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Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance
09:00

Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance

Published on: May 2, 2018

Gentamicin-resistance plasmids in an intensive care unit

D M Shlaes, C Currie-McCumber, M Eanes

    Infection Control : IC
    |July 1, 1986
    PubMed

    Insights

    Plasmids contribute to antibiotic resistance in Enterobacteriaceae. This study found specific R-plasmids spread, potentially explaining gentamicin resistance in hospital intensive care units.

    Area of Science:

    • Microbiology
    • Infectious Diseases
    • Molecular Biology

    Background:

    • Antibiotic resistance in Enterobacteriaceae is a significant healthcare concern.
    • Plasmids are known to play a role in the dissemination of antibiotic resistance.
    • Understanding resistance mechanisms in intensive care units is crucial.

    Purpose of the Study:

    • To investigate the role of plasmids in endemic antibiotic resistance among Enterobacteriaceae.
    • To identify the prevalence and characteristics of gentamicin-resistant gram-negative bacilli (GRGNB) in a medical/coronary care unit.
    • To determine if plasmid spread contributes to antibiotic resistance dissemination within the unit.

    Main Methods:

    • Prospective study involving culture surveys of patients, staff, and environment.
    • Sampling of new admissions and ongoing monitoring throughout their stay.
    • Isolation and characterization of GRGNB, including plasmid analysis via restriction endonuclease digestion and conjugation/transformation experiments.

    Main Results:

    • 12% of patients (147 total) were colonized with 20 strains of GRGNB.
    • 7 of 24 GRGNB strains (29%) were Enterobacteriaceae carrying plasmids with gentamicin-resistance determinants.
    • Identical plasmids (93 kb and 60 kb) were found in different bacterial species and environments within the hospital, indicating spread.

    Conclusions:

    • Specific R-plasmids are implicated in the dissemination of gentamicin resistance in this intensive care unit.
    • The spread of plasmids like the 93 kb and 60 kb plasmids likely contributes to endemic antibiotic resistance.
    • This highlights the importance of monitoring plasmid dynamics in healthcare settings to control resistance.

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