香鳞毛蕨素抗甲氧西林耐药金黄色葡萄球菌分子作用机制研究

In recent years, the bacterial drug resistance appears greatly due to widely abuse of antibiotics, which resulted in the ratio of Methicillin-resistant staphylococcus epidermidis (MRSA) in clinical isolated staphylococcus aureus increasing. Beside β- lactam antibiotics, MRSA showed resistant to multiple antibiotics, it will bring serious damage to the livestock health and cause great economic loss of animal husbandry. Therefore, MRSA has been a worldwide problem of prevention and treatment of bacterial infections. However, in the veterinary clinical, the effective drug to treatment of MRSA infection is very limited. It still relied on increasing antibiotic dose or a combination of variety of antibiotics, while these treatment means will bring hidden trouble to Animal origin food safety. In our previous works, we found dryofragin has significant anti-MASA activities in vivo and in vitro. Hence, the purpose of this project was to determine the drug target protein in inhibition of MRSA, to clear its exact binding sites with target protein and to reveal the molecular mechanism of inhibition of MRSA by the method of the transcriptome sequencing, Itraq technology, molecular docking simulation, the surface plasma resonance technology. The results of our project are expected to develop prevention drugs of MRSA with independent intellectual property rights in our country, to find new drug targets for inhibition of MRSA, and to provide a theory basis and practice in new anti-MRSA drug research and development. Base on these results, it was supposed that this project have important public health significance and application prospect.

抗生素的长期大量使用导致细菌耐药性问题空前严峻。甲氧西林耐药金黄色葡萄球菌（MRSA）在临床分离金黄色葡萄球菌中的比例不断增加，因其具有强而广泛的耐药性，导致畜禽感染和疾病问题日益广泛和严重。目前兽医临床中能够有效治疗MRSA感染的药物十分有限，主要依靠加大抗生素剂量或多种抗生素联用等手段，这又给动物源食品安全带来了极大的隐患。因此，防治MRSA已经成为当今世界范围内防治细菌感染的难题和热点。在前期的工作中，我们发现香鳞毛蕨素在体内外均具有显著的抗MRSA活性，显示了其具有进一步开发成抗菌新药的可能性。本项目拟通过转录组测序、Itraq技术、分子对接模拟、表面等离子共振等技术确定香鳞毛蕨素抑制MRSA的靶蛋白，明确其与靶蛋白的确切结合位点，揭示其抑制MRSA的分子作用机制。本项目结果可为进一步研发出具有我国自主知识产权的抗MRSA新药提供理论与实践依据，具有重要的公共卫生意义及应用前景。

由于抗生素在人类疾病治疗与畜牧业生产中的不合理使用，导致了细菌耐药性问题空前严峻。耐甲氧西林金黄色葡萄球菌在临床的分离比例不断增加，造成了畜禽感染和疾病问题日益广泛和严重。目前，兽医临床中能够有效治疗MRSA感染的药物十分有限，因此防治MRSA已经成为当今世界范围内防治细菌感染的难题和热点。.本项目以MRSA标准株和临床分离株为研究对象，筛选具有抗菌活性的中药单体化合物，通过大量筛选我们发现香鳞毛蕨素在体内外均具有显著的抗MRSA活性，且达到了万古霉素抗菌效果。同时，我们发现香鳞毛蕨素可以抑制MRSA生物膜的生长，也能抑制MRSA毒力因子的产生。为了研究香鳞毛蕨素抗MRSA的分子机制，我们利用转录组测序和蛋白质组测序技术对绵马酚作用前后MRSA菌株转录组数据进行比较，确定了绵马酚抑制MRSA的关键通路，并通过荧光定量PCR方法对转录数据进行了验证。组学数据和荧光定量PCR结果均比较符合，说明我们的结果真是可信。.以上结果表明香鳞毛蕨素在体内、体外均具有显著的抗MRSA活性，其作用机制可能与其抑制核糖体相关基因、铁蛋白合成，最主要的抑制了MRSA的双组份系统，进而抑制了菌株毒力因子的表达，最终发挥抗菌活性。