title: Methicillin-resistant Staphylococcus aureus in skin and soft tissue infections presenting to the Emergency Department of a Canadian Academic Health Care Center.
abstract: OBJECTIVE
  This study aimed to estimate the city-wide prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in patients (≥18 years old) presenting with skin and soft tissue infections (SSTIs) to the emergency departments (EDs) of a Canadian Academic Health Care Center. Secondary objectives were to identify demographic and clinical variables associated with MRSA, and determine MRSA antimicrobial susceptibilities and genotypes.
  
  
  METHODS
  This prospective observational study was conducted over 2 months. Participants completed a Health and Lifestyle Questionnaire. Cultures of the infection site, nares, and throat were obtained and MRSA isolates were confirmed by polymerase chain reaction. Patient characteristics were summarized using descriptive statistics and MRSA prevalence and 95% confidence intervals were estimated using standard equations. Backwards stepwise multivariate logistic regression models determined predictor variables independently associated with MRSA colonization or infection.
  
  
  RESULTS
  Of 205 patients, 35 (17.1%) were infected or colonized with MRSA. Seventy-eight (38.0%) of the infection site cultures grew S. aureus of which 27 (34.6%) were MRSA. Incarceration, known exposure to MRSA and involvement in competitive sports were significant predictors of MRSA SSTIs. Antimicrobial susceptibility among MRSA isolates was trimethoprim/sulfamethoxazole, vancomycin, gentamicin, and linezolid 100%, clindamycin 75%, ciprofloxacin 59.3%, and erythromycin 7.4%. Sixty-nine percent of MRSA cases fit the clinical definition of community associated; subsequently 77% were confirmed as CMRSA 10, a recognized community-acquired MRSA.
  
  
  CONCLUSIONS
  Community-acquired -MRSA is a significant pathogen of SSTIs in EDs of a Canadian teaching center. MRSA should be considered when initiating empiric antibiotic therapy, particularly in patients with risk factors.
authors.affiliation: aDivision of Emergency Medicine, Schulich School of Medicine and Dentistry bDepartment of Pediatrics and Sociology, Children's Health Research Institute, The University of Western Ontario cDepartment of Pediatrics dDepartment Pathology, Medical Microbiology, Schulich School Medicine and Dentistry, The University of Western Ontario eClinical Microbiology and Infection Control, London Health Sciences Center, London, Ontario, Canada.
authors.forename: Cimi C
authors.initials: CC
authors.lastname: Achiam
authors.forename: Christopher Mahendra Bernard
authors.initials: CM
authors.lastname: Fernandes
authors.forename: Shelley L
authors.initials: SL
authors.lastname: McLeod
authors.forename: Marina I
authors.initials: MI
authors.lastname: Salvadori
authors.forename: Michael
authors.initials: M
authors.lastname: John
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Seabrook
authors.forename: Karl D
authors.initials: KD
authors.lastname: Theakston
authors.forename: Susan
authors.initials: S
authors.lastname: Milburn
authors.forename: Zafar
authors.initials: Z
authors.lastname: Hussain
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002170:Canada / Q000453:epidemiology; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008875:Middle Aged; D018461:Soft Tissue Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D013207:Staphylococcal Skin Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000302:isolation & purification; D014505:Urban Population / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents