Resumen

HERRERA A., Fanny  y  SUAREZ Q., William. ISOLATION AND IDENTIFICATION OF Listeria spp. FROM FRESH FISH SAMPLES, MARKETED IN PAMPLONA (NORTE DE SANTANDER). rev.udcaactual.divulg.cient. [online]. 2012, vol.15, n.2, pp.257-265. ISSN 0123-4226.

The genus Listeria comprises eight species between them Listeria monocytogenes, pathogenic to humans, causing gastroenteritis, meningitis, neuro-encephalitis, septicemia, abortions and even death. L. monocytogenes is an ubiquitous bacterium which can be isolated from ecosystems inhabited by fish, reaching the finished product, even at high concentrations, when the fish is processed using inadequate cleaning and disinfection practices and/or is stored for a long time at refrigeration temperatures because it is psychrotrophic. The objectives of this study were to determine the presence of Listeria spp. in fresh fish samples expended in the market place of Pamplona, comparing the traditional method with an immunochromatografic one, and to verify whether there is a correlation between the presence of Escherichia coli and Listeria spp. in the samples. L. monocytogenes, L. innocua and L. grayi were isolated, with prevalences of 3.9%, 17.6% and 13.7%, respectively, with an overall incidence of 35.3%. By comparing the isolation methods, traditional and immunochromatografic, no significant differences between them were found. Finally, it was established that the presence of E.coli is a good indicator of the presence of strains of Listeria in the samples. The presence of L. monocytogenes in the samples indicates that fish sold in the market place of Pamplona can be an important vehicle for this pathogen and implies, that this food might pose a health risk to consumers, especially the vulnerable population.

Palabras clave : Listeria monocytogenes; fish; Escherichia coli; prevalence.

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