans and animals. Recent studies have indicated that methicillin-resistant S. haemolyticus (MRSH) is one of the most frequent isolated Staphylococcus species among neonates in intensive care units. The aim of this study was to determine the presence of MRSH in different groups of companion animals and to characterize isolates according their antimicrobial resistance.
  
  
  METHODS
  Samples (n = 754) were collected from healthy and diseased dogs and cats, female dogs in pure-breed kennels, healthy horses, and kennel owners. Classical microbiological tests along with molecular testing including PCR and 16S rRNA sequencing were performed to identify MRSH. Clonality of the isolates was assessed by Pulsed Field Gel Electrophoresis using the SmaI restriction enzyme. Antimicrobial susceptibility testing was performed using the broth micro-dilution method. Detection of genes encoding antimicrobial resistance was performed by PCR. Statistical analysis was performed using the R Project of Statistical Computing, "R 1.8.1" package.
  
  
  RESULTS
  From a total of 754 samples tested, 12 MRSH isolates were obtained. No MRSH were found in horses and cats. Eleven isolates were obtained from dogs and one from a kennel owner. Ten of the dog isolates were detected in pure-breed kennels. The isolates demonstrated the same clonality only within separate kennels.The most frequent resistances of MRSH isolates was demonstrated to benzylpenicillin (91.7%), erythromycin (91.7%), gentamicin (75.0%), tetracycline (66.7%), fluoroquinolones (41.7%) and co-trimoxazole (41.7%). One isolate was resistant to streptogramins. All isolates were susceptible to daptomycin, rifampin, linezolid and vancomycin. The clone isolated from the kennel owner and one of the dogs was resistant to beta-lactams, macrolides, gentamicin and tetracycline.
  
  
  CONCLUSIONS
  Pure-breed kennels keeping 6 or more females were determined to be a risk factor for the presence of MRSH strains. MRSH isolated from companion animals were frequently resistant to some classes of critically important antimicrobials, although they remain susceptible to antibiotics used exclusively in human medicine.
authors.affiliation: Microbiology and Virology Institute, Lithuanian University of Health Sciences, Mickeviciaus g, 9, Kaunas LT44307, Lithuania. ruzauskas@lva.lt.
authors.forename: Modestas
authors.initials: M
authors.lastname: Ruzauskas
authors.forename: Rita
authors.initials: R
authors.lastname: Siugzdiniene
authors.forename: Irena
authors.initials: I
authors.lastname: Klimiene
authors.forename: Marius
authors.initials: M
authors.lastname: Virgailis
authors.forename: Raimundas
authors.initials: R
authors.lastname: Mockeliunas
authors.forename: Lina
authors.initials: L
authors.lastname: Vaskeviciute
authors.forename: Dainius
authors.initials: D
authors.lastname: Zienius
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D002415:Cats; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004285:Dogs; D016521:Electrophoresis, Gel, Pulsed-Field; D005798:Genes, Bacterial; D005838:Genotype; D006736:Horses; D006801:Humans; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D057805:Pets / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D041162:Staphylococcus haemolyticus / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S