title: Prevalence of Propionibacterium acnes in Intervertebral Discs of Patients Undergoing Lumbar Microdiscectomy: A Prospective Cross-Sectional Study.
abstract: BACKGROUND
  The relationship between intervertebral disc degeneration and chronic infection by Propionibacterium acnes is controversial with contradictory evidence available in the literature. Previous studies investigating these relationships were under-powered and fraught with methodical differences; moreover, they have not taken into consideration P. acnes' ability to form biofilms or attempted to quantitate the bioburden with regard to determining bacterial counts/genome equivalents as criteria to differentiate true infection from contamination. The aim of this prospective cross-sectional study was to determine the prevalence of P. acnes in patients undergoing lumbar disc microdiscectomy.
  
  
  RESULTS
  The sample consisted of 290 adult patients undergoing lumbar microdiscectomy for symptomatic lumbar disc herniation. An intraoperative biopsy and pre-operative clinical data were taken in all cases. One biopsy fragment was homogenized and used for quantitative anaerobic culture and a second was frozen and used for real-time PCR-based quantification of P. acnes genomes. P. acnes was identified in 115 cases (40%), coagulase-negative staphylococci in 31 cases (11%) and alpha-hemolytic streptococci in 8 cases (3%). P. acnes counts ranged from 100 to 9000 CFU/ml with a median of 400 CFU/ml. The prevalence of intervertebral discs with abundant P. acnes (≥ 1x103 CFU/ml) was 11% (39 cases). There was significant correlation between the bacterial counts obtained by culture and the number of P. acnes genomes detected by real-time PCR (r = 0.4363, p<0.0001).
  
  
  CONCLUSIONS
  In a large series of patients, the prevalence of discs with abundant P. acnes was 11%. We believe, disc tissue homogenization releases P. acnes from the biofilm so that they can then potentially be cultured, reducing the rate of false-negative cultures. Further, quantification study revealing significant bioburden based on both culture and real-time PCR minimize the likelihood that observed findings are due to contamination and supports the hypothesis P. acnes acts as a pathogen in these cases of degenerative disc disease.
authors.affiliation: Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, NY, United States of America.|Department of Molecular Oncology, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic.
authors.forename: Manu N
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 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 Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, United States of America.
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Schmitz
authors.affiliation: 1st Department of Pathological Anatomy, St. Anne's University Hospital, Masaryk University, Brno, Czech Republic.
authors.forename: Marketa
authors.initials: M
authors.lastname: Hermanova
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 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: John C
authors.initials: JC
authors.lastname: Baird
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 Neurosurgery, University Hospital Brno, Masaryk University, Brno, Czech Republic.
authors.forename: Karel
authors.initials: K
authors.lastname: Maca
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 Orthopedic Surgery, Stanford University Medical Center, Stanford University, Stanford, CA, United States of America.
authors.forename: Todd F
authors.initials: TF
authors.lastname: Alamin
authors.affiliation: Department of Orthopedic Surgery, OrthoIndy Hospital, Indianapolis, IN, United States of America.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Coscia
authors.affiliation: Department of Anesthesia, The Johns Hopkins Hospital, Baltimore, MD, United States of America.
authors.forename: Jerry L
authors.initials: JL
authors.lastname: Stonemetz
authors.affiliation: Department of Neurosurgery, The Johns Hopkins Hospital, Baltimore, MD, United States of America.
authors.forename: Timothy
authors.initials: T
authors.lastname: Witham
authors.affiliation: Center for Genomic Sciences, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America.|Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America.|Department of Otolaryngology Head and Neck Surgery, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America, and Institute of Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States of America.
authors.forename: Garth D
authors.initials: GD
authors.lastname: Ehrlich
authors.affiliation: Department of Neurosurgery, The Warren Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, United States of America.
authors.forename: Ziya L
authors.initials: ZL
authors.lastname: Gokaslan
authors.affiliation: Celgene Corporation, Information Knowledge and Utilization, San Francisco, CA, United States of America.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Mavrommatis
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, NY, 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; D000367:Age Factors; D003430:Cross-Sectional Studies; D017586:Diskectomy / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000150:complications / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D007403:Intervertebral Disc / Q000382:microbiology* / Q000601:surgery; D055959:Intervertebral Disc Degeneration / Q000150:complications / Q000382:microbiology* / Q000601:surgery; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011425:Propionibacterium acnes; D011446:Prospective Studies; D060888:Real-Time Polymerase Chain Reaction; D012307:Risk Factors