Prevalence of Listeria monocytogenes in fresh tomatoes (Lycopersicum esculentum) and coriander (Coriandrum sativum) in three markets of Valencia, Venezuela
Ramírez Mérida, L.G.; Morón de Salim, A.; Alfieri Graterol, A.Y.; Gamboa, O.
Archivos Latinoamericanos de Nutricion 59(3): 318-324
2009
ISSN/ISBN: 0004-0622 PMID: 19886518 Document Number: 628568
The incidence of L. monocytogenes in tomatoes and coriander obtained from three different markets, during eight weeks were determined. 192 samples were evaluated: 96 of tomatoes, and 96 of coriander. The isolation of L. monocytogenes was performed using COVENIN 3718:2001. The data were analyzed by SPSS version 12.0. Kolmogorov Smirnov, Mann Whitney U, Kruskal Wallis U test; Spearman's correlation were applied, and p<0.05 significance level was aplied. It was not found significant differences between the medias values and standard deviations of Most Probable Number (MPN) of Listeria spp to tomatoes and coriander during the eight weeks of recollection in the markets; neither between the distributions of MPN of tomatoes and coriander from the markets (Chi2=5,233 p<0,073; Chi2=1,624 p<0,444 respectively) neither the samples per weeks (Chi2=6,547 p<0,477; Chi2=2,667 p<0,914 respectively). In the number of MPN between tomatoes and coriander both distributions were significant different according to test U Mann Whitney U=3040,5 (Z=-4,216 p<0,0001). It was found statistical significance (p<0,001) between the number of MPN of tomatoes and coriander. The presence of Listeria spp in tomatoe was 41,66% (25,0% L. monocytogenes and 16,7% L. ivanovii); in coriander 77,08% (36,5% L. monocytogenes, 33,3% L. ivanovii and 7,3% L. seelige). We concluded that the high level of L. monocytogenes in tomatoes and coriander is independent of the markets store; we see the necessity of a microbiological control on the irrigation system, collection and distribution to ensure the quality of the product.