全基因组测序分析生畜肉中沙门氏菌血清型、耐药性与毒力因子OA北大核心CSTPCD

This study aimed to investigate the serotype and sequence type(ST)distribution,drug sensitivity and virulence factors of Salmonella in raw meat and to explore the relationship between ST and drug resistance and virulence factors.In total,68 Salmonella strains isolated from raw meat from 2020 to 2023 were serotyped by serum agglutination,and their drug susceptibility was detected by the broth micro-dilution method.Genome-wide sequencing was used for analysis of multilocus sequence typing(MLST),drug resistance genes and virulence factors,and the correlation between ST and drug resistance and virulence factors was analyzed by constructing phylogenetic tree.Our results showed that the 68 Salmonella strains were divided into 14 serotypes,with Salmonella typhimurium and Salmonella enteritidis being the main ones,and ST19,ST34 and ST11 were the predominant sequence types.A total of 47(69.12%)out of the 68 strains were multi-drug resistant,and the drug resistance rates to ampicillin(76.47%),tetracycline(55.88%)and nalidixic acid(52.94%)were high.All 68 Salmonella strains carried virulence factors related to fimbrial adherence,magnesium ion transport,nonfimbrial adherence,regulation,and the secretion system.A variety of Salmonella serotypes having serious drug resistance and carrying many virulence factors could contaminate raw meat.Therefore,efforts should be made to strengthen the management of livestock breeding,meat production and sales.