Wren B W, Heard S R, al-Saleh A I, Tabaqchali S
Department of Medical Microbiology, St Bartholomew's Hospital Medical College, West Smithfield, London.
J Med Microbiol. 1993 Feb;38(2):109-13. doi: 10.1099/00222615-38-2-109.
A total of 218 Clostridium difficile strains was examined for production of toxin A by ELISA, production of toxin B by a cytotoxin assay and the presence of toxin A and B gene-associated sequences by the polymerase chain reaction (PCR). After saturation amplification with toxin B-specific primers, the characteristic amplification product (591 bp) was detected in all 184 toxigenic strains examined. PCR with toxin A-specific primers gave positive results with all but one of the toxigenic strains. By contrast, PCR with toxin A- and toxin B-specific primers yielded negative results with all 34 non-toxigenic strains tested. This suggests that PCR detection of either the toxin A or B gene is a good indication of toxin production. PCR did not require DNA extraction or hybridisation and was convenient, sensitive and rapid. Toxigenic C. difficile could be detected in mixed cultures, suggesting a role for PCR in the identification of toxigenic C. difficile in primary culture.
总共对218株艰难梭菌菌株进行了检测，通过酶联免疫吸附测定法（ELISA）检测毒素A的产生，通过细胞毒素测定法检测毒素B的产生，并通过聚合酶链反应（PCR）检测毒素A和B基因相关序列的存在。在用毒素B特异性引物进行饱和扩增后，在所检测的184株产毒菌株中均检测到特征性扩增产物（591 bp）。用毒素A特异性引物进行的PCR除了一株产毒菌株外，其余所有产毒菌株均得到阳性结果。相比之下，用毒素A和毒素B特异性引物进行的PCR对所有34株非产毒菌株检测均得到阴性结果。这表明PCR检测毒素A或B基因是毒素产生的良好指标。PCR不需要DNA提取或杂交，且方便、灵敏、快速。在混合培养物中可以检测到产毒艰难梭菌，这表明PCR在原代培养中产毒艰难梭菌的鉴定中具有作用。
