SEW working with Cranfield University on a Flow Cytometry Project

At the end of 2018, the foundations of a four year collaboration were established between Cranfield University and our Water Quality Department, led by Dr. Neil Hudson (Head of Water Quality). Within the project, SEW Scientific Services is utilizing a Flow Cytometer from the institution in Bedfordshire aiming to start a long-term process of gathering data from treatment works and reservoirs. For the duration of the partnership, the Water Quality team, assisted by Richard Brown (Laboratory Manager) and Marcus Bedford (Microbiology Manager), will assess how bacterial flow cytometry can be used by South East Water as an asset for the monitoring of microbiological activity. As part of the joint efforts, the instrument is being operated by Leïla Claveau, EngD Research Engineer at STREAM Industrial Doctorate Centre – School of Water, Energy and Environment. Both parties have entered the agreement sharing a common vision for better understanding the benefits of flow cytometry when processing large numbers of samples, in comparison to the more traditional heterotrophic plate counting method (HPC). In the following interview, among other things, Leïla Claveau shares her view on the emerging uses of this technology and talks about the goals she is aiming to achieve through the project with South East Water.

How did you become interested in flow cytometry?

I graduated with a Master of Science Degree in Analytical Chemistry. During my studies, I had the opportunity to conduct different internships and courses, where I was able to learn how to use existing analytical tools and techniques. Indeed, the possibility of analysing very small objects, near to the atom size, still impresses me. Flow cytometry uses the same principle, but instead of chemical elements, it analyses microbiological compounds. I have always thought that microbiology often helps to understand what chemistry cannot explain. Therefore, it was worthy and logical for me to experience and learn more about this field. Furthermore, the flow cytometer is an instrument that is starting to be increasingly used by water companies. This is an exciting process that I want to be a part of.

How do you find working in our laboratory?

Throughout my career I’ve had the opportunity to work in different lab environments. In all these places, there was a common denominator, organisation. Organisation to improve work conditions. In addition to that, South East Water Scientific Services has a good atmosphere. From the very first moment, people were friendly and willing to help. My initial impression was confirmed after talking to the employees and realising that most of them have been working at SEW for over 10 years. It’s great to see how they still have their enthusiasm intact. I am glad to work with these people for the next 4 years.

What goals are you aiming to achieve through this project?

Recently, water companies have shown a strong interest in flow cytometry. One of the reasons is the improved accuracy when counting bacteria in water, an important parameter to monitor in the production process. Consequently, on this project, I aim to collect relevant data, such as ICC (Intact Cell Count), TCC (Total Cell Count), HNA (High Nucleic Acid – High fluorescence) and LNA (Low Nucleic Acid – Low Fluorescence), using flow cytometry and microbial community fingerprint, allowing to source-track the origin of bacteria in treated water and distribution systems. Using this data, we expect to be able to understand some events that can occur in the network. We hope to prevent them once an exhaustive database is ready, adopt proper measures to avoid potential disruptions and continue to deliver safe drinking water to customers.

What do you think are the benefits of FCM compared to more conventional testing methods, like HPC?

It has been proved that conventional methods like HPC are not always representative of the bacterial growth due to a lack of specificity. On the other hand, flow cytometry is able to detect cultivable and non-cultivable bacteria, which means that there is no need for specificity. Moreover, FCM is less time-consuming, more accurate and can be transported on-site.

Do you think significant data can be obtain in reasonable time using flow cytometry?

The flow cytometer can collect different types of data simultaneously: TCC and LNA/HNA. The sample preparation takes about 30 minutes and the analysis only 15. An autosampler can also be used, allowing the analysis of 96 samples consecutively. Therefore, within a working day, hundreds of samples could be analysed. Additionally, there is an automatic mode which allows the instrument to run in the evening.

How do you believe FCM can be used to identify potential problems before they happen?

Flow cytometry can determine parameters which form a microbial community fingerprint characteristic for the monitored water. A shift in these constituents shows a change in the production process that can be related to chlorine concentration, an ingress or other reasons. Thus, the data can help water companies detect potential events and act pro-actively before these happen.

What are your plans after the project with South East Water?

Right now, I’m fully committed to this project and I find it difficult to predict its impact on my professional career in 4 years’ time. I have always thought that I am both a consumer and a producer of knowledge. That’s my law of supply and demand. Fortunately, this Engineering Doctorate fully satisfies both ends. I just want to make sure that my personal “knowledge market” keeps growing with every single step I take in my career.