Chromobacteriumspp. harbour Ambler class A β-lactamases showing high identity with KPC
| Autor: | Laurent Poirel, Aurélie Jayol, Luca Guardabassi, Dereje Dadi Gudeta, Valeria Bortolaia, Patrice Nordmann |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Microbiology (medical) Klebsiella pneumoniae 030106 microbiology Gene Expression Sequence Homology Microbial Sensitivity Tests beta-Lactams medicine.disease_cause beta-Lactamases Microbiology Evolution Molecular 03 medical and health sciences Start codon Chromobacterium Escherichia coli polycyclic compounds medicine Pharmacology (medical) Cloning Molecular Peptide sequence Gene Phylogeny Pharmacology Phylogenetic tree biology Hydrolysis biochemical phenomena metabolism and nutrition bacterial infections and mycoses biology.organism_classification 030104 developmental biology Infectious Diseases Heterologous expression |
| Zdroj: | Journal of Antimicrobial Chemotherapy. 71:1493-1496 |
| ISSN: | 1460-2091 0305-7453 |
| Popis: | 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 β-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 β-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 β-lactamases were phylogenetically more related to KPC than to other Ambler class A β-lactamases. The 27 bp region preceding the start codon of blaCRP-1 displayed high nucleotide identity to the corresponding region upstream from blaKPC (74%). Heterologous expression of blaCRP-1 and to a lesser extent of blaCRH-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 β-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. |
| Databáze: | OpenAIRE |
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