Identification of Listeria sp. in Hams and Frankfurters Products Exhibited for Sale

摘要

The aim of this study was to analyse the occurrence of Listeria species in frankfurters and hams products packed under vacuum and exhibited for sale in Mexicali, Baja California. One hundred and eighty-two packages of frankfurters and 72 of hams belonging to 17 commercial brands were collected randomly among packages exposed for sale, according to simple randomized sampling. The sampling was carried out between May and November. Positive samples of Listeria were submitted to biochemical tests in order to differentiate and confirm their species. Sixteen point five percent (42/254) presented some species of Listeria: 19.2% in frankfurters (35/182) and 9.7% in hams (7/72) products. L. monocytogenes was identified from 19 of 182 frankfurters and only 1 of 72 hams products analysed. Other species of Listeria were detected in 16 frankfurters samples (8.8%) and in 6 of the hams (8.3%). Presence of L. monocytogenes in these kinds of meat products, specifically frankfurters product, suggest inefficiency and inefficacy in the microbiological control programs during the process of elaboration. Thus, it should be considered possible source of listeriosis.