title: Propionibacterium acnes biofilm is present in intervertebral discs of patients undergoing microdiscectomy.
abstract: BACKGROUND
  In previous studies, Propionibacterium acnes was cultured from intervertebral disc tissue of ~25% of patients undergoing microdiscectomy, suggesting a possible link between chronic bacterial infection and disc degeneration. However, given the prominence of P. acnes as a skin commensal, such analyses often struggled to exclude the alternate possibility that these organisms represent perioperative microbiologic contamination. This investigation seeks to validate P. acnes prevalence in resected disc cultures, while providing microscopic evidence of P. acnes biofilm in the intervertebral discs.
  
  
  METHODS
  Specimens from 368 patients undergoing microdiscectomy for disc herniation were divided into several fragments, one being homogenized, subjected to quantitative anaerobic culture, and assessed for bacterial growth, and a second fragment frozen for additional analyses. Colonies were identified by MALDI-TOF mass spectrometry and P. acnes phylotyping was conducted by multiplex PCR. For a sub-set of specimens, bacteria localization within the disc was assessed by microscopy using confocal laser scanning and FISH.
  
  
  RESULTS
  Bacteria were cultured from 162 discs (44%), including 119 cases (32.3%) with P. acnes. In 89 cases, P. acnes was cultured exclusively; in 30 cases, it was isolated in combination with other bacteria (primarily coagulase-negative Staphylococcus spp.) Among positive specimens, the median P. acnes bacterial burden was 350 CFU/g (12 - ~20,000 CFU/g). Thirty-eight P. acnes isolates were subjected to molecular sub-typing, identifying 4 of 6 defined phylogroups: IA1, IB, IC, and II. Eight culture-positive specimens were evaluated by fluorescence microscopy and revealed P. acnes in situ. Notably, these bacteria demonstrated a biofilm distribution within the disc matrix. P. acnes bacteria were more prevalent in males than females (39% vs. 23%, p = 0.0013).
  
  
  CONCLUSIONS
  This study confirms that P. acnes is prevalent in herniated disc tissue. Moreover, it provides the first visual evidence of P. acnes biofilms within such specimens, consistent with infection rather than microbiologic contamination.
authors.affiliation: Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, New York, United States of America.|Department of Molecular Oncology, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic.
authors.forename: Manu N
authors.identifier: http://orcid.org/0000-0002-8450-0584
authors.initials: MN
authors.lastname: Capoor
authors.affiliation: Department of Microbiology, Faculty of Medicine, Masaryk university, St. Anne's Faculty Hospital, Brno, Czech Republic.
authors.forename: Filip
authors.initials: F
authors.lastname: Ruzicka
authors.affiliation: Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America.
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Schmitz
authors.affiliation: Center for Biofilm Engineering, Montana State University, Bozeman, Montana, United States of America.
authors.forename: Garth A
authors.initials: GA
authors.lastname: James
authors.affiliation: Department of Molecular Oncology, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic.
authors.forename: Tana
authors.initials: T
authors.lastname: Machackova
authors.affiliation: Department of Neurosurgery, St. Anne's University Hospital, Masaryk University, Brno, Czech Republic.
authors.forename: Radim
authors.initials: R
authors.lastname: Jancalek
authors.affiliation: Department of Neurosurgery, University Hospital Brno, Masaryk University, Brno, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Smrcka
authors.affiliation: Department of Neurosurgery, University Hospital Ostrava, Ostrava University, Ostrava, Czech Republic.
authors.forename: Radim
authors.initials: R
authors.lastname: Lipina
authors.affiliation: Department of Molecular Oncology, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic.
authors.forename: Fahad S
authors.initials: FS
authors.lastname: Ahmed
authors.affiliation: Department of Orthopedic Surgery, Stanford University Medical Center, Stanford University, Stanford, California, United States of America.
authors.forename: Todd F
authors.initials: TF
authors.lastname: Alamin
authors.affiliation: Cedars-Sinai Institute for Spinal Disorders, Los Angeles, California, United States of America.
authors.forename: Neel
authors.initials: N
authors.lastname: Anand
authors.affiliation: Department of Molecular Oncology, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic.
authors.forename: John C
authors.initials: JC
authors.lastname: Baird
authors.affiliation: Department of Orthopaedic Surgery, University of California Irvine, School of Medicine, Irvine, California, United States of America.
authors.forename: Nitin
authors.initials: N
authors.lastname: Bhatia
authors.affiliation: Spine Center, UCSF Medical Center, San Francisco, California, United States of America.
authors.forename: Sibel
authors.initials: S
authors.lastname: Demir-Deviren
authors.affiliation: Scripps Clinic Division of Orthopedic Surgery, San Diego, California, United States of America.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Eastlack
authors.affiliation: Center for Biofilm Engineering, Montana State University, Bozeman, Montana, United States of America.
authors.forename: Steve
authors.initials: S
authors.lastname: Fisher
authors.affiliation: Department of Orthopaedic Surgery, University of California San Diego, San Diego, California, United States of America.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Garfin
authors.affiliation: Department of Orthopedic Surgery, Kaiser Permanente-San Jose Medical Center, San Jose, California, United States of America.
authors.forename: Jaspaul S
authors.initials: JS
authors.lastname: Gogia
authors.affiliation: Department of Neurosurgery, The Warren Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, United States of America.
authors.forename: Ziya L
authors.initials: ZL
authors.lastname: Gokaslan
authors.affiliation: Department of Orthopedic Surgery, Kaiser Permanente-Oakland Medical Center, Oakland, California, United States of America.
authors.forename: Calvin C
authors.initials: CC
authors.lastname: Kuo
authors.affiliation: Department of Orthopaedic Surgery, University of California Irvine, School of Medicine, Irvine, California, United States of America.
authors.forename: Yu-Po
authors.initials: YP
authors.lastname: Lee
authors.affiliation: Celgene Corporation, Information Knowledge and Utilization, San Francisco, California, United States of America.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Mavrommatis
authors.affiliation: Department of Molecular Oncology, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic.
authors.forename: Elleni
authors.initials: E
authors.lastname: Michu
authors.affiliation: Department of Molecular Oncology, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Noskova
authors.affiliation: Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, New York, United States of America.
authors.forename: Assaf
authors.initials: A
authors.lastname: Raz
authors.affiliation: Department of Molecular Oncology, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic.
authors.forename: Jiri
authors.initials: J
authors.lastname: Sana
authors.affiliation: Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America.
authors.forename: A Nick
authors.initials: AN
authors.lastname: Shamie
authors.affiliation: Center for Biofilm Engineering, Montana State University, Bozeman, Montana, United States of America.
authors.forename: Philip S
authors.initials: PS
authors.lastname: Stewart
authors.affiliation: Department of Anesthesia, The Johns Hopkins Hospital, Baltimore, Maryland, United States of America.
authors.forename: Jerry L
authors.initials: JL
authors.lastname: Stonemetz
authors.affiliation: Department of Orthopedic Surgery, University Southern California, Los Angeles, California, United States of America.
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, The Johns Hopkins Hospital, Baltimore, Maryland, United States of America.
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Witham
authors.affiliation: Department of Orthopedic Surgery, OrthoIndy Hospital, Indianapolis, Indiana, United States of America.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Coscia
authors.affiliation: Department of Orthopedics, Physical Medicine & Rehabilitation, University of Munich (LMU), Munich, Germany.
authors.forename: Christof
authors.initials: C
authors.lastname: Birkenmaier
authors.affiliation: Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, New York, United States of America.
authors.forename: Vincent A
authors.initials: VA
authors.lastname: Fischetti
authors.affiliation: Department of Molecular Oncology, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Slaby
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018441:Biofilms / Q000254:growth & development*; D017586:Diskectomy; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000150:complications / Q000382:microbiology; D006801:Humans; D007403:Intervertebral Disc / Q000382:microbiology* / Q000601:surgery; D055959:Intervertebral Disc Degeneration / Q000209:etiology / Q000382:microbiology; D007405:Intervertebral Disc Displacement / Q000209:etiology / Q000382:microbiology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011425:Propionibacterium acnes / Q000302:isolation & purification* / Q000472:pathogenicity / Q000502:physiology*; D055815:Young Adult