Comparison of Listeria monocytogenes alternative detection methods for food microbiology official controls in Europe

Listeriosis remains one of the most severe foodborne diseases regarding mortality rate. L. monocytogenes can grow under stressful conditions and contaminate various food categories. Regulation (EC) No 2073/2005 modified on microbiological criteria for foodstuffs includes either qualitative or quantitative food safety criteria on L. monocytogenes and mentions EN ISO 11290-1 Standard as the reference detection method. The use of alternative certified methods is allowed at European level for own checks and by certain European countries in the frame of official controls. Here we report the comparison of alternative certified methods for the detection of L. monocytogenes, according to the criteria expressed by the National Reference Laboratories (NRLs) for L. monocytogenes network in Europe, through an enquiry conducted in 2022 by the European Union Reference Laboratory (EURL) for L. monocytogenes. Emerging detection methods make it possible to diversify the panel of available detection methods. Each method has advantages and limitations and the choice of a method depends on the needs, organization and objectives of the laboratory. Our study focused on a comparison by category in order to provide an overview of the differences between the methods as complete and simple as possible, mainly by examining the certification files of the alternative methods, which constitute a reliable and publicly accessible source of information about performances of the methods.