title: Clonal spread of multidrug-resistant Acinetobacter baumannii in eastern Taiwan.
abstract: OBJECTIVE
  This study was conducted to investigate the molecular epidemiology and antimicrobial susceptibility of multidrug-resistant (MDR) Acinetobacter baumannii to three types of antibiotics.
  
  
  METHODS
  One hundred and thirty-four specimens of MDR A baumannii were collected from three branches (Taipei, Dalin, and Hualien branches) of Buddhist Tzu Chi Hospital, which are located in northern, southern, and eastern Taiwan, during 2007. Genotyping was performed by pulsed-field gel electrophoresis. Antibiotic susceptibilities to colistin, rifampicin, and tigecycline were determined. The synergistic effects of rifampin and colistin were also evaluated.
  
  
  RESULTS
  Antibiotic susceptibility testing showed that 10.4%, 47.8% and 45.5% of the MDR A baumannii isolates are resistant to colistin, rifampicin, and tigecycline, respectively. A majority of the rifampicin-resistant isolates (62.7%) were found in the Haulien branch, whereas 62.2% of tigecycline-resistant isolates were found in the Taipei branch. The combination of colistin and rifampicin had a synergistic effect on all of the isolates. Genotyping by pulsed-field gel electrophoresis identified 17, 23, and 11 pulsotypes in the Taipei, Dalin, and Haulien branches, respectively. Furthermore, 74.5% of isolates in the Haulien branch were identified as one of three pulsotypes. Among 37 rifampicin-resistant and 22 tigecycline-resistant MDR A baumannii isolates found in the Haulien branch, 51.3% (19/37) and 50% (11/22) of the isolates belonged to the same clone, respectively.
  
  
  CONCLUSIONS
  This study confirms the high prevalence of resistance to rifampicin and tigecycline in MDR A baumannii in the three hospitals that were studied, and the high proportion of identical strains that exist in eastern Taiwan.
authors.affiliation: Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien City, Taiwan.
authors.forename: Kai-Chih
authors.initials: KC
authors.lastname: Chang
authors.forename: Ming-Feng
authors.initials: MF
authors.lastname: Lin
authors.forename: Nien-Tsung
authors.initials: NT
authors.lastname: Lin
authors.forename: Wen-Jui
authors.initials: WJ
authors.lastname: Wu
authors.forename: Han-Yueh
authors.initials: HY
authors.lastname: Kuo
authors.forename: Teng-Yi
authors.initials: TY
authors.lastname: Lin
authors.forename: Tsai-Lian
authors.initials: TL
authors.lastname: Yang
authors.forename: Yu-Chuan
authors.initials: YC
authors.lastname: Chen
authors.forename: Ming-Li
authors.initials: ML
authors.lastname: Liou
mesh_terms: D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000145:classification* / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016000:Cluster Analysis; D003091:Colistin / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D004357:Drug Synergism; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000031:analogs & derivatives / Q000494:pharmacology; D017720:Molecular Epidemiology; D058889:Molecular Typing; D015995:Prevalence; D012293:Rifampin / Q000494:pharmacology; D013624:Taiwan / Q000453:epidemiology; D000078304:Tigecycline
chemical_list: D000900:Anti-Bacterial Agents; D000078304:Tigecycline; D008911:Minocycline; D012293:Rifampin; D003091:Colistin