Identification of virulence genes of Streptococcus pneumoniae in fulminant cases.

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K08449
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 54030:Infectious disease medicine-related
• Research Institution: Teikyo University
• Principal Investigator: Kikuchi-Ueda Takane 帝京大学, 医学部, 講師 (80459312)
• Co-Investigator(Kenkyū-buntansha): 斧 康雄 帝京大学, 医学部, 教授 (10177272) ; 西田 智 帝京大学, 医学部, 講師 (10409386) ; 藤崎 竜一 帝京大学, 医療技術学部, 准教授 (00527442)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 細菌感染 / 炎症 / ゲノム解析

Outline of Final Research Achievements

Acute Infectious Purpura Fulminans (AIPF), with its rapid progression of skin and muscle necrosis, has a high mortality rate, and even if the patient is saved, the QOL of the patient is extremely low due to excision of ischemic and necrotic areas. Although there are several known strains of AIPF, we performed whole genome analysis of two PF strains isolated from two patients with purpura pneumoniae, two Sepsis strains isolated from six patients with sepsis, and three strains from patients with pneumonia using Nanopore and Illumina MiSeq. The genome analysis of 11 strains was completed. All strains were approximately 2 Mb in length. Registration of these 11 strains to DDBJ was completed. The capsular types of PF strains were 6(6A/6B/6C/6D) and 35B, which were the most distant in the genome-wide phylogenetic tree of the core gene.

Free Research Field

感染症

Academic Significance and Societal Importance of the Research Achievements

本研究課題の学術的意義は、起因菌が髄膜炎菌(主に米国)、肺炎球菌、溶血性連鎖球菌など複数種のため、短時間に播種生血管内凝固と抹消の紫斑を形成し、皮膚・筋肉の壊死が進み致死率が高い急性感染性電撃紫斑病(Acute Infectious Purpura Fulminans; AIPF)の病原因子の同定を試み、候補分子を明らかにしたことである。肺炎球菌と同定された２例のAIPF患者から分離したPF株に他の株に見られない配列部位を持つ遺伝子Nan Aを明らかにした。
社会的意義は、Nan Aという病原因子候補を同定したことは本因子を標的としたPCRや抗体による検出系が創成と早期診断の可能性の貢献した。