title: Identification of a plasmid-borne blaIMP-11 gene in clinical isolates of Escherichia coli and Klebsiella pneumoniae.
abstract: The acquired metallo-β-lactamases represent a significant clinical threat due to their unrivalled hydrolysis spectrum and their resistance to therapeutic inhibitors of β-lactamase. In this study, we identified plasmid- and integron-borne bla(IMP-11) in clinical isolates of Escherichia coli and Klebsiella pneumoniae. The bla(IMP-11) gene cassette was carried by a typical class 1 integron together with aacA1 and orfG gene cassettes. The integron, intI1-bla(IMP-11)-aacA1-orfG-qacEΔ1-sul1, was easily transferred by intraspecies and intergenus conjugation of bacteria, indicating that the integron is located on a transferable plasmid. The integrated genes were preceded by TGGACA-N(17)-TAAACT, a hybrid P(c) promoter. Similar to the wild-type donors, the transconjugants also showed reduced susceptibility or resistance to carbapenems, amikacin and kanamycin. The identical integron was detected in four bacterial strains which were genetically different but were isolated from infant inpatients in the same paediatric department. These results demonstrate the colonization of the plasmid- and integron-borne bla(IMP-11) and aacA1 in the hospital environment, highlighting the importance of surveying and controlling the spread of such resistance determinants in nosocomial pathogens.
authors.affiliation: Department of Microbiology and Immunology, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Zhao
authors.affiliation: Department of Clinical Pathology, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Gelin
authors.initials: G
authors.lastname: Chen
authors.affiliation: Clinical Laboratory, Showa University Hospital, Showa University, Tokyo, Japan.
authors.forename: Ribu
authors.initials: R
authors.lastname: Ito
authors.affiliation: Department of Laboratory Medicine and Central Clinical Laboratory, Showa University Northern Yokohama Hospital, Yokohama, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kimura
authors.affiliation: Department of Microbiology and Immunology, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Zhi-Qing
authors.initials: ZQ
authors.lastname: Hu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015780:Carbapenems / Q000494:pharmacology; D016000:Cluster Analysis; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology*; D022761:Gene Transfer, Horizontal; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D032023:Integrons; D007710:Klebsiella Infections / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D010957:Plasmids; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D001618:beta-Lactamases