Occurrence of Listeria monocytogenes in different cold-smoked salmon products in Lithuania

Abstract

Listeria monocytogenes is the causative agent of human listeriosis, a potentially fatal foodborne infection. It has the ability to gow in vacuum-packaged food at chiller temperatures and is relatively tolerant to salt and low pH, thus it is difficult to control its growth in food. Smoked salmon is the food commonly associated with L. monocytogenes., The processing of cold-smoked salmon products involves no processing steps to eliminate L. monocytogenes, therefore it may remain on the final product and may cause the risk of human infection. In this sudy we investigated the occurrence of L. monocytogenes in different cold-smoked salmon products in Lithuania. The samples were purchased at comercial centers and markets two times in a month from October 2011 till August 2012. Overall 150 samples of ready-to-eat vacum packed cold smoked salmon products were collected and tested for the presence of L. monocytogenes. Each sample was tested two times: have just purchased and at the end of expiry date. The products were divided into four groups: cold-smoked fish belly, fish fillet, fish back meat, and chopped fillet samples. L. monocytogenes was isolated according to ISO 11290-1. Half and full-strenght Fraser broths were used for the enrichment of Listeria spp. in the sample (25 g). [...].