Listeria monocytogenes serotypes in Italian meat products.

Listeria monocytogenes was isolated and enumerated in Italian fresh ground beef, fresh pork meat and industrial sausages. All the samples contained less than 2000 L. monocytogenes/g of meat. The main serotype isolated was 1/2c (56.9%). Other serotypes isolated included 1/2a, 1/2b, 3c, 4b and 4c. A prevalence of less virulent serotypes over more virulent was thus noted. It seems that the low incidence of listeriosis from these products is related to the low concentration and virulence of L. monocytogenes present.