Summary
R38, R931-1, and R933 are conjugative plasmids derived from strains of Pseudomonas aeruginosa. They confer resistance to mercuric ions (Hg-r), and do not transfer from P. aeruginosa to Escherichia coli at detectable frequencies. Hybrids between each of these plasmids and the P-group plasmid, RP1, have been detected among the rare Hg-r transconjugants arising from matings of P. aeruginosa PAO donors (RP1+ R+) and E. coli K12 recipients. Two independently isolated hybrid plasmids from each of the three mating combinations have been studied. All were found to confer the entire marker phenotype of RP1, but only the Hg-r phenotype of their second parent. Moreover, all were larger than RP1 but comprised only two groups of sizes; those increased by about 14×106 daltons (the RP1/R38 hybrids), and those increased by about 30×106 daltons (the RP1/R931-1 and RP1/R933 hybrids).
The hybrid plasmids were all too large to be transduced intact by phage F116L, but transduction of fragments was possible. Thus, the determinants for both carbenicillin-resistance (Cb-r) (from RP1) and mercuric-ion-resistance could be “rescued” by recipients that already carried an RP1-like plasmid and were recombination-proficient. A molecular analysis of the plasmids recovered from such transductants suggested that each of the parental hybrids was comprised of an entire RP1 genome into which a fragment of heterologous DNA had been inserted. In similar experiments in which the recipient carried a derivative of R931-1, the Hg-r but not the Cb-r determinant could be rescued. This suggested that R38, R931-1, and R933 shared sufficient homology in the region of the mer gene for recombination to occur between them. The reason for the inability to rescue the Cb-r determinant was also investigated.
Similar content being viewed by others
References
Achtman, M., Willetts, N.S., Clark, A.J.: Beginning a genetic analysis of conjugational transfer determined by the F factor in Escherichia coli by isolation and characterisation of transferdeficient mutants. J. Bact. 106, 529–538 (1971)
Bryan, L.E., Semaka, S.D., van den Elzen, H.M., Kinnear, J.E., Whitehouse, R.L.S.: Characteristics of R931 and other Pseudomonas aeruginosa R factors. Antimicrob. Ag. Chemo. 3, 625–637 (1973)
Chandler, P.M., Krishnapillai, V.: Isolation and properties of recombination deficient mutants of Pseudomonas aeruginosa. Mutation Res. 23, 15–23 (1974)
Datta, N., Hedges, R.W., Shaw, E.J., Sykes, R.B., Richmond, M.H.: Properties of an R factor from Pseudomonas aeruginosa 1822. J. Bact. 108, 1244–1249 (1971)
Demerec, M., Adelberg, E.A., Clark, A.J., Hartman, P.E.: A proposal for a uniform nomenclature in bacterial genetics. Genetics 54, 61–76 (1966)
Dryburgh, D., Stanisich, V.A.: Properties of plasmids derived from Pseudomonas aeruginosa 931. Proc. Soc. gen. Microbiol. 2, 66 (1975)
Hedges, R.W., Jacob, A.E.: Transposition of ampicillin resistance from RP4 to other replicons. Molec. gen. Genet. 132, 31–40 (1974)
Holloway, B.W., Rossiter, H., Burgess, D., Dodge, J.: Aeruginocin tolerant mutants of Pseudomonas aeruginosa. Genet. Res. 22, 239–253 (1974)
Jacoby, G.A.: Properties of R plasmids determining gentamicin resistance by acetylation in Pseudomonas aeruginosa. Antimicrob. Ag. Chemo. 6, 239–252 (1974)
Kawakami, Y., Mikoshiba, F., Nagasaki, S., Matsumoto, H., Tazaki, T.: Prevalence of Pseudomonas aeruginosa strains possessing R factors in a hospital. J. Antibiot. 25, 607–609 (1972)
Krishnapillai, V.: The use of bacteriophages in differentiating plasmids of Pseudomonas aeruginosa. Genet. Res. 23, 327–334 (1974)
Krishnapillai, V.: Resistance to ultraviolet light and enhanced mutagenesis conferred by Pseudomonas aeruginosa plasmids. Mutation Res 29, 363–372 (1975)
Loutit, J.S.: Investigation of the mating system of Pseudomonas aeruginosa strain 1 VI. Mercury resistance associated with the sex factor (FP). Genet. Res. 16, 179–184 (1970)
Novick, R.P., Clowes, R.C., Cohen, S.N., Curtiss III, R., Datta, N., Falkow, S.: Uniform nomenclature for bacterial plasmids: a proposal. Bact. Rev. 40, 168–189 (1976)
Olsen, R.H., Shipley, P.: Host range and properties of the Pseudomonas aeruginosa R factor R1822. J. Bact. 113, 772–780 (1973)
Pemberton, J.M.: F116: a DNA bacteriophage specific for the pili of Pseudomonas aeruginosa strain PAO. Virology 55, 558–560 (1973)
Pemberton, J.M., Holloway, B.W.: A new sex factor of Pseudomonas aeruginosa. Genet. Res. 21, 263–272 (1973)
Shahrabadi, M.S., Bryan, L.E., van den Elzen, H.M.: Further properties of the P2 R factors of Pseudomonas aeruginosa and their relationship to other plasmid groups. Canad. J. Microbiol. 21, 592–605 (1975)
Stanisich, V.A.: Interaction between an R factor and an element conferring resistance to mercuric ions in Pseudomonas aeruginosa. Molec. gen. Genet. 128, 201–212 (1974a)
Stanisich, V.A.: Properties and host range of male-specific bacteriophages of Pseudomonas aeruginosa. J. gen. Microbiol. 84, 332–342 (1974b)
Stanisich, V.A., Bennett, P.M.: Isolation and characterisation of deletion mutants involving the transfer genes of P-group plasmids in Pseudomonas aeruginosa. Molec. gen. Genet. 149, 211–216 (1976)
Stanisich, V.A., Bennett, P.M., Ortiz, J.M.: A molecular analysis of transductional marker rescue involving P-group plasmids in Pseudomonas aeruginosa. Molec. gen. Genet. 143, 333–337 (1976a)
Stanisich, V.A., Bennett, P.M., Richmond, M.H.: Characterisation of a translocation unit encoding resistance to mercuric ions that occurs on a non-conjugative plasmid in Pseudomonas aeruginosa. J. Bact. (submitted) (1976b)
Stanisich, V.A., Ortiz, J.M.: Similarities between plasmids of the P-incompatibility group derived from different bacterial genera. J. gen. Microbiol. 94, 281–289 (1976)
Author information
Authors and Affiliations
Additional information
Communicated by W. Arber
Rights and permissions
About this article
Cite this article
Stanisich, V.A., Bennett, P.M. The properties of hybrids formed between the P-group plasmid RP1 and various plasmids from Pseudomonas aeruginosa . Molec. gen. Genet. 149, 217–223 (1976). https://doi.org/10.1007/BF00332892
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00332892