A contribution to the improvement of Listeria monocytogenes enumeration at low level of contamination, in the frame of the international standardization.

Listeriosis remains one of the most severe foodborne diseases in terms of fatality rate. Listeria monocytogenes can grow under stressful conditions and contaminate various food categories. Regulation (EC) No 2073/2005 modified on microbiological criteria for foodstuffs includes both qualitative and quantitative food safety criteria on L. monocytogenes and mentions EN ISO 11290-2 Standard as the reference enumeration method for the quantitative criteria. As food products are usually contaminated at very low levels, more sensitive enumeration methods are necessary to provide reliable data for research studies or routine analysis. This study, conducted by the EURL Lm, in collaboration with a group of NRLs, allowed to evaluate 2 more sensitive alternative methods derived from ISO 11290-2 Standard. In particular, the practicability, relative trueness, repeatability and accuracy profile were examined.