Reduction of capsular production of S.pneumoniae in children of acute otitis media

• Project/Area Number: 24592556
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Wakayama Medical University
• Principal Investigator: Togawa Akihisa 和歌山県立医科大学, 医学部, 講師 (70305762)
• Co-Investigator(Kenkyū-buntansha): Yamanaka Noboru 和歌山県立医科大学, 医学部, 教授 (10136963) ; Ikeda Yorihiko 和歌山県立医科大学, 医学部, 講師 (20423949) ; Ogami Masashi 和歌山県立医科大学, 医学部, 博士研究員 (90423946)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2014: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2013: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: 肺炎球菌 / フェーズ変化 / 莢膜 / 急性中耳炎 / 莢膜多糖体

Outline of Final Research Achievements

Streptococcus pneumoniae, a leading cause of acute otitis media (AOM), undergoes spontaneous intra-strain phase variations such as transparent or opaque in colony morphology depending on the capsular productionsynthesis. Most isolates of S.pneumoniae are mixed population of transparent and Opaque colony phenotypes.The pneumococcus exhibit spontaneous phase variation between Transparent variants with thin capsule and Opaque variants with thick capsule。Sub-MIC levels of clarithromycin reduced the capsule of inter-cellular invaded pneumococci. The effect of clarithromycin against pneumococcal phase variation will suggest that clarithromycin would reduce the virulence of pneumococci

Research Products

• [Journal Article] An application of outer membrane protein p6-specific enzyme-linked immunosorbent assay for detection of haemophilus influenzae in middle ear fluids and nasopharyngeal secretions. (2013)
  • Author(s): Hotomi M
  • Journal Title: PLos One Volume: 8
  • Peer Reviewed
• [Journal Article] Incidence survey of acute otitis media in children in Sado Island, Japan--Sado Otitis Media Study (SADOMS). (2013)
  • Author(s): Otsuka T
  • Journal Title: PLos One Volume: 8
  • Peer Reviewed
• [Journal Article] PspA family distribution, antimicrobial resistance and serotype of Streptococcus pneumoniae isolated from upper respiratory tract infections in Japan. (2013)
  • Author(s): Hotomi M
  • Journal Title: PLos One Volume: 8
  • Peer Reviewed
• [Journal Article] Individual risk factors associated with nasopharyngeal colonization with Streptococcus pneumoniae and Haemophilus influenzae: a Japanese birth cohort study. (2013)
  • Author(s): Otsuka T
  • Journal Title: Pedeatr Infect Dis J. Volume: 32 Pages: 709-714
  • Peer Reviewed
• [Presentation] 肺炎球菌性中耳炎における病原性因子の発現と抗菌薬の影響. (2015)
  • Author(s): 武田早織、平岡政信、山内一真、戸川彰久、保富宗城、山中昇
  • Organizer: 第3回日本耳鼻咽喉科感染症・エアロゾル学会
  • Place of Presentation: 札幌
  • Year and Date: 2015-09-03
• [Presentation] Population Shift Of Infants' Nasopharyngeal Microbiota After Antibiotic Therapy (2013)
  • Author(s): Hiraoka M
  • Organizer: The 8th International Symposium on Tonsils and Mucosal Barriers of the Upper Airways
  • Place of Presentation: Zurich,Switzerland
• [Presentation] 7価肺炎球菌結合型ワクチンによる急性中耳炎由来肺炎球菌のワクチンカバー率と予防効果の予測 (2012)
  • Author(s): 池田頼彦
  • Organizer: 日本化学療法学会西日本支部総会
  • Place of Presentation: 福岡
• [Presentation] 急性中耳炎中における肺炎球菌フェーズ変化の検討 (2012)
  • Author(s): 保富宗城
  • Organizer: 日本化学療法学会西日本支部総会
  • Place of Presentation: 福岡
• [Presentation] 上気道感染症における鼻咽腔肺炎球菌の量的変化 (2012)
  • Author(s): 小上真史
  • Organizer: 日本化学療法学会西日本支部総会
  • Place of Presentation: 福岡
• [Presentation] Clinical efficacy of middle ear ventilation tube insertion against intractable acute otitis media (2012)
  • Author(s): Akihisa Togawa
  • Organizer: The 9th international Conference on Cholesteatoma and Ear Surgery
  • Place of Presentation: Nagasaki