title: Characterization of a vancomycin-resistant Enterococcus faecium outbreak caused by 2 genetically different clones at a neonatal intensive care unit.
abstract: In July 2010, we identified an outbreak of vancomycin-resistant enterococci (VRE) in our 26-bed neonatal intensive care unit. We performed an epidemiological investigation after clinical cultures of 2 neonates were positive for VRE. Identification, susceptibility testing, and molecular characterization were performed. Cultures of 3 surveillance stool samples of inpatients and 5 environmental samples were positive for VRE. All isolates were identified as Enterococcus faecium containing the vanA gene. Two distinct clones were identified by performing pulsed-field gel electrophoresis. The 2 clones exhibited different pulsotypes, but they represented identical Tn1546 types. Two sequence types, ST18 and ST192, were identified among all of the isolates with multilocus sequence typing. Our investigation determined that the outbreak in the neonatal intensive care unit was caused by 2 genetically different clones. The outbreak may have occurred through clonal spread and horizontal transfer of the van gene.
authors.affiliation: Department of Laboratory Medicine, Ajou University School of Medicine, Suwon, Korea. weegyo@ajou.ac.kr
authors.forename: Wee Gyo
authors.initials: WG
authors.lastname: Lee
authors.forename: Sun Hyun
authors.initials: SH
authors.lastname: Ahn
authors.forename: Min Kwon
authors.initials: MK
authors.lastname: Jung
authors.forename: Hye Young
authors.initials: HY
authors.lastname: Jin
authors.forename: Il Joong
authors.initials: IJ
authors.lastname: Park
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D019729:Carbon-Oxygen Ligases / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D008297:Male; D058885:Multilocus Sequence Typing; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C071437:VanA ligase, Bacteria; D014640:Vancomycin; D019729:Carbon-Oxygen Ligases