嗜线虫致病杆菌北京变种的抗生素抗性及质粒pLA2917的转化

Antibiotic Resistance and Plasmid pLA2917 Transformation of Xenorhabdus nematophila var. pekingensis

用最小抑制浓度法对嗜线虫致病杆菌北京变种野生型菌株的抗生素抗性进行了测定。结果表明,该菌株对氯霉素、新霉素和卡那霉素敏感,而对链霉素、氨苄青霉素和青霉素具有不同程度的抗性。利用滤膜三亲交配的接合转移方法,以嗜线虫致病杆菌北京变种作为受体细菌,在卡那霉素、四环素和氨苄青霉素的选择压力下,筛选得到接合转移子。经过菌落PCR鉴定,证明质粒pLA2917已经成功转移到嗜线虫致病杆菌北京变种细胞内。对昆虫病原线虫共生细菌的质粒转移方法进行了讨论。

The antibiotic resistance of primary phase of the bacterium Xenorhabdus nematophila var. pekingensis was assayed with Minimum Inhibitory Concentration （MIC） analysis. The result showed that it is sensitive to chloramphenicol, neomycin, and kanamycin, whereas this strain possesses resistance to streptomycin, ampicillin and penicillin in some degrees, respectively. With approach of conjugation of three parents mating on membrane, plasmid pLA2917 was transferred into strain X. nematophila var. pekingensis. The conjugators were identified and confirmed through PCR amplification and plasmid isolation.