title: Electron microscopic structures, serum resistance, and plasmid restructuring of New Delhi metallo-β-lactamase-1 (NDM-1)-producing ST42 Klebsiella pneumoniae emerging in Japan.
abstract: Enterobacteriaceae, carrying the New Delhi metallo-β-lactamase-1 (NDM-1) gene (bla                 (NDM-1)), have emerged and posed a threat since 2006. In Japan, bla                 (NDM-1)-carrying Escherichia coli was first described in 2010. In this study, we characterized NDM-1-positive Klebsiella pneumoniae strain 419 in Japan, which was isolated from the urine of a 90-year-old Japanese patient who had never been to the Indian subcontinent. K. pneumoniae 419 belonged to ST42. It possessed a surface capsule (with untypeable capsular PCR types) and was resistant to serum killing. K. pneumoniae 419 cells were occasionally flagellated or piliated and autoaggregated. K. pneumoniae 419 was resistant to β-lactams (including carbapenems), aminoglycosides, and fluoroquinolones, and was susceptible to imipenem (or biapenem), aztreonam, polymixin B, and colistin. It possessed at least eight plasmids; of those, a 74-kb plasmid (pKPJ1) of the replicon FIIA carried bla                 (NDM-1) and was conjugally transferred to E. coli strains, with a 71-kb transferable azithromycin-resistant (mphA                 (+)) plasmid of the replicon F (pKPJ2), as a large (145-kb) plasmid (pKPJF100) through a transposition event. In addition to bla                 (NDM-1), pKPJ1 carried arr-2, pKPJ2 carried mphA, and pKPJF100 carried both. They were negative for the 16S rRNA methylase gene, e.g., which is frequently associated with bla                 (NDM-1). The data demonstrate that K. pneumoniae 419 possessed virulence- and fitness-associated surface structures, was resistant to serum killing, and possessed a unique (or rare) genetic background in terms of ST type and bla                 (NDM-1)-carrying plasmid.
authors.affiliation: Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. tatsuoy@med.niigata-u.ac.jp
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Tomomi
authors.initials: T
authors.lastname: Takano
authors.forename: Takehito
authors.initials: T
authors.lastname: Fusegawa
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Shibuya
authors.forename: Wei-Chun
authors.initials: WC
authors.lastname: Hung
authors.forename: Wataru
authors.initials: W
authors.lastname: Higuchi
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Iwao
authors.forename: Olga
authors.initials: O
authors.lastname: Khokhlova
authors.forename: Ivan
authors.initials: I
authors.lastname: Reva
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017963:Azithromycin / Q000494:pharmacology; D001770:Blood Bactericidal Activity; D003227:Conjugation, Genetic; D024881:Drug Resistance, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000235:genetics* / Q000302:isolation & purification / Q000648:ultrastructure*; D008826:Microbial Sensitivity Tests; D008854:Microscopy, Electron; D010957:Plasmids / Q000235:genetics*; D014552:Urinary Tract Infections / Q000382:microbiology; D014556:Urine / Q000382:microbiology; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1