Investigation,traceability analysis,and discussion of food poisoning caused by Salmonella typhimurium ST19
10.3969/j.issn.1002-2694.2024.00.012
- VernacularTitle:1起ST19型鼠伤寒沙门氏菌引起的食物中毒调查、溯源分析与探讨
- Author:
Shu-Kun YU
1
;
Lang LIU
;
Ya-Xin TAN
;
Zi-Yan CUI
;
Xing-Yu XU
;
Zhi-Yang TAO
Author Information
1. 武汉市东西湖区疾病预防控制中心,武汉 430040
- Keywords:
Salmonella typhimurium;
whole genome sequences;
pulsed-field gel electrophoresis;
drug resistance genes;
serotype
- From:
Chinese Journal of Zoonoses
2024;40(1):82-89
- CountryChina
- Language:Chinese
-
Abstract:
To perform a comprehensive analysis of the pathogenic causes of a food poisoning case in a district of Wuhan Cit-y,we investigated the molecular epidemiological relationships among pathogenic bacteria,to aid in traceability analysis of food-borne disease outbreaks,as well as clinical diagnosis and treatment.The pathogenic bacteria in this food poisoning case were i-solated and identified according to GB789.4-2016.The isolated strains were subjected to genotyping with pulsed field gel elec-trophoresis(PFGE).Drug resistance gene analysis,multi-locus sequence typing(MLST),and genome-wide single-nucleotide polymorphism analysis(wgSNP)were conducted via whole genome sequencing(WGS).The evolutionary tree for cluster analy-sis was constructed in fasttree software.Drug susceptibility testing was conducted with the broth microdilution method.A total of 12 strains of Salmonella were detected in seven anal swab samples and two fecal samples from the case,as well as three anal swab samples from unaffected individuals.The serotype of the strains was Salmonella typhimurium.The strain exhibited severe multiple drug resistance,including resistance to amikacin,ampi-cillin,cefazolin,gentamicin,piperacillin,and tetracycline,but susceptibility to other antibiotics.The coincidence rate between drug resistance genes and drug resistance phenotypes was high.PFGE revealed that nine strains from this food poisoning case were highly homologous.WGS revealed that the MLST type was ST19,and varying numbers of SNPs(1-6)were present a-mong strains.The phylogenetic tree revealed nine isolated strains forming a distinct cluster,differing from other Salmonella strains in the database and belonging to a novel clonal branch.The single nucleotide site in the strains was highly homologous to that of GCF in Jiangxi_020221795.1.The food poisoning case was caused by Salmonella typhimurium ST19,and all nine iso-lated strains originated from the same source.The chef is closely connected to this food poisoning case.This strain of Salmo-nella typhimurium belongs to a new clonal branch and exhibits multiple drug resistance.
