pIMP-PH114 carrying bla IMP-4 in a Klebsiella pneumoniae strain is closely related to other multidrug-resistant IncA/C2 plasmids

Pak-Leung Ho, Wai-U Lo, Jane Chan, Yuk-Yam Cheung, Kin-Hung Chow, Wing-Cheong Yam, Chi-Ho Lin, Tak-Lun Que

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28 Citations (SciVal)


The IncA/C plasmids are broad host-range vehicles which have been associated with wide dissemination of CMY-2 among Enterobacteriaceae of human and animal origins. Acquired metallo-β-lactamases (MBLs) such as the IMP-type enzymes are increasingly reported in multidrug-resistant Gram-negative bacteria worldwide, particularly in Enterobacteriaceae. We described the complete sequence of the first IMP-4-encoding IncA/C2 plasmid, pIMP-PH114 (151,885 bp), from a sequence type 1 Klebsiella pneumoniae strain that was recovered from a patient who was hospitalized in the Philippines. pIMP-PH114 consists of a backbone from the IncA/C2 plasmids, with the insertion of a novel Tn21-like class 1 integron composite structure (containing the cassette array bla IMP-4-qacG-aacA4-catB3, followed by a class C β-lactamase bla DHA-1 and the mercury resistance operon, merRTPCADE) and a sul2-floR encoding region. Phylogenetic analysis of the IncA/C repA sequences showed that pIMP-PH114 formed a subgroup with other IncA/C plasmids involved in the international spread of CMY-2, TEM-24 and NDM-1. Identical bla IMP-4 arrays have been described among different Enterobacteriaceae and Acinetobacter spp. in China, Singapore and Australia but the genetic context is different. The broad host range of IncA/C plasmids may have facilitated dissemination of the bla IMP-4 arrays among different diverse groups of bacteria.

Original languageEnglish
Pages (from-to)227-32
Number of pages6
JournalCurrent microbiology
Issue number2
Publication statusPublished - 1 Feb 2014


  • Anti-Bacterial Agents/pharmacology
  • Drug Resistance, Multiple, Bacterial/genetics
  • Gene Order
  • Genotype
  • Klebsiella pneumoniae/classification
  • Microbial Sensitivity Tests
  • Phenotype
  • Phylogeny
  • Plasmids/genetics
  • beta-Lactamases/genetics


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