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Evidence for plasmid DNA in Alcaligenes faecalis

G H Luginbuhl, J M Rader, D G Simmons

    American Journal of Veterinary Research
    |August 1, 1984
    PubMed

    Insights

    A plasmid isolated from virulent Alcaligenes faecalis conferred streptomycin and sulfonamide resistance. Its removal resulted in an avirulent, antibiotic-sensitive bacterial strain, highlighting the plasmid's role in virulence.

    Area of Science:

    • Microbiology
    • Bacterial Genetics
    • Plasmid Biology

    Background:

    • Alcaligenes faecalis is an opportunistic pathogen.
    • Plasmids are extrachromosomal DNA elements that can carry genes for virulence and antibiotic resistance.
    • The role of specific plasmids in bacterial virulence is not always well-defined.

    Purpose of the Study:

    • To investigate the role of a specific plasmid in the virulence and antibiotic resistance of Alcaligenes faecalis.
    • To compare the characteristics of a virulent strain with its plasmid-free derivative.

    Main Methods:

    • Isolation of a 10.6 megadalton plasmid from a virulent Alcaligenes faecalis strain (NC-D).
    • Generation of a plasmid-free mutant derivative (strain NC-D1).
    • Comparative analysis of virulence and antibiotic sensitivity between the parent strain and the mutant derivative.

    Main Results:

    • The virulent strain NC-D harbored a 10.6 megadalton plasmid.
    • The plasmid-free derivative, strain NC-D1, was avirulent.
    • Strain NC-D1 lacked the streptomycin and sulfonamide resistance observed in the parent strain NC-D.

    Conclusions:

    • The isolated plasmid is associated with the virulence of Alcaligenes faecalis strain NC-D.
    • The plasmid carries genes conferring resistance to streptomycin and sulfonamide.
    • Plasmid loss in Alcaligenes faecalis results in avirulence and loss of specific antibiotic resistances.

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