New types of toxin A-negative, toxin B-positive strains among clinical isolates of Clostridium difficile in Australia
New types of toxin A-negative, toxin B-positive strains among clinical isolates of Clostridium difficile in Australia
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DOI：
10.1099/jmm.0.031062-0
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发表时间：
2011-08-01
影响因子：
3
通讯作者：
Riley, Thomas V.
中科院分区：
文献类型：
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作者：
Elliott, Briony;Squire, Michelle M.;Riley, Thomas V.
通过毒素基因 PCR 检测，对来自澳大利亚各州的总共 817 株艰难梭菌人类临床分离株进行了 A(-)B(+) 菌株筛查。通过产毒酶联免疫分析，9株（1.1%）菌株被确认为A(-)B(+)。其中，6 例（66.7%）经 PCR 检测呈二元毒素阳性。使用PCR核糖分型和毒素分型，A(-)B(+)菌株可分为七种核糖型和三种毒素型。之前仅报道过其中一种核糖型（017）。本研究中核糖型 017 的流行率较低，仅检测到两种菌株。还定义了两种新的 A(-)B(+) 毒素型（XXX、XXXI）。毒素型 XXX 具有与毒素型 IV (A(+)B(+)) 相似的毒素 B 基因，但具有新的细胞病变区域。毒素型 XXXI 与其他 A(-)B(+) 类型（X、XVII）相似，但毒素 A 基因的缺失比这两种类型中的任何一种都要大。本研究中鉴定出的 A(-)B(+) 菌株类型与其他地区描述的菌株类型明显不同。
A total of 817 human clinical isolates of Clostridium difficile from all Australian states were screened for A(-)B(+) strains by toxin gene PCR assays. Nine (1.1 %) strains were confirmed to be A(-)B(+) by enzyme immunoassay for toxin production. Of these, six (66.7%) were binary toxin-positive by PCR. Using PCR ribotyping and toxinotyping, the A(-)B(+) strains could be grouped into seven ribotypes and three toxinotypes. Only one of the ribotypes had been reported previously (017). The prevalence of ribotype 017 was low in this study with only two strains detected. Two new A(-)B(+) toxinotypes were also defined (XXX, XXXI). Toxinotype XXX had a toxin B gene similar to that of toxinotype IV (A(+)B(+)) but with a novel cytopathic region. Toxinotype XXXI was similar to other A(-)B(+) types (X, XVII), but had a larger deletion to the toxin A gene than in either of those types. The types of A(-)B(+) strains identified in this study differed markedly from those described in other regions.