Molecular characteristics of extended-spectrum β-lactamase-producing Klebsiella pneumoniae in Japan: Predominance of CTX-M-15 and emergence of hypervirulent clones.

• Material Type: 博士論文
• Title: Molecular characteristics of extended-spectrum β-lactamase-producing Klebsiella pneumoniae in Japan: Predominance of CTX-M-15 and emergence of hypervirulent clones.
• Author/Editor: Kakuta, Naoki; Nakano, Ryuichi; Nakano, Akiyo; Suzuki, Yuki; Masui, Takashi; Horiuchi, Saori; Kakuta, Risako; Tsubaki, Kohsuke; Ogawa, Miho; Yano, Hisakazu
• Author Heading: Kakuta, Naoki; Nakano, Ryuichi; Nakano, Akiyo; Suzuki, Yuki; Masui, Takashi; Horiuchi, Saori; Kakuta, Risako; Tsubaki, Kohsuke; Ogawa, Miho; Yano, Hisakazu
• Publication, Distribution, etc.: Elsevier
• Publication Date: 2020-09
• Publication Date (W3CDTF): 2020-09
• Alternative Title: 日本における基質特異性拡張型β-ラクタマーゼ産生肺炎桿菌の分子遺伝学的特徴：CTX-M-15の優位性と高病原性クローンの出現
• Periodical title: International journal of infectious diseases
• No. or year of volume/issue: 98
• Volume: 98
• Pages: 281-286
• ISSN (Periodical Title): ISSN : 1201-9712
• Degree grantor/type: 奈良県立医科大学
• Date Granted: 2021-03-15
• Dissertation Number: 甲第769号
• Degree Type: 博士（医学）
• Text Language Code: und
• Subject Heading: Klebsiella pneumoniae; Extended-spectrum β-lactamase; CTX-M-15; Hypervirulent
• Target Audience: 一般
• Note (General): type:Thesis; Objective: To provide data on the molecular characteristics of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae clinical isolates in Japan. Methods: A total of 100 clinical isolates of ESBL-producing K. pneumoniae collected throughout Japan between June and July 2018 were studied. ESBL genes were analyzed using PCR and DNA sequencing. Transferability of ESBL genes was investigated by conjugation experiments. Plasmid replicon types, virulence genes (rmpA, rmpA2, iucA, iroB, and peg-344) associated with hypervirulent K. pneumoniae (hvKp), and capsule types were detected using PCR. Genotyping was performed using multilocus sequence typing. Results: All ESBL-producing isolates carried blaCTX-M genes. The most predominant CTX-M-type identified was CTX-M-15 (n=55). We identified 24 sequence types (STs) among the CTX-M-15 producers, with ST25 (n=8) being the most common. Most of the transconjugants carrying blaCTX-M-15 contained the FIIk replicon. Of the 100 ESBL-producing isolates, 31 were hvKp defined by the presence of the virulence genes. These ESBL-producing hvKp isolates belonged to eight STs (STs 23, 25, 36, 65, 86, 268, 412, and 4492), with five capsule types (K1, K2, K20, K57, and undefined). Conclusions: CTX-M-15 was the predominant ESBL among K. pneumoniae isolates from Japan. This study shows that ESBL-producing hvKp strains comprising various clones are emerging in Japan.; 博士（医学）・甲第769号・令和3年3月15日; © 2020 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).; identifier:International journal of infectious diseases Vol.98 p.281-286 (2020 Sep); identifier:12019712; identifier:http://ginmu.naramed-u.ac.jp/dspace/handle/10564/3893; identifier:International journal of infectious diseases, 98: 281-286
• Access Restrictions: インターネット公開
• Related Material (DOI): 10.1016/j.ijid.2020.06.083
• Data Provider (Database): 国立情報学研究所 : 学術機関リポジトリデータベース（IRDB）（機関リポジトリ）; https://irdb.nii.ac.jp
• Original Data Provider (Database): 奈良県立医科大学 : 奈良県立医科大学機関リポジトリ GINMU

Table of Contents

http://ginmu.naramed-u.ac.jp/dspace/bitstream/10564/3893/1/01%e7%94%b2769%e6%9c%ac%e6%96%87%e3%81%ae%e8%a6%81%e6%97%a8.pdf fulltext

http://ginmu.naramed-u.ac.jp/dspace/bitstream/10564/3893/2/02%e7%94%b2769%e5%af%a9%e6%9f%bb%e8%a6%81%e6%97%a8.pdf fulltext

http://ginmu.naramed-u.ac.jp/dspace/bitstream/10564/3893/3/03%e7%94%b2769%e6%9c%ac%e6%96%87.pdf fulltext

http://ginmu.naramed-u.ac.jp/dspace/bitstream/10564/3893/4/04%e7%94%b2769Suppl..pdf fulltext