Investigation of acquisition mechanism of hyper virulence by spontaneous mutation mechanism of group A streptococcus using next generation sequencers.

2014 Fiscal Year Final Research Report

• Project/Area Number: 24390109
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Bacteriology (including Mycology)
• Research Institution: Research Institute, International Medical Center of Japan
• Principal Investigator: MIYOSHI-AKIYAMA Tohru 独立行政法人国立国際医療研究センター, その他部局等, その他 (20246466)
• Co-Investigator(Kenkyū-buntansha): KIRIKAE Teruo 国立研究開発法人, 国立国際医療研究センター (50192563)
• Co-Investigator(Renkei-kenkyūsha): WATANABE Shinya 国立研究開発法人, 国立国際医療研究センター (60614956)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 次世代シーケンサー / レンサ球菌 / マウスモデル / 自発的変異

Outline of Final Research Achievements

Ten genes related to in vivo spontaneous mutation of group A streptococcus were deleted individually, and the mutants were tested for in vivo mutation spectral by using a mouse infection model. Deletion sdn1 or csn1 resulted in reduction of covS mutation rate.
After inoculation in mouse, gene expression profile of SDSE was analyzed comprehensively. The results showed that expression of virulence factors such as hemolysins, and enzymes degrading sugars were elevated. SDSE clinical isolates harboring st6297-type emm gene, which is prevalent type in Japanese patients, produced significantly higher amount of hemolysins in comparison with isolates harboring other types of the emm genes.

Free Research Field

細菌学・感染症学