好気性および嫌気性膜分離活性汚泥法における薬剤耐性遺伝子の動態に関する研究

Research Project

Project/Area Number	18J15071
Research Category	Grant-in-Aid for JSPS Fellows
Allocation Type	Single-year Grants
Section	国内
Research Field	Environmental engineering and reduction of environmental burden
Research Institution	Kyoto University
Research Fellow	馬緻宇京都大学, 工学研究科, 特別研究員(DC2)
Project Period (FY)	2018-04-25 – 2020-03-31
Project Status	Granted (Fiscal Year 2019)
Budget Amount *help	¥1,500,000 (Direct Cost: ¥1,500,000) Fiscal Year 2019: ¥700,000 (Direct Cost: ¥700,000) Fiscal Year 2018: ¥800,000 (Direct Cost: ¥800,000)
Keywords	antibiotic resistance / e.coli / wwtp effluent / lake biwa
Outline of Annual Research Achievements	The aim of this study was to investigate the presence and spread of antimicrobial resistance among Escherichia coli (E. coli) isolated from WWTPs effluent and Lake Biwa and to characterize E. coli isolates by microbial source tracking, multi-locus sequence typing, and analysis of E. coli phylogroups. A total of 93 E. coli isolates (51 from Lake Biwa and 42 from WWTPs effluent) were characterized through whole genome sequencing. As a result, we found that high prevalence of antibiotic resistant E. coli was detected in both WWTP effluent (21.4%) and Lake Biwa (35.3%) and the isolate which contained 11 different kinds of resistance gene also be found in WWTP effluent. Different distribution patterns of phylogenetic types and host sources were observed between isolates from effluent and Lake Biwa. Moreover, 49 % of E. coli isolates from Lake Biwa were classified from chicken and cow, which were significantly higher than those from WWTPs effluent (17.9%). Those results suggest that livestock industry and wild animal can be considered as one of pollution sources as well. Based on our results we conclude that WWTPs can be seen as an important route for spreading antibiotic resistance, particularly multidrug resistance, into the environment, But WWTPs effluent is not the only source of ARB dissemination, other possible causes (e.g. livestock industry, waterfowl) have to be further considered.
Current Status of Research Progress	Current Status of Research Progress 2: Research has progressed on the whole more than it was originally planned. Reason In the present study, whole-genome sequencing (WGS) analysis was used for predicting antimicrobial resistance phenotypes in Escherichia coli (E. coli) in the effluent from wastewater treatment plants and Lake Biwa. Our results provide the quite important monitor data on spread of antimicrobial resistance on aquatic environment. Also, those data can be further discussed the relationship between pathway and host source of antimicrobial resistance.
Strategy for Future Research Activity	The release of antibiotics into the environment can result in antimicrobial resistance (AMR) spread, which in turn can impede the effective prevention of infections caused by pathogens. Ampicillin is one kind of penicillin-based antibiotics which is used to treat a wide variety of bacterial infections. and veterinary use of ampicillin is estimated to 49000 kg per year in Japan. The aims of this study are to monitor antimicrobial resistance trends and to clarify molecular characterization of ampicillin-resistant Escherichia coli (E. coli) isolated from WWTPs influent, effluent and the receiving aquatic environment (Lake Biwa) in Japan.