title: Characterization of a novel Klebsiella pneumoniae sequence type 476 carrying both bla KPC-2 and bla IMP-4.
abstract: Carbapenemase-producing Klebsiella pneumoniae has recently spread rapidly throughout China. In this study, we characterized a carbapenem-resistant K. pneumoniae isolate that produced both KPC-2 and IMP-4 type carbapenemases. A clinical isolate of K. pneumoniae, resistant to both meropenem and imipenem, was recovered from a urine sample. Antibiotic susceptibility was determined using the broth microdilution method and Etest (bioMérieux, France). Pulsed-field gel electrophoresis and multilocus sequence typing (MLST) were used for gene type analysis. bla                         (KPC) and the encoding genes of ESBLs and plasmid-mediated AmpC enzymes were polymerase chain reaction (PCR) amplified and sequenced. Plasmids were analyzed by transformation, enzyme restriction and Southern blot. PCR analysis revealed that the isolate was simultaneously carrying bla                         (KPC-2), bla                         (IMP-4), bla                         (TEM-1), and bla                         (OKP-B) genes. MLST assigned the isolate to a novel sequence type, ST476. bla                         (KPC-2)-harbouring plasmids of the isolate and comparative strains had similar EcoRI and HindIII restriction maps, while IMP-4-harbouring plasmids had variable HindIII restriction maps. Coexistence of bla                         (KPC-2) and bla                         (IMP-4) was probably due to bla                         (IMP-4)-harbouring plasmid transmission into KPC-2-producing K. pneumoniae (ST476). The concomitant presence of these genes is alarming and poses both therapeutic and infection control problems.
authors.affiliation: Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: W
authors.initials: W
authors.lastname: Cao
authors.forename: X
authors.initials: X
authors.lastname: Zhu
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: B
authors.initials: B
authors.lastname: Zhang
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.forename: L
authors.initials: L
authors.lastname: Tian
authors.forename: F
authors.initials: F
authors.lastname: Wang
authors.forename: C
authors.initials: C
authors.lastname: Liu
authors.forename: Z
authors.initials: Z
authors.lastname: Sun
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015139:Blotting, Southern; D002681:China; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005838:Genotype; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D007223:Infant; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D010957:Plasmids / Q000032:analysis; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013845:Thienamycins / Q000494:pharmacology; D014556:Urine / Q000382:microbiology; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D013845:Thienamycins; D015378:Imipenem; C425142:beta-lactamase IMP-4; D001618:beta-Lactamases; C547585:beta-lactamase KPC-2, Klebsiella pneumoniae; D000077731:Meropenem