title: Virulence of Klebsiella pneumoniae isolates harboring bla KPC-2 carbapenemase gene in a Caenorhabditis elegans model.
abstract: Klebsiella pneumoniae carbapenemase (KPC) is a carbapenemase increasingly reported worldwide in Enterobacteriaceae. The aim of this study was to analyze the virulence of several KPC-2-producing K. pneumoniae isolates. The studied strains were (i) five KPC-2 clinical strains from different geographical origins, belonging to different ST-types and possessing plasmids of different incompatibility groups; (ii) seven transformants obtained after electroporation of either these natural KPC plasmids or a recombinant plasmid harboring only the bla KPC-2 gene into reference strains K. pneumoniae ATCC10031/CIP53153; and (iii) five clinical strains cured of plasmids. The virulence of K. pneumoniae isolates was evaluated in the Caenorhabditis elegans model. The clinical KPC producers and transformants were significantly less virulent (LT50: 5.5 days) than K. pneumoniae reference strain (LT50: 4.3 days) (p<0.01). However, the worldwide spread KPC-2 positive K. pneumoniae ST258 strains and reference strains containing plasmids extracted from K. pneumoniae ST258 strains had a higher virulence than KPC-2 strains belonging to other ST types (LT50: 5 days vs. 6 days, p<0.01). The increased virulence observed in cured strains confirmed this trend. The bla KPC-2 gene itself was not associated to increased virulence.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, U1047, Université Montpellier 1, UFR de Médecine, Nîmes, France. jean.philippe.lavigne@chu-nimes.fr
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Lavigne
authors.forename: Gaelle
authors.initials: G
authors.lastname: Cuzon
authors.forename: Christophe
authors.initials: C
authors.lastname: Combescure
authors.forename: Gisèle
authors.initials: G
authors.lastname: Bourg
authors.forename: Albert
authors.initials: A
authors.lastname: Sotto
authors.forename: Patrice
authors.initials: P
authors.lastname: Nordmann
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D017173:Caenorhabditis elegans / Q000254:growth & development* / Q000382:microbiology; D054884:Host-Pathogen Interactions; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000472:pathogenicity / Q000502:physiology; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D013997:Time Factors; D014774:Virulence / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases; C531581:carbapenemase-2, Klebsiella pneumoniae