title: Role of IncHI2 plasmids harbouring blaVIM-1, blaCTX-M-9, aac(6')-Ib and qnrA genes in the spread of multiresistant Enterobacter cloacae and Klebsiella pneumoniae strains in different units at Hospital Vall d'Hebron, Barcelona, Spain.
abstract: Seven Enterobacter cloacae isolates and seven Klebsiella pneumoniae isolates harbouring a phenotype compatible with the production of a metallo-β-lactamase were recovered between 2009 and 2011 in three Intensive Care Units of Hospital Vall d'Hebron (Barcelona, Spain). The presence of bla(VIM), bla(IMP), bla(NDM), bla(CTX-M), aac(6')-Ib, qnrA, qnrB and qnrS genes was screened by polymerase chain reaction (PCR) and sequencing. Clonal relatedness of the isolates was assessed by pulsed-field gel electrophoresis (PFGE) and, in the case of K. pneumoniae isolates, by multilocus sequence typing (MLST). PCR-based replicon typing, Southern hybridisation, plasmid double-locus sequence typing and MOB relaxase classification methods were used to identify and characterise the plasmids carrying the resistance genes. Transferability of the identified plasmids was tested by conjugation assays. All 14 isolates were found to carry bla(VIM-1), bla(CTX-M-9) (except one isolate), aac(6')-Ib and qnrA genes. Clonality assessment demonstrated that E. cloacae isolates were distributed in three clonal clusters, whereas all of the K. pneumoniae isolates belonged to one unique clone, identified as sequence type ST252. All studied isolates harboured a large conjugative IncHI2 MOB(H11) plasmid carrying all of the detected resistance genes. Plasmid DNA analysis showed that all of them belonged to the ST1 IncHI2 plasmid cluster and shared the same relaxase partial sequence. In conclusion, the present study describes the dissemination within a hospital of multiresistant E. cloacae and K. pneumoniae isolates producing VIM-1. A complex clonal epidemiology of the E. cloacae isolates was observed and plasmid DNA analysis strongly supports horizontal exchanges of the same IncHI2 plasmid between different strains and species.
authors.affiliation: Servicio de Microbiología, Hospital Vall d'Hebron, Barcelona, Spain. alicia.coelho@vhir.org
authors.forename: A
authors.initials: A
authors.lastname: Coelho
authors.forename: N
authors.initials: N
authors.lastname: Piedra-Carrasco
authors.forename: R
authors.initials: R
authors.lastname: Bartolomé
authors.forename: J N
authors.initials: JN
authors.lastname: Quintero-Zarate
authors.forename: N
authors.initials: N
authors.lastname: Larrosa
authors.forename: T
authors.initials: T
authors.lastname: Cornejo-Sánchez
authors.forename: G
authors.initials: G
authors.lastname: Prats
authors.forename: M P
authors.initials: MP
authors.lastname: Garcillán-Barcia
authors.forename: F
authors.initials: F
authors.lastname: de la Cruz
authors.forename: J J
authors.initials: JJ
authors.lastname: González-Lopéz
mesh_terms: D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics*; D016972:Enterobacter cloacae / Q000187:drug effects* / Q000235:genetics; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D029968:Escherichia coli Proteins / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D010957:Plasmids / Q000235:genetics*; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013030:Spain / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; C412613:CTX-M-9 protein, E coli; C417264:VIM-1 metallo-beta-lactamase; D001618:beta-Lactamases