Rapid detection of blaIMP-6 by amplification refractory mutation system

Shizuo Kayama1, Norifumi Shigemoto, Ryuichi Kuwahara

  • 1Project Research Center for Nosocomial Infectious Disease, Hiroshima University, 1-2-3 Kasumi Minami-ku, Hiroshima 734-8551, Japan.

Insights

A new Klebsiella pneumoniae strain, ISMRK, resistant to most ß-lactams but susceptible to imipenem, is emerging in Japan. Researchers developed a rapid ARMS PCR method to detect the bla(IMP-6) gene responsible for this resistance.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Antimicrobial Resistance

Background:

  • Emergence of multidrug-resistant bacteria poses a significant global health threat.
  • Klebsiella pneumoniae is a common cause of hospital-acquired infections and exhibits increasing resistance to antibiotics.
  • A specific strain, imipenem-susceptible meropenem-resistant Klebsiella (ISMRK), exhibiting resistance to nearly all ß-lactams except imipenem, is emerging in Japan.

Purpose of the Study:

  • To identify the genetic basis of imipenem-susceptible meropenem-resistant Klebsiella (ISMRK) resistance.
  • To develop a rapid and accurate method for detecting the specific resistance gene in ISMRK.

Main Methods:

  • Whole-genome sequencing and comparative analysis of ISMRK strains.
  • Identification of the bla(IMP-6) gene, a variant of bla(IMP-1), in all ISMRK isolates.
  • Development and validation of an Allele-Specific Polymerase Chain Reaction (ARMS PCR) assay for rapid bla(IMP-6) detection.

Main Results:

  • All imipenem-susceptible meropenem-resistant Klebsiella (ISMRK) strains examined carried the bla(IMP-6) gene.
  • The bla(IMP-6) gene differs from bla(IMP-1) by a single nucleotide polymorphism at position 640.
  • The developed ARMS PCR assay demonstrated high specificity and sensitivity for detecting bla(IMP-6).

Conclusions:

  • The bla(IMP-6) gene is the key determinant of the imipenem-susceptible meropenem-resistant Klebsiella (ISMRK) phenotype.
  • Rapid detection of bla(IMP-6) using ARMS PCR is feasible and crucial for surveillance.
  • Effective monitoring and control strategies are needed to manage the spread of ISMRK.

Related Concept Videos