Egg white versus Salmonella Enteritidis! A harsh medium meets a resilient pathogen
Résumé
Salmonella enterica serovar Enteritidis is the prevalent egg-product-related food-borne pathogen. The
egg-contamination capacity of S. Enteritidis includes its exceptional survival capability within the harsh
conditions provided by egg white. Egg white proteins, such as lysozyme and ovotransferrin, are well
known to play important roles in defence against bacterial invaders. Indeed, several additional minor
proteins and peptides have recently been found to play known or potential roles in protection against
bacterial contamination. However, although such antibacterial proteins are well studied, little is known
about their efficacy under the environmental conditions prevalent in egg white. Thus, the influence of
factors such as temperature, alkalinity, nutrient restriction, viscosity and cooperative interactions on the
activities of antibacterial proteins in egg white remains unclear. This review critically assesses the
available evidence on the antimicrobial components of egg white. In addition, mechanisms employed by
S. Enteritidis to resist egg white exposure are also considered along with various genetic studies that
have shed light upon egg white resistance systems.We also consider how multiple, antibacterial proteins
operate in association with specific environmental factors within egg white to generate a lethal protective
cocktail that preserves sterility.