Shimoda K, Kuhara T, Maejima K
Laboratory Animal Center, School of Medicine, Keio University, Tokyo, Japan.
Jikken Dobutsu. 1991 Oct;40(4):425-30. doi: 10.1538/expanim1978.40.4_425.
In order to examine the ability of R plasmid-bearing Escherichia coli strains to colonize in the mouse alimentary tract, an R plasmid-positive (R(+)) E. coli strain and its R plasmid-negative (R(-)) counterpart were together inoculated into the streptomycin-treated mouse alimentary tract, and the numbers of fecal E. coli strains were enumerated. The numbers of R(+) strains were always at the level similar to or lower than those of their counterparts and rapidly decreased in the fecal population. However, when R plasmids, which were originated from a cryptic plasmid of the host E. coli strain, were utilized, an R(+) strain dominated over its R(-) counterpart during the experimental period. These experimental results indicated that the relationship between the host strain and R plasmids affected the ability of the host strain to colonize in the alimentary tract.
为了检测携带R质粒的大肠杆菌菌株在小鼠消化道定殖的能力，将一株R质粒阳性（R(+)）大肠杆菌菌株及其R质粒阴性（R(-)）对应菌株一起接种到经链霉素处理的小鼠消化道中，并对粪便中的大肠杆菌菌株数量进行计数。R(+)菌株的数量始终与对应菌株相似或低于对应菌株，且在粪便菌群中迅速减少。然而，当使用源自宿主大肠杆菌菌株隐蔽质粒的R质粒时，在实验期间R(+)菌株比其R(-)对应菌株占优势。这些实验结果表明，宿主菌株与R质粒之间的关系影响宿主菌株在消化道定殖的能力。
