Genome characteristics of Salmonella typhimurium isolated in Urumqi from 2018 to 2021
This study was aimed at analyzing the genomic characteristics of Salmonella typhimurium(1,4,[5],12:i:1,2)in Urumqi from 2018 to 2021,to provide evidence for the monitoring of this serotype and handling of public health emergen-cies.A total of 26 Salmonella typhimurium isolates were obtained from the feces of people with diarrhea in Urumqi.Whole-genome sequencing(WGS)combined with bioinformatic analysis was used to predict serovars,MLST types,plasmid repli-cons,antimicrobial resistance genes,and virulence genes;in addition phylogenomic analysis based on genome-wide single nucleotide polymorphisms(wgSNPs)was conducted to determine the epidemiological relatedness among isolates.A total of 47 resistance genes representing ten categories were de-tected with a high prevalence,including aac(6')-Iaa(100％),blaTEM-1B(30.8％),tet(A)(42.3％),qnrS1(30.8％),and sul3(23.1％),encoding resistance to aminoglycosides,β-lac-tams,tetracyclines,quinolones,and sulfa,in addition to chro-mosomic mutations affecting the gyrA gene.Moreover,12 plasmids were detected,among which IncFIB(S)and IncFII(S)(34.6％)were dominant.The differences in virulence genes a-mong strains isolated in different periods were reflected primarily in the typical virulence genes associated with Salmonella vir-ulence mechanisms.In addition,cgMLST indicated that the dominant type of Salmonella typhimurium was cgST36414,con-tainning 10 strains.Moreover,wgSNP analysis indicated that Salmonella typhimurium isolates in Urumqi were consistent with the epidemic trends in 15 provinces and cities in China and also showed local evolution.Salmonella typhimurium isolates in Urumqi frequently carried a variety of resistance genes and plasmid replicons,which are key in the dissemination and evolution of drug resistance.Close communication links may exist with various sources of flora in the food chain,thus posing severe chal-lenges in public health monitoring and prevention.Therefore,the construction of the laboratory routine monitoring network based on internet information systems should be strengthened to improve the timeliness of monitoring and limit the spread of multidrug-resistant strains.
万方数据
维普
