Properties of an R Factor from Bordetella bronchiseptica Hedges, R. W. and Jacob, A. E. and Smith, J. T.,, 84, 199-204 (1974), doi = https://doi.org/10.1099/00221287-84-1-199, publicationName = Microbiology Society, issn = 1350-0872, abstract= SUMMARY: R906, a plasmid derived from a wild strain of Bordetella bronchiseptica, was transferred to Escherichia coli k12. In this host it is stably heritable, replicating as a DNA molecule with a molecular weight of 34.6 megadaltons. There are approximately three copies of the plasmid per chromosome. It is a member of compatibility group P. In E. coli, 906 confers resistance to ampicillin, streptomycin, sulphonamides and mercury salts. Resistance to ampicillin is determined by an oxacillin-hydrolysing β-lactamase whereas the resistance to streptomycin is not determined by either of the previously described streptomycin-inactivating enzymes but by some other mechanism., language=, type=