An approach towards public health and foodborne human listeriosis--the Austrian Listeria monitoring.

The Institute for Milk Hygiene, Milk Technology and Food Science has launched a Listeria monitoring for Austrian cheese factories in 1988 which is nowadays a valuable tool to control the safety of cheese production. It is a means to qualify the proper hygienic conditions in the participating cheese plants. Proper hygiene protects cheese plants from getting contaminated by L. monocytogenes. The preventive elimination of foodborne pathogens facilitates a thriving economical development of the domestic cheese industry as contamination by L. monocytogenes may lead to a stop of delivery, product recall and other costly measures. This report comprehensively describes the principle of the monitoring including a description of the microbiological and molecular tools. It summarizes data on the detection frequency of Listeria contamination with respect to the different matrices under investigation. Furthermore an overview is given on the course of 17 contamination periods in 10 cheese plants and the outcome of the decontamination endeavours is described. Apart from epidemiological investigations, this report summarizes data regarding molecular species confirmation in the genus Listeria as the species assignment was comparatively examined by both conventional microbiology and molecular tools. Genotyping by Pulsed Field Gel Electrophoresis was applied in three plants which were confronted with a long term contamination period. The data presented in this paper rely on results which were collected through a decade of investigation (1990-2000).