The mechanism of spread of epidemic clones of antimicrobial resistant bacteria

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K08846
• 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: Suzuki Masato 国立感染症研究所, 薬剤耐性研究センター, 主任研究官 (70444073)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 薬剤耐性 / 病原性

Outline of Final Research Achievements

Acinetobacter baumannii is one of the most serious antimicrobial resistant bacteria, and the epidemic clones have acquired antimicrobial resistance genes. In this study, we collected A. baumannii clinical isolates in the world, and performed comparative genomic analysis of the isolates and functional analysis of the type VI secretion system (T6SS). Some multidrug-resistant epidemic clones of A. baumannii utilized T6SS to compete neighbour bacteria depending on bactericidal activities of effecter proteins secreted via T6SS, and seemed to have accumulated useful genes, such as antimicrobial resistant genes and virulence-associated genes, on their genomes and plasmids. We identified enzymatic activities of several T6SS effecter proteins, and elucidated the effect of T6SS on bacterial conjugation of antimicrobial resistance plasmids among A. baumannii.

Free Research Field

細菌学

Academic Significance and Societal Importance of the Research Achievements

病原細菌において、菌種・菌株毎に保存性が異なるT6SSの分泌タンパク質は、菌株間のビルレンスの差違や菌株の地域・人種特異性などを説明することが可能な重要な因子であり、最新の細菌学と分子疫学の知見を結び付ける成果を得られることが期待できる。また今後、細菌感染症の創薬やワクチンの開発を考える上で、病原細菌の宿主内生存・増殖を阻害することが可能な効果的な標的になることが期待できる。