Molecular epidemiological study of pneumococcal serotypes, drug resistance, and surface antigen for novel vaccine development

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K09101
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Hygiene and public health
• Research Institution: Sapporo Medical University
• Principal Investigator: Kawaguchiya Mitsuyo 札幌医科大学, 医学部, 助教 (70733062)
• Co-Investigator(Kenkyū-buntansha): 小林 宣道 札幌医科大学, 医学部, 教授 (80186759) ; 漆原 範子 札幌医科大学, 医学部, 准教授 (80396308)
• Research Collaborator: ITO Masahiko
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 肺炎球菌 / 蛋白結合型ワクチン / 表層蛋白 / 血清型 / 非ワクチン血清型 / 分子疫学 / 薬剤耐性

Outline of Final Research Achievements

After the introduction of the pneumococcal conjugate vaccine (PCV) for children, an increase in pneumococcal diseases caused by non-PCV serotypes is a worldwide concern. The prevalence of serotypes, antimicrobial resistance, and its relevance to PspA which is a considered as promising vaccine candidate were investigated for 729 (678 children, 51 adults) non-invasive pneumococcal isolates. Isolates were collected in hospitals and clinics in Hokkaido between June and November 2016. As a results, 87.9% of isolates from children belonged to non-PCV13 serotypes and most isolates (81-100%) of the dominant serotypes 15A, 35B and 23A were non-susceptible to penicillin. While most of the isolates (99%) had PspA belonging to either family 1 or 2, PspA family 3/clade 6 was detected in only non-PCV13 serotype 37 isolates assigned to ST447 and ST7970 showing the mucoid phenotype.

Free Research Field

衛生学

Academic Significance and Societal Importance of the Research Achievements

小児に対する肺炎球菌結合型ワクチン導入後、国内外においてワクチンに含まれない血清型の増加とその薬剤耐性傾向が臨床上問題となっている。この現況に対し、肺炎球菌血清型分布とその薬剤耐性の状況、流行株の分子疫学的特徴を明らかにすることで、今後の肺炎球菌感染症対策に寄与する知見を得る。加えて、莢膜型（血清型）に依存しない、次世代肺炎球菌ワクチン抗原の候補である菌表層蛋白PspAの分子疫学的性状を含めた研究を行なう。これらの成果を国内外で発信・報告することは、新規ワクチン開発の早期の実現に結び付く基礎資料として、クローバルな肺炎球菌感染症対策に貢献するものであると考える。