2018年烟台市同期五起伤寒病原学研究及溯源分析

Etiological survey and traceability analysis of five cases of typhoid fever during the same period in Yantai city

目的分析烟台市5起伤寒病原学特征及分子流行病学关联。方法2018年自烟台市5例伤寒确诊病例样本和流行病调查样本分离获得6株伤寒沙门菌菌株,病例发病时间自2018年5月26日至7月24日,分别分布于烟台牟平区水道镇、烟台蓬莱区登州街道、烟台龙口东莱街道、烟台牟平区文化街道、烟台芝罘区福莱山街道。采用常规细菌分离方法和XbaⅠ/BlnⅠ双酶切脉冲场凝胶电泳(PFGE)技术对伤寒杆菌进行溯源分析,同时开展viaB毒力基因检测和27种临床常用抗生素敏感试验对伤寒杆菌进行病原学研究。结果6株伤寒杆菌经PFGE-XbaⅠ和PFGE-BlnⅠ电泳分为4个PFGE模式,其中3株菌同源性100%;1株多耐药菌(外籍患者),1株单耐药菌(外省滞留史患者),1株完全敏感菌,同一PFGE模式的3株菌药敏表型一致,除对氨基糖甙类和喹诺酮类部分抗生素中介外,对其他抗生素均敏感;除外籍患者标本分离株viaB基因阴性外,其他菌viaB基因均阳性。结论烟台寒杆菌对临床常用抗生素敏感性良好,仍需重视伤寒散发病例发生和伤寒输入感染。

Objective To analyze the etiological characteristics and molecular epidemiological correlation of five cases of typhoid fever during the same period in yantai city.Methods Six S.Typhis strains were isolated from 5 typhoid patients and epidemiological samples in Yantai city in 2018.The onset time of the cases were from May 26,2018 to July 24,2018,distributed in Shuidao Town of Muping District,Dengzhou Street of Penglai District,Donglai Street of Longkou District,Wenhua Street of Muping District and Fulaishan Street of zhifu District.S.Typhis strains were analyzed by conventional bacterial isolation method and XbaⅠ/BlnⅠdouble-enzyme digestion pulse-field gel electrophoresis(PFGE).Meanwhile,ViaB virulence gene detection and 27 common antibiotics sensitivity tests were conducted to study the etiology of S.Typhis.Results Six strains of S.Typhi were isolated from 5 patients and the domestic egg of one patient,which were divided into 4 PFGE patterns by PFGE-XbaⅠand PFGE-BlnⅠand among which 3 strains had the same PFGE patterns.One multi-drug resistant strain(foreign patient),one single-drug resistant strain(patient with a history of provincial retention),and one completely sensitive strain were detected.The three strains of the same PFGE pattern exhibit the same drug-sensitive phenotype which were intermediate against aminoglycosides and quinolones and susceptibility against the other antibiotics.All of the strains carried the ViaB virulence factor except the strain from the foreign patient.Conclusion Local S.Typhi is susceptibility or intermediate against antibiotics commonly used in clinic.Sporadic cases of typhoid fever and typhoid imported infections still need attention.