Investigation of molecules involved in pathogenic mechanism and innate immune evasion of Streptococcus suis

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K15658
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 42020:Veterinary medical science-related
• Research Institution: National Institute of Infectious Diseases (2021-2023); The University of Tokyo (2020)
• Principal Investigator: Ishida-Kuroki Kasumi (石田香澄) 国立感染症研究所, 薬剤耐性研究センター, 主任研究官 (80760272)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 豚レンサ球菌 / Streptococcus suis / 全ゲノム解析 / ヒアルロニダーゼ

Outline of Final Research Achievements

Streptococcus suis is known to cause zoonotic diseases, such as meningitis and bacteremia. However, the specific virulence factors have remained unclear. This study revealed that virulent strains of Streptococcus suis harbored a gene cluster consisting of genes encoding hyaluronidase and heparinase that degrade host glycosaminoglycans, a phosphotransferase system for importing these degraded products into bacterial cells, and enzymes of the Entner-Doudoroff pathway for metabolizing these products. This gene cluster was also found in Streptococcus ruminantium, which is a close relative of S. suis, Streptococcus pneumoniae, and Group G streptococci, suggesting that the gene cluster associates with the pathogenicity of Streptococcus suis and other streptococci.

Free Research Field

細菌学

Academic Significance and Societal Importance of the Research Achievements

本研究ではブタやヒトに髄膜炎や菌血症を引き起こす豚レンサ球菌の発症に関与する可能性がある遺伝子群を見出した。また、この遺伝子群は豚レンサ球菌だけでなく、ヒトに病原性を示す他のレンサ球菌でも認められ、レンサ球菌が共通して保有する病原因子である可能性が示唆された。今後、この遺伝子群について精査することで、レンサ球菌感染症の発症機序や病態の解明に繋がることが期待される。