Outbreak of multidrug resistant NDM-1-producing Klebsiella pneumoniae from a neonatal unit in Shandong Province, China

PLoS One. 2015 Mar 23;10(3):e0119571. doi: 10.1371/journal.pone.0119571. eCollection 2015.

Abstract

Despite worldwide dissemination of New Delhi metallo-β-lactamase1 (blaNDM-1), outbreaks remain uncommon in China. In this study, we describe the characteristics of the outbreak-related blaNDM-1-producing K. pneumonia isolates in a neonatal unit in Shandong province, China. We recovered 21 non-repetitive carbapenem-resistant K. pneumoniae isolates with a positively modified Hodge test (MHT) or EDTA synergistic test from patients and environmental samples in Shandong provincial hospital. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) data show K. pneumoniae isolates from 19 patients were clonally related and belong to the clonal groups ST20 and ST17. We note two outbreaks, the first caused by ST20 during August 2012 involving four patients, and the second caused by ST20 and ST17 during January 2012 and September 2013 involving fourteen patients. We found the bed railing of one patient was the source of the outbreak. We verified the presence of the blaNDM-1 gene in 21 K. pneumoniae isolates. The genes blaCTX-M-15, blaCTX-M-14, blaDHA-1, blaTEM-1 and Class I integron were also present in 18 (85.7%), 3 (14.3%), 18 (85.7%), 19 (90.5%) and 19 (90.5%) isolates, respectively. We also found an isolate with both blaNDM-1 and blaIMP-4. All of the isolates exhibited a multidrug-resistance phenotype. The β-lactam resistance of 20 isolates was transferable via conjugation. In addition, we show the resistance of 21 K. pneumoniae isolates to carbapenem is not related to lack of outer-membrane proteins OmpK35 and OmpK36 nor overpression of efflux pumps. This study provides the first report confirming blaNDM-1-producing K. pneumoniae ST20 and ST17 were associated with outbreak. Early detection of resistance genes is an effective strategy in preventing and controlling infection by limiting the dissemination of these organisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Carbapenems / pharmacology*
  • China / epidemiology
  • DNA, Bacterial / genetics
  • Disease Outbreaks*
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Electrophoresis, Gel, Pulsed-Field
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Klebsiella Infections / epidemiology*
  • Klebsiella Infections / genetics
  • Klebsiella Infections / microbiology
  • Klebsiella pneumoniae / genetics
  • Klebsiella pneumoniae / isolation & purification*
  • Male
  • Microbial Sensitivity Tests
  • Multilocus Sequence Typing
  • Neonatal Screening
  • beta-Lactam Resistance / genetics*
  • beta-Lactamases / genetics*

Substances

  • Anti-Bacterial Agents
  • Carbapenems
  • DNA, Bacterial
  • beta-Lactamases
  • beta-lactamase NDM-1

Grants and funding

This study was supported by the Shandong province of Science and Technology Development Program of China (grant 2012G0021844) whose role was the study design and decision to publish; the National Natural Science Foundation of China (no.81401696) whose role was data collection and analysis; the Shandong Provincial Natural Science Foundation of China (ZR2011HM019) whose role was data collection and analysis; the Shandong Provincial Awards Foundation for Young Scientists (BS2011SW035) whose role was data collection and analysis; and the Construction Program of Shandong key clinical specialty whose role was the contribution of equipment.