@article{3060862,
    title = "Phylogenetic lineages, clones and β-lactamases in an international collection of Klebsiella oxytoca isolates non-susceptible to expanded-spectrum cephalosporins",
    author = "Izdebski, R. and Fiett, J. and Urbanowicz, P. and Baraniak, A. and Derde, L.P.G. and Bonten, M.J.M. and Carmeli, Y. and Goossens, H. and Hryniewicz, W. and Brun-Buisson, C. and Brisse, S. and Gniadkowski, M. and Herda, M. and Dautzenberg, M.J. and Adler, A. and Kazma, M. and Navon-Venezia, S. and Malhotra-Kumar, S. and Lammens, C. and Legrand, P. and Chalfine, A. and Giamarellou, H. and Petrikkos, G.L. and Balode, A. and Dumpis, U. and Stammet, P. and Aragăo, I. and Esteves, F. and Torres Martí, A. and Lawrence, C. and Salomon, J. and Paul, M. and Lerman, Y. and Rossini, A. and Salvia, A. and Vidal Samso, J. and Fierro, J. and MOSAR WP2, WP3 and WP5 Study Groups",
    journal = "The Journal of antimicrobial chemotherapy",
    year = "2015",
    volume = "70",
    number = "12",
    pages = "3230-3237",
    publisher = "Oxford University Press",
    doi = "10.1093/jac/dkv273",
    keywords = "bacterial enzyme;  beta lactamase AmpC;  carbapenemase;  cephalosporin derivative;  cephalosporinase;  extended spectrum beta lactamase;  OXY 1 beta lactamase;  OXY 2 beta lactamase;  OXY 3 beta lactamase;  OXY 4 beta lactamase;  OXY 5 beta lactamase;  unclassified drug;  antiinfective agent;  beta lactamase;  cephalosporin derivative, antibiotic resistance;  Article;  bacterial chromosome;  bacterial gene;  bacterial strain;  bacterium isolate;  clonal evolution;  comparative study;  controlled study;  enzyme analysis;  gene amplification;  gene sequence;  genetic variability;  genotype;  human;  hydrolysis;  Klebsiella oxytoca;  major clinical study;  nonhuman;  nucleotide sequence;  phenotype;  phylogenetic tree;  species diversity;  antibiotic resistance;  classification;  DNA sequence;  drug effects;  Europe;  feces;  genetic variation;  genetics;  genotype;  heterozygote;  hospital;  isolation and purification;  Israel;  Klebsiella Infections;  Klebsiella oxytoca;  microbial sensitivity test;  microbiology;  molecular typing;  phylogeny;  polymerase chain reaction, Anti-Bacterial Agents;  beta-Lactam Resistance;  beta-Lactamases;  Carrier State;  Cephalosporins;  Europe;  Feces;  Genetic Variation;  Genotype;  Hospitals;  Humans;  Israel;  Klebsiella Infections;  Klebsiella oxytoca;  Microbial Sensitivity Tests;  Molecular Typing;  Phylogeny;  Polymerase Chain Reaction;  Sequence Analysis, DNA",
    abstract = "Objectives: The objective of this study was to examine Klebsiella oxytoca clonal and phylogenetic diversity, based on an international collection of carriage isolates non-susceptible to expanded-spectrum cephalosporins (ESCs). Methods: The study material comprised 68 rectal carriage K. oxytoca isolates non-susceptible to ESCs recovered in 2008-11 from patients in 14 hospitals across Europe and Israel. ESC resistance was tested phenotypically; genes encoding ESBLs, AmpC cephalosporinases and carbapenemases were amplified and sequenced. The isolates were typed by PFGE and MLST, followed by sequencing of blaOXY genes. Results: MLSTand PFGE distinguished 34 STs and 47 pulsotypes among the isolates, respectively. Six STswere split into several pulsotypes each. Five STs were more prevalent (n=2-9) and occurred in several countries each, including ST2, ST9 and ST141, which belong to a growing international clonal complex (CC), CC2. Four phylogenetic lineages were distinguished, each with another type of chromosomal OXY-type β-lactamase. Three of these, with OXY-1/-5, OXY-2 types and OXY-4, corresponded to previously described phylogroups KoI, KoII and KoIV, respectively. A single isolate from Israel represented a distinct lineage with a newly defined OXY-7 type. The phylogroups showed interesting differences in mechanisms of ESC resistance; KoI strains rarely overexpressed the OXY enzymes but commonly produced ESBLs, whereas KoII strains often were OXY hyperproducers and carried ESBLs much less frequently. AmpCs (DHA-1) and carbapenemases (VIM-1) occurred sporadically. Conclusions: The study confirmed the high genetic diversity of the collection of K. oxytoca ESC-non-susceptible isolates, composed of phylogroups with distinct types of OXY-type β-lactamases, and revealed some STs of broad geographical distribution."
}