title: Molecular epidemiology of a Pseudomonas aeruginosa hospital outbreak driven by a contaminated disinfectant-soap dispenser.
abstract: OBJECTIVE
  Pseudomonas aeruginosa infection represents a main cause of morbidity and mortality among immunocompromised patients. This study describes a fatal epidemic of P. aeruginosa that occurred in a hematology unit in Italy.
  
  
  METHODS
  Retrospective cohort study, prospective surveillance, auditing, extensive testing on healthcare workers and environmental investigation were performed to define the dynamics and potential causes of transmission. RAPD, macrorestriction analyses and sequence typing were used to define relationships between P. aeruginosa isolates.
  
  
  RESULTS
  Eighteen cases of infection were identified in the different phases of the investigation. Of these, five constitute a significant molecular cluster of infection. A P. aeruginosa strain with the same genetic fingerprint and sequence type (ST175) as clinical isolates strain was also isolated from a heavily contaminated triclosan soap dispenser.
  
  
  CONCLUSIONS
  Our results are consistent with the hypothesis that patients became indirectly infected, e.g., during central venous catheter handling through contaminated items, and that the triclosan soap dispenser acted as a common continuous source of P. aeruginosa infection. Since P. aeruginosa is intrinsically unsusceptible to triclosan, the use of triclosan-based disinfectant formulations should be avoided in those healthcare settings hosting patients at high risk of P. aeruginosa infection.
authors.affiliation: National Institute for Infectious Diseases "Lazzaro Spallanzani", I.R.C.C.S., Rome, Italy. simone.lanini@inmi.it
authors.forename: Simone
authors.initials: S
authors.lastname: Lanini
authors.forename: Silvia
authors.initials: S
authors.lastname: D'Arezzo
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Puro
authors.forename: Lorena
authors.initials: L
authors.lastname: Martini
authors.forename: Francesco
authors.initials: F
authors.lastname: Imperi
authors.forename: Pierluca
authors.initials: P
authors.lastname: Piselli
authors.forename: Marco
authors.initials: M
authors.lastname: Montanaro
authors.forename: Simonetta
authors.initials: S
authors.lastname: Paoletti
authors.forename: Paolo
authors.initials: P
authors.lastname: Visca
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ippolito
mesh_terms: D054869:Clinical Audit; D015331:Cohort Studies; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D004202:Disinfectants / Q000009:adverse effects / Q000592:standards; D004866:Equipment Contamination / Q000706:statistics & numerical data; D006235:Hand Disinfection / Q000379:methods / Q000592:standards; D006405:Hematology / Q000295:instrumentation / Q000458:organization & administration / Q000592:standards; D006801:Humans; D017720:Molecular Epidemiology; D011159:Population Surveillance; D011552:Pseudomonas Infections / Q000453:epidemiology* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification / Q000502:physiology; D012189:Retrospective Studies; D012915:Soaps / Q000009:adverse effects / Q000592:standards; D014260:Triclosan / Q000592:standards
chemical_list: D004202:Disinfectants; D012915:Soaps; D014260:Triclosan