title: Effectiveness of current disinfection procedures against biofilm on contaminated GI endoscopes.
abstract: OBJECTIVE
  Attention to patient safety has increased recently due to outbreaks of nosocomial infections associated with GI endoscopy. The aim of this study was to evaluate current cleaning and disinfection procedures of endoscope channels with high bioburden and biofilm analysis, including the use of resistant mycobacteria associated with postsurgical infections in Brazil.
  
  
  METHODS
  Twenty-seven original endoscope channels were contaminated with organic soil containing 10(8) colony-forming units/mL of Pseudomonas aeruginosa, Staphylococcus aureus, or Mycobacterium abscessus subsp bolletii. Biofilms with the same microorganisms were developed on the inner surface of channels with the initial inoculum of 10(5) colony-forming units/mL. Channels were reprocessed following current protocol, and samples from cleaning and disinfection steps were analyzed by bioluminescence for adenosine triphosphate, cultures for viable microorganisms, and confocal microscopy.
  
  
  RESULTS
  After contamination, adenosine triphosphate levels increased dramatically, and high bacterial growth was observed in all cultures. After cleaning, adenosine triphosphate levels decreased to values comparable to precontamination levels, and bacterial growth was demonstrated in 5 of 27 catheters, 2 with P aeruginosa and 3 with M abscessus. With regard to induced biofilm, a remarkable reduction occurred after cleaning, but significant microbial growth inhibition occurred only after disinfection. Nevertheless, viable microorganisms within the biofilm were still detected by confocal microscopy, more so with glutaraldehyde than with peracetic acid or O-phataladehyde.
  
  
  CONCLUSIONS
  After the complete disinfection procedure, viable microorganisms could still be detected within the biofilm on endoscope channels. Prevention of biofilm development within endoscope channels should be a priority in disinfection procedures, particularly for ERCP and EUS.
authors.affiliation: Division of Gastroenterology, Internal Medicine Department, Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Marcelo S
authors.initials: MS
authors.lastname: Neves
authors.affiliation: Mycobacteria Laboratory, Medical Microbiology Department, Institute of Microbiology, Health Sciences Center, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Marlei Gomes
authors.initials: MG
authors.lastname: da Silva
authors.affiliation: Unity of Confocal Microscopy, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil.
authors.forename: Grasiella M
authors.initials: GM
authors.lastname: Ventura
authors.affiliation: Mycobacteria Laboratory, Medical Microbiology Department, Institute of Microbiology, Health Sciences Center, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Patrícia Barbur
authors.initials: PB
authors.lastname: Côrtes
authors.affiliation: Mycobacteria Laboratory, Medical Microbiology Department, Institute of Microbiology, Health Sciences Center, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Rafael Silva
authors.initials: RS
authors.lastname: Duarte
authors.affiliation: Division of Gastroenterology, Internal Medicine Department, Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil.
authors.forename: Heitor S
authors.initials: HS
authors.lastname: de Souza
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D018441:Biofilms / Q000254:growth & development*; D001938:Brazil; D057785:Catheters / Q000382:microbiology; D015169:Colony Count, Microbial; D004202:Disinfectants; D004203:Disinfection / Q000379:methods*; D020776:Endoscopes, Gastrointestinal / Q000382:microbiology*; D004866:Equipment Contamination / Q000517:prevention & control*; D005976:Glutaral; D008163:Luminescent Measurements; D018613:Microscopy, Confocal; D009161:Mycobacterium / Q000254:growth & development; D010463:Peracetic Acid; D011550:Pseudomonas aeruginosa / Q000254:growth & development; D013211:Staphylococcus aureus / Q000254:growth & development; D009764:o-Phthalaldehyde
chemical_list: D004202:Disinfectants; D009764:o-Phthalaldehyde; D000255:Adenosine Triphosphate; D010463:Peracetic Acid; D005976:Glutaral