沙门菌监测基于细菌学技术的关键点研究和控制

Study and control of bacteriological key points in Salmonella surveillance

目的研究和控制沙门菌分离方法的技术关键点,评价监测效果。方法用库存菌株和粪便肛拭、食品增菌标本比较5种沙门菌选择性平板分别与3种选择性增菌液配伍检测沙门菌的敏感性;将亚硒酸煌绿增菌液(SBG)与木糖赖氨酸脱氧胆酸盐琼脂平板(XLD)和CHROMagarTM沙门菌显色琼脂平板(CAS)配伍作为方法1在上海市4个疾病预防控制中心(CDC)实验室用于沙门菌监测(GSS);8个临床医院实验室使用SBG-XLD组合的方法2和CDC实验室进行平行检测。结果 CAS和XLD菌株测试的敏感性为100.0%和85.7%,肛拭标本经SBG增菌后使用CAS和XLD分离的敏感性为94.4%和89.7%。2006-2009年GSS监测阳性率在2.6%～3.8%;阳性峰值在5%～7%。临床实验室检测敏感性达到CDC的78.7%,最高为88.9%。结论有效增菌是沙门菌分离技术的关键点,强化实验室人员培训和使用统一的分离材料是控制沙门菌监测实施的关键点。方法1适用所有沙门菌的检测;方法2适用非伤寒沙门菌的检测,模块化、可选择的分离组合能兼顾效率和成本。

Objective To study and control the technical key points in Salmonella isolation,and evaluate the surveillance results.Methods Stock strains,anal swabs and food enrichment samples were used to compare the sensitivity of the separate combinations of 5 Salmonella-selective plates with 3 selective enrichment broths for detection of Salmonella.The combination of selenite brilliant green（SBG） enrichment with xylose lysine deoxycholate（XLD） agar and CHROMagar（TM） Salmonella（CAS） chromogenic medium was used as Method 1 for global salmonella surveillance（GSS） in the laboratories of four centers for disease control and prevention（CDCs） in Shanghai.The SBG-XLD combination as Method 2 was employed to parallel the CDC laboratory tests.Results The sensitivity of CAS and XLD was 100.0% and 85.7%,respectively.As for the rectal swabs enriched by SBG,the isolation sensitivity was 94.4% and 89.7% using CAS and XLD,respectively.The positive rate of GSS ranged between 2.6% to 3.8% from 2006 to 2009 with a peak of 5% to 7%.The clinical sensitivity reached 78.7% of the sensitivity of laboratory results with a maximum of 88.9%.Conclusion Effective enrichment is a key point in Salmonella isolation,and strengthening training for laboratory staff and using uniform isolation materials are the one in controlling Salmonella surveillance.Method 1 was applicable for detection of all Salmonella,while Method 2 was suitable for detection of non-typhoid Salmonella.Modular,alternative combinations may balance between efficiency and cost for isolation of strains.