IMMUNOMAGNETIC SEPARATION AS A SENSITIVE METHOD FOR ISOLATING ESCHERICHIA-COLI O157 FROM FOOD SAMPLES
IMMUNOMAGNETIC SEPARATION AS A SENSITIVE METHOD FOR ISOLATING ESCHERICHIA-COLI O157 FROM FOOD SAMPLES
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DOI：
10.1017/s0950268800051438
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发表时间：
1994-08-01
影响因子：
4.2
通讯作者：
SIDDONS, CA
中科院分区：
文献类型：
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作者：
WRIGHT, DJ;CHAPMAN, PA;SIDDONS, CA
将接种大肠杆菌O 157的牛肉糜样品在添加万古霉素、头孢磺啶和头孢克肟的缓冲蛋白胨水中培养（BPW-VCC），并直接和用抗大肠杆菌抗体包被的磁珠免疫磁性分离（IMS）微生物后在头孢克肟亚碲山梨醇麦康基琼脂（CT-SMAC）上传代培养。coli O157（Dynabeads anti-E. coli O 157，Dynal，奥斯陆）。E.大肠杆菌O 157的初始接种量为200个/g，直接传代法和IMS法分别回收2个/g。12株E.用IMS从2个菌/g的初始接种物中回收了不同噬菌体类型、H抗原和毒素基因型组合的大肠杆菌O 157。通过在含吐温-20 0. 002 - 0.005%E的PBS中洗涤磁珠，可以减少其他生物与磁珠的非特异性结合。大肠杆菌O 157不被涂有无关抗体的磁性结合。大肠杆菌O 157，从279个个体牛的前流乳样品中分离出该微生物;两种分离株仅通过IMS技术制备。IMS是一种快速、简便、特异的分离大肠杆菌的方法。coli O 157，在流行病学研究中有一定的应用价值。
Minced beef samples inoculated with Escherichia coli O157 were cultured in buffered peptone water supplemented with vancomycin, cefsulodin and cefixime (BPW-VCC) and subcultured to cefixime tellurite sorbitol MacConkey (CT-SMAC) agar both directly and after immunomagnetic separation (IMS) of the organism with magnetic beads coated with an antibody against E. coli O157 (Dynabeads anti-E. coli O157, Dynal, Oslo). E. coli O157 was recovered from initial inocula of 200 organisms/g by direct subculture and 2 organisms/g by IMS. Twelve strains of E. coli O157 of different combinations of phage type, H antigen and toxin genotype were all recovered from initial inocula of two organisms/g by IMS. Nonspecific binding of other organisms to the magnetic beads could be reduced by washing of the beads in PBS with Tween-20 0.002-0.005 % E. coli O157 was not bound by magnetic coated with an unrelated antibody.During investigation of a dairy herd that was possibly linked to a small outbreak of infection with E. coli O157, the organism was isolated from 2 of 279 forestream milk samples from individual cattle; both isolates were made only by the IMS technique. IMS is rapid, technically simple, and a specific method for isolation of E. coli O157 and will be useful in epidemiological studies.