Research

Development of loop-mediated isothermal amplification (LAMP) assays for rapid detection of pathogens involved in foodborne infections and intoxications.

This research project is focused on developing and validating LAMP assays for the detection of Salmonella spp., Listeria monocytogenes, Bacillus cereus, Campylobacter jejuni, Campylobacter coli and Staphylococcus aureus. All species are food-associated zoonotic pathogens that can cause acute, self-limiting gastroenteritis, but sometimes also lead to severe intestinal and extraintestinal sequelae.

The LAMP method is used to identify the pathogens by amplification of specific DNA sequences. Six primers bind to a selected region within the pathogen genome and initiate sequence amplification under isothermal conditions. The use of a dye that intercalates with the LAMP products produces a fluorescent signal that can be measured using optical instruments (e.g., Genie® II real-time fluorometer). The performance of the assays is first tested using pure DNA and thereafter evaluated in complex matrices from various foods containing defined amounts of the pathogens. Finally, the assays are validated by testing naturally contaminated food samples from retail outlets and will then be available for analysis in the laboratory and further investigations in future research.

Development of a loop-mediated isothermal amplification (LAMP) assay for detection of hepatitis E virus (HEV) and semiquantitative evaluation of viral load in pork liver, pork meat and pork products

HEV is a partly underestimated and underdiagnosed cause of foodborne illness. This pathogen is primarily detected in pig livers and can be transmitted through the consumption of inadequately heated or recontaminated meat products, such as liver sausage. In the first phase of the project, a HEV-specific LAMP assay will be established, optimized and validated for virus detection and semi-quantitative evaluation of the viral load in pork liver, pork meat and pork products. Compared to PCR, the LAMP technique provides significantly faster results and requires less labor and cost. This makes the method suitable for use in the field.

In the second phase of the project, different production methods for reducing the viral load in liver sausages produced with HEV-positive porcine liver will be established and evaluated applying the previously established LAMP assay. The results obtained will be used to derive a manufacturing recommendation that can contribute to improving food safety. Additionally, the LAMP assay will provide a tool for identifying the HEV contamination status of unknown matrices. Due to its field-proven properties, this LAMP assay could also be applied directly to prevent the use or consumption of contaminated products.