Abstract:Salmonella is a common bacterial pathogen causing foodborne diseases in China; therefore, it is crucial to closely monitor its presence in relation to meat consumption. From 2018 to 2021, a total of 545 pork and pork products in Nanjing were collected for this study. The selective culture method was utilized to isolate Salmonella, and the strains were identified via serological and molecular biological methods, such as multilocus sequence typing (MLST). Finally, the antibiotic susceptibility test was utilized to analyze the drug resistance of the isolated strains. The results show that a total of 44 Salmonella strains were identified in the samples available in the market, with an average detection rate of 8.07%. In particular, pig viscera exhibited the highest detection rate at 30.49%. Serotype analysis revealed the four most commonly isolated Salmonella species in the pork products: Salmonella typhimurium, Salmonella enterica serovar Rissen, Salmonella enterica subsp. enterica serovar Derby, and Salmonella enterica serovar London. Genotyping results further suggested that the ST19 was the dominant Salmonella strain in contaminated pork samples, accounting for nearly 20.45% of all isolated strains. Among the detected Salmonella, 38 strains exhibited obvious resistance to tetracycline, accounting for 86.36% of the total. Meanwhile, the resistance of all strains to ceftazidime, cefotaxime, and cefoxitin was <10%. Additionally, one multidrug resistant Salmonella strain was isolated. The presence of resistance-related genes and a total of seven categories of antibiotics associated were successfully identified. Collectively, this study provides detailed data analysis for Salmonella contamination in pork and pork products in Nanjing, Jiangsu, establishing a theoretical foundation for the comprehensive control of Salmonella in meat products.
