The appearance of this new SARS-CoV-2 virus, commonly known as Covid-19, on Luxembourg territory has given rise to an unprecedented collaboration between players in scientific research. In view of its profound repercussions on our society, the scientific community has started a real race against time to better understand this virus, and to be able to follow its evolution in time and space within a population.
"This respiratory tropism virus is different from other viruses we have known so far, which is why we did not expect possible detection of it in stool samples. As soon as we became aware of this fact we took action through the CORONASTEP+ project to be able to detect and monitor it in Luxembourg wastewater,” explains Leslie Ogorzaly.
Complementary to clinical diagnoses, this research conducted by LIST allows us to visualise where, when, and in what concentration SARS-CoV-2 is present in the Grand Duchy. “This notably made it possible to trace the arrival of the virus in the country, as well as to note that the results from wastewater corroborated with those from clinical tests,” details Leslie. Beyond monitoring over time, this data is also particularly useful, for example, in identifying a new focus in the population in near real time.
As the coordinator of the CORONASTEP+ project, LIST works in close collaboration with the Luxembourg Institute of Health (LIH), the National Health Laboratory (LNS) as well as the University of Luxembourg (LCSB). “We have succeeded in bringing together all the players in microbiology in Luxembourg through this research,” says Leslie.
LIST has extensive experience in monitoring the spread of viruses in wastewater. "We already have adequate methods and protocols for monitoring gastroenteritis viruses, for example. In addition, we have the opportunity to work in a multidisciplinary framework where the fields of environmental microbiology and hydrology can come together for concrete applications such as the CORONASTEP+ project," says Leslie.
As part of this research, LIST researchers use their expertise to establish a reliable protocol and methodology for the detection of SARS-CoV-2. With the concentration of the virus being relatively low in water, Leslie and his team practice what is called a phase of concentration before any analysis: “We process a relatively large volume of samples which we reduce in order to obtain sufficient virus concentration. This first step opens the way to detecting the virus using a certain type of PCR (Polymerase Chain Reaction). ” This process makes it possible to identify the virus by recognising specific sequences of its genome, that is to say its genetic identity card.
“As Project Coordinator, I am responsible for its proper implementation and management. I also regularly pull up my sleeves to join my team (Cécile Walczak and Delphine Collard) and carry out processing and analysis of samples collected. My colleague Christian Penny travels the country every week to collect samples from more than 10 treatment plants," explains Leslie, before specifying that her expertise focuses, "both on the development of methods for detecting viral particles in water, but also on the relationship between viral contamination and the cycle of water ”.
Dr Leslie Ogorzaly is Principal Investigator (R&T Associate) in the research group "Environmental Microbiology and Biotechnology" at LIST. She is a virologist and holds a doctorate in environment and health from the University of Lorraine (2009). Since then, Dr Leslie Ogorzaly has been initiating and participating in R&D projects in the field of water microbiology at LIST. His research focuses mainly on methods for detecting viral particles in water, with a marked interest in characterising the infectious state of viruses. Dr Leslie Ogorzaly has developed some of the latest technological tools available for monitoring viruses in water, combining new molecular tools (aptamer, real-time detection, next generation sequencing) with conventional culture-based approaches. More recently, emphasis has also been placed on the relationship between viral contamination and the water cycle thanks to close collaboration with LIST hydrologists.