Fifth external quality assessment scheme for Listeria monocytogenes typing

This report presents the results of the fifth round of the external quality assessment (EQA-5) scheme for typing of Listeria monocytogenes organised for laboratories in the Food- and Waterborne Diseases and Zoonoses Network (FWD-Net). The objectives of the EQA are to assess the quality and comparability of the typing data reported by the National Public Health Reference Laboratories. The EQA-5 contain first time molecular typing-based cluster analysis. Fifteen (75%) laboratories took part in the cluster analysis, 12 using WGS-derived data. EQA results indicate that cgMLST is a good method for inter-laboratory comparability and cluster definition and cgMLST is more robust compared with nonstandardised SNP based analysis.