Genomic characterization of Salmonella typhimurium and its monophasic variants in Ningxia
This study was aimed at exploring the epidemiological characteristics of Salmonella typhimurium(S.typhi-murium)and Salmonella typhimurium monophasic variants(S.1,4,[5],12:i:-)at the genome-wide level in Ningxia.Estab-lishment of a whole genome genotyping database would provide a theoretical basis for source and prevention and control of fu-ture outbreaks.We conducted serotyping,MLST,cgMLST typing,and virulence gene and drug resistance phenotype prediction of 92 strains of S.typhimurium and its monophasic variants through whole genome sequencing.Among all strains,21 were S.typhomurium,accounting for 22.83％,71 strains were S.1,4,[5],12:i:-,accounting for 77.17％.MLST and cgMLST typing results indicated that all S.typhimurium strains were ST19-type,and were divided into five evolutionary bran-ches.Five clusters were found,and S.1,4,[5],12:i:-were all ST34-type;on the same evolutionary branch,17 clusters were found.VFDB predicted 155 virulence genes in eight classes,of which 33.33％were S.typhimurium carried nine virulence genes on plasmids,and both serotypes carried virulence genes related to SPI virulence island on chromosomes,12:I:-resistant to 4-14 antibiotics,resulting in 22 multi-drug resistance spectrum.S.typhimurium was resistant to 2-13 antibiotics and produced eight multi-drug resistance profiles.S.1,4,[5],12:i:-was the predominant serotype of S.enteritidis in Ningxia.Typhimurium carried fewer virulence genes than S.typhimurium,and showed a high risk of local outbreaks.
万方数据
维普
