Development of antibacterial agents targeting an extracellular signal transduction.

开发针对细胞外信号转导的抗菌剂。

• 批准号: 10557031
• 负责人: SHIMIZU Tohru
• 金额: $ 8.58万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10557031/
• 关键词: Clostridium perfringens; pheromone; virulence; toxin produxtion; genetic regulation

One mutant strain of C. perfringens strain 13, SI112 that scarcely produce alpha-, kappa-, and theta-toxins was isolated. When the strain SI112 was cross-streaked with the virR/virS- mutant strain TS133, production of theta-toxin from SI112 was clearly observed in the crossing portion on a sheep blood agar plate. This indicated that an extracellular stimulating substance released from TS133 activated the production of theta-toxin from SI112 that could not produce the substance. We tentatively named the substance as VAP (virulence activating pheromone) and analyzed further. VAP in conditioned medium (CM) was produced mainly during the exponential phase and activated theta-toxin production at the transcriptional level. The stimulation of the pfoA gene by CM appeared to be dose-dependent. CM activated the pfoA transcription mostly at 15 min after addition, indicating a quick response to VAP exists in C. perfringens. VAP in CM seemed to be highly unstable loosing its activity within 30 min at 37゜C, and appeared to be a small molecule (M.W.<10,000). Since this extracellular communication for the virulence of C. perfringens would be important for understanding the pathogenicity and preventing infections, we are now trying to purify VAP from the culture medium of strain 13.

一株C.分离出几乎不产生α-、κ-和θ-毒素的产气荚膜杆菌菌株13，SI 112。当菌株SI 112与virR/virS突变菌株TS 133交叉划线时，在羊血琼脂平板上的交叉部分中清楚地观察到来自SI 112的θ-毒素的产生。这表明从TS 133释放的细胞外刺激物质激活了不能产生该物质的SI 112的θ-毒素的产生。我们将该物质初步命名为VAP（毒力激活信息素），并对其进行了进一步的分析。条件培养基（CM）中的VAP主要在指数期产生，并在转录水平上激活θ-毒素的产生。CM对pfoA基因的刺激似乎具有剂量依赖性。CM激活pfoA转录的时间主要集中在15 min，表明CM对VAP有快速反应。产气荚膜杆菌CM中的VAP似乎是高度不稳定的，在37 ℃下30分钟内失去其活性，并且似乎是小分子（M.W. <10，000）。由于这种胞外通讯对C.由于产气荚膜杆菌对于理解致病性和预防感染是重要的，我们现在试图从菌株13的培养基中纯化VAP。

项目成果

Bunu,S.etal: "Identification of noval VivR/VivS-regulated genes in Clotridium perfringens."Molecular Microbiology. 35. 854-864 (2000)

Bunu,S.etal：“产气荚膜梭菌中新型 VivR/VivS 调节基因的鉴定。”分子微生物学。

Bonu S.et al.: "Identification of novel VirR/VirS-regulated genes in clostridium perfvin gens"Molecular Microbiology. 35. 854-864 (2000)

Bonu S.等人：“产气荚膜梭状芽胞杆菌中新型 VirR/VirS 调节基因的鉴定”分子微生物学。

Banu, S. et al.: "Identification of novel VirR/VirS-regulated genes in Clostridium perfringens"Mol. Microbiology.. 35. 854-864 (2000)

Banu, S. 等人：“产气荚膜梭菌中新型 VirR/VirS 调节基因的鉴定”Mol。

Ohtani K.et al.: "Genetic analysis of the ycgJ-metB-cysK-ygaG operon negatively regulated by the VirR/VirS system in Clostridium per*geus"Microbiology and Immunology. (in press).

Ohtani K.等人：“Clostridium per*geus 中 VirR/VirS 系统负调控的 ycgJ-metB-cysK-ygaG 操纵子的遗传分析”微生物学和免疫学。

Ohtani, K. et al.: "Genetic analysis of the ycgJ-metB-cysK-ygaG operon negatively regulated by the VirR/VirS system in Clostridium perfringens"Microbiol. Immunol.. (in press). (2000)

Ohtani, K. 等人：“产气荚膜梭菌中 VirR/VirS 系统负调控的 ycgJ-metB-cysK-ygaG 操纵子的遗传分析”微生物学。