Watanabe Hiroki, Koizumi Yusuke, Matsumoto Asami, Asai Nobuhiro, Yamagishi Yuka, Mikamo Hiroshige
Department of Clinical Infectious Diseases, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan; Department of Infection Control and Prevention, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan.
Department of Clinical Infectious Diseases, Aichi Medical University Graduate School of Medicine, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan.
Anaerobe. 2018 Dec;54:140-143. doi: 10.1016/j.anaerobe.2018.09.002. Epub 2018 Sep 7.
Clostridioides difficile strains cause severe infection. Previous studies suggested that the virulence of C. difficile is dependent on ribotype; however, this hypothesis is still controversial. We aim to investigate the relationship between ribotypes, restriction endonuclease analysis (REA) types, and toxin gene expression in C. difficile strains.
We utilized 53 clinical C. difficile strains. All strains were assigned a molecular strain type using PCR ribotyping and REA typing and classified into 17 ribotypes and six REA types. The expression of toxin genes (tcdA, tcdB, and cdtB) in C. difficile strains were quantified by real-time PCR using each specific primer set, and expression was normalized to that of the housekeeping gene rpoA.
All 53 strains expressed tcdB and four strains expressed cdtB. Five strains did not express tcdA. Most ribotype and REA type strains expressed tcdA and tcdB similar to the BAA-1870 strain. In cdtB-positive strains, the cdtB expression levels were similar to those in the BAA-1870 strain. tcdA and tcdB expression levels were similar in the cdtB-positive and cdtB-negative strains.
Toxin gene expression was not associated with the ribotype. Production of binary toxin C. difficile transferase was not related to tcdA and tcdB expression levels.
艰难梭菌菌株可引起严重感染。先前的研究表明，艰难梭菌的毒力取决于核糖体分型；然而，这一假设仍存在争议。我们旨在研究艰难梭菌菌株的核糖体分型、限制性内切酶分析（REA）类型与毒素基因表达之间的关系。
我们使用了53株临床分离的艰难梭菌菌株。所有菌株均通过PCR核糖体分型和REA分型确定分子菌株类型，并分为17种核糖体分型和6种REA分型。使用各特异性引物组通过实时PCR对艰难梭菌菌株中毒素基因（tcdA、tcdB和cdtB）的表达进行定量，并将表达量标准化为管家基因rpoA的表达量。
所有53株菌株均表达tcdB，4株表达cdtB。5株未表达tcdA。大多数核糖体分型和REA分型的菌株表达tcdA和tcdB的情况与BAA - 1870菌株相似。在cdtB阳性菌株中，cdtB的表达水平与BAA - 1870菌株中的相似。cdtB阳性和cdtB阴性菌株中tcdA和tcdB的表达水平相似。
毒素基因表达与核糖体分型无关。艰难梭菌二元毒素转移酶的产生与tcdA和tcdB的表达水平无关。
