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目的探索马桑水提取物(CSE)对耐药金黄色葡萄球菌(MRSA)的抗菌作用机制。方法分别用AFFX原核表达谱芯片、Western-blotting、SDS-PAGE凝胶电泳等方法,测定CSE对MRSA相关基因表达、自溶酶以及β-内酰胺酶的影响。结果 MRSA对绝大多数抗生素耐药,而CSE与多种β-内酰胺类抗生素合用具有显著地协同效应(P<0.05);可显著下调MRSA的RNA表达总量,单用CSE或与氨苄西林合用均能呈剂量依赖性调控基础代谢基因、肽聚糖水解酶(lytM)基因、转运子基因、青霉素结合蛋白(PBPs)以及β-内酰胺酶活性(P<0.05);可显著提高MRSA菌体内头孢唑啉浓度(P<0.05)。结论 CSE具有抑制MRSA作用,与β-内酰胺类抗生素合用具有协同作用。其机制与调控ribA、PBPs、lytM等相关靶基因的表达与转录,影响药物主动外排、细菌自溶及代谢等多种因素有关。
Objective To explore the antibacterial mechanism of water extract of Ma Sang (CSE) against drug-resistant Staphylococcus aureus (MRSA). Methods AFFX prokaryotic expression microarray, Western-blotting and SDS-PAGE gel electrophoresis were used to determine the effect of CSE on MRSA-related gene expression, autolysin and β-lactamase. Results MRSA was resistant to most antibiotics, while CSE was significantly synergistic with various β-lactam antibiotics (P <0.05). It could significantly down-regulate the total RNA expression of MRSA. CSE alone or combined with ampicillin (P <0.05), which could significantly increase the rate of MRSA (P <0.05), and the combination of them could dose-dependently regulate the metabolism of basal metabolic genes, lytM gene, transporter gene, penicillin binding protein (PBPs) and β-lactamase Cefazolin concentration in vivo (P <0.05). Conclusion CSE can inhibit MRSA and has a synergistic effect with β-lactam antibiotics. The mechanism and regulation of ribA, PBPs, lytM and other related target gene expression and transcription, affecting drug efflux, bacterial autolysis and metabolism and other factors.