Natural transfer of conjugative transposon Tn916 between gram-positive and gram-negative bacteria

Abstract

The conjugative streptococcal transposon Tn916 was found to transfer naturally between a variety of gram-positive and gram-negative eubacteria. Enterococcus faecalis hosting the transposon could serve as a donor for Alcaligenes eutrophus, Citrobacter freundii, and Escherichia coli at frequencies of 10(-6) to 10(-8). No transfer was observed with several phototrophic species. Mating of an E. coli strain carrying Tn916 yielded transconjugants with Bacillus subtilis, Clostridium acetobutylicum, Enterococcus faecalis, and Streptococcus lactis subsp. diacetylactis at frequencies of 10(-4) to 10(-6). Acetobacterium woodii was the only gram-positive organism tested that did not accept the transposon from a gram-negative donor. The results prove the ability of conjugative transposable elements such as Tn916 for natural cross-species gene transfer, thus potentially contributing to bacterial evolution.

Distribution of Tetracycline Resistance Gene, tet(M), in Gram-Positive and Gram-Negative Bacteria Isolated from Sediment and Seawater at a Coastal Aquaculture Site in Japan

“…This suggests that the transfer of tet(M) happened recently at this site. Tet(M) is frequently associated with a mobile element such as Tn916 which mediates its transfer between different bacterial species 9,31) including both Grampositive and Gram-negative bacteria 5) , phylogenetic analysis suggests that RPPs including tet(M) have an ancient origin 19) , and it is unlikely that each tet(M) evolved respectively in each host without mutations. Chee-Sanford et al 8) also suggested that the fact that several species of Enterococcus possessed the same allele of tet(M) indicated the likelihood of the transfer of tet(M) among species.…”

The sex pheromone system of Enterococcus faecalis

“…Clewell and Flannagan, 1993). Recently it was shown that not only can they be maintained in Gram-negative bacteria under selective pressure, but they can even transfer conjugatively from those to other Gramnegative or Gram-positive bacteria (Bertram et al, 1991). Transfer between Gram-positive bacteria is in general by a conjugative mechanism, during which the element is transferred as a circular intermediate.…”

Transformation of the gram-positive bacterium Clavibacter xyli subsp. cynodontis by electroporation with plasmids from the IncP incompatibility group

“…To determine whether restriction barriers might be limiting the ability of DNA derived from E. coli to (2,16,19,23). In addition, there have been previous reports of gram-positive plasmids replicating in gram-negative bacteria (1,9,12,20 These results represent a significant step forward for studying the molecular biology of C. xyli subsp.…”

“…cynodontis, and we have defined optimal conditions for transforming C. xyli subsp. cynodon-(is, which yielded more than 2 ,ug/ml; kanamycin, 67 ,ug/ml; neomycin, 25 p,g/ml; and gentamicin, 25 ,g/ml.…”