Escola Superior de Biotecnologia

Article on Listeria distinguished as “Hot Paper”

Friday, December 09, 2015 - 15:51

Prof. Paula Teixeira and her post-doc Vania Borges Ferreira published a paper in the Journal of Food Protection that became, with 340 downloads, the most popular item of the year in this magazine. In addition, in May / June 2015 it received enough quotes to reach the top of the 0.1% best articles in their academic area (according to the ISI Web of Science – Essential Science Indicators).

This visibility naturally reflects both the relevance of the topic as the quality of work. Listeriosis is an infection that has origin in eating food contaminated with the bacteria Listeria monocytogenes and is proving to be an important public health problem due to the severity of the disease and its significant economic impact. Although it is a rare disease with a relatively low incidence, listeriosis has the highest mortality rate of all foodborne diseases under surveillance in the European Union. In countries with established surveillance programs for listeriosis has been registered an increase in its incidence and a change in the distribution of cases, with an increase in individuals aged over 60 years.

In recent years several studies have suggested that persistent strains of L. monocytogenes in food processing environments over several months or even years is an important factor, not only in the contamination of food but also in the transmission of this pathogen to people. Typically, persistence is identified by the re-isolation of a molecular subtype of samples taken at a particular location over time. Technical and environmental factors such as equipment and places of difficult access and sanitation, have been identified as key to this persistence. The specific mechanisms that cause it are still poorly understood.

Although some studies indicate that persistent strains of L. monocytogenes have specific phenotypic characteristics that enhance persistence (such as biofilm formation and better adaptation to adverse environmental conditions), other studies point to the absence of significant differences between persistent strains and sporadically isolates. This review article in the Journal of Food Protection analyzes and discusses current scientific knowledge about the persistence of L. monocytogenes, with particular focus on (i) persistence associated with habitats and food processing, (ii) persistence in the environment in general, ( iii) phenotypic and genotypic characteristics of persistent strains, (iv) niches, and (v) the impact of persistence in the economy and public health.

Those interested in reading the article should contact Vania Ferreira.