Higher isolation of NDM-1 producing Acinetobacter baumannii from the sewage of the hospitals in Beijing

PLoS One. 2013 Jun 3;8(6):e64857. doi: 10.1371/journal.pone.0064857. Print 2014.


Multidrug resistant microbes present in the environment are a potential public health risk. In this study, we investigate the presence of New Delhi metallo-β-lactamase 1 (NDM-1) producing bacteria in the 99 water samples in Beijing City, including river water, treated drinking water, raw water samples from the pools and sewage from 4 comprehensive hospitals. For the bla NDM-1 positive isolate, antimicrobial susceptibility testing was further analyzed, and Pulsed Field Gel Electrophoresis (PFGE) was performed to determine the genetic relationship among the NDM-1 producing isolates from sewage and human, as well as the clinical strains without NDM-1. The results indicate that there was a higher isolation of NDM-1 producing Acinetobacter baumannii from the sewage of the hospitals, while no NDM-1 producing isolates were recovered from samples obtained from the river, drinking, or fishpond water. Surprisingly, these isolates were markedly different from the clinical isolates in drug resistance and pulsed field gel electrophoresis profiles, suggesting different evolutionary relationships. Our results showed that the hospital sewage may be one of the diffusion reservoirs of NDM-1 producing bacteria.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter baumannii / enzymology*
  • Acinetobacter baumannii / isolation & purification*
  • Carbapenems / pharmacology
  • China
  • Conjugation, Genetic
  • DNA, Bacterial / metabolism
  • Drug Resistance, Bacterial / drug effects
  • Drug Resistance, Microbial / drug effects
  • Electrophoresis, Gel, Pulsed-Field
  • Hospitals*
  • Humans
  • Microbial Sensitivity Tests
  • Phylogeny
  • Plasmids / metabolism
  • Sewage / microbiology*
  • beta-Lactamases / biosynthesis*


  • Carbapenems
  • DNA, Bacterial
  • Sewage
  • beta-Lactamases
  • beta-lactamase NDM-1

Grant support

This work was supported in part by the National Science and technology Major Project of China (2012ZX10004-215, 2013ZX10004-218, 2013ZX10004-607, 2012ZX10004-801, 2013ZX10004-203, 2013ZX10004-217-002) and the National Natural Science Foundation of China (81000723, 81070969, 81171554). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.