The National Reference Laboratory for Listeria is responsible for the differentiation and characterization of listeria isolates from food and environmental samples. The isolates received are typed by whole genome sequencing. For the clarification of epidemiological questions, such as the confirmation of a foodborne listeriosis outbreak, the sequences are evaluated by means of core genome MLST (cgMLST) analysis. This method, used by the National Reference Laboratory, was developed in 2015 in collaboration with Münster University Hospital and Ridom Bioinformatics and has since been used internationally. The cgMLST scheme is integrated in the Ridom SeqSphere+ software. For typing, 1701 defined target sequences are analyzed and aligned via a nomenclature server.

• Typing of Listeria monocytogenes isolates by genome sequencing
• Evaluation of genome sequencing (core-genome analysis) on request
• Strain collection
• Outbreak clarification