Development of a simple and rapid quantification method of pathogenic bacteria and drug-resistant bacteria based on fluorogenic substrates

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K18894
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Civil engineering and related fields
• Research Institution: Hokkaido University
• Principal Investigator: Satoh Hisashi 北海道大学, 工学研究院, 教授 (80326636)
• Project Period (FY): 2017-06-30 – 2019-03-31
• Keywords: センサ

Outline of Final Research Achievements

Monitoring of Escherichia coli concentrations at wastewater treatment plants (WWTPs) is important to ensure process performance and protect public health. However, conventional E. coli enumeration methods are complicated, and time- and labor-consuming. Here, we developed a novel simple, rapid, and reliable method to enumerate E. coli concentrations in
wastewater samples. The method is simple and does not require sample pretreatment. By incubating sample-medium mixture in a microplate reader for <2 h, β-D-glucuronidase (GUS) activities were obtained. Positive correlations were observed between GUS activities and E. coli concentrations in wastewater samples, although correlation equations were specific to WWTP. Difference in the E. coli population structures among WWTPs may explain the difference in the correlation equations. By using a WWTP-specific correlation equation as a calibration curve, E. coli concentrations could be estimated based on the GUS activities in wastewater samples.

Free Research Field

水環境工学

Academic Significance and Societal Importance of the Research Achievements

大腸菌は糞便汚染の指標であり大腸菌群に変わる指標細菌として利用することが議論されている．現在の大腸菌数測定法は培地の作製，希釈，18時間以上の培養，陽性の判定作業など多大な労力を要する．本研究で開発した技術を用いれば、サンプルを液体培地の入ったマイクロプレートに添加するだけという極めて簡便な操作のみで希釈も必要なく、大腸菌数が100 MPN/mL程度およびそれ以上の最終沈殿池越流水であれば2時間で測定が終了する。本技術が普及すれば世界中で頻繁に下水中や河川水中の大腸菌数を測定することができるようになる。