Listeria monocytogenes in vacuum-packed fish products in the retail market

Lauri Merivirta ja Meija Kivisaari


A total of 67 vacuum-packed ‘gravad’ or cold-smoked fi sh products were collected from the retail market and examined for the presence of Listeria monocytogenes. L. monocytogenes grew from 14 samples (21 %). Four samples (17 %) of ’gravad’ products and 10 samples of cold-smoked products were positive for the bacteria. The number of colony forming units (cfu/g) varied between <10 and 6000. The number tended to be larger in samples that were closer to the use-by date than in other samples. All L. monocytogenes strains were of serotype 1/2a.