摘要
目的确定儿茶素类化合物——儿茶素(C)、表儿茶素没食子酸酯(ECG)、表没食子酸儿茶素(EGC)联合增强β-内酰胺类抗生素对耐甲氧西林的金黄色葡萄球菌(MRSA)产生抗菌增敏作用的最佳配伍比并对其可能的抗菌增敏作用的机制进行初步探讨。方法以微量稀释法测定C、ECG、EGC和几种β-内酰胺类抗生素单独对MRSA WHO-2菌株的最小抑菌浓度(MIC),以棋盘法测定C、ECG和EGC联合β-内酰胺类抗生素后对MRSA WHO-2菌株和25株MRSA临床分离株的最小抑菌浓度(MIC);以荧光分光光度计法和激光共聚焦扫描显微镜法观察C、ECG、EGC单独、两两联合、三者联合后对柔红霉素在MRSA WHO-2菌株菌体聚集的影响。结果 C、ECG、EGC三者联用时可以增强苯唑西林抗MRSA WHO-2菌株的能力,其中C、ECG、EGC按照1:1:1的比例配伍后可以取得最佳的抗菌增敏效果,后续实验选用此药物配伍。药物总浓度为16μg/mL的C2E(C+ECG+EGC)与苯唑西林、头孢唑林、氨苄西林联合时对于MRSA WHO-2菌株可产生抗菌增敏作用,对应的FIC指数均为0.38,同样浓度的C2E联合苯唑西林、氨苄西林、头孢唑林、头孢吡肟、泰能后对25株MRSA临床分离株中可产生抗菌增敏作用的菌株数所占比例分别为80%、76%、88%、80%、92%,说明C2E在MRSA临床分离株中同样存在广泛的抗菌增敏作用。经过均为16μg/mL的C、ECG、EGC三者联合处理后,MRSA WHO-2菌株菌体内的柔红霉素在荧光分光光度计下测得的A值为9.26±0.16,大于单独或两两联合处理时的A值(P<0.05),提示三者联合处理后增强了柔红霉素在MRSA WHO-2菌体内的聚集;激光共聚焦扫描显微镜法也显示出相同的结果。结论 C、ECG、EGC三者联合后可显著增强β-内酰胺类抗生素抗MRSA的作用,其最佳配伍比为1:1:1。抗菌增敏作用机制可能与其增加药物在菌体内的聚集有关。
Objective To determine the best compatible proportion of the catechins those were catechin, epicatechin gallate, epigallocatechin which could enhance the anti-MRSA （methicillin resistant Staphylococcus aureas） effect used together on β-lactam antibiotics and to study the probable mechanisms of the antibacterial sensitizing effect. Methods The exclusive minimum inhibitory concentration（MIC） of C, ECG, EGC and some β-lactam antibiotics against WHO-2 strain was determined by inminidilution method. The MIC values of C, ECG, EGC and some β-lactam antibiotics against WHO-2 strain and 25 clinical strains of MRSA were detected by chessboard method. The effects on daunorubicin assemblying in the intracellular body of MRSA WHO-2 after being dealt with C, ECG and EGC together were observed by fluorescence spectrophotometer method and confocal laser scanning microscopy method. Results It would enhance the antibacterial effect on oxacillin against MRSA WHO-2 strain when C, ECG, EGC were combined together. Especially, it would derive the best antibacterial sensitizing effect from C, ECG, EGC being combined in the compatable proportion of 1：1：1, the very compatable proportion was used in the latter experiments. C2E （C ＋ ECG ＋ EGC） under the total drug concentration of 16μg/mL played an antibacterial sensitizing role combined with ampicillin, oxacillin and cefazolin against MRSA WHO-2, the corresponding FIC indices were all 0.38. The proportions of the strains amounts of C2E exhibiting the effect of antibacterial sensitizing among the 25 MRSA clinical strains were 80%, 76%, 88%, 80%, 92% under the C2E total drug concentration of 16μg/mL combined with oxacillin, ampicillin, cefazolin, cefepime, tienam, illustrating that it exhibited extensively antibacterial sensitizing effect among the MRSA clinical strains as well. The optical density （A） value of daunorubicin existing in the intracellular body of MRSA WHO-2 was 9.26±0.16, tested under the fluorescence spectrophotometer after being dealt with the r
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2012年第5期397-400,I0001-I0004,共8页
Chinese Journal of Antibiotics
