A novel toxinotyping scheme and correlation of toxinotypes with serogroups of Clostridium difficile isolates
A novel toxinotyping scheme and correlation of toxinotypes with serogroups of Clostridium difficile isolates
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DOI：
10.1128/jcm.36.8.2240-2247.1998
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发表时间：
1998-08-01
影响因子：
9.4
通讯作者：
Delmée, M
中科院分区：
文献类型：
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作者：
Rupnik, M;Avesani, V;Delmée, M
筛选了来自22个血清群的219株艰难梭菌分离株，以检测毒素B（tcdB）和毒素A（tcdA）编码基因的变化。扩增部分毒素基因，并检查PCR片段的长度多态性，并用几种限制性内切酶切割以监测限制性片段长度多态性（RFLP）。对于47株（21%），与参考菌株VPI 10463的毒素基因相比，发现毒素基因存在差异。在这两个毒素基因中通常观察到多态性。RFLP在tcdB基因中更常见，其中单个限制性内切酶可以给出多达五种不同的模式。限制性位点在tcdA基因中的异质性似乎较低，其中对于大多数酶，仅识别两种不同的RFLP。然而，在tcdA中观察到缺失，并且描述了四种新类型的缩短的tcdA基因。根据毒力基因的变化，变异株可分为10个毒力型（毒力型I ~ X）。一个toxinotype的特点是在毒素基因的变化，并在其他地区的致病性位点，也类似的脉冲场凝胶电泳模式相似的模式。在所研究的22个血清群中的9个中发现了变异的毒素型，并且某些毒素型与特定血清群明显相关。毒素型VIII是血清群F所有菌株的特征。常见变异毒素型的其他血清群为A1、A15、E和X。C中的变异性测试。艰难梭菌毒素基因不仅可用作分子分型系统，而且可在诊断和发病机制中具有意义。
Two hundred nineteen Clostridium difficile isolates from 22 serogroups were screened for changes in the genes coding for toxin B (tcdB) and toxin A (tcdA). Parts of the toxin genes were amplified, and the PCR fragments were checked for length polymorphisms and cut with several restriction enzymes to monitor restriction fragment length polymorphisms (RFLPs). For 47 strains (21%), differences in the toxin genes were found compared to the toxin genes of reference strain VPI 10463. Polymorphisms were usually observed in both toxin genes. RFLPs were more commonly found in the tcdB gene, in which a single restriction enzyme could give up to five different patterns. Restriction sites seemed to be less heterogeneous in the tcdA gene, in which for most enzymes only two different RFLPs were recognized. However, deletions were observed in tcdA, and four new types of shortened tcdA genes are described. According to the changes in their toxin genes, variant strains could be divided into 10 groups (toxinotypes I to X). A toxinotype was characterized by similar patterns of changes in the toxin genes and in other regions of the pathogenicity locus and also similar pulsed-field gel electrophoresis patterns. Variant toxinotypes were found in 9 of the 22 serogroups studied, and some toxinotypes were clearly associated with specific serogroups. Toxinotype VIII is characteristic for all strains of serogroup F. Other serogroups in which variant toxinotypes were commonly found are A1, A15, E, and X. Testing of variability in C. difficile toxin genes not only might be useful as a molecular typing system but also could have implications in diagnostics and pathogenesis.