中国艰难梭菌高分离株和欧洲流行高毒株tcdA、tcdB基因转录及其毒素的表达（英文）

Transcription of tcdA and tcdB and toxins expression of Clostridium difficile between Chinese high isolates and European epidemic hyper-virulent strain

目的研究和比较中国艰难梭菌A-B+高分离株BJ08和欧洲流行A+B+高毒株(BI/NAP1/027)UK1的tcdA、tcdB转录和毒素表达。方法每隔3h提取艰难梭菌和培养上清,用实时荧光定量PCR的方法测定各个时间段BJ08和UK1菌株tcdA、tcdB基因的表达;用ELISA的方法检测BJ08和UK1菌株各个时间段的细胞和培养上清液中A毒素、B毒素的含量。结果 BJ08的生长速率显著大于UK1;BJ08不表达A毒素,但是检测到tcdA基因的转录,tcdA基因表达量显著低于UK1;tcdB的表达以及B毒素在两种菌株的培养上清液中和声波处理的细胞内的差异都不大。结论中国艰难梭菌A-B+高分离株BJ08和欧洲流行A+B+高毒株UK1的B毒素的转录和表达没有明显差异,BJ08菌株在中国有爆发流行的可能。

In this study, we analyze the gene transcriptions of tcdA and tcdB and expressions of toxins between strain BJ08 with toxin typing A^-B^＋ that highly isolated in China and the strain UK1 with toxin typing A^＋ B^＋ in European epidemic hyper-virulent strain （BI/NAPl/027）. Gene transcriptions of tcdA and tcdB were detected by real-time PCR and expressions of extracellular and intracellular toxin A and toxin B were measured by ELISA for every 3 hours. Results showed the growth rate of BJ08 was significantly faster than that of UK1 ; no toxin A, but tcdA mRNA was detected in strain BJ08, and the level of tcdA mRNA in BJ08 was significantly lower than that in strain UK1. There was no significant difference of production of toxin B in cultured supernatants and sonicated cells between strain BJ08 and UK1. In summary, there was no significant difference in transcriptions level of tcdB and expressions level of toxin B between strain BJ08 and UK1. It is theoretical possibility that outbreaks infection of Clostridium difficile may be caused by strain BJ08 in China.