沙门菌分离技术关键点的研究和评价

Study and evaluation on the key point of Salmonella isolation techniques

目的研究沙门菌常规分离方法的技术关键点。方法用库存菌株和肛拭、食品增菌标本测试评估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)与木糖赖氨酸胆酸盐琼脂平板(XLD)和CHROMagarTM沙门菌显色琼脂平板(CAS)配伍组合作为首选优化方法 (方法 1)通过全球沙门菌监测(GSS)和静安区预防性职业体检标本进行验证;8家临床医院实验室使用SBG-XLD组合的次选优化方法 (方法 2)和4个CDC实验室使用方法 1进行平行检测。结果 CAS和XLD菌株测试的敏感性为100%和85.7%,肛拭标本经SBG增菌后用CAS和XLD分离的敏感性为94.4%和89.7%,优于其他2种选择性增菌液与平板组合的检测效果。方法 1检测2005-2009年GSS和2008年体检标本的高峰阳性率达到5%～7%和1%。方法 2经2年的室间比对敏感性达到方法 1的78.7%,最高为88.9%。结论沙门菌常规分离的技术关键点在于有效增菌,实验室使用模块化的可选平板进行组合分离才能兼顾效率和成本。优化方法 1适用所有沙门菌的检测,优化方法 2适用非伤寒沙门菌的检测。

To study and evaluate the key point of Salmonella isolating techniques,the stock of Salmonella strains,feces swab and food specimen,were used to test the susceptibility in five Salmonella selectively agar combining three Salmonella selective enrichment broth.The optimized process of Selenite Brilliant Green enrichment broth（SBG）and CHROMagarTM Salmonella（CAS）,Xylose Lysine Deoxycholate agar（XLD）presume to priority method（method 1）that were verified by the feces swab from Global Salm-Surv（GSS）project and physical examination in Jing-an district.Another process of SBG and XLD presume to secondary method（method 2）that were parallel verified between 8 hospital and 4 CDC laboratories.It was demonstrated that susceptibility of Salmonella strains in CAS and XLD was 100% and 85.7%,then after enrichment with SBG in clinical feces swab,the susceptibility was 94.4% and 89.7%,respectively.This compatibility was superior to other two selective enrichment broth and agar combining.The peak of positive rate was 5-7% and 1% by method 1,respectively,from specimen of GSS in 2005-2009 and from physical examination in Jing-an district in 2008.The susceptibility of method 2 compared with method 1 was 78.7%,88.9% was the high point within two years by laboratories contrast.It is concluded that the key point of traditional techniques for Salmonella isolation is effective enrichment.Combinatorial separation of modularizedly alternative agar could balance efficiency and cost.Method 1 is applicable for detection of all Salmonella spp.while Method 2 is for detection of non-typhoidal Salmonella spp.