title: The effect of staphylococcal cassette chromosome mec (SCCmec) type on clinical outcomes in methicillin-resistant Staphylococcus aureus bacteremia.
abstract: OBJECTIVE
  The impact of staphylococcal cassette chromosome mec (SCCmec) type on mortality in methicillin-resistant Staphylococcus aureus (MRSA) infections remains unclear. The objective of this study was to determine the association between SCCmec type and mortality in MRSA bacteremia.
  
  
  METHODS
  A cohort study of patients who were hospitalized with MRSA bacteremia was conducted within a university health system. A multivariable logistic regression model was developed to evaluate the association of SCCmec type with 30-day in-hospital mortality.
  
  
  RESULTS
  Thirty-four of a total of 184 patients with MRSA bacteremia died, resulting in a mortality rate of 18.5%. Adjusted risk factors for 30-day mortality included APRDRG Risk of Mortality score (odds ratio [OR], 5.33; 95% confidence interval [CI], 2.28-12.4; P<0.001), white blood cell count (OR, 1.09; 95% CI, 1.03-1.15; P=0.002), and malignancy (OR, 3.25; 95% CI, 1.17-9.02; P=0.02). On multivariable analyses, SCCmec II was not significantly associated with mortality in patients with MRSA bacteremia (OR, 1.85; 95% CI, 0.69-4.92; P=0.22).
  
  
  CONCLUSIONS
  Mortality in MRSA bacteremia was independent of SCCmec type. SCCmec type II is most likely a marker for disease severity rather than a direct mediator of mortality. Further research is needed to elucidate the factors associated with poor clinical outcomes in MRSA infections.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, University of Pennsylvania School of Medicine, Hospital of the University of Pennsylvania, Philadelphia, 19104, USA. jennifer.han@uphs.upenn.edu
authors.forename: Jennifer H
authors.initials: JH
authors.lastname: Han
authors.forename: Paul H
authors.initials: PH
authors.lastname: Edelstein
authors.forename: Warren B
authors.initials: WB
authors.lastname: Bilker
authors.forename: Ebbing
authors.initials: E
authors.lastname: Lautenbach
mesh_terms: D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics*; D015331:Cohort Studies; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D016106:Methicillin Resistance; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D008875:Middle Aged; D058889:Molecular Typing; D015999:Multivariate Analysis; D016017:Odds Ratio; D046915:Penicillin-Binding Proteins; D012189:Retrospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology*; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D001426:Bacterial Proteins; D046915:Penicillin-Binding Proteins; C487789:mecA protein, Staphylococcus aureus