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Nontyphoidal Salmonella (NTS) in children remains a growing burden on public health and often causes children to be hospitalized with diarrheic symptoms. In this work, 260 strains of human Salmonella isolated from Jilin, China were characterized by serotypes and antimicrobial resistance using whole genome sequencing (WGS). The most prevalent serotype was Salmonella enteritidis (47.3%), followed by S. I 4,[5],12:i:- (33.1%), and Salmonella Typhimurium (7.3%). Furthermore, the consistency between resistance phenotype and genotype was confirmed. Similarly, strains harbored bla TEM −1 B and tetA genes were detected, which verified the level of resistant phenotype in β-lactams and tetracyclines. The presence of a single mutation in parC, gyrA , and qnrS1 genes corresponding to quinolones was also observed. In our work, multilocus sequence typing (MLST) and core genome multilocus sequence typing (cgMLST) were found to have a high resolution to molecular traceability, and the combination of both was conducive to practical application in an actual situation. Taking all of this into account, we suggested that the comprehensive surveillance of Salmonella infection in children should be carried out to monitor antimicrobial-resistant trends from various sources and to alert on outbreaks of foodborne diseases to protect public health. [ABSTRACT FROM AUTHOR]

[Display omitted] • Theprevalent serogroup and sequence type were IIa (44.7%) and ST9(38.5%). • Phenotypic antimicrobial resistance, virulence, and persistent-associated were found among Jilin strains. • Genetic diversity of L. monocytogenes strains was both observed in retail markets and slaughterhouses. • The wgSNP analysis revealed close genetic relationships between meat production and circulation. Human listeriosis outbreaks are often associated with consumption of contaminated food, especially meat products. To better understand meat contamination of L. monocytogenes , whole genome sequencing(WGS) was performed on all detected isolates to investigate genetic relationships between retail markets and slaughterhouses. 110 and 13 isolates were isolated from 1914 food samples and 67 food and environmental samples, respectively. IIa (51/123,41.5%) and IIc (7/123,5.7%) were detected as the dominant serogroups of 123 L. monocytogenes isolates.Most isolates were penicillin-resistant (22/123,17.9%) in the phenotypic test, and all isolates were also found to be susceptible to ampicillin, meropenem, and vancomycin. All of them harbored virulence-associated genes and premature stop codons (PMSCs) in inlA genes were occurred in 35 strains. 22 multilocus sequence types and 19 clonal complexes were identified with ST9 being most common. This study also showed the prevalence and uniqueness of strains from Jilin, China compared with worldwide epidemic international strains. The findings of this study will contribute to the epidemiological understanding of transmission of L. monocytogenes from production and circulation in the region of northern China. [ABSTRACT FROM AUTHOR]