title: Epidemiological characteristics and genetic structure of blaNDM-1 in non-baumannii Acinetobacter spp. in China.
abstract: OBJECTIVE
  The goal of this study was to investigate the epidemiological characteristics and the surrounding genetic structure of bla(NDM-1) in non-baumannii Acinetobacter spp. in China.
  
  
  METHODS
  Non-baumannii Acinetobacter spp. were collected from 28 provinces in China and were screened for the presence of bla(NDM-1) using PCR. The following four methods were used to classify the Acinetobacter isolates: the Vitek 2 system, 16S-23S rRNA gene intergenic spacer sequencing, amplified rDNA restriction analysis and partial rpoB sequence analysis. An S1-PFGE assay and Southern blot hybridization were performed to determine the plasmid location of bla(NDM-1). The transferability of bla(NDM-1)-harbouring plasmids was confirmed by conjugation experiments and electrotransformation. The surrounding genetic structure of the bla(NDM-1) gene was analysed using a restriction endonuclease-based cloning approach and primer walking.
  
  
  RESULTS
  Among 726 non-baumannii Acinetobacter spp., nine isolates collected from six different provinces and assigned to seven different Acinetobacter spp. contained the bla(NDM-1) gene. None of these isolates was directly infectious to the patients or demonstrated an epidemiological importation from abroad. These bla(NDM-1) genes were located on plasmids that could be transferred to Escherichia coli J53 by conjugation and Acinetobacter baylyi ADP1 by electrotransformation. Seven of the nine strains shared a common genetic structure in which bla(NDM-1) was flanked by two copies of ISAba125.
  
  
  CONCLUSIONS
  The clinical challenge posed by bla(NDM-1) is currently minimal in China; however, more attention should be devoted to monitoring the dissemination of this gene due to its potential transferability via the ISAba125-associated transposon.
authors.affiliation: Department of Infectious Diseases,  Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016,  China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Fu
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Du
authors.forename: Jingshu
authors.initials: J
authors.lastname: Ji
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.forename: Yan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Yunsong
authors.initials: Y
authors.lastname: Yu
mesh_terms: D000150:Acinetobacter / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology*; D000328:Adult; D000368:Aged; D015373:Bacterial Typing Techniques; D015139:Blotting, Southern; D002648:Child; D002681:China; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D058889:Molecular Typing; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1