高耐庆大霉素粪肠球菌质粒接合转移试验的方法探讨

Plasmid Conjugation Method for High Level Gentamicin Resistant Enterococcus

目的筛选出较好的高耐庆大霉素粪肠球菌质粒接合转移的试验方法。方法使用NCCLS推荐的琼脂稀释法筛选临床分离36株高耐庆大霉素(HLGR)粪肠球菌,质粒接合转移试验采用肉汤接合法和滤膜接合法。结果36株粪肠球菌用普通肉汤(NB)、普通肉汤加马血清(NBH)、心脑浸液(BHI)、心脑浸液加马血清(BHIH)4种培养基作为接合前及接合过程培养介质,HLGR接合转移率分别为50%、75%、89%、89%,滤膜接合法转移率达到100%,所形成的HLGR接合子也不同程度的获得了对其他抗菌药物的耐药性。结论采用BHI或BHI加马血清的肉汤培养基接合转移效果较好,结果一致,滤膜接合法可获得更高的转移通过率。

OBJECTIVE To choose the best methods of conjugation experiment for high level gentamicin resistant(HLGR) Enterococcus faecalis. METHODS Conjugation was performed by broth mating and filter mating method and its results were compared with other four culture media. RESULTS Transfer rates of HLGR plasmid from 36 strains of E.faecalis to recipient strain JH2-2 in NB,NB with horse serum, BHI, and BHI with horse serum were 50%(18/36), 75%(27/36), 89%(32/36)and 89%(32/36),respectively,and rose up to 100%(36/36) by filter mating method. CONCLUSIONS Better results are obtained in conjugation experiments in BHI and BHI broth with horse serum. Preferable transfer rate is acquired by filter mating method.