title: Removal of biofilms from tracheoesophageal speech valves using a novel marine microbial deoxyribonuclease.
abstract: OBJECTIVE
  The growth of biofilms on tracheoesophageal speech valves shortens their life span and produces a reservoir of pathogens that may infect the respiratory tract. The authors have discovered a novel nontoxic deoxyribonuclease, NucB, from a marine isolate of Bacillus licheniformis that is effective at dispersing a variety of mono and mixed-species bacterial biofilms. The aim of this preliminary study was to determine whether NucB could also disrupt and remove mixed-species biofilms from tracheoesophageal speech valves.
  
  
  METHODS
  Laboratory-based treatment and analysis of discarded tracheoesophageal speech valves.
  
  
  METHODS
  University human biology laboratory and the Department of Speech and Language Therapy at a tertiary referral hospital.
  
  
  METHODS
  Seventeen ex vivo tracheoesophageal speech valves fouled with natural human biofilms were collected and divided into 2 equal parts. One half was treated with NucB and the other half with a control buffer solution. Biofilm removal was measured by microscopy and by culture of dispersed biofilm organisms on agar plates.
  
  
  RESULTS
  Significantly more organisms were released from biofilms using NucB than with buffer solution alone. On nonselective medium, more organisms were cultured in 11 samples (65%, n = 17, P < .05). Using growth media favoring fungi, more organisms were cultured in 14 samples (82%, n = 17, P < .05).
  
  
  CONCLUSIONS
  The nontoxic deoxyribonuclease NucB was effective in releasing more microorganisms from biofilms on tracheoesophageal speech valves. This reflects its potential ability to break up and disperse these biofilms. Future studies will aim to develop NucB as a novel agent to prolong the life span of tracheoesophageal speech valves, thus reducing health care costs.
authors.affiliation: James Cook University Hospital, Cleveland, UK.
authors.forename: Adam
authors.initials: A
authors.lastname: Shakir
authors.forename: Mohamed Reda
authors.initials: MR
authors.lastname: Elbadawey
authors.forename: Robert Colquhoun
authors.initials: RC
authors.lastname: Shields
authors.forename: Nicholas Stephen
authors.initials: NS
authors.lastname: Jakubovics
authors.forename: James Grant
authors.initials: JG
authors.lastname: Burgess
mesh_terms: D001407:Bacillus; D058491:Bacterial Load; D001426:Bacterial Proteins / Q000494:pharmacology*; D001431:Bacteriological Techniques; D018441:Biofilms; D016022:Case-Control Studies; D003851:Deoxyribonucleases / Q000494:pharmacology*; D006801:Humans; D007825:Laryngectomy / Q000534:rehabilitation*; D007831:Larynx, Artificial / Q000382:microbiology*; D050296:Microbial Viability / Q000187:drug effects; D011474:Prosthesis Design; D016459:Prosthesis-Related Infections / Q000382:microbiology / Q000517:prevention & control
chemical_list: D001426:Bacterial Proteins; D003851:Deoxyribonucleases; C576265:NucB protein, Bacillus licheniformis; C020069:deoxyribonuclease B