title: Ralstonia mannitolilyticainfections in an oncologic day ward: description of a cluster among high-risk patients.
abstract: BACKGROUND
  Ralstonia spp, an environmental microorganism, has been occasionally associated with healthcare infections. The aim of this study was to investigate an outbreak caused byRalstonia mannitolilyticain oncology patients.
  
  
  METHODS
  Case definition: Oncology outpatients attending a day ward, with positive blood and/or central venous catheter (CVC) culture forRalstoniaspp from September 2013 - June 2014. We analysed medical records, procedures and environmental samples.R. mannitolilyticawas identified by 16S rRNA sequencing, and typed by Pulsed Field Gel Electrophoresis (PFGE); resistance to carbapenemes was investigated by phenotypic and molecular methods.
  
  
  RESULTS
  The patients (N= 22) had different malignancies and received different therapy; all had a CVC and 16 patients presented chills and/or fever.R. mannitolilyticawas isolated from both blood and CVC (n= 12) or only blood (n= 6) or CVC tips (n= 4). The isolates had indistinguishable PFGE profile, and showed resistance to carbapenems. All the isolates were negative for carbapenemase genes while phenotypic tests suggests the presence of an AmpC β-lactamase activity,responsible for carbapenem resistance. All patients had had CVC flushed with saline to keep the venous access pervious or before receiving chemotherapy at various times before the onset of symptoms. After the first four cases occurred, the multi-dose saline bottles used for CVC flushing were replaced with single-dose vials; environmental samples were negative forR. mannitolilytica.
  
  
  CONCLUSIONS
  Although the source ofR. mannitolilyticaremains unidentified, CVC flushing with contaminated saline solution seems to be the most likely origin ofR. mannitolilyticaCVC colonization and subsequent infections. In order to prevent similar outbreaks we recommend removal of any CVC that is no longer necessary and the use of single-dose solutions for any parenteral treatment of oncology patients.
authors.affiliation: Istituto Superiore di Sanità Viale Regina Elena, 299 00161 Rome, Italy.|European Program for Public Health Microbiology Training (EUPHEM), European Centre for Disease Prevention and Control, (ECDC), Stockholm, Sweden.
authors.forename: Claudia
authors.identifier: 0000-0002-7917-4657
authors.initials: C
authors.lastname: Lucarelli
authors.affiliation: Istituto Nazionale Tumori Regina Elena, Istituto Dermatologico San Gallicano, Rome, Italy.
authors.forename: Enea Gino
authors.initials: EG
authors.lastname: Di Domenico
authors.affiliation: Istituto Nazionale Tumori Regina Elena, Istituto Dermatologico San Gallicano, Rome, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Toma
authors.affiliation: Istituto Nazionale Tumori Regina Elena, Istituto Dermatologico San Gallicano, Rome, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Bracco
authors.affiliation: Istituto Nazionale Tumori Regina Elena, Istituto Dermatologico San Gallicano, Rome, Italy.
authors.forename: Grazia
authors.initials: G
authors.lastname: Prignano
authors.affiliation: Istituto Nazionale Tumori Regina Elena, Istituto Dermatologico San Gallicano, Rome, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Fortunati
authors.affiliation: Istituto Nazionale Tumori Regina Elena, Istituto Dermatologico San Gallicano, Rome, Italy.
authors.forename: Lorella
authors.initials: L
authors.lastname: Pelagalli
authors.affiliation: Istituto Nazionale Tumori Regina Elena, Istituto Dermatologico San Gallicano, Rome, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Ensoli
authors.affiliation: Istituto Superiore di Sanità Viale Regina Elena, 299 00161 Rome, Italy.
authors.forename: Patrizio
authors.initials: P
authors.lastname: Pezzotti
authors.affiliation: Istituto Superiore di Sanità Viale Regina Elena, 299 00161 Rome, Italy.
authors.forename: Aurora
authors.initials: A
authors.lastname: García-Fernández
authors.affiliation: Istituto Superiore di Sanità Viale Regina Elena, 299 00161 Rome, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Pantosti
authors.affiliation: Istituto Superiore di Sanità Viale Regina Elena, 299 00161 Rome, Italy.|European Program for Public Health Microbiology Training (EUPHEM), European Centre for Disease Prevention and Control, (ECDC), Stockholm, Sweden.
authors.forename: Loredana
authors.initials: L
authors.lastname: Ingrosso
keywords: Carbapenem resistance; Central venous catheter; Oncologic patients; Outbreak; Ralstonia mannitolilytica