Transfer of conjugative plasmid pAM beta 1 from Lactococcus lactis to mouse intestinal bacteria.
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.
Igimi
S
S
Department of Biomedical Food Research, National Institute of Health, Tokyo, Japan. igimi@nih.go.jp
Ryu
C H
CH
Park
S H
SH
Sasaki
Y
Y
Sasaki
T
T
Kumagai
S
S
D000818:Animals; D001483:Base Sequence; D003227:Conjugation, Genetic; D013293:Enterococcus faecalis / Q000235:genetics*; D018014:Gene Transfer Techniques; D007422:Intestines / Q000382:microbiology*; D013294:Lactococcus lactis / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010957:Plasmids; D014169:Transformation, Bacterial