Chromobacterium spp. harbour Ambler class A beta-lactamases showing high identity with KPC

Dereje Dadi Gudeta, Valeria Bortolaia, Aurelie Jayol, Laurent Poirel, Patrice Nordmann, Luca Guardabassi

Research output: Contribution to journalJournal articleResearchpeer-review


Objectives: The origin of KPC is unknown. The aim of this study was to detect progenitors of KPC in silico and to functionally verify their beta-lactam hydrolysis activity.Methods: The sequence of KPC-2 was used to mine the NCBI protein sequence database. The best non-KPC hits were analysed by amino acid (aa) alignment and phylogenetic tree construction. Genes encoding KPC-2 homologues were expressed in Escherichia coli. The carbapenemase activities of the recombinant strains were characterized by the CarbaNP test and UV spectrophotometry and MICs of selected beta-lactams were determined.Results: Genes encoding the closest KPC-2 homologues were identified on the chromosome of Chromobacterium piscinae strain ND17 (CRP-1, 76% aa identity), Chromobacterium sp. C-61 (CRS-1, 70% aa identity) and Chromobacterium haemolyticum DSM19808 (CRH-1, 69% aa identity). All three Chromobacterium beta-lactamases were phylogenetically more related to KPC than to other Ambler class A beta-lactamases. The 27 bp region preceding the start codon of bla(CRP-1) displayed high nucleotide identity to the corresponding region upstream from bla(KPC) (74%). Heterologous expression of bla(CRP-1) and to a lesser extent of bla(CRH-1) in E. coli significantly increased the MICs of meropenem and most cephalosporins. The CarbaNP test was positive for both recombinant strains, but spectrophotometric analysis confirmed higher carbapenemase activity for CRP-1-producing clones.Conclusions: The recovery of three class A beta-lactamases with up to 76% aa identity to KPC from distinct Chromobacterium species is highly indicative of the role played by this genus in the evolution of KPC.
Original languageEnglish
JournalJournal of Antimicrobial Chemotherapy
Issue number6
Pages (from-to)1493-1496
Number of pages4
Publication statusPublished - 2016
Externally publishedYes


  • Pharmacology
  • Pharmacology (medical)
  • Infectious Diseases
  • Bacterial Infections
  • Genetics - General
  • Genetics - Human
  • Biochemistry studies - General
  • Pathology - Therapy
  • Pharmacology - General
  • Pharmacology - Clinical pharmacology
  • Physiology and biochemistry of bacteria
  • Genetics of bacteria and viruses
  • Medical and clinical microbiology - Bacteriology
  • Chemotherapy - General, methods and metabolism
  • Chemotherapy - Antibacterial agents
  • cephalosporin
  • meropenem
  • carbapenemase
  • Bacteria, Eubacteria, Microorganisms
  • Animals, Chordates, Humans, Mammals, Primates, Vertebrates
  • GenBank sequence data
  • enzyme activity
  • NCBI protein sequence database


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