title: Adherence and biofilm formation of Staphylococcus epidermidis and Mycobacterium tuberculosis on various spinal implants.
abstract: METHODS
  Bacterial adherence and biofilm formation in implant-associated infection may vary depending on species of microorganisms and characteristics of implant surfaces.
  
  
  OBJECTIVE
  We evaluated the differences in adherence and biofilm formation between Staphylococcus epidermidis and Mycobacterium tuberculosis on various spinal implant surfaces.
  
  
  BACKGROUND
  In implant-associated infections, bacteria in biofilm are resistant to antibiotics or host defense mechanism. The removal of implants is usually necessary to eradicate infection. On the contrary, in tuberculous infection, complete debridement and antituberculous chemotherapy without removal of implant have been regarded as a safe procedure.
  
  
  METHODS
  S. epidermidis and M. tuberculosis were cultured with 4 types of metal segments, smooth or rough-surfaced stainless steel, and titanium alloy, respectively. After isolation of colonized microorganisms and biofilm with trypsin treatment and culture on plate media, colony-forming units were counted. The features of adherence and biofilm formation were observed under scanning electron microscopy.
  
  
  RESULTS
  Biofilm-forming S. epidermidis showed heavy adhesion and multiplication on the surface of all 4 metal segments, 16.5 times more colony-forming units than nonbiofilm-forming ones. On scanning electron microscopy, there were many aggregated microcolonies with thick biofilm in biofilm-forming S. epidermidis but much less in nonbiofilm-forming S. epidermidis. M. tuberculosis were rarely adhered to metal surfaces and showed scanty biofilm formation.
  
  
  CONCLUSIONS
  On the contrary to S. epidermidis, adherence and biofilm formation of M. tuberculosis on implant surface are less likely, and it can provide the basis of successful instrumentation in spine tuberculosis.
authors.affiliation: Department of Orthopaedic Surgery, Kang-Nam St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul. kyh@cmc.cuk.ac.kr
authors.forename: Kee-Yong
authors.initials: KY
authors.lastname: Ha
authors.forename: Yang-Guk
authors.initials: YG
authors.lastname: Chung
authors.forename: Seung-Joon
authors.initials: SJ
authors.lastname: Ryoo
mesh_terms: D000497:Alloys; D001422:Bacterial Adhesion; D018441:Biofilms; D066298:In Vitro Techniques; D008828:Microbiological Techniques; D008855:Microscopy, Electron, Scanning; D009169:Mycobacterium tuberculosis / Q000254:growth & development* / Q000648:ultrastructure; D019736:Prostheses and Implants / Q000382:microbiology*; D016459:Prosthesis-Related Infections / Q000382:microbiology*; D013123:Spinal Fusion / Q000295:instrumentation; D013193:Stainless Steel; D013203:Staphylococcal Infections / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000254:growth & development* / Q000648:ultrastructure; D014025:Titanium; D014399:Tuberculosis, Spinal / Q000382:microbiology*
chemical_list: D000497:Alloys; D013193:Stainless Steel; D014025:Titanium