亚MIC剂量的甲硝唑和万古霉素对中国株A^-B^+艰难梭菌毒力转录和表达的影响(英文)  

Effect of sub-MIC concentration of metronidazole and vancomycin on toxin genes transcription and production in Chinese A^-B^+ Clostridium difficile

作　　者：李先平[1] 高洪元[2] 李文革[1] 王晶[1] 卢金星[1] 

机构地区：[1]中国疾病预防控制中心传染病预防控制所,传染病预防控制国家重点实验室,北京102206 [2]山东省泰安市中医二院检验科,泰安271000

出　　处：《中国人兽共患病学报》2014年第2期116-120,124,共6页Chinese Journal of Zoonoses

基　　金：Supported by the National Science and Technology Major Project during the"12th Five-Year Plan"(No.2013ZX10004217)~~

摘　　要：目的艰难梭菌是医院获得性感染性腹泻的主要原因。有些抗生素能够诱导和促进艰难梭菌相关性腹泻(CDAD)。本研究探讨治疗CDAD的一线药物甲硝唑和万古霉素的亚最小抑菌浓度(MIC)剂量对中国艰难梭菌A-B+高分离株BJ08生长、毒力基因转录和毒素分泌的影响。方法 BJ08菌株分别生长在含有1/4MIC的甲硝唑或万古霉素以及无抗生素的BHI液体培养基中。每4h通过检测其OD值以确定其生长曲线;通过实时荧光定量PCR检测其毒力基因的表达;通过ELISA检测上清和细胞内B毒素的表达。结果实验发现BJ08在1/4MIC剂量的甲硝唑和万古霉素存在的情况为,到达指数生长期的时间延迟;毒力基因及其毒素的表达增高且提前;但甲硝唑和万古霉素对其影响的程度不同。结论实验证明中国株A-B+在亚MIC剂量抗生素存在的情况下,其生长延迟,毒力基因和毒素表达提前且升高。本实验为临床规范治疗CDAD与合理用药提供一定的参考价值。Clostridium difficile is the major cause of hospital-acquired infectious diarrhea. Certain antibiotics are known to induce and promote C. difficile-associated diarrhea. Effect of sub-MIC of metronidazole （MTR） and vancomycin （VAN）, the first line antibiotics for CDAD, on growth, toxin genes transcription and toxin production were investigated in strain A B＋ which was highly isolated in China, named strain BJ08. BJ08 was grown with and without 1/4-MIC concentrations of MTR or VAN, and growth curve was measured by reading OD values. Real-time PCR was used to detect the level of tcd A and tcd B mRNA, and the toxin B was detected using ELISA in culture supernatants and also in sonicated ceils. There was a lag in reaching exponential growth phase, and the transcription of toxin genes and production of toxin B were earlier and higher in the presence of 1/4-MIC concentrations of MTR or VAN compared to that of antibiotics-free control group. But effects varied between MTR and VAN. Our results showed Chinese strain A-B＋ C. difficile was lag in growth, and both the expression of toxicity genes and toxin B were higher and earlier. Our study is of certain reference value to clinician for clinical standard treatment of CDAD and rational antibiotics use.

关 键 词：艰难梭菌 甲硝唑 万古霉素 B毒素 

分 类 号：R383.3[医药卫生—医学寄生虫学]