Occurrence of Listeria in food matrices

The A.A. report data about a research carried out along a ten-years period (1989-1999) in order to obtain information about the occurrence of Listeria in different types of food: 494 samples of dairy products, 509 of raw meat and meat products, 183 of fish and fish products, 180 of vegetables have b een investigated. From the 494 samples of daily products examined, 87 strains (18%) belonging to genus Listeria have been recorded, 40 of which (8%) belonging to Lister ia monocytogenes species. From 509 samples of raw meat and meat products 32 1 (63%) strains of Listeria have been recorded, 77 of which (15%) belonging to L. monocytogenes species. From 183 samples of fish, 44 (24%) strains of Listeria have been recorded, 14 of which (7.6%) belonging to L. monocytoge nes species. From 180 samples of vegetables 6 strains (3.3%) belonging to t he genus Listeria have been recorded; L. monocytogenes was not recovered in vegetables. Smoked fish samples appeared to be the most contamined with L. monocytogenes (38%), followed by sausages (28%) and "mozzarella" (16%).