Industry Action and Reaction

Abstract

Listeria monocytogenes as a species is subdivided into serotypes and genetic techniques are used to further differentiate strains of the organism. There has been a great deal of debate concerning the specific pathogenicity of individual strains of L. monocytogenes and their relevance to public health. In 1995, in a case concerning fitness for human consumption of some batches of Lanark Blue cheese allegedly found to contain high levels of L. monocytogenes serotype 3a, the food condemnation orders requested by the local authority under the UK Food Safety Act, 1990 (Anon., 1990a) were refused. This was in part due to evidence presented indicating that this serotype had never been associated with listeriosis caused by the consumption of contaminated food. In 1996, the UK Health and Agriculture Departments asked the Advisory Committee on the Microbiological Safety of Food (ACMSF) for advice on whether all strains of L. monocytogenes were pathogenic or should be regarded as pathogenic. Following consultation and discussion with other expert groups, the Committee advised that, for public health purposes, it would be prudent to treat all strains of L. monocytogenes as pathogenic. In a detailed review of the pathogenicity of L. monocytogenes, McLauchlin (1997) concluded ‘in the interests of public safety and for considerations for public health purposes, all L. monocytogenes, including those recovered from food, should be regarded as potentially pathogenic.’