Ohno A
Department of Microbiology, School of Medicine, Toho University.
Kansenshogaku Zasshi. 1990 Apr;64(4):436-43. doi: 10.11150/kansenshogakuzasshi1970.64.436.
The conjugative transfer by using a filter mating method in 109 cases of combinations between 20 strains of beta-hemolytic Enterococcus faecalis and 28 strains of alpha-hemolytic Enterococcus faecium was tried. A stable transconjugation was observed in two cases: from E. faecalis No. 170 to E. faecium No. 49 and from E. faecalis No. 500 to E. faecium No. 48. From the results, it was proved that the beta-hemolysin plasmid of E. faecalis is transferred by conjugation to E. faecium. The virulence (LD50) of E. faecium No. 17049, No. 50048 (heterogeneous transconjugant) and E. faecalis No. 17067, No. 50067 (homologous transconjugant) in mice was compared with their parent strains. The virulence of E. faecalis transconjugants was more marked than that of the recipients. However, the virulence of E. faecium transconjugants was not enhanced. This fact suggests that, only in E. faecalis, does beta-hemolysin play a role in its pathogenicity in mice. beta-Hemolysin in E. faecium transconjugants does not participate in pathogenicity in mice. It may be due to the fact that it takes more time to cause beta-hemolysis on blood agar plate or beta-hemolysin production in B-YEG broth by E. faecium transconjugants than by E. faecalis transconjugants.
尝试采用滤膜杂交法对20株β - 溶血粪肠球菌和28株α - 溶血屎肠球菌的109种组合进行接合转移。在两例中观察到稳定的转接合子：从粪肠球菌170号菌株到屎肠球菌49号菌株，以及从粪肠球菌500号菌株到屎肠球菌48号菌株。结果证明，粪肠球菌的β - 溶血素质粒通过接合转移到了屎肠球菌。将屎肠球菌17049号菌株、50048号菌株（异源转接合子）以及粪肠球菌17067号菌株、50067号菌株（同源转接合子）与其亲本菌株在小鼠中的毒力（半数致死量）进行了比较。粪肠球菌转接合子的毒力比受体菌株更显著。然而，屎肠球菌转接合子的毒力并未增强。这一事实表明，仅在粪肠球菌中，β - 溶血素在其对小鼠的致病性中发挥作用。屎肠球菌转接合子中的β - 溶血素不参与对小鼠的致病性。这可能是由于屎肠球菌转接合子在血琼脂平板上引起β - 溶血或在B - YEG肉汤中产生β - 溶血素比粪肠球菌转接合子需要更多时间。
