The analysis of the novel mechanism of hypermucoviscosity of K. pneumoniae.

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K07112
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 49050:Bacteriology-related
• Research Institution: National Institute of Infectious Diseases
• Principal Investigator: Kayama Shizuo 国立感染症研究所, 薬剤耐性研究センター, 主任研究官 (50432761)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 薬剤耐性 / 病原性 / 遺伝子

Outline of Final Research Achievements

In this study, we analyzed the genome of hypermucoviscous K. pneumoniae clinical isolates in Japan and examined the relationship between hypermucoviscosity and pathogenic genes and antibiotic resistance genes. As a result, a large proportion of strains carrying the rmpA/rmpA2 gene expressed hypermucoviscosity at 37°C. On the other hand, the strains without the rmpA/rmpA2 gene showed hypermucoviscosity at room temperature. In addition, it was inferred that an antibiotic resistant plasmid was transferred to the originally hypermucoviscous strain, resulting in the development of a hypermucoviscous antibiotic resistant strain. This suggests the possibility of clarifying the mechanism of the development of highly pathogenic strains showing antibiotic resistance.

Free Research Field

細菌学

Academic Significance and Societal Importance of the Research Achievements

粘稠性を示すK. pneumoniaeは、病原性が高いとの報告がある。また、このような株は薬剤耐性を示すことがほとんどないとも報告されてきた。しかし近年、粘稠性を示す薬剤耐性菌の分離が散見されるようになった。そこで、本研究では、日本で臨床分離された粘稠性を示すK. pneumoniaeのゲノム解析を実施し、粘稠性と病原遺伝子および薬剤耐性遺伝子との相関を検討した。これにより、薬剤耐性を示す高病原性株が発生するメカニズムを明らかにできる可能性を示した。