Geric Barbara, Rupnik Maja, Gerding Dale N, Grabnar Miklavz, Johnson Stuart
Department of Biology, University of Ljubljana, Vecna pot 111, 1000 Ljubljana, Slovenia 2Hines VA Hospital, Hospital/151 Fifth Avenue & Roosevelt Road, Hines, IL 60141, USA 3Loyola University Medical Center, 2160 South First Avenue, Maywood, IL 60153, USA.
J Med Microbiol. 2004 Sep;53(Pt 9):887-894. doi: 10.1099/jmm.0.45610-0.
Genetic variants of Clostridium difficile have been reported with increasing frequency, but their true incidence is unknown. C. difficile strains have been classified into variant toxinotypes according to variations in the pathogenicity locus encoding the major virulence factors, toxins A and B. Some strains produce an additional toxin, binary toxin CDT. This survey of clinical isolates (153) from patients in a single hospital set out to ascertain the distribution of variant toxinotypes and strains possessing binary toxin genes. A PCR-RFLP-based method of toxinotyping identified 123 (80.4 %) isolates as toxinotype 0, 13 (8.5 %) strains as non-toxigenic and 17 (11.1 %) as belonging to variant toxinotypes. Binary toxin genes were amplified by PCR in nine strains (5.8 %), all of which were variant toxinotypes. Toxin variants of C. difficile are pathogenic and commonly isolated and need to be considered when evaluating new diagnostic testing strategies for C. difficile disease.
艰难梭菌的基因变异报道频率日益增加，但其实际发生率尚不清楚。艰难梭菌菌株已根据编码主要毒力因子毒素A和毒素B的致病位点变异，被分类为不同的毒素型变体。一些菌株会产生另一种毒素——二元毒素CDT。本研究对一家医院患者的153份临床分离株进行调查，旨在确定毒素型变体和携带二元毒素基因菌株的分布情况。一种基于PCR-RFLP的毒素分型方法鉴定出123株（80.4%）为毒素型0，13株（8.5%）为无毒株，17株（11.1%）属于毒素型变体。通过PCR在9株菌株（5.8%）中扩增出二元毒素基因，所有这些菌株均为毒素型变体。艰难梭菌的毒素变体具有致病性且常见，在评估艰难梭菌疾病的新诊断检测策略时需要考虑。
