Whole-Genome Sequencing Analysis of Antimicrobial Resistance, Virulence Factors, and Genetic Diversity of Salmonella from Wenzhou, China

<i>Salmonella</i> species are important foodborne pathogens worldwide. <i>Salmonella</i> pathogenicity is associated with multiple virulence factors and enhanced antimicrobial resistance. To determine the molecular characteristics and genetic correlations of <i>Salmonella</i>, 24 strains of <i>Salmonella</i> isolated from different sources (raw poultry, human stool, and food) in the Wenzhou area were investigated to determine the distribution of antimicrobial resistance and virulence determinants using whole-genome sequencing (WGS). Aminoglycoside resistance genes were detected in all samples. Over half of the samples found antimicrobial resistance genes (ARGs) and point mutations for several clinically frequently used antibiotic, beta-lactams, tetracyclines, and quinolones. Of these strains, 62.5% were predicted to be multidrug-resistant (MDR). The quinolone-modifying enzyme gene <i>aac(6')-Ib-cr</i>, detected in five samples (S1-S4 and S10), was located on integrons. The analysis of <i>Salmonella</i> pathogenicity island (SPI) profiles suggests that serotypes with close genetic relationships share the same distribution of virulence factors, revealing a link between genotype and SPI profiles. cgMLST analysis indicated that five isolates S14-S18 were closely related to strains originating from the United Kingdom, suggesting that they may share a common origin. Data from this study may enrich the molecular traceability database for <i>Salmonella</i> and provide a basis for effective public health policies.