title: Effect of metallo-β-lactamase production and multidrug resistance on clinical outcomes in patients with Pseudomonas aeruginosa bloodstream infection: a retrospective cohort study.
abstract: BACKGROUND
  Blood stream infections (BSI) with Pseudomonas aeruginosa lead to poor clinical outcomes. The worldwide emergence and spread of metallo-β-lactamase (MBL) producing, often multidrug-resistant organisms may further aggravate this problem. Our study aimed to investigate the effect of MBL-producing P. aeruginosa (MBL-PA) and various other resistance phenotypes on clinical outcomes.
  
  
  METHODS
  A retrospective cohort study was conducted in three German hospitals. Medical files from 2006 until 2012 were studied, and a number of 113 patients with P. aeruginosa BSI were included. The presence of VIM, IMP and NDM genes was detected using molecular techniques. Genetic relatedness was assessed through multilocus sequence typing (MLST). The effect of resistance patterns or MBL production on clinical outcomes was investigated by using multivariate Cox regression models.
  
  
  RESULTS
  In-hospital mortality was significantly higher in patients with MBL-PA and multidrug-resistant P. aeruginosa. However, neither BSI with MBL-PA nor BSI with various resistance phenotypes of P. aeruginosa were independently associated with mortality or length of hospital stay. In multivariate models, the SAPS II score (HR 1.046), appropriate definitive treatment (HR range 0.25-0.26), and cardiovascular disease (HR range 0.44-0.46) were independent predictors of mortality. Concomitant infections were associated with an excess length of stay (HR < 1).
  
  
  CONCLUSIONS
  Medication with appropriate antimicrobial agents at any time during the course of infection remains the key for improving clinical outcomes in patients with P. aeruginosa BSI and should be combined with a strict implementation of routine infection control measures.
authors.affiliation: Institute of Medical Microbiology and Hygiene, University of Tübingen, Elfriede-Aulhorn-Str, 6, 72076 Tübingen, Germany. will80@gmx.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Willmann
authors.forename: Ines
authors.initials: I
authors.lastname: Kuebart
authors.forename: Matthias
authors.initials: M
authors.lastname: Marschal
authors.forename: Klaus
authors.initials: K
authors.lastname: Schröppel
authors.forename: Wichard
authors.initials: W
authors.lastname: Vogel
authors.forename: Ingo
authors.initials: I
authors.lastname: Flesch
authors.forename: Uwe
authors.initials: U
authors.lastname: Markert
authors.forename: Ingo B
authors.initials: IB
authors.lastname: Autenrieth
authors.forename: Florian
authors.initials: F
authors.lastname: Hölzl
authors.forename: Silke
authors.initials: S
authors.lastname: Peter
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality; D015331:Cohort Studies; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D005858:Germany / Q000453:epidemiology; D017052:Hospital Mortality; D006761:Hospitals; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011552:Pseudomonas Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D012189:Retrospective Studies; D016896:Treatment Outcome; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases