title: Efficacy of bacteriophage treatment on Pseudomonas aeruginosa biofilms.
abstract: BACKGROUND
  Bacterial viruses (phages) have been used successfully in the treatment of animal and human bacterial infections. This study examined the potential use of phage therapy against Pseudomonas aeruginosa strain PA14 biofilms in a root canal model.
  
  
  METHODS
  Part 1: The 24-hour and 96-hour PA14 biofilms grown in microplates were treated with phages identified as possessing potential biofilm-degrading activities, and the post-treatment bacterial biomass was quantified by using crystal violet staining. Part 2: The 24-hour and 96-hour PA14 biofilms grown in prepared root canals of extracted human mandibular incisors were treated with phages identified with potential biofilm-degrading activities. Post-treatment intracanal samples were taken by using paper points and round burs to assess phage and bacterial counts.
  
  
  RESULTS
  Part 1: We identified 2 phages (JBD4 and JBD44a) with putative biofilm-degrading activities. Treatment of PA14 biofilms with these phages produced a significant reduction in the mean percentage of biomass in 24-hour (P< .05) and 96-hour (P= .08) biofilms. Part 2: In 24-hour and 96-hour PA14 biofilms in a root canal model, no significant difference was found in the number of colony-forming units after phage treatment (P> .05).
  
  
  CONCLUSIONS
  Phage application significantly reduced the biomass of 24-hour and 96-hour PA14 biofilms grown on microplates but did not produce significant reduction of 24-hour or 96-hour PA14 biofilms grown in the extracted tooth model.
authors: Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
authors: Alysen
authors: A
authors: Phee
authors: Joe
authors: J
authors: Bondy-Denomy
authors: Anil
authors: A
authors: Kishen
authors: Bettina
authors: B
authors: Basrani
authors: Amir
authors: A
authors: Azarpazhooh
authors: Karen
authors: K
authors: Maxwell
mesh_terms: D000704:Analysis of Variance; D018441:Biofilms / Q000254:growth & development*; D001691:Biological Therapy / Q000379:methods; D015169:Colony Count, Microbial; D003786:Dental Pulp Cavity / Q000382:microbiology* / Q000821:virology; D003788:Dental Pulp Diseases / Q000628:therapy / Q000821:virology; D006801:Humans; D010485:Periapical Periodontitis / Q000628:therapy* / Q000821:virology*; D017105:Pseudomonas Phages; D011550:Pseudomonas aeruginosa / Q000821:virology*; D018709:Statistics, Nonparametric