Clarification of drug resistance of mucoid type Streptococcus pneumoniae

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K08103
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Medical pharmacy
• Research Institution: Sapporo Medical University
• Principal Investigator: Miyamoto Atsushi 札幌医科大学, 医学部, 教授 (50166196)
• Co-Investigator(Kenkyū-buntansha): 横田 伸一 札幌医科大学, 医学部, 教授 (10325863) ; 白石 宗 札幌医科大学, 医学部, 助教 (70725168) ; 北川 学 札幌医科大学, 医学部, 研究員 (70751270)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 肺炎球菌 / ムコイド / 抗菌ペプチド / 納豆由来ペプチド

Outline of Final Research Achievements

We obtained 51 mucoid strains from 1,061 Streptococcus pneumoniae clinical isolates collected in Hokkaido Prefecture, Japan. We evaluated biofilm formation, minimum biofilm eradication concentration of various antimicrobials, and growth rate. Significant differences between mucoid and non-mucoid strains were not observed. On the other hand, we found that Natto peptide, which is from a Japanese soy bean fermented food, showed specific bactericidal activity against S. pneumoniae, and Bacillus subtilis group　of Bacillus genus. We clarified that its mechanism was failure of cell separation during cell division in S. pneumoniae. The Natto peptide showed similar antimicrobial activity against mucoid, non-mucoid, antimicrobial susceptible, and multidrug resistant strains of S. pneumoniae.

Free Research Field

医療薬学