Salmonella biofilm development: Structure and significance

Abstract

Salmonella spp. is capable of adhering and forming a biofilm on materials of different kinds during their life cycle, contaminating the food chain, thus representing a potential danger for consumers. This review discusses the ability of Salmonella to form biofilm as the main obstacle to reducing the prevalence of these pathogens in food production. The components of Salmonella biofilm, such as cellulose, curli fimbriae, outer membrane proteins (OMPs) and their molecular bases are described, as well as various Salmonella morphotypes (rdar, bdar, pdar and saw). OMPs play very important roles in the cells of Salmonella strains, because they are at the interface between the pathogenic cells and the host tissue and they can contribute to adherence, colonization, virulence and biofilm formation. Furthermore, the importance of quorum sensing is discussed as a crucial factor regulating the properties of biofilm formation and pathogenicity. To further illustrate that biofilm formation is a mechanism used by Salmonella to adapt to various environments, the resistance of Salmonella biofilms against different stress factors including antimicrobials (disinfectants, antibiotics and plant extracts) is described.