Contamination of Staphylococcus aureus in food sold in Jiading District, Shanghai from 2021 to 2023

ObjectiveTo investigate the contamination status of Staphylococcus aureus in food and the presence of enterotoxin genes in Jiading District, Shanghai, and to provide a basis for the prevention and treatment of foodborne Staphylococcus aureus disease.MethodsFrom 2021 to 2023, 15 types of food were sampled for S. aureus testing, and the presence of five enterotoxin genes, including sea⁃see, was tested in the strains.ResultsOut of 705 food samples, 88 (12.48%) were positive for S. aureus. S. aureus was detected in 12 of the 15 food types, with the three food types with the highest positive rates being cold noodles (45.00%), raw poultry (26.25%), and vegetable salads (20.00%). The enterotoxin gene carriage rate was 32.95% in food strains. The carriage rates for sea, seb, and sec were 7.95%, 12.50%, and 14.77%, respectively. Neither sed nor see was detected. The detection rate of strains carrying two types of enterotoxin genes was 2.27%. The enterotoxin carriage rates in strains from vegetables, beverages, and raw meat were 57.14%, 40.00%, and 30.00%, respectively.ConclusionThe S. aureus detection rate in food in Jiading District is much higher than the national average. The enterotoxin gene carriage rates are high, with food strains carrying sea, seb, and sec, with sec being the most prevalent. There is a need to enhance monitoring of S. aureus and enterotoxins, especially in high-risk foods such as noodles, vegetables, and non-packaged beverages.