Molecular epidemiological analysis of Streptococcus pneumoniae in middle ear fluid isolates on acute otitis media in children after thirteen-valent pneumococcal conjugate vaccine introduction

• Project/Area Number: 17K16885
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Otorhinolaryngology
• Research Institution: Tohoku University
• Principal Investigator: OZAWA DAIKI 東北大学, 医学系研究科, 非常勤講師 (80792267)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
• Keywords: 急性中耳炎 / 肺炎球菌 / 血清型 / 薬剤感受性 / 13価肺炎球菌ワクチン / 13価結合型肺炎球菌ワクチン

Outline of Final Research Achievements

We surveyed the serotypes and antimicrobial susceptibility profile of 44 S. pneumoniae isolates obtained from the middle ear fluid of children with acute otitis media from March 2017 to February 2018, in order to research serotype replacement after the 13-valent pneumococcal conjugate vaccine (PCV13) introduction in Japan.
The most prevalent serotypes found were serotype 15A (15.9%), and serotype 23B (11.4%). 7-valent pneumococcal conjugate vaccine (PCV7) types accounted for 0% of all strains, while 9.1% were PCV13 types. Serotype 15A strains were 100% non-susceptible to penicillin G.
Finally, the high prevalence of non-susceptible serotype 15A highlights the serotype 15A should be noted as a cause of intractable acute otitis media in children.

Academic Significance and Societal Importance of the Research Achievements

肺炎球菌は急性中耳炎の代表的な原因菌である。13価結合型肺炎球菌ワクチン (PCV13) は導入後にPCV13が効果を示さない血清型の肺炎球菌が増加する菌交代現象が問題となる。本研究によりPCV13では効果がなく、なおかつペニシリン非感性の血清型15Aが増加していることがわかり、今後の小児急性中耳炎の難治化の原因になる可能性が示唆された。

Research Products

• [Journal Article] 小児急性中耳炎より分離された肺炎球菌のワクチン導入後における血清型と薬剤感受性 (2020)
  • Author(s): 髙島且統、真崎純子、小澤大樹
  • Journal Title: 日本臨床微生物学会雑誌 Volume: 31 Pages: 11-16
  • NAID: 40022455621
  • Peer Reviewed / Open Access
• [Journal Article] Infantile hemangiopericytoma of the tongue-Efficacy of ex utero intrapartum treatment procedure and combined-modality therapy. (2018)
  • Author(s): Ogawa T, Ishii R, Ozawa D, Rikiishi T, Usubuchi H, Watanabe M, Imai Y, Sato K, Saito M, Sasahara Y, Matsuda T, Kure S, Katori Y.
  • Journal Title: Auris Nasus Larynx. Volume: 45 Issue: 1 Pages: 186-189
  • DOI: 10.1016/j.anl.2017.02.009
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Clinical and bacteriological differences of deep neck infection in pediatric and adult patients: review of 123 cases. (2017)
  • Author(s): Yuichi Shimizu, Hiroshi Hidaka, Daiki Ozawa, Risako Kakuta, Kazuhiro Nomura, Hisakazu Yano, Ken-ichi Watanabe, Yukio Katori.
  • Journal Title: Int J Pediatr Otorhinolaryngol. Volume: 99 Pages: 95-99
  • DOI: 10.1016/j.ijporl.2017.05.028
  • Peer Reviewed
• [Journal Article] Risk factors for delayed oral dietary intake in patients with deep neck infections including descending necrotizing mediastinitis. (2017)
  • Author(s): Hidaka H, Ozawa D, Kuriyama S, Obara T, Nakano T, Kakuta R, Nomura K, Watanabe K, Katori Y.
  • Journal Title: Eur Arch Otolaryngol. Volume: 274 Issue: 11 Pages: 3951-3958
  • DOI: 10.1007/s00405-017-4716-3
  • Peer Reviewed / Open Access