Listeria monocytogenes in meat, meat products and meat-processing environment

Food-borne Listeria monocytogenes has been recognised as the causative agent of several outbreaks and sporadic cases of human listeriosis. Meat and meat products are now more frequently becoming vehicles for transmitting L. monocytogenes. This paper focuses on the occurrence, persistence and possible ways of transmitting this pathogen in abattoirs and meat-processing environments. The problem of the significantly higher contamination of poultry and poultry products is also highlighted. It is suggested that possible sources of L. monocytogenes in the above environments are selected, well-adapted and clonally related strains which enter and colonise them by means of cross contamination. The persistent existence of selected L. monocytogenes strains over longer periods in meat-processing plants, despite cleaning and disinfecting procedures, has recently been described by several authors. Due to it forming biofilms, L. monocytogenes is able to attach and survive on various working contact surfaces. The construction of the biofilms makes it particularly resistant to elimination procedures: Due to the possible health hazard caused by the presence of L. monocytogenes in Polish meat and meat products it is strongly suggested that research on the Polish sub-population of L. monocytogenes should be undertaken.