Pathogenicity acquisition mechanism of oral streptococci via gene transfer and expression of cytolysin genes

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K11012
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Morphological basic dentistry
• Research Institution: The University of Tokushima
• Principal Investigator: Nagamune Hideaki 徳島大学, 大学院社会産業理工学研究部(生物資源産業学域), 教授 (40189163)
• Co-Investigator(Kenkyū-buntansha): 友安 俊文 徳島大学, 大学院社会産業理工学研究部(生物資源産業学域), 准教授 (20323404) ; 田端 厚之 徳島大学, 大学院社会産業理工学研究部(生物資源産業学域), 講師 (10432767)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 口腔連鎖球菌 / 細胞溶解毒素 / 溶血毒素

Outline of Final Research Achievements

In oral streptococci such as mitis group streptococci (MGS) and anginosus group streptococci (AGS), we investigated the search and characterization of unknown molecule of hemolytic cytolysin (HL), the relation between the regulation of HL expression and the pathogenicity, and the mechanism of pathogenicity acquisition via HL gene transfer in S. mitis (SM). In a S. infantis strain belonging to MGS, a HL that is most-closely related to 5 domain-type cholesterol-dependent HL (5D-CDC) of SM and shows quite similar property to 5D-CDC was discovered. This suggests the HL gene transfer among MGS species. Moreover, it was suggested that SM might obtain pathogenicity via HL gene transfer that IS participated in, because the 5D-CDC gene transfer was detected by cultivation of a SM strain with no HL gene in the presence of the genomic DNA from the strains with 5D-CDC gene and IS at the adjacent loci and a competence-stimulating peptide of SM.

Free Research Field

細菌学