2017年扬州市广陵区食品和公共场所从业人员沙门菌血清学及PFGE分型研究

Serological distribution and PFGE molecular characteristics of Salmonella among catering service staffs in Guangling district of Yangzhou city in 2017

目的探讨扬州市广陵区食品和公共场所从业人员沙门菌感染情况与血清型和分子分型特征。方法2017年采集食品和公共卫生服务行业从业人员肛拭子标本,进行肠道致病菌的分离培养,对分离株进行血清学分型,再以脉冲场凝胶电泳(PFGE)进行分子分型和聚类分析。结果2017年共采集肛拭子标本22522份,检出沙门菌34株,检出率0.15%;男性0.10%,女性0.18%,差异无统计学意义(χ^2=2.15,P=0.14);夏秋季检出率(0.24%)高于冬春季(0.021%),差异有统计学意义(χ^2=16.9,P<0.01)。分离株以C1群最多(占35.29%),其次为B群(占32.35%);以里森沙门菌(占17.64%)和鼠伤寒沙门菌(占11.76%)为优势株。将血清凝集能分型的33株沙门菌进行PFGE分型分析,检出30个型别(P1~P30),其中3株为P29型、2株为P30型,上述5株相似度为85.42%,具有高度同源性;分离出的6株里森沙门菌中5株相似度相似度为60.56%,B群中的2株和E4群中的1株相似度为64.85%、C1群中的2株相似度为69.70%,均为相似菌株;其余型别相似度<50%,为流行病学不相关。结论2017年扬州市广陵区食品从业人员沙门氏血清型以C1群和B群为主。优势株为里森沙门菌、鼠伤寒沙门菌。菌株PFGE带型较分散。

Objective To investigate the infection status,seological distribution and molecular characteristics of Salmonella among catering service staffs in Guangling district of Yangzhou city.Methods In 2017,anal swabs of catering service staffs in Guangling district of Yangzhou city were collected for the isolation and culture of intestinal pathogens,the isolated were subjected to serological identification,molecular typing analysis and clustering analysis by pulse field gel electrophoresis(PFGE).Results A total 34 Salmonella strains were isolated from 22522 collected anal swabs,resulting the positive rate of 0.15%.The male and female detection rates were 0.10%and 0.18%,respectively,with no statistically significant difference(χ^=2.15,P=0.14).The detection rate in summer and autumn(0.24%)was significantly higher than that in winter and spring(0.021%),with statsitically significant difference(χ^=16.9,P<O.01).Isolated strains were mainly Cl group(accounted for 35.29%),followed by B group(accounted for 32.35%);Salmonella lissen(accounted for 17.64%)and Salmonella typhimurium(accounted for 11.76%)were dominant strains.The 33 isolates with positive results for serological identification were subjected to PFGE analysis,a total of 30 types were detected(P1-P30),including 3 strains of P29 and 2 strains of P30,the similarity of the above 5 strains was 85.42%,which was highly homologous.The similarity among 5 of the 6 Salmonella lissen isolates was 60.56%,while the similarity among 2 B group isolates and 1 E4 group isolate was 64.85%,the similarity of 2 o£Cl group isolates was 69.70%,with certain similarity.The similarities among other types were less than 50%,which were not epidemiological related.Conclusion The main serotypes of Salmonella in Guangling district o£Yangzhou city in 2017 were Cl group and B group and the dominant strains were Salmonella lissen and Salmonella typhimurium.PFGE analysis showed scattered band patterns.