2019—2020年桂林市食源性沙门菌耐药分析及PFGE分型研究

Analysis of drug resistance and PFGE molecular type of foodborne Salmonella in Guilin from 2019 to 2020

目的了解2019—2020年桂林市沙门菌耐药情况及分子分型特征,以期了解桂林市食源性沙门菌的流行变化规律。方法对2019—2020年食源性风险监测及突发公共卫生事件检出的69株沙门菌进行血清分型,根据CLSI 2020推荐标准,采用微量肉汤稀释法测定最低抑菌浓度(MIC),分析耐药性,以脉冲场凝胶电泳法(PFGE)进行分子分型。结果69株沙门菌分属20个血清型,优势血清型为鼠伤寒沙门菌(27.54%)和肠炎沙门菌(14.49%);2019年的32株菌共产生17个耐药谱,其中9株鼠伤寒沙门菌对四环素100%耐药;2020年的37株菌共产生24个耐药谱,其中10株鼠伤寒沙门菌对磺胺异噁唑100%耐药。69株沙门菌呈现出多个不同的基因型别。相同血清型的基因型比较相近,具有同源性,不同血清型的PFGE结果具有多态性。结论2019—2020年桂林市沙门菌的优势菌株为肠炎沙门菌和鼠伤寒沙门菌,检出的沙门菌存在耐药现象,不同沙门菌菌株之间可能具有亲缘性关系。

Objective To understand the drug resistance and molecular type of Salmonella in Guilin from 2019 to 2020,so as to understand the epidemiological changes of foodborne Salmonella in Guilin city.Methods 69 Salmonella strains detected in foodborne risk surveillance and public health emergencies from 2019 to 2020 were serologically classified.According to recommended standards(CLSI 2020),minimal inhibitory concentration(MIC)was determined by micro broth dilution method,drug resistance was analyzed,and molecular typing was performed by pulsed field gel electrophoresis(PFGE).Results 69 salmonella strains belonged to 20 serotypes,and dominant serotypes were Salmonella typhimurium(27.54%)and Salmonella enteritidis(14.49%).In 2019,32 strains of bacteria produced a total of 17 drug resistance profiles,of which 9 strains of Salmonella typhimurium were 100%resistant to tetracycline.In 2020,a total of 24 resistance profiles were generated in 37 strains,of which 10 Salmonella typhimurium were 100%resistant to sulfonoxazole.69 strains of Salmonella exhibited multiple different genotypes.The genotypes of the same serotype were relatively similar and had homology,while PFGE results of different serotypes had polymorphism.Conclusion The dominant strains of Salmonella in Guilin from 2019 to 2020 are Salmonella enteritidis and Salmonella typhimurium.The detected Salmonella shows drug resistance,and different Salmonella strains may have a genetic relationship.