黄芩活性成分对金黄色葡萄球菌生物膜干预作用及药动学/药效学的体内研究

Staphylococcus aureus（S.a） is a common pathogen which results in lung infection. It is characterised by resistance due to the formation of a biofilm. In this research, the in vivo intervention to the biofilm of S.a was undertaken by using the scutellaria active ingredients. On this basis, the research established a novel model of the S.a biofilm infection in rats and conducted the necessary intervention on the biofilm by means of the scutellaria active ingredients. By using a viable count method, and a pathological analysis, the effects of the active ingredients on intervention of S.a biofilm, and its synergetic germicidal effect on antibiotics, were investigated. Meanwhile, the reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect the expressions of inflammatory factors and virulence factors so as to explore the mechanism underpinning this in vivo intervention at a molecular level. Thereafter, high-performance liquid chromatography (HPLC) and a microbiological method were used to measure the plasma concentrations of the scutellaria active ingredients and antibiotics in the rats in vivo at different times. Then based on the pharmacokinetic parameters calculated, and the biofilm, the pharmacodynamics of the active ingredients of scutellaria on anti-biofilm activity and its effects on the pharmacodynamics and pharmacokinetics of antibiotics on the removal of S. a were analysed quantitatively. Furthermore, the authors investigated the mechanism underpinning the synergetic germicidal effect of active ingredients, such as scutellaria, on antibiotics. This work lays a foundation for research into, and the development of, new drugs utilising this anti-S.a biofilm.

金黄色葡萄球菌是常见的能导致肺部感染的病原菌，其耐药的特点与生物膜形成有密切关系。本研究在前期研究中利用黄芩活性成分在体外成功干预金黄色葡萄球菌生物膜的基础上，进一步建立大鼠金黄色葡萄球菌生物膜感染模型，并利用黄芩活性成分对其干预。采用活菌计数法、病理分析等方法观测黄芩活性成分对金黄色葡萄球菌生物膜的干预作用及其对抗生素的协同杀菌作用；采用RT-PCR、ELISA 等方法检测炎性因子、毒力因子的表达，从分子水平上探讨体内干预作用的机制；通过高效液相色谱法、微生物法测定黄芩活性成分及抗生素在大鼠体内各时间点的血药浓度，计算出药动学参数，结合生物膜定量数据分析黄芩活性成分抗生物膜活性的药效学及其对抗生素清除金黄色葡萄球菌的药效学及药动学影响，进一步探索黄芩活性成分对抗生素协同杀菌作用的机制，为进一步研发抗金黄色葡萄球菌生物膜的新药奠定研究基础。

金黄色葡萄球菌（S.a）是能导致肺部感染的常见病原菌，其耐药的特点与生物膜形（BF）成密切相关。前期体外研究中已证实，黄芩活性成分（黄芩苷、黄芩素）在体外可有效干预金黄色葡萄球菌生物膜的形成。本研究则在此基础上拟在动物体内进一步验证黄芩活性成分对S.a-BF感染的干预作用。通过大鼠背部CMC-Pounch囊袋和硅胶片植入法建立正常及免疫抑制背景下的大鼠S.a-BF感染模型，并比较上述模型的优缺点及成模型稳定性，最终选择正常大鼠背部硅胶片植入物S.a-BF感染模型作为药物干预实验的最佳模型。采用活菌计数法、扫描电镜形态学及病理分析等方法证实，黄芩活性成分联合抗生素（万古霉素、利奈唑胺）可有效干预大鼠体内S.a-BF的形成，并对BF内细菌产生协同杀菌作用，同时还可以减轻局部组织的炎症细胞浸润程度。采用血液常规生化及ELISA 等方法在分子水平检证实黄芩活性成分可下调S.a BF大鼠体内炎性因子（C-反应蛋白、降钙素原）、毒力因子（金黄色葡萄球菌肠毒素）的表达。通过高效液相色谱法测定治疗剂量的黄芩活性成分在大鼠体内各时间点的血药浓度，计算出药动学参数，证实亚抑菌浓度的黄芩苷可在大鼠体内产生抗S.a BF、抗炎及减少毒力因子产生的作用，为进一步研发抗金黄色葡萄球菌生物膜的新药奠定研究基础。