DETECTION BY ELISA OF LOW NUMBERS OF SHIGA-LIKE TOXIN-PRODUCING ESCHERICHIA-COLI IN MIXED CULTURES AFTER GROWTH IN THE PRESENCE OF MITOMYCIN-C
DETECTION BY ELISA OF LOW NUMBERS OF SHIGA-LIKE TOXIN-PRODUCING ESCHERICHIA-COLI IN MIXED CULTURES AFTER GROWTH IN THE PRESENCE OF MITOMYCIN-C
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DOI：
10.1099/00222615-36-3-198
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发表时间：
1992-03-01
影响因子：
3
通讯作者：
ACHESON, DWK
中科院分区：
文献类型：
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作者：
LAW, D;GANGULI, LA;ACHESON, DWK
目前可用于检测产志贺样毒素(SLT)的大肠杆菌的技术缺乏敏感性，或需要专门的设备和设施，在某些情况下只检测属于O157型的菌株。我们用从包虫包虫中提取的粗制P1糖蛋白建立了一种能同时检测SLTI和SLTII的ELISA技术，并用丝裂霉素C促进了毒素的产生。对于SLTI，用多粘菌素B预处理的细胞裂解物进行检测。在大肠杆菌O157：H7与大肠杆菌C600单独混合培养，或与大肠杆菌C600、奇异变形杆菌和粪肠球菌混合培养时，当产毒菌比例为1%时，可检出SLTI，当产毒素菌比例为0.025%时，可检出SLTII。在该系统中检测添加了O157：H7大肠杆菌的粪便样本时，当它们占大肠菌群的0.1%时，就能检测到SLTII产生菌。这项技术是检测混合培养物中少量SLT产生菌的灵敏和特异的方法，例如在溶血性尿毒症综合征和出血性结肠炎病例中发生的情况。
Techniques currently available to detect Shiga-like toxin (SLT)-producing Escherichia coli lack sensitivity or require specialised equipment and facilities, and in some cases detect only strains belonging to serotype O157. We have used an ELISA technique, capable of detecting both SLTI and SLTII with crude P1 glycoprotein from hydatid cysts, in combination with enhancement of toxin production by culture with mitomycin C. Supernates of Tryptone Soya Broth cultures containing mitomycin C 200 ng/ml were tested for SLTII. For SLTI, cell lysates pre-treated with polymyxin B were tested. In tests with E. coli O157:H7 in mixed culture with E. coli strain C600 alone, or with E. coli C600, Proteus mirabilis and Enterococcus faecalis, SLTI could be detected when the proportion of toxigenic organisms represented 1% of the mixture, and SLTII when the proportion was 0.025%. When faecal samples with added E. coli O157:H7 were examined in this system, SLTII-producing strains were detected when they comprised < 0.1% of the coliform population. This technique is a sensitive and specific assay for detecting low numbers of SLT-producing organisms in mixed culture such as occurs in cases of haemolytic uraemic syndrome and haemorrhagic colitis.