title: Clinical impact of methicillin resistance on outcome of patients with Staphylococcus aureus infection: a stratified analysis according to underlying diseases and sites of infection in a large prospective cohort.
abstract: OBJECTIVE
  This study was conducted to identify the predictors of mortality and to evaluate the impact of methicillin resistance on outcome in patients with Staphylococcus aureus infection according to underlying conditions and type of infection.
  
  
  METHODS
  An observational cohort study including 4949 patients with S. aureus infection was conducted. We compared data from patients with MRSA infection with those with MSSA infection.
  
  
  RESULTS
  The 30-day mortality rate of MRSA group was significantly higher than that of MSSA group (15.6% vs. 6.2%, P < 0.001). However, MRSA infection was not found to be independent risk factor for mortality after adjusting for other variables (OR = 1.03, 95% CI = 0.80-1.32). When we analyzed patients with S. aureus bacteremia (n = 709), MRSA infection was found to be significantly associated with mortality in multivariate analysis (Adjusted OR = 1.69, 95% CI = 1.15-2.49). When the 30-day mortality rates were compared according to underlying diseases, the 30-day mortality rate of MRSA group was significantly higher than that of MSSA group in patients with malignancy or renal diseases. MRSA infection was also found to be one of the independent risk factors for mortality in patients with malignancy (adjusted OR = 1.69, 95% CI = 1.06-2.70) and in those with renal disease (adjusted OR = 1.70, 95% CI = 1.0-2.89), after adjustment for host variables.
  
  
  CONCLUSIONS
  Methicillin resistance adversely affected the outcome of patients with S. aureus infection, in patients with cancer or renal disease and in those with S. aureus bacteremia, although MRSA infection was not found to be significantly associated with higher mortality in overall patient population.
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
authors.forename: Cheol-In
authors.initials: CI
authors.lastname: Kang
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Song
authors.forename: Doo Ryeon
authors.initials: DR
authors.lastname: Chung
authors.forename: Kyong Ran
authors.initials: KR
authors.lastname: Peck
authors.forename: Kwan Soo
authors.initials: KS
authors.lastname: Ko
authors.forename: Joon-Sup
authors.initials: JS
authors.lastname: Yeom
authors.forename: Shin-Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: Hyun-Ha
authors.initials: HH
authors.lastname: Chang
authors.forename: Yeon-Sook
authors.initials: YS
authors.lastname: Kim
authors.forename: Sook-In
authors.initials: SI
authors.lastname: Jung
authors.forename: Jun Seong
authors.initials: JS
authors.lastname: Son
authors.forename: Po-Ren
authors.initials: PR
authors.lastname: Hsueh
authors.forename: Thomas Man-kit
authors.initials: TM
authors.lastname: So
authors.forename: M K
authors.initials: MK
authors.lastname: Lalitha
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Yang
authors.forename: Shao-Guang
authors.initials: SG
authors.lastname: Huang
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Quan
authors.initials: Q
authors.lastname: Lu
authors.forename: Celia C
authors.initials: CC
authors.lastname: Carlos
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Perera
authors.forename: Cheng-Hsun
authors.initials: CH
authors.lastname: Chiu
authors.forename: Jien-Wei
authors.initials: JW
authors.lastname: Liu
authors.forename: Anan
authors.initials: A
authors.lastname: Chongthaleong
authors.forename: Visanu
authors.initials: V
authors.lastname: Thamlikitkul
authors.forename: Hung
authors.initials: H
authors.lastname: Van Pham
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007674:Kidney Diseases / Q000150:complications; D008297:Male; D016106:Methicillin Resistance; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents