Proceedings of the International Symposium Salmonella and Salmonellosis I3S pages:80-84
I3S International Symposium Salmonella and Salmonellosis location:Saint-Malo, France date:27-29 May 2013
Subtyping of Salmonella enterica subsp. enterica serovar Typhimurium, a frequent cause of food-borne diseases, is critical for surveillance and identification, tracking and ultimately confinement of outbreaks. We present a preliminary proof of concept of a molecular subtyping method for S. Typhimurium which combines different types of markers in a multiplex assay with detection on a liquid bead suspension array in a high-throughput format. Selected markers include, amongst others, markers based on AFLP fragments, prophage genomes, sequence repeats, antibiotic resistance genes and SNPs.
The optimal multiplex design was evaluated and a ligation dependent amplification (LDA) assay was found to be the most efficient strategy to target the selected markers. The in vitro stability of the selected markers was verified. To determine the discriminatory ability, S. Typhimurium isolates of most common phage types in Belgium were subjected to the proposed subtyping method. The capability to identify outbreaks was tested with strains from two outbreaks in Belgium that occurred in 2008 and 2011. The resulting profiles were examined for correlation with phage types, MLVA and antimicrobial resistance profiles. The potential of the new method to provide a new subtyping scheme for S. Typhimurium will be discussed.