Development of a new mouthwash for reducing risk of ventilator-associated pneumonia (VAP)

Research Project

Project/Area Number	17K17172
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Prosthodontics/ Dental materials science and
Research Institution	Hiroshima University
Principal Investigator	Okazaki Yohei 広島大学, 病院(歯), 助教 (00706898)
Project Period (FY)	2017-04-01 – 2020-03-31
Project Status	Completed (Fiscal Year 2019)
Budget Amount *help	¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000) Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000) Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Keywords	人工呼吸器関連肺炎（VAP) / 洗口剤 / 抗菌剤
Outline of Final Research Achievements	Oral health care is a viable method of reducing the risk of ventilator-associated pneumonia (VAP). However, in Japan, oral care with chlorhexidine has been little used to prevent the development of pneumonia. The purpose of this study was to evaluate the in vitro antimicrobial effect of low- and high-viscosity experimental mouthwashes containing cetylpyridinium chloride (CPC) and 4-isopropyl-3-methylphenol (IPMP) on Streptococcus pneumoniae, Klebsiella pneumoniae, Porphyromonas gingivalis, Streptococcus mutans, and Candida albicans. Non-viscous mouthwashes containing either CPC- or IPMP were used as controls. The antimicrobial activity (sterilization or exposure time) of mouthwashes was evaluated based on the bactericidal criterion of <10 viable cells in 0.1 mL of culture medium. Consequently, the low-viscosity mouthwash containing anodal CPC and neutral IPMP exhibited superior antimicrobial effects against pneumonia- and oral infection-related bacteria compared with the controls.
Academic Significance and Societal Importance of the Research Achievements	人工呼吸器関連肺炎（VAP）の口腔ケアにおいて、欧米ではグルコン酸クロルヘキシジンを0.12～0.2％の高濃度で含有した洗口剤が使用されている。しかしながら、日本ではアナフィラキシーショックの発症以来、グルコン酸クロルヘキシジンの濃度は0.05％以下とされ効果は十分でない。そこで、本研究で開発した洗口剤は、グルコン酸クロルヘキシジンに代わり、VAP発症リスクの軽減に寄与するものと考える。