title: Influence of ACB complex genospecies on clinical outcomes in a U.S. hospital with high rates of multidrug resistance.
abstract: OBJECTIVE
  Bacteria within the Acinetobacter calcoaceticus-Acinetobacter baumannii (ACB) complex commonly cause nosocomial infection and are often multidrug resistant. Advances in genospecies typing allow for speciation within the ACB complex; however, little is known about the effect of genospecies on patient outcomes.
  
  
  METHODS
  Adult patients with ACB complex bacteremia from Jan 2005-Oct 2012 were included. Bacterial isolates were speciated by rpoB gene sequence analysis, and clinical data were collected.
  
  
  RESULTS
  Of 147 patients with ACB complex bacteremia, 116 had A. baumannii (78.9%), 28 had Acinetobacter pittii (19.0%), and 3 had Acinetobacter nosocomialis (2.0%). A. baumannii bacteremia was associated with greater comorbidity and was more frequently multidrug resistant (79% vs. 16%, p < 0.01). Multidrug resistant A. baumannii but not susceptible A. baumannii was associated with worse outcomes compared to non-baumannii ACB complex bacteremia. Neither multidrug resistance nor genospecies was an independent predictor of mortality, but receipt of appropriate therapy was associated with decreased risk of mortality (OR, 0.13; 95% CI, 0.04-0.44; p < 0.01).
  
  
  CONCLUSIONS
  A. baumannii bacteremia is associated with worse clinical outcomes than non-baumannii ACB complex bacteremia. The difference, however, appears to be related to multidrug resistance and attendant receipt of appropriate therapy rather than genospecies.
authors.affiliation: Department of Medicine, Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL, USA. Electronic address: Margaret-fitzpatrick-0@northwestern.edu.
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Fitzpatrick
authors.affiliation: Department of Medicine, Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Egon
authors.initials: E
authors.lastname: Ozer
authors.affiliation: Department of Medicine, Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Maureen K
authors.initials: MK
authors.lastname: Bolon
authors.affiliation: Department of Medicine, Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL, USA; Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Alan R
authors.initials: AR
authors.lastname: Hauser
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality*; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000235:genetics*; D016954:Acinetobacter calcoaceticus / Q000187:drug effects / Q000235:genetics*; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality*; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D007087:Illinois / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents
keywords: Acinetobacter baumannii; Acinetobacter calcoaceticus; Bacteremia; Genome; Multidrug resistance