Analysis of biliary-pathogenic Escherichia coli detected from bacteremia with acute biliary tract infection

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K16171
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 54030:Infectious disease medicine-related
• Research Institution: The University of Tokyo
• Principal Investigator: Ikeda Mahoko 東京大学, 医学部附属病院, 助教 (40723200)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 大腸菌菌血症 / 急性胆道感染症 / 病原性 / iutA遺伝子 / ibeA遺伝子 / 重症度

Outline of Final Research Achievements

Information on cases of bacteremia in acute biliary tract infection in a retrospective study was collected from 2013 to 2015 at a tertiary care hospital in Japan. Factors related to the severity of infection were investigated.
In total, 72 E. coli strains were identified in 71 cases, most of which primarily belonged to the B2 phylogroup (68.1%). The presence of the iutA gene (77.3% in the non-severe group, 46.4% in the severe group) and the ibeA gene (9.1% in the non-severe group, and 35.7% in the severe group) was significantly associated with the severity of infection. Among the patient characteristics, diabetes mellitus with organ involvement and alkaline phosphatase were different in the severe and non-severe groups.

Free Research Field

感染症における大腸菌の病原性

Academic Significance and Societal Importance of the Research Achievements

大腸菌は、尿路感染症や髄膜炎以外にも、急性胆道感染症を起こす病原微生物だが、その病原性の解析は進んでいない。本研究では、急性胆道感染症および菌血症を起こした大腸菌の病原性を解析し、iutAおよびibe遺伝子が重症度に関与していることが明らかにした。将来的に、これらの因子がどのように重症化を起こすのかを解明し、治療薬やワクチン、および再発予防の病原性大腸菌スクリーニングなどの対策に活用できる。この結果、急性胆道感染症による死亡率を下げ、入院期間や医療費の削減にも役立つと思われる。