title: Biofilm formation increases treatment failure in Staphylococcus epidermidis device-related osteomyelitis of the lower extremity in human patients.
abstract: The ability to form biofilm on the surface of implanted devices is often considered the most critical virulence factor possessed by Staphylococcus epidermidis in its role as an opportunistic pathogen in orthopaedic device-related infection (ODRI). Despite this recognition, there is a lack of clinical evidence linking outcome with biofilm forming ability for S. epidermidis ODRIs. We prospectively collected S. epidermidis isolates cultured from patients presenting with ODRI. Antibiotic resistance patterns and biofilm-forming ability was assessed. Patient information was collected and treatment outcome measures were determined after a mean follow-up period of 26 months. The primary outcome measure was cure at follow-up. Univariate logistic regression models were used to determine the influence of biofilm formation and antibiotic resistance on treatment outcome. A total of 124 patients were included in the study, a majority of whom (n = 90) involved infections of the lower extremity. A clear trend emerged in the lower extremity cohort whereby cure rates decreased as the biofilm-forming ability of the isolates increased (84% cure rate for infections caused by non-biofilm formers, 76% cure rate for weak biofilm-formers, and 60% cure rate for the most marked biofilm formers, p = 0.076). Antibiotic resistance did not influence treatment cure rate. Chronic immunosuppression was associated with a statistically significant decrease in cure rate (p = 0.044).
  
  
  
  The trend of increasing biofilm-forming ability resulting in lower cure rates for S. epidermidis ODRI indicates biofilm-forming ability of infecting pathogens does influence treatment outcome of infections of the lower extremity. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1905-1913, 2016.
authors.affiliation: Department of Trauma-Surgery, Trauma Centre Murnau, Prof. Kuentscher Strasse 8, 82418, Murnau, Germany.|AO Research Institute Davos, AO Foundation, Clavadelerstrasse 8, Davos Platz CH7270, Switzerland.
authors.forename: Mario
authors.initials: M
authors.lastname: Morgenstern
authors.affiliation: AO Research Institute Davos, AO Foundation, Clavadelerstrasse 8, Davos Platz CH7270, Switzerland.
authors.forename: Virginia
authors.initials: V
authors.lastname: Post
authors.affiliation: Department of Trauma-Surgery, Trauma Centre Murnau, Prof. Kuentscher Strasse 8, 82418, Murnau, Germany.|AO Research Institute Davos, AO Foundation, Clavadelerstrasse 8, Davos Platz CH7270, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Erichsen
authors.affiliation: Department of Trauma-Surgery, Trauma Centre Murnau, Prof. Kuentscher Strasse 8, 82418, Murnau, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Hungerer
authors.affiliation: Department of Trauma-Surgery, Trauma Centre Murnau, Prof. Kuentscher Strasse 8, 82418, Murnau, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Bühren
authors.affiliation: Department of Trauma-Surgery, Trauma Centre Murnau, Prof. Kuentscher Strasse 8, 82418, Murnau, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Militz
authors.affiliation: AO Research Institute Davos, AO Foundation, Clavadelerstrasse 8, Davos Platz CH7270, Switzerland.
authors.forename: R Geoff
authors.identifier: 0000-0002-7778-2480
authors.initials: RG
authors.lastname: Richards
authors.affiliation: AO Research Institute Davos, AO Foundation, Clavadelerstrasse 8, Davos Platz CH7270, Switzerland.
authors.forename: T Fintan
authors.initials: TF
authors.lastname: Moriarty
mesh_terms: D000328:Adult; D000368:Aged; D000890:Anti-Infective Agents / Q000627:therapeutic use; D018441:Biofilms; D005260:Female; D006801:Humans; D008297:Male; D016106:Methicillin Resistance; D008875:Middle Aged; D010641:Phenotype; D011446:Prospective Studies; D016459:Prosthesis-Related Infections / Q000188:drug therapy / Q000382:microbiology*; D012008:Recurrence; D013212:Staphylococcus epidermidis / Q000472:pathogenicity* / Q000502:physiology; D017211:Treatment Failure
chemical_list: D000890:Anti-Infective Agents
keywords: Staphylococcus epidermidis; antibiotic resistance; biofilm formation; orthopaedic device related infections; risk factor