上海市虹口区2010-2012年腹泻病例沙门菌监测及分子型特征

[目的]研究基于公共卫生实验室主动监测哨点医院沙门菌腹泻及优势菌型的耐药性和分子型特征。[方法]选择辖区内2家医院作为主动监测哨点,甄别食源性感染性腹泻的病例并采集粪便标本进行沙门菌培养、血清型鉴定和抗菌药物耐药性试验,通过脉冲场凝胶电泳(PFGE)分析优势菌型的遗传同源性。[结果]2010-2012年,共检测2 579份标本,分离沙门菌185株(年度阳性率分别为9.1%、6.8%、5.1%,总阳性率为7.2%),涵盖23种不同血清型,最常见的为肠炎和鼠伤寒沙门菌。所有沙门菌感染病例的男女性别比为0.9:1;肠炎和鼠伤寒沙门菌感染均以21~60岁(68.9%)和60岁以上(21.4%)者居多。肠炎和鼠伤寒沙门菌对萘啶酸、磺胺异噁唑、链霉素、甲氧嘧啶、庆大霉素、四环素等6种抗菌药物的耐药率分别为27.7%~96.9%和2.6%~63.2%,且肠炎沙门菌的耐药率显著高于鼠伤寒沙门菌(P值均<0.05)。22株肠炎和20株鼠伤寒沙门菌经PFGE各自分为11个和6个分子型。[结论]肠炎和鼠伤寒是区域内最常见的沙门菌腹泻菌型,分子分型提示存在优势克隆的聚集性爆发和分散爆发,应警惕多重耐药的肠炎沙门菌克隆株形成潜在爆发的风险。加强以实验室为基础的主动监测对控制食源性感染性腹泻具有重要的公共卫生意义。

Salmonella serotyping and molecular subtyping analysis on diarrhea cases in Hongkou District of Shanghai,in 2010-2012

[Objective] To study the molecular characteristics and antibiotic resistance of Salmonella diarrhea cases in sentinel hospitals through active surveillance system conducted by public health laboratory. [Methods] Two sentinel hospitals were chosen for collection of stool specimens from food-borne infectious diarrhea cases and for Salmonella separation and detection immediately following serotyping and antimicrobial susceptible test (AST) on those isolates. Moreover, pulsed field gel electrophoresis (PFGE) was used for the genetic homology analysis. [Results] A total of 2 579 diarrhea specimens were collected and analyzed from 2010 to 2012, with 185 Salmonella isolates, covering 23 different serotypes (annual positive rates were 9.1%, 6.8%, 5.1%, with an average 7.2%). Salmonella enterica serovar Enteritidis(S. Enteritidis) and Typhimurium(S. Typhimurium) were the most common serotypes, of which 68.9% cases were seen in those aged 21 to 60 and 21.4% cases in those over 60 years old. 27.7%-96.9% S. Enteritidis and 2.6%-63.2% S. Typhimurium(P all<0.05) proved resistant to Nalidixic acid,Sultisoxazole, Streptomycin, Sulfamethoxydiazine, Gentamicinand Tetracycline. PFGE analysis on 22 S. Enteritidis strains showed 11 different clusters, while 20 S. Typhimurium strians showed 6.[Conclusion] S. Enteritidis and S. Typhimurium are the most common Salmonella serotypes, and molecular typing indicates the existence of clustering and sporadic outbreaks caused by dominance clones. We should be alert to early warnings on potential outbreaks of multiple-drug-resistant (MDR) S. Enteritidis. Active surveillance system based on public health laboratory should play an important role in the control of food-borne infectious diseases.