第十一届外部质量评估方案 利斯特氏菌单核细胞增生型在欧盟/欧洲经济区及欧盟扩大国家，2024

ECDCASSESSMENT Eleventhexternal quality assessmentscheme forListeria monocytogenestyping This report was commissioned by the European Centre for DiseasePrevention and Control, coordinated by TainaNiskanen (ECDC Emerging, Food-and Vector-borne Diseases Programme) and produced bySusanne Schjørring,Kasper Rømer Villumsen, Vera Irene Erickson and Anne Sophie M Uldallof the Section for Foodborne Infections at Suggested citation: European Centre for Disease Prevention and Control.Eleventhexternal quality assessmentscheme forListeria monocytogenestypingin EU/EEA and EU enlargement countries, 2024.Stockholm: ECDC; Stockholm,May2026 ISBN978-92-9498-881-2doi:10.2900/8284025 © European Centre for Disease Prevention and Control,2026Reproduction is authorised, provided the source is acknowledged. Contents Eleventh external quality assessment scheme forListeria monocytogenestyping in EU/EEA and EU enlargementcountries, 2024...............................................................................................................................................iAbbreviations................................................................................................................................................vExecutive summary........................................................................................................................................11 Introduction...............................................................................................................................................22 Study design...............................................................................................................................................43 Results.......................................................................................................................................................74 Discussion................................................................................................................................................215 Conclusions..............................................................................................................................................236 Recommendations.....................................................................................................................................24References..................................................................................................................................................25Annex 1. Participation details........................................................................................................................26 Figures Figure 1. Countries participating in EQA-11, EU/EEA and candidate countries, 2024.............................................4Figure 2. Correctly assigned conventional serotypes for three repeat strains from EQA-1 to EQA-11 for fourlaboratories participating in EQA-11.................................................................................................................8Figure 3. Participant scores for molecular serogrouping of sevenL. monocytogenestest strains............................9Figure 4. Number of correctly assigned molecular serogroups for three repeat strains from EQA-1 to EQA-11 forlaboratories participating in EQA-11.................................................................................................................9Figure 5.Average scores for seven test strains in EQA-11................................................................................10Figure 6. Reported single-nucleotide polymorphism distances or allelic differences for each test strain to selectedcluster representative strain13......................................................................................................................15 Tables Table 1.Characteristicsof test strains and sequences.......................................................................................5Table 2. Number and percentage of laboratories submitting results for each method...........................................7Table 3.Correctly assigned conventional serotypes for three repeat strainsfrom EQA-1 to EQA-11 for twolaboratories participating in EQA-11.................................................................................................................8Table 4. Number of correctly assigned molecular serogroups for three repeat strainsfrom EQA-1 to EQA-11 forlaboratories participating in EQA-11...............................................................................................................10Table 5. Results of participants’ quality control assessment of the modified sequences provided for EQA-11........11Table 6. Results of cluster analysis based on WGS-derived data.......................................................................12Table 7. Results of SNP-based cluster analysis................................................................................................13Tab