title: Emergence of NDM-1-producing Acinetobacter baumannii in China.
abstract: OBJECTIVE
  To investigate the prevalence of bla(NDM-1) in Gram-negative bacilli in China.
  
  
  METHODS
  A total of 11 298 clinical Gram-negative bacilli, covering Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa, were collected for PCR-based surveillance of bla(NDM-1) from 57 hospitals representing 18 provinces in China. For bla(NDM-1)-positive isolates, antibiotic susceptibilities were assessed and molecular typing was performed using PFGE. The genetic location of bla(NDM-1) was determined by analysis of PFGE profiles of S1 nuclease-digested genomic DNA and Southern blot hybridization. Plasmid transfer to E. coli recipients was investigated using filter mating and electroporation.
  
  
  RESULTS
  Four A. baumannii isolates with bla(NDM-1) were identified in four different provinces in China: no positive isolates were detected among E. coli, K. pneumoniae and P. aeruginosa. These bla(NDM-1)-positive A. baumannii were resistant to all carbapenems and cephalosporins, and three remained susceptible to fluoroquinolones, aminoglycosides and colistin. The four NDM-1-producing A. baumannii were clonally diverse and carried bla(NDM-1) on different plasmids. Plasmids carrying bla(NDM-1) were successfully transferred from three of the four isolates to E. coli recipients, although the transconjugants and transformants were prone to lose the transferred plasmids after passage in the absence of ampicillin selection.
  
  
  CONCLUSIONS
  We describe the emergence of A. baumannii producing NDM-1 in China. Systemic surveillance network should be established for monitoring these resistant bacteria.
authors.affiliation: Department of Infectious Diseases, Sir Run Run Shaw Hospital, Affiliated with School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Zhou
authors.forename: Yan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Yunsong
authors.initials: Y
authors.lastname: Yu
mesh_terms: D040981:Acinetobacter baumannii / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D015373:Bacterial Typing Techniques; D015139:Blotting, Southern; D002681:China; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000302:isolation & purification; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006761:Hospitals; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007711:Klebsiella pneumoniae / Q000302:isolation & purification; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D058889:Molecular Typing; D010957:Plasmids; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D001618:beta-Lactamases; C552864:beta-lactamase NDM-1