Colonisation with vancomycin- and linezolid-resistant Enterococcus faecium in a university hospital: molecular epidemiology and risk factor analysis.
During a hospital-wide prospective point prevalence survey of faecal carriage and environmental colonisation of vancomycin-resistant enterococci in a tertiary care university hospital in Athens (Greece), five clinical and one environmental isolate from a light switch (all in the haematology ward) were identified as vancomycin- and linezolid-resistant vanA-positive Enterococcus faecium (VLRE). The studied isolates exhibited a linezolid minimum inhibitory concentration of 12microg/mL and carried at least one mutated copy of the 23S rRNA gene, as shown by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis to detect the G2576T mutation. The enterococcal surface protein (esp) gene was detected by PCR in all isolates. Molecular typing with pulsed field gel electrophoresis (PFGE) showed that the environmental and four of the five clinical isolates were genetically related. None of the colonised patients were previously exposed to linezolid, although heavy linezolid use was noted in the institution. A case-control study was performed to assess risk factors for VLRE colonisation. In univariate analysis, immunodeficiency, underlying haematological malignancy, duration of any antimicrobial treatment before VLRE isolation, and hospitalisation in the haematology ward were pointed out as possible risk factors. A multidisciplinary approach including intensified hand hygiene, patient contact isolation, disinfection of the inanimate environment and antibiotic restriction resulted in early containment of the VLRE colonisation outbreak.
Souli
Maria
M
4th Department of Internal Medicine, Athens University School of Medicine, University General Hospital Attikon, Chaidari, Greece. msouli@med.uoa.gr
Sakka
Vissaria
V
Galani
Irene
I
Antoniadou
Anastasia
A
Galani
Lambrini
L
Siafakas
Nikolaos
N
Zerva
Loukia
L
Fytrou
Helen
H
Tsiodras
Sotirios
S
Giamarellou
Helen
H
D000081:Acetamides / Q000494:pharmacology; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002353:Carrier State / Q000382:microbiology*; D016172:DNA Fingerprinting; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D004783:Environmental Microbiology; D005243:Feces / Q000382:microbiology; D005260:Female; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology / Q000382:microbiology*; D006115:Greece; D006785:Hospitals, University; D006801:Humans; D000069349:Linezolid; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D017720:Molecular Epidemiology; D023303:Oxazolidinones / Q000494:pharmacology; D017354:Point Mutation; D012150:Polymorphism, Restriction Fragment Length; D012329:RNA, Bacterial / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D012307:Risk Factors; D020713:Vancomycin Resistance
D000081:Acetamides; D000900:Anti-Bacterial Agents; D023303:Oxazolidinones; D012329:RNA, Bacterial; D012338:RNA, Ribosomal, 23S; D000069349:Linezolid