Population Structure, Antimicrobial Susceptibility, and Virulence-Associated Gene Profiling of Salmonella from Clinical Patients in the Jiangsu Province, China, from 2015 to 2019.

Salmonella is a foodborne zoonotic pathogen and a hazard to public health. Surveillance of the prevalence of Salmonella is important. This study sought to understand the population structure, antimicrobial susceptibility, and virulence-associated gene profile of 100 Salmonella, which were randomly selected from clinical foodborne diarrhea fecal samples during 2015 and 2019 in the Jiangsu Province, China. After whole-genome sequencing and in silico analysis, we found that the prevalence of clinical foodborne Salmonella in Jiangsu Province was periodic and that the serotypes were diverse, covering 9 serogroups and 19 serotypes. S. Enteritidis was the most prevalent serotype, followed by S. Typhimurium. A high prevalence of antimicrobial resistance was also observed in this study, nearly half (47/100) of Salmonella isolates were determined to be multidrug-resistant (resistant to ≥3 antimicrobial agents), the antimicrobial resistance genotype and phenotype were associated but not closely related, and antimicrobial resistance differed between the major Salmonella sequence types. Additionally, we found that the virulence-associated gene profile is highly concordant with the serotype. Our work shows the association among serotype, antimicrobial resistance, and virulence gene profile, demonstrating the connection between genotype and phenotype and providing epidemiological data for Salmonella.