Where the problem is with Listeria monocytogenes ?

Abstract

Foodborne diseases are considerate an important public health concern in many countries and each year, ingestion of foods contaminated with pathogens causes millions of episodes of diarrhea and other debilitating effects. As results, large number of hospitalizations and thousands of deaths occur, and billions of Euros and Dollars are spent every year with recalls and patients medical treatment. The emergence of some of these diseases is the result of complex interactions, such as the advances in the medical field, the expansion of the food industry, cold storage systems, as well as the change in eating habits. Since the consumption of contaminated food has been associated with the development of diseases, various studies were developed, especially in industrialized countries, in order to clarify the relationship between these pathogens and their persistence in the food processing environment, their main routes of contamination, how they can survive and multiply in foods, and their potential to cause disease. Among these microorganisms, Listeria monocytogenes is a concern for Public Health agencies. Several countries adopt a zero tolerance policy regarding the presence of L. monocytogenes in foods. However, the environment conditions of food processing industries were always partially located in secondary importance in the tracking presence of reservoirs for L. monocytogenes and other foodborne pathogens. In recent years, phenotypic and genotypic studies led to new insights into ecology, epidemiology, virulence potential and genetic evolution of various genuses of bacteria. L. monocytogenes is the causative agent of listeriosis, a severe foodborne disease that affects mainly the elderly, immunocompromised individuals, pregnant women and neonates. Listeriosis is characterised by gastroenteritis and septicaemia, leading to abortion and infections in the nervous system. Its mortality rate varies from 20 to 30%, this being common mainly when the pathogen is able to cause encephalitis and meningitis.