Abstract: As a natural nutritious food, egg is rich in proteins, amino acids, minerals, vitamins and other nutrients needed by the human body. However, the rich nutrients in egg make it a breeding ground for bacteria. The pathogenic bacteria of egg-borne infectious diseases such as Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes can produce poisonous and harmful substances that cause food poisoning and bring harm to human health. The non-pathogenic spoilage bacteria such as Enterobacter, Enterococcus and Pseudomonas can change food composition and reduce the nutritional value, the direct consumption value and the processing and application potential of foods. In this paper, the species and invasion pathways of bacterial contamination during egg storage, and the quality changes of contaminated eggs caused by bacterial growth, multiplication and metabolism are summarized, with the aim of providing further insights into the microbial and biochemical aspects of egg spoilage and also providing a rationale for developing specific strategies to control egg spoilage, prolong the shelf-life of eggs, and ensure food safety.

Key words: egg, bacterial contamination, egg quality, invasion pathways