Introduction
Salmonella, the pathogen of salmonellosis, is Enterobacteriaceae, Gram-negative enterobacter. Nearly a thousand of strains have been discovered. According to its antigenic composition, it can be divided into basic bacteria such as A, B, C, D, and E. Among them, there are mainly group A of A. paratyphi, B. parahaemolyticus and Salmonella typhimurium in group B, C. parahaemolyticus and C. cholerae in group C, and typhoid bacillus and enterobacteria in group D are responsible for human diseases. In addition to cause human diseases, Salmonella typhimurium, M. parahaemolyticus and B. paratyphimurium can only cause diseases of animals such as livestock, rodents and poultry, but sometimes they can also contaminate human food and cause food poisoning. Salmonella is not easy to reproduce in water, but it can survive for 2-3 weeks, can survive for 3-4 months in the refrigerator, and can survive for 1-2 months in the feces of the natural environment. The optimal breeding temperature of Salmonella is 37 °C, and it can multiply at above 20 °C. Therefore, storage of food at low temperature is an important preventive measure. Salmonella is a common foodborne pathogen. The traditional methods for identification of Salmonella are mainly based on morphological characteristics, culture characteristics, physiological and biochemical characteristics, antigen characteristics, phage characteristics, etc.