Analysis of the predisposing host factors to severe pathological conditions caused by Acinetobacter baumannii infections and the search the new virulence factors of multi-drug resistant strains

2014 Fiscal Year Final Research Report

• Project/Area Number: 24591490
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Infectious disease medicine
• Research Institution: Teikyo University
• Principal Investigator: ONO YASUO 帝京大学, 医学部, 教授 (10177272)
• Co-Investigator(Kenkyū-buntansha): UBAGAI Tsuneyuki 帝京大学, 医学部, 講師 (10311416) ; KIKUCHI Hirotoshi 帝京大学, 医学部, 講師 (80338681) ; NAGAKAWA Shigeru 帝京大学, 医学部, 助教 (50266300) ; UEDA Takane 帝京大学, 医学部, 助教 (80459312) ; NAKANO Ryuichi 帝京大学, 医学部, 助教 (80433712)
• Co-Investigator(Renkei-kenkyūsha): GO Kamoshida 帝京大学, 医学部, 助手 (40707410) ; AKIYO Nakano 帝京大学, 医学部, 助手 (10707441)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: アシネトバクター・バウマニ / 好中球機能 / 好中球細胞外トラップ / リポ多糖 / 膜小胞 / 遺伝子発現 / 多剤耐性アシネトバクター / LAMP法

Outline of Final Research Achievements

1)Acinetobacter baumannii (A.baumannii) were resistant to phagocytosis and bactericidal activity by neutrophils as compared with Pseudomonas aeruginosa, neutrophil extracellular traps (NETs) formation was very little. 2) The lethality in a pulmonary infection mouse model caused by P. aeruginosa was higher than that of A.baumannii infection. 3) When neutrophils were stimulated with the lipopolysaccharides (LPS) derived from an A.baumannii standard strain or a multi-drug resistant strain (MDRA), gene expression levels of inflammatory cytokines in neutrophils were equally upregulated. Membrane vesicles derived from A.baumannii could not stimulate the production of reactive oxygen in neutrophils, but acted as a chemoattractant. 4) A. baumannii-derived LPS enhanced the TNF-α and IL-8 production in mast cells. 5) We have developed a LAMP method to detect MDRA. 6) Humoral immunodeficiency may be a predisposing factor to severe pathological conditions during A. baumannii infections.

Free Research Field

感染免疫学