Research – Listeria monocytogenes in dairy plants in Southern Brazil: Occurrence, virulence potential, and genetic diversity

Posted on December 5, 2019 by | Leave a comment

Wiley Online

Abstract

Listeria monocytogenes is a foodborne pathogen widely distributed in nature. The aims of this study were to evaluate the occurrence of Listeria spp. in three dairy plants located in Southern Brazil, and to characterize the L. monocytogenes isolates according to serotypes, virulence genes, and PFGE. A total of 212 samples were collected, and 15 were positive for Listeria spp., of which seven were L. monocytogenes. L. monocytogenes isolates harbored all the 11 virulence genes evaluated and belonged to the main virulent serotypes, indicating potential risks of listeriosis for consumers. The PFGE analysis indicated low genetic diversity among the isolates, and the same pulsotypes were detected in a 2‐month period, indicating persistence of L. monocytogenes.

Practical applications

The study evaluated the occurrence of Listeria spp. in three dairy plants located in Southern Brazil, as well as characterized the L. monocytogenes isolates according to serotypes, virulence genes and PFGE. The presence of Listeria species indicated postprocessing contamination in the dairy plants and threat to public health. Furthermore, the isolates showed a low genetic diversity, since only two pulsotypes were identified, highlighting the strain’s persistence in the processing environment and/or the presence of clones in this region.

This entry was posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Listeria, Listeria monocytogenes, microbial contamination, Microbiology, Research, Uncategorized. Bookmark the permalink.

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