Czarny A, Lagowska-Złotorzycka M, Mulczyk M
Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław.
Arch Immunol Ther Exp (Warsz). 1989;37(1-2):191-9.
A pR351 plasmid (Tc Ap Cb) conferring drug resistance of naturally occurring E. coli strain was examined. Conjugation and transduction experiments have indicated that this plasmid is R plasmid aggregate consisting of three independent plasmids: a) conjugative plasmid pR351 A (SuTc) fi- (F) belonging to incompatibility group L, b) conjugative plasmid pR351 B (SuApCb) fi- (F) belonging to incompatibility O, and c) non-conjugative plasmid pR351 C (ApCb). The existance of these plasmids in pR351 plasmid aggregate was confirmed by the agarose gel analysis of plasmid DNA isolated from the lysates of E. coli J53 transconjugants carrying pR351 A or pR351 B plasmids and from E. coli K12 C600 transductant carrying pR351 C plasmid. Molecular mass of these plasmids was found to be 55.60 and 3 Mdal respectively. The non-conjugative pR351 C plasmid could be mobilized by Col B and F factors. Our findings have indicated that two fi- (F) R plasmids can stably coexist in R plasmid aggregate.
对赋予天然存在的大肠杆菌菌株耐药性的pR351质粒(Tc Ap Cb)进行了检测。接合和转导实验表明,该质粒是由三个独立质粒组成的R质粒聚集体:a)属于不相容群L的接合性质粒pR351 A(SuTc)fi-(F),b)属于不相容群O的接合性质粒pR351 B(SuApCb)fi-(F),以及c)非接合性质粒pR351 C(ApCb)。通过对从携带pR351 A或pR351 B质粒的大肠杆菌J53转接合子裂解物以及携带pR351 C质粒的大肠杆菌K12 C600转导子中分离的质粒DNA进行琼脂糖凝胶分析,证实了这些质粒在pR351质粒聚集体中的存在。发现这些质粒的分子量分别为55.60和3 Mdal。非接合性质粒pR351 C可被Col B和F因子动员。我们的研究结果表明,两个fi-(F)R质粒可以在R质粒聚集体中稳定共存。