Evolution of penicillin-resistant Streptococcus pneumoniae of serotype 3 by capsular switching after introductions of 7-valent pneumococcal vaccine in children, in Japan

• Project/Area Number: 26870568
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Bacteriology (including mycology); Infectious disease medicine
• Research Institution: Keio University
• Principal Investigator: CHIBA NAOKO 慶應義塾大学, 医学部(信濃町), 共同研究員 (50420815)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2016: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2015: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2014: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: Streptococcus pneumoniae / capsular switchingne / ゲノム解析 / 莢膜型3型 / PRSP / MLST / cps / homologous recombination / capsular switching / streptococcus peumoniae / 肺炎球菌 / 侵襲性肺炎球菌感染症 / 莢膜遺伝子

Outline of Final Research Achievements

The present study is the first report of a genotypic penicillin-resistant Streptococcus pneumoniae (gPRSP) derived from a Taiwan23F-15 clone prevalent in Asia that acquired a cps-locus region encoding a type 3 capsule by homologous recombination, resulting in emergence of gPRSP of serotype 3. Additionally, this recombinant event most likely occurred in recent years because the nucleotide sequencein recombination region of KK0981 were completely consistent with these of KK0381 of serotype 3.

Research Products

• [Presentation] 肺炎球菌23価ワクチン（PPSV23）に含まれない莢膜型にみいだされたgPRSPの分子疫学解析 (2015)
  • Author(s): 千葉菜穂子，高田美佐子，諸角美由紀，花田豪郎，輪島丈明 岩田 敏，生方公子
  • Organizer: 第８９回日本感染症学会総会・学術講演会
  • Place of Presentation: 国立京都国際会館（京都府京都市）
  • Year and Date: 2015-04-17
• [Presentation] 肺炎球菌23価ワクチン（PPSV23）に含まれない莢膜型にみいだされたgPRSPの分子疫学解析 (2015)
  • Author(s): 千葉菜穂子，高田美佐子，諸角美由紀，花田豪郎，輪島丈明，岩田 敏，生方公子
  • Organizer: 第89回日本感染症学会総会・学術講演会
  • Place of Presentation: 国立京都国際会館 (京都府京都市左京区)
  • Year and Date: 2015-04-17
• [Presentation] Genetic Analysis of Streptococcus pneumoniae Isolates from Pneumococcal Infections Showing High Resistance to β-Lactam Agents (2014)
  • Author(s): N. Chiba, M. Morozumi, T. Wajima, S. Iwata, K. Ota, K. Ubukata
  • Organizer: Interscience Conference of Antimicrobial Agents and Chemotherapy
  • Place of Presentation: Walter E. Washington Convention Center (Washington, D.C. 20001, United States)
  • Year and Date: 2014-09-05 – 2014-09-09
• [Presentation] 小児へのPCV7導入による成人侵襲性感染症由来肺炎球菌(IPD)由来株の変化 (2014)
  • Author(s): 千葉菜穂子，荘司 路，諸角美由紀 ，生方公子，岩田 敏
  • Organizer: 第88回日本感染症学会学術講演会
  • Place of Presentation: ヒルトン福岡シーホーク (福岡県福岡市中央区)
  • Year and Date: 2014-06-19