title: Identification of vancomycin-resistant enterococci clones and inter-hospital spread during an outbreak in Taiwan.
abstract: BACKGROUND
  In 2003, nosocomial infections caused by vancomycin-resistant enterococci (VRE) occurred rarely in Taiwan. Between 2003 and 2010, however, the average prevalence of vancomycin resistance among enterococci spp. increased from 2% to 16% in community hospitals and from 3% to 21% in medical centers of Taiwan. We used molecular methods to investigate the epidemiology of VRE in a tertiary teaching hospital in Taiwan.
  
  
  METHODS
  Between February 2009 and February 2011, rectal samples and infection site specimens were collected from all inpatients in the nephrology ward after patient consent was obtained. VRE strain types were determined by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).
  
  
  RESULTS
  A total of 59 vanA gene-containing VRE isolates (1 per patient) were obtained; 24 originated from rectal sample surveillance of patients who exhibited no symptoms (22 Enterococcus faecium and 2 Enterococcus faecalis), and 35 had developed infections over 3 days after admission (32 E. faecium, 2 E. faecalis, and 1 Enterococcus durans). The 59 VRE isolates demonstrated vancomycin minimum inhibitory concentrations (MICs) of ≥256 μg/m. The MIC range for linezolid, tigecycline, and daptomycin was 0.25-1.5 μg/mL, 0.032-0.25 and 1-4 μg/mL, respectively. For 56 isolates, the MIC for teicoplanin was >8 μg/mL. The predominant types in the nephrology ward were MLST types 414, 78, and18 as well as PFGE types A, C, and D.
  
  
  CONCLUSIONS
  VREs are endemic in nephrology wards. MLST 414 is the most predominant strain. The increase VRE prevalence is due to cross-transmission of VRE clones ST 414,78,18 by undetected VRE carriers. Because similar VRE STs had been reported in a different hospital of Taiwan, this finding may indicate inter-hospital VRE spread in Taiwan. Active surveillance and effective infection control policies are important controlling the spread of VRE in high risk hospital zones. All endemic VRE strains are resistant to teicoplanin but are sensitive to daptomycin, linezolid, and tigecycline.
authors.affiliation: Division of Infectious Diseases, Chang Gung Memorial Hospital, Keelung, Chang Gung University, 222, Mai Chin Road, Kwei-Shan, Tao-Yuan, Taiwan. Lee.sch@msa.hinet.net
authors.forename: Sai-Cheong
authors.initials: SC
authors.lastname: Lee
authors.forename: Mi-Si
authors.initials: MS
authors.lastname: Wu
authors.forename: Hsiang-Ju
authors.initials: HJ
authors.lastname: Shih
authors.forename: Shu-Huan
authors.initials: SH
authors.lastname: Huang
authors.forename: Meng-Jiun
authors.initials: MJ
authors.lastname: Chiou
authors.forename: Lai-Chu
authors.initials: LC
authors.lastname: See
authors.forename: Liang-Kee
authors.initials: LK
authors.lastname: Siu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D019729:Carbon-Oxygen Ligases / Q000235:genetics; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D019353:Endemic Diseases; D016983:Enterococcus / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D006784:Hospitals, Teaching; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D013624:Taiwan / Q000453:epidemiology; D062606:Tertiary Care Centers; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C071437:VanA ligase, Bacteria; D014640:Vancomycin; D019729:Carbon-Oxygen Ligases
references.citation: Infect Control Hosp Epidemiol. 1995 Feb;16(2):105-13
references.pmid: 7759811
references.citation: J Antimicrob Chemother. 2012 Sep;67(9):2243-9
references.pmid: 22618861
references.citation: Med J Aust. 1999 Aug 2;171(3):133-6
references.pmid: 10474604
references.citation: Ann Intern Med. 1992 Jul 15;117(2):112-6
references.pmid: 1605425
references.citation: Antimicrob Agents Chemother. 1990 May;34(5):924-7
references.pmid: 2360831
references.citation: MMWR Morb Mortal Wkly Rep. 1993 Aug 6;42(30):597-9
references.pmid: 8336690
references.citation: Gene. 1993 Feb 14;124(1):143-4
references.pmid: 8440477
references.citation: Antimicrob Agents Chemother. 1994 Jun;38(6):1363-7
references.pmid: 8092838
references.citation: J Clin Microbiol. 1993 Jun;31(6):1609-11
references.pmid: 8315004
references.citation: J Clin Microbiol. 1990 Sep;28(9):2059-63
references.pmid: 1977766
references.citation: Antimicrob Agents Chemother. 2003 Aug;47(8):2492-8
references.pmid: 12878510
references.citation: J Clin Microbiol. 2000 Mar;38(3):1008-15
references.pmid: 10698988
references.citation: Infect Control Hosp Epidemiol. 1998 Jul;19(7):515-8
references.pmid: 9702578
references.citation: Clin Infect Dis. 1995 May;20(5):1126-33
references.pmid: 7619987
references.citation: Ann Intern Med. 1996 Sep 15;125(6):448-56
references.pmid: 8779456
references.citation: J Clin Microbiol. 1994 May;32(5):1148-53
references.pmid: 8051238
references.citation: Infect Control Hosp Epidemiol. 1993 Oct;14(10):595-600
references.pmid: 7901269
references.citation: Ann Intern Med. 1995 Aug 15;123(4):250-9
references.pmid: 7611590