title: Detection of bacteria in healthy middle ears during cochlear implantation.
abstract: OBJECTIVE
  To assess whether free-living and/or biofilm bacteria are present in the putative sterile middle ear cavity before insertion of the electrode array during cochlear implantation.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Tertiary academic hospital.
  
  
  METHODS
  The study included 45 healthy children (with or without a history of otitis media) undergoing cochlear implantation.
  
  
  METHODS
  Transmission electron microscopy or scanning electron microscopy was used to detect the presence of bacteria.
  
  
  METHODS
  Presence of both free-living bacteria and biofilm bacteria on the epithelial surface of biopsy specimens of middle ear mucosa.
  
  
  RESULTS
  A majority of all mucosal specimens from clinically healthy tympanic cavities displayed inflammatory areas as well as dispersed, nonmatrix-enclosed bacteria. Also, rarely, fragments of biofilms were found.
  
  
  CONCLUSIONS
  The presence of bacteria in the tympanic cavity, which is generally assumed to be sterile in healthy individuals, may provide an explanation for infectious complications after cochlear implantation. However, the possibility that the electrode array of a cochlear implant will actually become contaminated during insertion is unlikely because of the small amounts and dispersed presence of bacteria, which may account for the relatively low incidence of infectious complications after cochlear implantation.
authors.affiliation: Department of Otorhinolaryngology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands. e.tonnaer@kno.umcn.nl
authors.forename: Edith L
authors.initials: EL
authors.lastname: Tonnaer
authors.forename: Emmanuel A
authors.initials: EA
authors.lastname: Mylanus
authors.forename: Jef J
authors.initials: JJ
authors.lastname: Mulder
authors.forename: Jo H
authors.initials: JH
authors.lastname: Curfs
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D001706:Biopsy; D002648:Child; D019929:Cochlear Implantation; D003054:Cochlear Implants / Q000382:microbiology*; D004432:Ear, Middle / Q000382:microbiology* / Q000648:ultrastructure; D006801:Humans; D015994:Incidence; D007432:Intraoperative Period; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009092:Mucous Membrane / Q000382:microbiology / Q000648:ultrastructure; D009426:Netherlands / Q000453:epidemiology; D016459:Prosthesis-Related Infections / Q000453:epidemiology / Q000382:microbiology*; D012016:Reference Values; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000453:epidemiology / Q000382:microbiology*