title: Comparison of outcome and clinical characteristics of bacteremia caused by methicillin-resistant, penicillin-resistant and penicillin-susceptible Staphylococcus aureus strains.
abstract: BACKGROUND
  The aim of this study was to assess the association of methicillin resistance and penicillinase production with clinical characteristics and outcome of Staphylococcus aureus bacteremia.
  
  
  METHODS
  For 126 patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia, 378 age- and gender-matched controls with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia were selected. Of controls, 126 had bacteremia caused by penicillin-susceptible strains (PSSA) and 252 by penicillinase-producing strains (PRSA). Underlying diseases, clinical course and mortality were retrospectively assessed.
  
  
  RESULTS
  Patients with MRSA bacteremia were more often smokers than patients with MSSA bacteremia (OR 2.34, 95% CI 1.27-4.32). MRSA bacteremia was more often healthcare-associated (OR 4.23, 95% CI 2.47-7.24), associated with central venous catheters (OR 2.09, 95% CI 1.27-3.47), glucocorticoid therapy (OR 1.82, 95% CI 1.12-2.93) and prior surgery (OR 2.32, 95% CI 1.43-3.76). Patients with MRSA bacteremia received appropriate empiric antibiotic (31%) less often than controls (98%). Mortality within 28 days was higher in MRSA bacteremia (26.8%) than in MSSA bacteremia (15.5%) (OR 2.00, 95% CI 1.20-3.34), PRSA bacteremia (17.0%) (OR 1.79 95% CI 1.04-3.09) or PSSA bacteremia (12.5%) (OR 2.56 95% CI 1.27-5.15). The difference remained after adjusting for underlying diseases and foci. There was no significant difference in clinical course between PRSA and PSSA bacteremias.
  
  
  CONCLUSIONS
  MRSA bacteremia was associated with poorer outcome than either PRSA or PSSA bacteremia. We corroborated several risk factors found in previous studies.
authors.affiliation: a Department of Internal Medicine , Infectious Disease Unit, Tampere University Hospital , Tampere , Finland.
authors.forename: Elina
authors.initials: E
authors.lastname: Jokinen
authors.affiliation: a Department of Internal Medicine , Infectious Disease Unit, Tampere University Hospital , Tampere , Finland.
authors.forename: Janne
authors.initials: J
authors.lastname: Laine
authors.affiliation: a Department of Internal Medicine , Infectious Disease Unit, Tampere University Hospital , Tampere , Finland.
authors.forename: Reetta
authors.initials: R
authors.lastname: Huttunen
authors.affiliation: b The Health Centre of Heinola , Doctagon OY , Heinola , Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Rahikka
authors.affiliation: c Faculty of Social Sciences , University of Tampere , Tampere , Finland.
authors.forename: Heini
authors.initials: H
authors.lastname: Huhtala
authors.affiliation: d Department of Clinical Microbiology , Fimlab Laboratories , Tampere , Finland.
authors.forename: Risto
authors.initials: R
authors.lastname: Vuento
authors.affiliation: e Department of Infectious Diseases , National Institute for Health and Welfare , Helsinki , Finland.|f Department of Medical Microbiology and Immunology , University of Turku , Turku , Finland.
authors.forename: Jaana
authors.initials: J
authors.lastname: Vuopio
authors.affiliation: a Department of Internal Medicine , Infectious Disease Unit, Tampere University Hospital , Tampere , Finland.|g School of Medicine , University of Tampere , Tampere , Finland.
authors.forename: Jaana
authors.initials: J
authors.lastname: Syrjänen
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D016106:Methicillin Resistance; D010403:Penicillin Resistance; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents
keywords: MRSA; PRSA; PSSA; Staphylococcus aureus; bacteremia