表皮葡萄球菌污染对质粒转化和抽提影响的实验研究  

Staphylococcus Epidermidis Contamination: A Special Cause of Plasmid Extraction Failure

作　　者：江汕[1] 邵东华[2] 李玉华[1] 彭韬[1] 江千里[3] 冯振卿[1] 

机构地区：[1]南京医科大学病理学教研室,江苏南京210029 [2]江苏大学附属镇江市第一人民医院麻醉科,江苏镇江212002 [3]长海医院血液科,上海200433

出　　处：《江苏大学学报（医学版）》2002年第5期462-464,共3页Journal of Jiangsu University：Medicine Edition

摘　　要：目的 :探讨导致部分质粒转化和抽提失败的原因。方法 :使用同一批DH5 α细菌制备感受态 ,转化、碱裂解法抽提和鉴定两种质粒 ,经抗性LB琼脂平板筛选和菌落分析 ,对照成功抽提和鉴定的质粒 ,分析部分质粒反复转化和抽提失败的原因。结果 :发现在该抽提失败的质粒所转化的抗性LB琼脂平板上存在两种菌落 ,大量白色菌落为表皮葡萄球菌 ,其过夜振摇产物经碱裂解法抽提质粒失败 ;极少数淡黄色菌落为大肠杆菌 ,经鉴定 ,质粒抽提成功。结论 :隐蔽的表皮葡萄球菌污染可能是导致部分质粒反复抽提失败的重要原因。Objective: To find the causes of the failure in the extraction of plasmid BAG. Methods:The plasmids of two types (BAG and PET 24 a ) were transformed into the same TSS competent cell DH 5 α Escherichia coli (E. coli). Then under the same conditions, the plasmids were extracted by alkaline lysis and assaying. Screen by the Kanamycin (Kan) selective LB agar plate and analyse the colony. Results:Control plasmid (PET 24a ) can be done exactly well. But the extraction of plasmid BAG failed many times. After transformation, two kinds of colony were observed on the agar plate of BAG, most of the colony is ivory, and few is yellowish; while on the plate of PET 24, only yellowish colony was found. Ivory colony is from Staphylococcus epidermidis and the yellowish is from DH 5 α E. coli. Both bacteria obtained the Kan resistance after plasmid transformation, while Staphylococcus is alkaline lysis resistant, which caused the failure of plasmid extraction. Conclusion: This study suggested that contamination with Staphylococcus epidermidis should be a special cause of transformation and extraction failure to some vectors.

关 键 词：表皮葡萄球菌 实验研究 质粒抽提 质粒转化 污染 分子生物学 

分 类 号：R372[医药卫生—病原生物学] R378.11[医药卫生—基础医学]