title: Acetic acid as a decontamination method for sink drains in a nosocomial outbreak of metallo-β-lactamase-producing Pseudomonas aeruginosa.
abstract: BACKGROUND
  Pseudomonas aeruginosa may colonize water systems via biofilm formation. In hospital environments, contaminated sinks have been associated with nosocomial transmission. Here we describe a prolonged outbreak of a metallo-β-lactamase-producing P. aeruginosa (Pae-MBL) associated with sink drains, and propose a previously unreported decontamination method with acetic acid.
  
  
  OBJECTIVE
  To describe a nosocomial outbreak of Pae-MBL associated with hospital sink drains and to evaluate acetic acid as a decontamination method.
  
  
  METHODS
  The outbreak was investigated by searching the microbiology database, microbiological sampling and strain typing. Antibacterial and antibiofilm properties of acetic acid were evaluated in vitro. Pae-MBL-positive sinks were treated with 24% acetic acid once weekly and monitored with repeated cultures.
  
  
  RESULTS
  Fourteen patients with positive cultures for Pae-MBL were identified from 2008 to 2014. The patients had been admitted to three wards, where screening discovered Pae-MBL in 12 sink drains located in the patient bathrooms. Typing of clinical and sink drain isolates revealed identical or closely related strains. Pae-MBL biofilm was highly sensitive to acetic acid with a minimum biofilm eradication concentration of 0.75% (range: 0.19-1.5). Weekly treatment of colonized sink drains with acetic acid resulted in negative cultures and terminated transmission.
  
  
  CONCLUSIONS
  Acetic acid is highly effective against Pae-MBL biofilms, and may be used as a simple method to decontaminate sink drains and to prevent nosocomial transmission.
authors.affiliation: Department of Infection Control, Skåne County, Lund, Sweden. Electronic address: anna.stjarne_aspelund@med.lu.se.
authors.forename: A
authors.initials: A
authors.lastname: Stjärne Aspelund
authors.affiliation: Antibiotics and Hospital Infection Control, Swedish Institute for Communicable Disease Control, Stockholm, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Sjöström
authors.affiliation: Antibiotics and Hospital Infection Control, Swedish Institute for Communicable Disease Control, Stockholm, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Olsson Liljequist
authors.affiliation: Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Division of Infection Medicine, Lund, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Mörgelin
authors.affiliation: Department of Infection Control, Skåne County, Lund, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Melander
authors.affiliation: Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Division of Infection Medicine, Lund, Sweden.
authors.forename: L I
authors.initials: LI
authors.lastname: Påhlman
mesh_terms: D019342:Acetic Acid / Q000008:administration & dosage*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control* / Q000635:transmission; D003666:Decontamination / Q000379:methods; D004196:Disease Outbreaks; D018562:Disease Transmission, Infectious / Q000517:prevention & control; D004202:Disinfectants / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D017053:Infection Control / Q000379:methods; D008297:Male; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control* / Q000635:transmission; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D011795:Surveys and Questionnaires; D014871:Water Microbiology; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D004202:Disinfectants; D001618:beta-Lactamases; D019342:Acetic Acid
keywords: Acetic acid; Biofilm; Decontamination; Metallo-β-lactamase producing Pseudomonas aeruginosa; Nosocomial outbreak; Sink drains