鸡源金黄色葡萄球菌耐药性转移的研究

Studies on the Transfer of Antibiotic-Resistance of Staphylococcus aureus from Chickens

通过药敏试验及脱质粒试验选择了4株鸡源金黄色葡萄球进行滤膜交配,结果证明,鸡源金黄色葡萄球菌之间可通过接合方式传递抗药性,转移的抗性为四环素抗性。该抗性质粒可在受体菌内以完整的复制子形式存在,其稳定性较好。转化试验证明,39号鸡源金黄色葡萄球菌及接合筛选子"79+63"的四环素抗性质粒可以转化入经脱质粒的金黄色葡萄球菌,不能转化野外分离的金黄色葡萄球菌。限制系统缺陷株大肠杆菌 DH5α的转化试验证明,鸡源金黄色葡萄菌的红霉素抗性为质粒编码,并且是可转移的。转化试验得到的转化子,其获得的抗药性稳定性较差。

It was confirmed that the tetracycline-resistant plasmid could be trans- ferred by fiher-mating experiment between Staphylococcus aureus isolated from chickens. As a replicon,the plasmid was stable in recipients.The tetracycline--resistant plasmid of transconjugant 79+63 could be transformed to curing S.aureus from chickens.The results can partially explain the reason why more and more tetracycline-resistant S.aureus emerged in clinic,Only curing S.aureus strains could be transformed by the plasmids isolated from S. aureus.The field isolates could not be transformed.DH5α,a restriction-defective E.coli strain,could be transformed by erythromycin resistant plasmid of S.aureus.The result in- dicates that the erythromycin-resistance of S.aureus from chicken is encoded by plasmid and the plasmid is transferable. The transferred antibiotic-resistances of transformants were not stable.