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Molecular characterization of clinical multidrug-resistant Klebsiella pneumoniae isolates

Xiaoli Cao, Xuejing Xu, Zhifeng Zhang

  • 1Department of Laboratory Medicine, Nanjing Drum Tower Hospital, the affiliated Hospital of Nanjing University Medical School, Zhongshan Road, 321#, Gulou District, Nanjing, Jiangsu Province 210008, PR China. zhangkui6103@163.com.

Annals of Clinical Microbiology and Antimicrobials
|June 3, 2014
PubMed
Abstract

Insights

Multidrug-resistant Klebsiella pneumoniae, a major global health threat, was molecularly characterized. The study identified KPC-producing ST11 as the main clone, highlighting concerns over prevalent resistance determinants and integrons.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genetics

Background:

  • Klebsiella pneumoniae is a significant nosocomial pathogen.
  • Multidrug-resistant (MDR) K. pneumoniae poses a global health challenge due to difficult-to-treat infections.

Purpose of the Study:

  • To conduct a molecular characterization of clinical MDR K. pneumoniae isolates.
  • To investigate the prevalence of antimicrobial resistance genes and genetic relatedness.

Main Methods:

  • Polymerase chain reaction (PCR) amplification and DNA sequencing were used to detect resistance genes (ESBLs, PMQR, 16S-RMTase) and integrons.
  • Plasmid replicons were typed using PCR-based replicon typing (PBRT).
  • Multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were employed for strain characterization.

Main Results:

  • All 27 MDR K. pneumoniae isolates harbored at least three resistance determinants.
  • OqxAB, CTX-M-type ESBLs, and RmtB were the most frequent determinants.
  • Class 1 integrons were prevalent, and the ST11 sequence type was identified in a major cluster.

Conclusions:

  • KPC-producing ST11 was identified as the dominant clone.
  • High prevalence of multiple resistance determinants, class 1 integrons, and IncFII plasmid replicons were observed.
  • These factors contribute to the rapid development and spread of MDR K. pneumoniae strains.

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