Transformation of Actinomyces spp. by a gram-negative broad-host-range plasmid

The gram-negative broad-host-range vector pJRD215 was transferred by electroporation into strains of Actinomyces viscosus or Actinomyces naeslundii at efficiencies which ranged from 10(2) to 10(7) transformants per microgram of plasmid DNA. The Actinomyces transformants expressed pJRD215-encoded resistance to kanamycin and streptomycin. Moreover, the transforming plasmid DNA had not undergone any deletions or rearrangements, nor had it integrated into the genomes of these strains.