Escherichia coli o157 h7

Foodborne L. coryniformis NA-3 was obtained from our own laboratory and isolated from Chinese sauerkraut. The bacteria stored at −80 °C was cultured in solid Man, Rogosa and Sharpe (MRS) (Solarbio, Beijing, China) broth at 37 °C for 48 h. A single colony of L. coryniformis NA-3 was transferred into 10 mL of MRS broth and grown at 37 °C for 48 h under anaerobic conditions. Bacillus cereus (CICC 21261), Salmonella enterica subsp. enterica serovar Typhimurium (CICC 22956/ATCC 14028) and Escherichia coli O157:H7 (CICC 10907) were purchased from the China Center of Industrial Culture Collection (CICC), and Staphylococcus aureus (CGMCC 1.291) was purchased from the China General Microbiological Culture Collection Center (CGMCC). The four pathogenic bacteria were grown in trypticase soy broth (TSB) solid medium at 37 °C for 24 h under aerobic conditions. A single colony was transferred into 5 mL of fresh TSB broth and grown for 24 h at 37 °C with shaking. A one-percent bacterial suspension (10⁸ CFU/mL) was inoculated in another 5 mL of fresh TSB medium and cultured for 24 h at 37 °C with continuous shaking in order to obtain a pathogenic bacteria suspension for the following applications.

Salmonella enterica subsp. Enterica serovar Typhimurium (CICC 22956/ATCC 14028), Escherichia coli O157:H7 (CICC 10907), and Bacillus cereus (CICC 21261) were purchased from China Center of Industrial Culture Collection (CICC). Staphylococcus aureus (CGMCC 1.291) was purchased from the China General Microbiological Culture Collection Center (CGMCC). RAW264.7 macrophages were purchased from Beijing Dingguo Changsheng Biotechnology Co., Ltd., Beijing, China. Vero cells were purchased from Procell Life Science & Technology Co., Ltd., Wuhan, China. Dextran standards were obtained from Sigma-Aldrich (São Paulo, Brazil). The other chemicals used in this study were analytical grade and purchased from Solarbio Science &Technology Co., Ltd., Beijing, China and Thermo Fisher Scientific (Waltham, MA, USA).