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International Journal of Microbiology
Volume 2012, Article ID 497635, 10 pages
Research Article

Listeria monocytogenes in Ready-to-Eat Seafood and Potential Hazards for the Consumers

1Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Univeristà 10, 35020 Legnaro, Italy
2Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna, Via Antonio Bianchi 7/9, 25124 Brescia, Italy
3Dipartimento di Sanità Pubblica Veterinaria e Sicurezza Alimentare, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy

Received 18 January 2012; Accepted 10 April 2012

Academic Editor: Gabriella d'ettorre

Copyright © 2012 Patrizia Gambarin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The risk of exposure to Listeria monocytogenes (L. monocytogenes) when consuming Ready-to-Eat (RTE) seafood was assessed in the Veneto Region (Italy). Thirty-eight samples were analyzed, each sample consisted of three subunits belonging to the same batches. The first of the three units was examined immediately, the second was stored at +4°C (for all of its shelf-life) and the third at +10°C (for the latter third of its shelf-life) before the analysis. Chemical-physical and microbiological parameters were tested simultaneously. Culture results showed the presence of viable L. monocytogenes in 9 (23,68%) of the 38 samples analysed, 3 (33,33%) of which with a concentration >100 cfu/g. PCR tests yielded 12 L. monocytogenes positive samples. Semipreserves with aw (water activity) and pH values that favour L. monocytogenes growth were the only ones to result positive to microbiological and PCR tests. Temperature proved to be an important factor as it limits the growth of L. monocytogenes, including products with potentially high competitive microbial charges. Four different serotypes were recovered and ribotyping has helped to highlight the genomic variability of L. monocytogenes strains in food. This supports the hypothesis that L. monocytogenes continues to evolve genetically to the detriment of phenotypic conservation.