title: Clinical infectious outcomes associated with biofilm-related bacterial infections: a retrospective chart review.
abstract: BACKGROUND
  Biofilms are associated with persistent infection. Reports characterizing clinical infectious outcomes and patient risk factors for colonization or infection with biofilm forming isolates are scarce. Our institution recently published a study examining the biofilm forming ability of 205 randomly selected clinical isolates. This present study aims to identify potential risk factors associated with these isolates and assess clinical infectious outcomes.
  
  
  METHODS
  221 clinical isolates collected from 2005 to 2012 and previously characterized for biofilm formation were studied. Clinical information from the associated patients, including demographics, comorbidities, antibiotic usage, laboratory values, and clinical infectious outcomes, was determined retrospectively through chart review. Duplicate isolates and non-clinical isolates were excluded from analysis. Associations with biofilm forming isolates were determined by univariate analysis and multivariate analysis.
  
  
  RESULTS
  187 isolates in 144 patients were identified for analysis; 113 were biofilm producers and 74 were not biofilm producers. Patients were primarily male (78 %) military members (61 %) with combat trauma (52 %). On multivariate analysis, the presence of methicillin-resistant Staphylococcus aureus (p < 0.01, OR 5.09, 95 % CI 1.12, 23.1) and Pseudomonas aeruginosa (p = 0.02, OR 3.73, 95 % CI 1.46, 9.53) were the only characteristics more likely to be present in the biofilm producing isolate group. Infectious outcomes of patients with non-biofilm forming isolates, including cure, relapse/reinfection, and chronic infection, were similar to infectious outcomes of patients with biofilm-forming isolates. Mortality with initial infection was higher in the biofilm producing isolate group (16 % vs 5 %, p = 0.01) but attributable mortality was low (1 of 14). No characteristics examined in this study were found to be associated with relapse/reinfection or chronic infection on multivariate analysis.
  
  
  CONCLUSIONS
  Bacteria species, but not clinical characteristics, were associated with biofilm formation on multivariate analysis. Biofilm forming isolates and non-biofilm forming isolates had similar infectious outcomes in this study.
authors.affiliation: Infectious Disease Service, San Antonio Military Medical Center, JBSA Fort Sam Houston, San Antonio, TX, USA. alice.e.barsoumian.mil@mail.mil.
authors.forename: Alice E
authors.initials: AE
authors.lastname: Barsoumian
authors.affiliation: Infectious Disease Service, San Antonio Military Medical Center, JBSA Fort Sam Houston, San Antonio, TX, USA. katrin.mende.ctr@mail.mil.|Infectious Disease Clinical Research Program, Uniformed University of the Health Sciences, Bethesda, MD, USA. katrin.mende.ctr@mail.mil.
authors.forename: Katrin
authors.initials: K
authors.lastname: Mende
authors.affiliation: United States Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX, USA. carlos.j.sanchez47.vol@mail.mil.
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Sanchez
authors.affiliation: Department of Clinical Investigation, San Antonio Military Medical Center, JBSA Fort Sam Houston, San Antonio, TX, USA. miriam.l.beckius.civ@mail.mil.
authors.forename: Miriam L
authors.initials: ML
authors.lastname: Beckius
authors.affiliation: United States Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX, USA. joseph.c.wenke.civ@mail.mil.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Wenke
authors.affiliation: Infectious Disease Service, San Antonio Military Medical Center, JBSA Fort Sam Houston, San Antonio, TX, USA. clinton.k.murray.mil@mail.mil.
authors.forename: Clinton K
authors.initials: CK
authors.lastname: Murray
authors.affiliation: Infectious Disease Service, San Antonio Military Medical Center, JBSA Fort Sam Houston, San Antonio, TX, USA. kevin.s.akers.mil@mail.mil.|United States Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX, USA. kevin.s.akers.mil@mail.mil.
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Akers
mesh_terms: D000328:Adult; D001424:Bacterial Infections / Q000382:microbiology / Q000473:pathology*; D018441:Biofilms / Q000254:growth & development*; D003710:Demography; D005260:Female; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification / Q000502:physiology*; D008875:Middle Aged; D015999:Multivariate Analysis; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification / Q000502:physiology*; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors