title: Comparison between patients under hemodialysis with community-onset bacteremia caused by community-associated and healthcare-associated methicillin-resistant Staphylococcus aureus strains.
abstract: OBJECTIVE
  Patients receiving hemodialysis infected with methicillin-resistant Staphylococcus aureus (MRSA) have been considered to have healthcare-associated (HA) infections, but strains with community-associated (CA) characteristics have also been identified in this population. The authors compared infections of the two strains among patients with end-stage renal disease.
  
  
  METHODS
  From January 2004 to December 2008 the authors analyzed the demographic and microbiologic data of 57 patients with community-onset (defined as a positive culture obtained ≤ 48 hours after admission) MRSA bacteremia and end-stage renal disease at a 2900-bed tertiary medical center. MRSA isolate with staphylococcal cassette chromosome mec (SCCmec) type II/III was classified as HA strains, and SCCmec type IV/V as CA strains.
  
  
  RESULTS
  Forty-seven patients (82%) had HA-MRSA strains and 10 patients (18%) had CA-MRSA strains. The major clones of HA-MRSA were sequence type (ST) 5 with SCCmec type II and staphylococcal protein A (spa) t002 as well as ST239 carrying SCCmec type III and spa t037. The CA-MRSA strains were predominantly ST59, more susceptible to non-β-lactam antimicrobial agents, and had a higher percentage of carrying the Panton-Valentine leukocidin gene in comparision with the HA-MRSA strains. Patients infected with HA-MRSA isolates had a higher overall mortality (57.4%, p = 0.012). In multivariate analysis, male patients were more likely to be infected with HA-MRSA isolates than CA-MRSA strains (p = 0.037), and a history of receiving urinary catheterization within 1 year prior to bacteremia onset (p = 0.047) is an independent risk factor to acquiring HA-MRSA strains.
  
  
  CONCLUSIONS
  Patients undergoing dialysis and infected with HA-MRSA strains had higher mortality rates and were more commonly associated with urinary catheterization within 1 year before bacteremia.
authors.affiliation: Section of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Hau-Shin
authors.initials: HS
authors.lastname: Wu
authors.forename: Shu-Chen
authors.initials: SC
authors.lastname: Kuo
authors.forename: Liang-Yu
authors.initials: LY
authors.lastname: Chen
authors.forename: Mei-Chun
authors.initials: MC
authors.lastname: Chiang
authors.forename: Yi-Tsung
authors.initials: YT
authors.lastname: Lin
authors.forename: Fu-Der
authors.initials: FD
authors.lastname: Wang
authors.forename: Chang-Phone
authors.initials: CP
authors.lastname: Fung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000890:Anti-Infective Agents / Q000494:pharmacology; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D001427:Bacterial Toxins / Q000235:genetics; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D005098:Exotoxins / Q000235:genetics; D005260:Female; D006801:Humans; D007956:Leukocidins / Q000235:genetics; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D008875:Middle Aged; D058889:Molecular Typing; D006435:Renal Dialysis / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D016019:Survival Analysis; D062606:Tertiary Care Centers; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000890:Anti-Infective Agents; D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D037521:Virulence Factors