Molecular basis of streptococcal toxic shock-like syndrome caused by group B streptococci

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K08795
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Bacteriology (including mycology)
• Research Institution: National Institute of Infectious Diseases
• Principal Investigator: Ikebe Tadayoshi 国立感染症研究所, 細菌第一部, 主任研究官 (20333362)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: レンサ球菌 / 劇症型溶血性レンサ球菌感染症

Outline of Final Research Achievements

Mutations were identified in specific genes in streptococcal toxic shock-like syndrome (STSS) isolates. As a result of determining the nucleotide sequence of this gene in 50 strains of group B streptococcus of various serotypes that caused STSS, mutations were found in 13 of the 50 strains. On the other hand, in the vaginal strain, only 1 out of 50 strains had mutations. A mutant strain of this gene was constructed. In addition to genome-wide gene expression regulation analysis, in order to search for novel virulence genes, RNA was extracted from vaginal-derived strains and strains in which the causative gene of the vaginal-derived strain was mutated, and RNA-seq was performed. As a result, it was revealed that the expression of pathogenic factors such as hemolytic toxin, peptidase, and adhesion factor was increased.

Free Research Field

細菌学

Academic Significance and Societal Importance of the Research Achievements

B群レンサ球菌は、膣に常在していることや、小児に髄膜炎を引き起こすことが知られている。近年、B群レンサ球菌による劇症型感染症が報告されているが、その原因は分かっていなかった。本研究において、そのメカニズムが明らかとなり、将来的な治療や予防の観点から意義ある研究である。