title: Prevalence and Clinical Impact of Heterogeneous Vancomycin-Intermediate Staphylococcus aureus Isolated From Hospitalized Patients.
abstract: BACKGROUND
  We estimated the prevalence and clinical impact of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA). The concordance between macromethod and glycopeptide resistance detection (GRD) E tests was determined. In addition, predictors of clinical outcomes in hospitalized patients with S. aureus bacteremia (SAB) or pneumonia (SAP) were evaluated.
  
  
  METHODS
  We obtained 229 consecutive S. aureus isolates from all hospitalized patients at two university hospitals located in Busan and Yangsan, Korea. Standard, macromethod, and GRD E tests were performed. Additionally, we reviewed the medical records of all patients. Among the 229 patients, predictors of clinical outcomes were analyzed for 107 patients with SAB and 39 with SAP.
  
  
  RESULTS
  Among the 229 isolates, 34.5% of S. aureus isolates and 50.7% of methicillin-resistant S. aureus isolates exhibited the hVISA phenotype based on the macromethod E test. hVISA was nearly associated with treatment failure in patients with SAB (P=0.054) and was significantly associated with treatment failure in patients with SAP (P=0.014). However, hVISA was not associated with 30-day mortality in patients with SAB or SAP. The concordance between the macromethod and GRD E tests was 84.2%.
  
  
  CONCLUSIONS
  hVISA is quite common in the southeastern part of Korea. hVISA is associated with treatment failure in patients with SAP.
authors.affiliation: Department of Laboratory Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Young Rae
authors.initials: YR
authors.lastname: Koh
authors.affiliation: Department of Internal Medicine, Pusan National University Hospital, Busan, Korea.
authors.forename: Kye Hyung
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Chulhun L
authors.initials: CL
authors.lastname: Chang
authors.affiliation: Department of Laboratory Medicine, Pusan National University School of Medicine, Busan, Korea.|Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea.|Biomedical Research Institute, Pusan National University Hospital, Busan, Korea. csm410@naver.com.
authors.forename: Jongyoun
authors.initials: J
authors.lastname: Yi
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010641:Phenotype; D011014:Pneumonia / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D017334:Teicoplanin / Q000494:pharmacology; D014640:Vancomycin / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D000900:Anti-Bacterial Agents; D017334:Teicoplanin; D014640:Vancomycin
keywords: Glycopeptide resistance detection E test; Heterogeneous vancomycin-intermediate Staphylococcus aureus; Macromethod E test; S. aureus bacteremia; S. aureus pneumonia