NDM-producing Enterobacteriaceae in a Chinese hospital, 2014-2015: identification of NDM-producing Citrobacterwerkmanii and acquisition of blaNDM-1-carrying plasmid in vivo in a clinical Escherichia coli isolate

J Med Microbiol. 2016 Nov;65(11):1253-1259. doi: 10.1099/jmm.0.000357. Epub 2016 Sep 23.

Abstract

New Delhi metallo-β-lactamase (NDM)-producing Enterobacteriaceae (NPE) shows prevalence in China. Little is known about the mechanisms related to the spread of NPE. Recently, a total of 51 non-duplicated NPE isolates were collected from a tertiary-care hospital in China and analysed for genetic relatedness by PFGE, antimicrobial susceptibility by Etest and sequence type by multilocus sequence typing. S1-PFGE and Southern blot analysis or PCR amplification were used for plasmid profiling. Between 2014 and 2015, 22 Escherichia coli, 10 Klebsiella pneumoniae, 9 Enterobacter cloacae, 2 Enterobacter aerogenes, 3 Providencia rettgeri, 1 Klebsiella oxytoca, 1 Proteus mirabilis, 1 Citrobacter freundii, 1 Citrobacterwerkmanii and 1 Raoultella planticola were identified as NPE. Results of PFGE and multilocus sequence typing showed that most strains were genetically unrelated. Among the 45 blaNDM-carrying plasmids, there were 25 IncX3 plasmids with a size of about 30 to 50 kb, one 100 kb IncX3 plasmid, 11 IncA/C plasmids with a size range from 70 to 300 kb, six 90 to 120 kb IncB/O plasmids, one IncN plasmid with a size of 100 kb and one 140 kb IncFrep plasmid. An NDM-1-producing isolate of C. werkmanii was identified, which had not been reported previously. An Escherichia coli strain was found acquiring a blaNDM-1-carrying IncFrep plasmid in vivo during infection. In conclusion, an NDM-1-producing isolate of C. werkmanii was identified. An Escherichia coli strain acquired a blaNDM-1-carrying plasmid in vivo. IncX3 and IncA/C plasmids with various sizes might have emerged as the main platforms mediating the spread of the blaNDM genes in China.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • China
  • Enterobacter cloacae / drug effects
  • Enterobacter cloacae / enzymology
  • Enterobacter cloacae / genetics
  • Enterobacter cloacae / metabolism
  • Enterobacteriaceae / drug effects
  • Enterobacteriaceae / enzymology*
  • Enterobacteriaceae / genetics*
  • Enterobacteriaceae Infections / microbiology*
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology
  • Escherichia coli / genetics*
  • Hospitals
  • Humans
  • Klebsiella pneumoniae / drug effects
  • Klebsiella pneumoniae / enzymology
  • Klebsiella pneumoniae / genetics
  • Klebsiella pneumoniae / metabolism
  • Microbial Sensitivity Tests
  • Plasmids / genetics*
  • Plasmids / metabolism
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • beta-Lactamases
  • beta-lactamase NDM-1