The virulence plasmid of Salmonella typhimurium is self-transmissible

Brian M M Ahmer, Mimi Tran, Fred Heffron

    72 Scopus citations


    Most isolates of Salmonella enterica serovar Typhimurium contain a 90- kb virulence plasmid. This plasmid is reported to be mobilizable but nonconjugative. However, we have determined that the virulence plasmid of strains LT2, 14028, and SR-11 is indeed self-transmissible. The plasmid of strain SL1344 is not. Optimal conjugation frequency requires filter matings on M9 minimal glucose plates with a recipient strain lacking the virulence plasmid. These conditions result in a frequency of 2.9 x 10-4 transconjugants/donor. Matings on Luria-Bertani plates, liquid matings, or matings with a recipient strain carrying the virulence plasmid reduce the efficiency by up to 400-fold. Homologs of the F plasmid conjugation genes are physically located on the virulence plasmid and are required for the conjugative phenotype.

    Original languageEnglish (US)
    Pages (from-to)1364-1368
    Number of pages5
    JournalJournal of Bacteriology
    Issue number4
    Publication statusPublished - Feb 1999


    ASJC Scopus subject areas

    • Applied Microbiology and Biotechnology
    • Immunology

    Cite this

    Ahmer, B. M. M., Tran, M., & Heffron, F. (1999). The virulence plasmid of Salmonella typhimurium is self-transmissible. Journal of Bacteriology, 181(4), 1364-1368.