Igimi S, Ryu C H, Park S H, Sasaki Y, Sasaki T, Kumagai S
Department of Biomedical Food Research, National Institute of Health, Tokyo, Japan.
Lett Appl Microbiol. 1996 Jul;23(1):31-5. doi: 10.1111/j.1472-765x.1996.tb00023.x.
Conjugal transfer of plasmid pAM beta 1 from Lactococcus lactis to intestinal bacteria of BALB/c mice was studied. Plasmid transfer was observed to Enterococcus faecalis in vitro by a filter mating method with transfer frequencies of 2.3 x 10-3 and with lower frequencies to other species. In vivo, using gastric intubation with the pAM beta 1-bearing Lactococcus lactis as donor and Ent. faecalis as recipient, a few transconjugants were detected from faecal Ent. faecalis. However, when these mice were given erythromycin through drinking water, a large number of conjugated Ent. faecalis were detected in faeces. Plasmid transfer to Ent. faecalis occurred at high frequency, 1.2 x 10-3, in mice whose anus was artificially closed after gastric intubation with pAM beta 1-bearing Lactococcus lactis. These results demonstrate clearly that pAM beta 1 transfer occurs between Gram-positive bacteria in the gut of mice harbouring many species of bacteria.
研究了质粒pAMβ1从乳酸乳球菌向BALB/c小鼠肠道细菌的接合转移。通过滤膜交配法在体外观察到质粒向粪肠球菌的转移，转移频率为2.3×10-3，向其他物种的转移频率较低。在体内，以携带pAMβ1的乳酸乳球菌为供体、粪肠球菌为受体进行胃插管，从粪便中的粪肠球菌检测到少量转接合子。然而，当给这些小鼠通过饮水给予红霉素时，在粪便中检测到大量接合的粪肠球菌。在用携带pAMβ1的乳酸乳球菌进行胃插管后人工封闭肛门的小鼠中，质粒向粪肠球菌的转移高频发生，频率为1.2×10-3。这些结果清楚地表明，pAMβ1转移发生在含有多种细菌的小鼠肠道中的革兰氏阳性菌之间。
