Desarrollo de biofilms de listeria monocytogenes y microbiota acompañante en instalaciones cárnicas: cuantificación, acción sinérgica y antagonista

Student thesis: Doctoral thesis

Abstract

Food safety can be defined as the absence, or at least as safe and acceptable levels, of hazards in food that can affect health consumers. These food safety hazards can be classified as microbiological, chemical or physical. According to the Food and Agriculture Organization, each year, the impact of unsafe food causes around of 95,000 million dollars of food losses. Moreover, there is a new problem, the resistance to antimicrobials, which is one of the greatest threats to global health and food safety. Food can be contaminated by multiple ways, but one of them is by cross-contamination from surfaces. The food industries are constantly striving to minimize microbial contamination in the facilities. However, many microorganisms can resist cleaning and disinfection protocols by forming resistance structures called biofilms. These communities of microorganisms, which are part of the resident microbiota, can have an impact on the persistence of spoilers and foodborne pathogens. Among them, Listeria monocytogenes is one of the most worrisome bacteria in the food sector. Although this infection is rare, this foodborne disease is usually serious, with high rates of hospitalization and mortality. With the aim of providing new control strategies for this pathogen, an analysis of the microbiota present on the surfaces of an Iberian pig processing plant, was achieved, through the implementation of SCH sensors. This study revealed the predominance of Bacillus spp. and Pseudomonas spp. The profiles of microorganisms were also related to the presence of L. monocytogenes, being favored when Pseudomonas spp. and enterobacteria were dominant. Then, a series of preliminary tests were carried out with the species identified from the analysis of the microbiota of the processing plant under study, to screen the presence of interesting species. One species (patent pending) biofilms, generated in vitro, inhibited, significantly, multiple strains of L. monocytogenes, becoming subsequently a microorganism of great interest for the biological control of this pathogen on surfaces. Finally, continuing with the development of a potential new tool against L. monocytogenes, and approaching the industrial environment, tests in a pilot plant and involving final products such as Iberian sausages were performed
Date of Award24 Jul 2019
Original languageSpanish
Awarding Institution
  • Universitat Autònoma de Barcelona (UAB)
SupervisorCarolina Ripollés Àvila (Director), Jose Juan Rodriguez Jerez (Director) & Jose Juan Rodriguez Jerez (Tutor)

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