Abstract:In this study，chicken meat imported from Brazil and sold in Shanghai was utilized as the food matrix to isolate and identify Salmonella，quantify biofilm formation，measure sodium hypochlorite resistance，and detect biofilm-related and virulence genes. The results showed that 16 Salmonella strains were isolated from 63 imported chicken samples，with a contamination rate of 25.4%. All isolated strains were capable of forming biofilms，among which 50% exhibited moderate biofilm-forming ability，and 50% showed weak biofilm-forming ability. In the resistance tests，the minimum inhibitory concentration of sodium hypochlorite against the isolates reached 520 mg/L，which was higher than the current disinfection dosage for chicken meat. The polymerase chain reaction （PCR） method was used to detect the presence of Salmonella genes，and it was found that biofilm-related genes such as csrA，csgD，luxS，and csgB were universally present. Additionally，the detection rates of the csrB and fliC genes were higher in moderate biofilm-forming strains than in weak biofilm-forming ones. Furthermore，more than ten virulence genes，including mgtC，invJ，stn，and pipC，showed a 100% detection rate，underscoring the pathogenic potential of these strains.