The PhD-project SalMolType aims to develop an alternative, molecular method for the subtyping of a pathogen. Subtyping of pathogens is essential for surveillance and timely confinement of an outbreak, since it enables us to identify a link between a human isolate and the source of an infection. Molecular techniques allow, in comparison to traditional microbiological subtyping methods, a more convenient standardisation, higher accuracy, they are faster and, in general, more objective.
Salmonella, which is a frequent cause of food intoxication, was taken as a case study. We present a proof-of-concept of a molecular subtyping method for Salmonella Typhimurium (S. Typhimurium) which combines different types of markers in a multiplex assay with detection on a Luminex® platform in a high-throughput format.
After screening available software for in silico design of multiplex assays, the optimal multiplex assay to target the selected markers was determined and subsequently developed. To evaluate the discriminatory ability, S. Typhimurium isolates of most common phage types in Belgium were subjected to the proposed subtyping method. Extension of the proof-of-concept assay will lead to a cost-effective, rapid, highly discriminative and robust method with stable markers, more efficiently addressing the needs of S. Typhimurium subtyping than the currently used methods.