Flow cytometry is a powerful method to detect bacteria within minutes. In the FlowDetect project this method was validated in round robin tests with project partners from science and industry. Tests to further improve the significance and hygienic relevance of the results were also conducted.
Ground and surface water as well as drinking and mineral water are not sterile, but contain a multitude of bacteria. The observation of these bacteria via the total cell count allows statements about possible processes and changes in raw water, drinking water pipes or water treatment processes. With flow cytometry, this can be achieved within 15 minutes and thus offers an advantage when deviations in the microbiological composition need to be quickly detected and recorded.
Scopes of the project FlowDetect were the possibilities and limitations of flow cytometry. In addition to the validation and research tasks, a detailed work instruction (SOP) was prepared for users, which describes all relevant aspects of measuring water samples with flow cytometry.
Main topics of FlowDetect were:
- Comparison of flow cytometry with other microbiological methods
- Characterization of HNA and LNA signals
- Live/dead differentiation in the disinfection processes ozone, chlorine and UV
- Specific detection of E. coli and Bacteroides bacteria with Flow-FISH
- Monitoring in water treatment and water distribution
- Standardization and preparation of a detailed SOP
- Performance of flow cytometry in interlaboratory tests
The research and development work demonstrated the high potential of flow cytometry. With standard operation procedures, flow cytometry can be used as a routine analysis method. With practical application examples in cooperation with water suppliers and research work on live/dead differentiation as well as specific detection, the results of the project are directed both at users of flow cytometry and at scientifically interested experts.
Publications
Ho J., Nocker A., Bendinger B., West S., Tiehm A.: Durchflusszytometrie als schnelle Detektionsmethode für Bakterien. Veröffentlichungen aus dem Technologiezentrum Wasser, ISSN 1434-5765, TZW-Band 94 (2020)
Ho J., Tiehm A., Nocker A., Bendinger B., West S., Trimbach A.: Durchflusszytometrie als schnelle Detektionsmethode für Bakterien in Rohund Trinkwasser. DVGW energie | wasser-praxis (EWP), 01/2020: 56–59 (2020)
Ho J., Bendinger B., Nocker A., Trimbach A., West S., Tiehm A.: Evaluation of flowcytometry and advanced live/dead discrimination. In: 20th Symposium on Health-Related Water Microbiology (HRWM), Wien, Österreich, 15.-20. September 2019. ISBN 978-3-9503828-3-9, Book of abstracts: 122–123 (2019)
Ho J., Tiehm A.: Advanced microbiological water monitoring: Microbial source tracking (MST) and flow-cytometry (FCM). In: VACI 2019 – Vietnam International Water Week, Hanoi, Vietnam, 22.-25.03.2019, Book of abstracts: 181 (2019)
Ho J., Tiehm A.: Durchflusszytometrie für das mikrobiologische Monitoring. In: Zukunftsthemen der Wasserversorgung, 24. TZW-Kolloquium, Veröffentlichungen aus dem Technologiezentrum Wasser, ISSN 1434-5765, TZW-Band 90: 81–96 (2019)
Ho, J.: Mikrobiologische Lebend/tot-Unterscheidung. Veröffentlichungen aus dem Technologiezentrum Wasser, ISSN 1434-5765, TZW-Band 81 (2018)
The volumes of the TZW publications can be ordered here.
