Obana Y, Nishino T
Department of Microbiology, Kyoto Pharmaceutical University.
Kansenshogaku Zasshi. 1991 Sep;65(9):1116-22. doi: 10.11150/kansenshogakuzasshi1970.65.1116.
Penicillinase I-, II- and III-producing R-plasmid of Escherichia coli were transferred to Escherichia coli 177, KC-14, and 444. These strains are highly virulent in mice. This study was conducted to investigate the influence of conjugative R-plasmid on the virulence of its host strains. Escherichia coli 177 after penicillinase I- or III-producing R-plasmids transfer retained parental levels of virulence. On the other hand, penicillinase II-producing transconjugants showed reduced virulence in mice. The virulence of its revertants, in which R-plasmid was eliminated by heat, were equivalent to that of the host strain. It is suggested that the decrease in the virulence of transconjugants was not due to transferred R-plasmid. The reduced virulence of the these transconjugants may be due to alterations in their components such as the lipopolysaccharides in the cell envelope.
产青霉素酶I、II和III的大肠杆菌R质粒被转移到大肠杆菌177、KC - 14和444中。这些菌株对小鼠具有高度毒性。本研究旨在调查接合型R质粒对其宿主菌株毒力的影响。产青霉素酶I或III的R质粒转移后的大肠杆菌177保持了亲本的毒力水平。另一方面，产青霉素酶II的接合子在小鼠中显示出毒力降低。通过加热消除R质粒的回复株的毒力与宿主菌株相当。这表明接合子毒力的降低不是由于转移的R质粒。这些接合子毒力降低可能是由于其成分的改变，如细胞壁中的脂多糖。
