Variants of Shiga-like toxin II constitute a major toxin component in Escherichia coli O157 strains from patients with haemolytic uraemic syndrome.
Variants of Shiga-like toxin II constitute a major toxin component in Escherichia coli O157 strains from patients with haemolytic uraemic syndrome.
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志贺样毒素 II 的变体构成溶血性尿毒综合征患者的大肠杆菌 O157 菌株中的主要毒素成分。
DOI：
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发表时间：
1994
影响因子：
3
通讯作者：
H. Karch
中科院分区：
文献类型：
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作者：
H. Rüssmann;H. Schmidt;J. Heesemann;A. Caprioli;H. Karch
对来自德国的157株溶血性尿毒综合征（HUS）患者的大肠杆菌（O）中志贺样毒素（SLT）的流行情况和基因型进行了调查。这是通过用两个引物对PCR扩增B亚基基因来完成的-一个与slt-IB互补，另一个与slt-IIB和slt-IIvB序列同源。为了区分slt-II和slt-IIv，用限制性内切酶Hae III和Fok I消化扩增的DNA。在检查的38个菌株中，17个含有slt-IIv序列; 4个仅含有slt-IIv，3个同时携带slt-IIv和slt-I，10个菌株同时携带slt-IIv和slt-II。在剩余的21株菌株中发现另外三种基因型（slt-I、slt-II、slt-I/slt-II），导致总共六种slt基因型。为了确定slt基因是否表达，以及基因型是否与表型相关，对所有菌株进行细胞毒性测定和菌落ELISA。所有38株菌株对Vero细胞显示出相似数量的细胞毒性活性。SLT-I特异性单克隆抗体（MAb）13 C4与所有10种鉴定出slt-I序列的菌株反应。用SLT-II特异性MAb 11 E10进行的菌落印迹ELISA检测到28株具有slt-II序列的菌株中的27株，但不与携带slt-IIv或slt-I和slt-IIv的7株菌株中的任何一株反应。这里显示的高变异性具有诊断意义，并可能对与这些病原体相关的感染中的宿主反应产生影响。
The prevalence and genotype of Shiga-like toxins (SLTs) in Escherichia coli (O)157 strains from patients in Germany with haemolytic uraemic syndrome (HUS) were investigated. This was done by PCR amplification of the B-subunit genes with two primer pairs--one complementary to slt-IB, and the other homologous to both slt-IIB and slt-IIvB sequences. To distinguish between slt-II and slt-IIv, the amplified DNA was digested with restriction endonucleases HaeIII and FokI. Of the 38 strains examined, 17 harboured sequences for slt-IIv; four contained only slt-IIv, three carried both slt-IIv and slt-I, and 10 strains had slt-IIv and slt-II. A further three genotypes (slt-I, slt-II, slt-I/slt-II) were found in the remaining 21 strains resulting in a total of six slt genotypes. To determine whether the slt genes were expressed, and whether genotypes correlated with phenotypes, all strains were subjected to cytotoxicity assays and colony ELISA. All 38 strains displayed cytotoxic activity to Vero cells in similar quantities. The SLT-I-specific monoclonal antibody (MAb)13C4 reacted with all 10 strains in which slt-I sequences were identified. Colony blot ELISA with the SLT-II specific MAb11E10 detected 27 of 28 strains with slt-II sequences, but did not react with any of the seven strains that carried slt-IIv, or slt-I and slt-IIv. The high SLT variability shown here has diagnostic implications and may well have consequences for the host response in infections associated with these pathogens.