title: Incidence, management and outcomes of the first cfr-mediated linezolid-resistant Staphylococcus epidermidis outbreak in a tertiary referral centre in the Republic of Ireland.
abstract: OBJECTIVE
  To report the first Irish outbreak of cfr-mediated linezolid-resistant Staphylococcus epidermidis.
  
  
  METHODS
  Linezolid-resistant S. epidermidis isolated at University Hospital Limerick from four blood cultures, one wound and four screening swabs (from nine patients) between April and June 2013 were characterized by pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST) and staphylococcal cassette chromosome (SCCmec) typing. Antibiotic susceptibilities were determined according to the guidelines of the British Society for Antimicrobial Chemotherapy. The outbreak was controlled through prohibiting prescription and use of linezolid, adherence to infection prevention and control practices, enhanced environmental cleaning, isolation of affected patients, and hospital-wide education programmes.
  
  
  RESULTS
  PFGE showed that all nine isolates represented a single clonal strain. MLST showed that they belonged to ST2, and SCCmec typing showed that they encoded a variant of SCCmecIII. All nine isolates were cfr positive, and eight isolates were positive for the G2576T 23S rRNA mutation commonly associated with linezolid resistance. Isolates exhibited multiple antibiotic resistances (i.e. linezolid, gentamicin, methicillin, clindamycin, ciprofloxacin, fusidic acid and rifampicin). The adopted infection prevention intervention was effective, and the outbreak was limited to the affected intensive care unit.
  
  
  CONCLUSIONS
  This is the first documented outbreak of cfr-mediated linezolid-resistant S. epidermidis in the Republic of Ireland. Despite this, and due to existing outbreak management protocols, the responsible micro-organism and source were identified efficiently. However, it became apparent that staff knowledge of antimicrobial susceptibilities and appropriate hygiene practices were suboptimal at the time of the outbreak, and that educational interventions (and re-inforcement) are necessary to avoid occurrence of antimicrobial resistance and outbreaks such as reported here.
authors: Department of Clinical Microbiology, University Hospital Limerick, Limerick, Ireland; Department of Infection Prevention and Control, University Hospital Limerick, Limerick, Ireland; Centre for Interventions in Infection, Inflammation and Immunity, Graduate Entry Medical School, University of Limerick, Limerick, Ireland.
authors: C
authors: C
authors: O'Connor
authors: Department of Clinical Microbiology, University Hospital Limerick, Limerick, Ireland.
authors: J
authors: J
authors: Powell
authors: Department of Clinical Microbiology, University Hospital Limerick, Limerick, Ireland.
authors: C
authors: C
authors: Finnegan
authors: Department of Infection Prevention and Control, University Hospital Limerick, Limerick, Ireland.
authors: A
authors: A
authors: O'Gorman
authors: Department of Pharmacy, University Hospital Limerick, Limerick, Ireland.
authors: S
authors: S
authors: Barrett
authors: Antimicrobial Resistance and Healthcare Associated Infections Reference Unit, Public Health England, London, UK.
authors: K L
authors: KL
authors: Hopkins
authors: Antimicrobial Resistance and Healthcare Associated Infections Reference Unit, Public Health England, London, UK.
authors: B
authors: B
authors: Pichon
authors: Antimicrobial Resistance and Healthcare Associated Infections Reference Unit, Public Health England, London, UK.
authors: R
authors: R
authors: Hill
authors: Department of Clinical Microbiology, University Hospital Limerick, Limerick, Ireland; Department of Infection Prevention and Control, University Hospital Limerick, Limerick, Ireland.
authors: L
authors: L
authors: Power
authors: Antimicrobial Resistance and Healthcare Associated Infections Reference Unit, Public Health England, London, UK.
authors: N
authors: N
authors: Woodford
authors: Centre for Interventions in Infection, Inflammation and Immunity, Graduate Entry Medical School, University of Limerick, Limerick, Ireland.
authors: J C
authors: JC
authors: Coffey
authors: Antimicrobial Resistance and Healthcare Associated Infections Reference Unit, Public Health England, London, UK.
authors: A
authors: A
authors: Kearns
authors: Department of Clinical Microbiology, University Hospital Limerick, Limerick, Ireland; Department of Infection Prevention and Control, University Hospital Limerick, Limerick, Ireland; Centre for Interventions in Infection, Inflammation and Immunity, Graduate Entry Medical School, University of Limerick, Limerick, Ireland.
authors: N H
authors: NH
authors: O'Connell
authors: Centre for Interventions in Infection, Inflammation and Immunity, Graduate Entry Medical School, University of Limerick, Limerick, Ireland. Electronic address: colum.dunne@ul.ie.
authors: C P
authors: CP
authors: Dunne
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control; D004196:Disease Outbreaks / Q000517:prevention & control; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D015994:Incidence; D017053:Infection Control / Q000379:methods*; D007494:Ireland / Q000453:epidemiology; D000069349:Linezolid / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D012338:RNA, Ribosomal, 23S; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000517:prevention & control*; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D012338:RNA, Ribosomal, 23S; D000069349:Linezolid
keywords: 23S rRNA methyltransferase; First outbreak; Ireland; Multi-resistance; Oxazolidinone resistance; Plasmid-mediated; Staphylococci