title: Effective transfer of a 47 kb NDM-1-positive plasmid among Acinetobacter species.
abstract: OBJECTIVE
  To investigate the link between two NDM-1-positive Acinetobacter isolates from the same hospital, the plasmid profiles of the isolates were examined. These two isolates were found from a surveillance programme within 3 months from two patients without obvious physical contact or hospitalization time overlap.
  
  
  METHODS
  Antimicrobial susceptibility tests, genome sequencing of both isolates and plasmid transfer experiments were performed. A comparative study of similar plasmids was performed using BLAST analysis.
  
  
  RESULTS
  The antimicrobial susceptibility of the isolates (Acinetobacter soli M131 and Acinetobacter pittii MS32) and their Escherichia coli transconjugants revealed a conjugative plasmid that carried the carbapenem resistance determinant. Eleven plasmids were observed in M131 and three in MS32. Each isolate shared an identical plasmid that carried the blaNDM-1 gene. This 47 271 bp plasmid harbours a conserved blaNDM-1-containing region that is flanked by ISAba125 and ISAba11 elements, and also contains a Ti-type conjugative operon. The plasmid is nearly identical in sequence to those of Acinetobacter isolates from China. In contrast to the mobilization of the blaNDM-1 sequence in Enterobacteriaceae, which is mainly by transposition, this plasmid moves as a whole among Acinetobacter species. Consistently, this plasmid was found to transfer effectively by in vitro conjugation to several Acinetobacter species.
  
  
  CONCLUSIONS
  The clinical and laboratory findings suggest that Acinetobacter species may serve as a reservoir of this blaNDM-1 plasmid. Our study demonstrates the potential of applying genome sequencing to the surveillance of antimicrobial-resistant bacteria.
authors.affiliation: Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Taiwan.
authors.forename: Tzu-Wen
authors.initials: TW
authors.lastname: Huang
authors.affiliation: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Taiwan.
authors.forename: Tsai-Ling
authors.initials: TL
authors.lastname: Lauderdale
authors.affiliation: Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Taiwan.
authors.forename: Tsai-Lien
authors.initials: TL
authors.lastname: Liao
authors.affiliation: Division of Infectious Diseases, Min-Sheng General Hospital, Taoyuan, Taiwan.
authors.forename: Ming-Chia
authors.initials: MC
authors.lastname: Hsu
authors.affiliation: Director-General's Office, Centers for Disease Control, Taipei, Taiwan Department of Internal Medicine, and Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Feng-Yee
authors.initials: FY
authors.lastname: Chang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Shan-Chwen
authors.initials: SC
authors.lastname: Chang
authors.affiliation: Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, Singapore.
authors.forename: Wei Xin
authors.initials: WX
authors.lastname: Khong
authors.affiliation: Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, Singapore.
authors.forename: Oon Tek
authors.initials: OT
authors.lastname: Ng
authors.affiliation: Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Taiwan Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Ying-Tsong
authors.initials: YT
authors.lastname: Chen
authors.affiliation: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Taiwan.
authors.forename: Shu-Chen
authors.initials: SC
authors.lastname: Kuo
authors.affiliation: Division of Infectious Diseases, Taipei Veterans General Hospital, Taipei, Taiwan School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Te-Li
authors.initials: TL
authors.lastname: Chen
authors.affiliation: Bacterial Enteric and Emerging Diseases Laboratory, Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, Taipei, Taiwan.
authors.forename: Jung-Jung
authors.initials: JJ
authors.lastname: Mu
authors.affiliation: Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Taiwan Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan petsai@nhri.org.tw.
authors.forename: Shih-Feng
authors.initials: SF
authors.lastname: Tsai
mesh_terms: D000150:Acinetobacter / Q000187:drug effects / Q000235:genetics*; D000151:Acinetobacter Infections / Q000382:microbiology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003227:Conjugation, Genetic; D003428:Cross Infection; D004251:DNA Transposable Elements; D023061:Gene Order; D022761:Gene Transfer, Horizontal; D016680:Genome, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics*; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004251:DNA Transposable Elements; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1