Niamh is a research fellow in the Biomedical Diagnostic Institute and Applied Biochemistry Group led by Professor Richard O’Kennedy and based in the DCU School of Biotechnology.
For the past few years, I have worked on a project called BioliSME [projectbiolisme.eu] for the rapid and easy detection of Listeria monocytogenes. This is a European-funded project and is a consortium of various universities and SMEs.
One of the major issues in the food industry is Listeria contamination. Even if you're cleaning your surfaces every day, you can get biofilms that sometimes break away from the surface and contaminate food.
The EU regulation in relation to Listeria [Commission Regulation (EC) No 2073/2005] is very strict because, as those working in the food safety arena are all too aware, a resulting infection can kill vulnerable people such as the elderly, new-borns, pregnant women and people suffering from immuno-compromising diseases.
Cutting wait times
One of the major issues with testing for Listeria is having to wait up to a week for test results. It is one of the primary issues for food businesses when they are trying to meet the requirements of European food legislation and prove their food is not infected with Listeria. The BioliSME system takes less than an hour from sampling to detection so it's much quicker and easier.
Another improvement is removing the need for pre-enrichment, which is currently done to increase the concentration of Listeria. Instead, we use magnetic particles with antibodies specific to Listeria to concentrate the cells into a small volume that can be put through our system.
My work on the project included this immunoassay-based detection system as well as finding an antibody that was specific for L. monocytogenes, but didn’t pick up other Listeria species that don't cause infection. This was challenging.
One of the key issues with Listeria is that it forms biofilms, because of that, it can withstand environments that would otherwise kill it. Biofilms are notoriously difficult to sample but, with the BioliSME system, a biofilm sample can be removed from the surface using a combination of air and water, and put through the detection system.
This was also one of the biggest engineering challenges during the project as the regimes that are used to clean up Listeria biofilms can be quite harsh. We had to figure out how to get the Listeria off the surface without killing it so we could put it through the detection system.
Prototypes in action
The project started in 2009 and finished last year. We have two working prototypes, which we have brought to various food businesses in England and Spain. We’ve found that food firms are very willing to try out new detection systems. Companies that make ready-to-eat products have been most interested in our prototypes as these products are notoriously difficult in terms of Listeria.
It was great to get involved in research in Europe and see what was going on in different countries. I enjoyed working in the consortium as everybody brought different expertise to the various problems.
The other partners involved in the project were: the University of Southampton in the UK; AINIA, a technology centre in Spain; Betelgeux, a Spanish hygiene and food safety company; 40-30, a French engineering firm; and the UK-based company Photek, which is a specialist manufacturer of vacuum-based tubes and camera systems for photon detection.
When I’m not in the lab, I enjoy running and cycling. At the moment I'm training to do the Ring of Kerry cycle in July. That takes up a lot of my time!
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