title: Microbiological and clinical characteristics of bacteraemia caused by the hypermucoviscosity phenotype of Klebsiella pneumoniae in Korea.
abstract: Hypermucoviscous (HV) isolates of Klebsiella pneumoniae have been linked to virulence potential in experimental infections. We examined 33 isolates of K. pneumoniae from patients with bacteraemia for the HV phenotype on agar culture, and determined their virulence potential by screening for capsular (K) serotype by polymerase chain reaction and the presence of seven virulence factor genes. Fourteen (42·4%) isolates expressed the HV phenotype and 11 of these were serotype K1 or K2; these serotypes were not identified in HV-negative isolates. The genes rmpA, rmpA2, aerobactin, wabG and allS were significantly more frequent in HV than non-HV isolates. Multilocus sequence typing identified 21 sequence types (ST), eight of which were found in HV-positive isolates and the clonal relatedness of isolates of the most frequent types (ST23 and ST11) from different hospitals was confirmed by pulsed-field gel electrophoresis. The HV phenotype was more associated with community-acquired infection with a lower frequency of fatal underlying illness, but with significantly more focal infections, notably liver abscesses. Clinicians should be aware of such clinical impacts of the HV phenotype.
authors.affiliation: Department of Laboratory Medicine, Seoul St Mary's Hospital, Korea.
authors.forename: S W
authors.initials: SW
authors.lastname: Jung
authors.affiliation: Department of Laboratory Medicine, Seoul St Mary's Hospital, Korea.
authors.forename: H J
authors.initials: HJ
authors.lastname: Chae
authors.affiliation: Department of Laboratory Medicine, Seoul St Mary's Hospital, Korea.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Park
authors.affiliation: Department of Laboratory Medicine, Seoul St Mary's Hospital, Korea.
authors.forename: J K
authors.initials: JK
authors.lastname: Yu
authors.affiliation: Department of Laboratory Medicine, St Vincent's Hospital, Korea.
authors.forename: S Y
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Uijeongbu St Mary's Hospital, Korea.
authors.forename: H K
authors.initials: HK
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Yoido, St Mary's Hospital, Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Bucheon St Mary's Hospital, Korea.
authors.forename: J M
authors.initials: JM
authors.lastname: Kahng
authors.affiliation: Department of Laboratory Medicine, Incheon St Mary's Hospital, College of Medicine, The Catholic University of Korea, Korea.
authors.forename: S O
authors.initials: SO
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Chung Ang University College of Medicine, Korea.
authors.forename: M K
authors.initials: MK
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Lim
authors.affiliation: Department of Laboratory Medicine, College of Medicine, Yeungnam University-Daegu, Korea.
authors.forename: C H
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Chosun University Medical School, Gwangju, Korea.
authors.forename: S J
authors.initials: SJ
authors.lastname: Chang
authors.affiliation: Sooncheonhyang University College of Medicine, Gumi, Korea.
authors.forename: J Y
authors.initials: JY
authors.lastname: Ahn
authors.affiliation: Chungju Medical Center, Choongju, Korea.
authors.forename: J W
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Biostatistics, College of Medicine, The Catholic University of Korea.
authors.forename: Y G
authors.initials: YG
authors.lastname: Park
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000235:genetics* / Q000382:microbiology; D003428:Cross Infection / Q000209:etiology; D004352:Drug Resistance, Microbial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D007710:Klebsiella Infections / Q000235:genetics* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000145:classification / Q000235:genetics / Q000472:pathogenicity; D008100:Liver Abscess / Q000209:etiology; D058885:Multilocus Sequence Typing / Q000379:methods; D010641:Phenotype; D016133:Polymerase Chain Reaction; D056910:Republic of Korea; D012189:Retrospective Studies; D012703:Serotyping / Q000379:methods; D062606:Tertiary Care Centers; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D000890:Anti-Infective Agents; D037521:Virulence Factors