抗生素暴露大肠杆菌活性氧及抗氧化酶的变化

Variation of reactive oxygen species and antioxidant enzyme of Escherichia coli exposed to antibiotics

目的探究大肠杆菌Mach1-T1暴露于不同抗生素种类和浓度下,活性氧(reactive oxygen species,ROS)和抗氧化酶的变化。方法将大肠杆菌Mach1-T1分别暴露于8种抗生素分别测定亚抑菌浓度(sub-inhibitory concentration,subMIC)以及最小抑菌浓度(minimal inhibitory concentration,MIC),使用流式细胞仪及多功能酶标仪测定暴露于sub-MIC和MIC的8种抗生素的细菌体内ROS和抗氧化酶变化水平。结果当大肠杆菌暴露于不同抗生素时,8种抗生素均可以诱导大肠杆菌Mach1-T1体内ROS和抗氧化酶水平发生变化,其中,利福平诱导能力最强,与对照组相比,细菌经利福平诱导后ROS水平提高了80%。但细菌的抗氧化酶的变化会随着抗生素的变化而做出不同的响应,如红霉素只能引起大肠杆菌的过氧化氢酶变化,头孢氨苄可引起大肠杆菌的超氧化物歧化酶和谷胱甘肽还原酶发生变化等。结论当大肠杆菌Mach1-T1暴露于不同抗生素时,会引起细菌体内ROS的变化以及抗氧化系统做出不同响应。

Objective To study the responses changes of the reactive oxygen species(ROS) and antioxidant enzymes in Escherichia coli(E.coli) Mach1-T1 exposed to different antibiotics with various concentrations. Methods Sub-inhibitory concentration(Sub-MIC) and minimal inhibitory concentration(MIC) of E.coli Mach1-T1 exposed to eight antibiotics were determined respectively. The changes of ROS levels and antioxidant enzymes levels of E.coli stimulated by eight antibiotics with sub-MIC and MIC levels were determined by flow cytometry and microplate reader. Results The response changes of ROS and antioxidant enzymes in E.coli could be induced by eight antibiotics. Notably,rifampicin has the strongest inducing ability for ROS,the level of ROS in E.coli induced by rifampicin increased by 80% compared with that by control;But the antioxidant enzymes of E.coli responded differently with various antibiotics,for example,erythromycin could only induce changes in catalase in E.coli and cephalexin could induce changes in superoxide dismutase and glutathione reductase in E.coli.Conclusion The reactive oxygen species and antioxidant system of E.coli Mach1-T1 exposed to different antibiotics variate differently.