山东省动物源大肠杆菌多重抗药性及其遗传稳定性研究

Multi-drug resistance and hereditability of Escherichia coli isolated from animals in Shandong

目的:普查山东省动物源大肠杆菌多重抗药性现状,检测多重抗药性的遗传稳定性。方法:用微量肉汤稀释法检测712株大肠杆菌对15种抗生素的MIC;选取14株多重抗药菌株在MIC/2的各种抗生素中培养,将异常形态菌体接种至半固体LB培养基上,观察其再生能力;同时在无药培养基中传代8次,比较MIC的变化。结果:肉鸡场和病人大肠杆菌的抗药性最为严重,猪场次之,奶牛场最低。多数菌株对5到14种抗生素有抗性。在无药培养基中,丝状菌体能形成新的菌落。消除药物后,35%的菌株抗药性程度降低,甚至转为敏感。结论:细菌抗药性,尤其多重抗药性越来越普遍,对于稳定的抗药性突变可以更换敏感药物,而对于不能稳定遗传的抗药性,间歇用药或限制用药可以保障治疗效果。

Objective：To investigate in gerenal the status quo of the multi - drug resistance of E. coli isolated from animals in Shandong and detect hereditability of the multi - drug resistance. Methods：712 E. coli isolates were examined by Micro - dilution. Selected 14 multi - drug resistant isolates were cultivated in several MIC/2 concentration antibiotics mediums and selective abnormal configurations were transferred into semi - solid LB medium to observe their regeneration capacity. Simultaneously, these multi - drug resistant isolates were sub - cultured 8 times continuously to compare around MIC values. Results： Among the E. coli isolates of diverse sources, the resistance of E. coli isolates from broiler farm and patients occupied first place, that of pig farm came second, that of cow farm was lowest. Majority isolates were resistant to 5 to 14 kinds of antibiotics. Filiform thallus could form new colonies in no drug medium. After eliminated drug, the resistance of 35% strains declined, even became susceptible. Conclusion：Bacterial resistance, especially multi-drug resistance, is more and more universal Stable resistant mutation might replace sensitive drugs, then unstable hereditary resistance would medicate intermittently or restrictively to ensure treatment effect.