• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of geneticsGeneticsCurrent IssueInformation for AuthorsEditorial BoardSubscribeSubmit a Manuscript
Genetics. Oct 1977; 87(2): 209–228.
PMCID: PMC1213735

The Population Biology of Bacterial Plasmids: A PRIORI Conditions for the Existence of Conjugationally Transmitted Factors


A mathematical model for the population dynamics of conjugationally transmitted plasmids in bacterial populations is presented and its properties analyzed. Consideration is given to nonbacteriocinogenic factors that are incapable of incorporation into the chromosome of their host cells, and to bacterial populations maintained in either continuous (chemostat) or discrete (serial transfer) culture. The conditions for the establishment and maintenance of these infectious extrachromosomal elements and equilibrium frequencies of cells carrying them are presented for different values of the biological parameters: population growth functions, conjugational transfer and segregation rate constants. With these parameters in a biologically realistic range, the theory predicts a broad set of physical conditions, resource concentrations and dilution rates, where conjugationally transmitted plasmids can become established and where cells carrying them will maintain high frequencies in bacterial populations. This can occur even when plasmid-bearing cells are much less fit (i.e., have substantially lower growth rates) than cells free of these factors. The implications of these results and the reality and limitations of the model are discussed and the values of its parameters in natural populations speculated upon.

Full Text

The Full Text of this article is available as a PDF (1.1M).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Anderson ES. The ecology of transferable drug resistance in the enterobacteria. Annu Rev Microbiol. 1968;22:131–180. [PubMed]
  • Anderson ES, Lewis MJ. Drug resistance and its transfer in Salmonella typhimurium. Nature. 1965 May 8;206(984):579–583. [PubMed]
  • Anderson JD. The effect of R-factor carriage on the survival of Escherichia coli in the human intestine. J Med Microbiol. 1974 Feb;7(1):85–90. [PubMed]
  • Rheinwald JG, Chakrabarty AM, Gunsalus IC. A transmissible plasmid controlling camphor oxidation in Pseudomonas putida. Proc Natl Acad Sci U S A. 1973 Mar;70(3):885–889. [PMC free article] [PubMed]
  • Smith DH. R factor infection of Escherichia coli lyophilized in 1946. J Bacteriol. 1967 Dec;94(6):2071–2072. [PMC free article] [PubMed]
  • Starlinger P, Saedler H. IS-elements in microorganisms. Curr Top Microbiol Immunol. 1976;75:111–152. [PubMed]
  • WATANABE T. Infective heredity of multiple drug resistance in bacteria. Bacteriol Rev. 1963 Mar;27:87–115. [PMC free article] [PubMed]

Articles from Genetics are provided here courtesy of Genetics Society of America


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


  • PubMed
    PubMed citations for these articles

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...