Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2013

Outbreak of Linezolid-Resistant, Vancomycin-Resistant Enterococcus faecium (LR-VRE) Report of the First Isolates in Australia (#216)

Marianne Martinello 1 , Kelly Papanaoum 1 , Craig Riddle 1 , Tania A Sadlon 1 , Sharon Stendt 2 , David L Gordon 1
  1. Flinders Medical Centre -SA Pathology, BEDFORD PARK, SA, Australia
  2. Infection Control, Flinders Medical Centre, Bedford Park, SA, Australia

Vancomycin‐resistant enterococci (VRE) are an important cause of healthcare‐associated infection. With limited treatment options, linezolid remains first line therapy.
We report the first detection and outbreak of linezolid‐resistant VRE (E.faecium van B) in Australia. The index patient was a liver transplant recipient with complicated polymicrobial intra‐abdominal sepsis. Resistance developed in previously susceptible E faecium via the known point mutation G2576T in the peptidyl‐transferase region of 23S rRNA after prolonged administration of linezolid without adequate abscess drainage. Extensive screening of potential contacts identified 4 further cases of LRVRE colonisation, with limited nosocomial transmission occurring in the Intensive Care, Liver Transplant and Haemodialysis Units. The MIC of linezolid for the resistant isolates ranged between 32mg/L ‐ >256mg/L. An extensive suite of infection control responses, including reduction in transfers, enhanced cleaning, improved hand hygiene and stringent antimicrobial stewardship, appeared to terminate the outbreak. Akin to the index case, one subsequent unrelated case of LRVRE colonisation was detected after protracted linezolid therapy in a patient with linezolid sensitive VRE infection with unrecognised oesophageal perforation and undrained empyema transferred from another hospital; no secondary transmission occurred.
While resistance to linezolid remains rare, this episode has important clinical implications. On the
basis of prior published literature and our own experience, linezolid should be used with caution in certain clinical settings, including undrained infected sites with poor drug penetration, retained infected foreign bodies, lengthy and/or repeated courses of linezolid, long‐term suppression and patients undergoing haemodialysis.