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Published on: June 16, 2011

Virulence of temperature-sensitive mutants of foot-and-mouth disease virus

J S MacKenzie

    Archives of Virology
    |January 1, 1975
    PubMed

    Insights

    Most temperature-sensitive foot-and-mouth disease virus mutants showed reduced virulence in mice. However, genetic recombinants were more virulent than parent strains, indicating complex viral evolution.

    Area of Science:

    • Virology
    • Molecular Biology
    • Animal Models

    Background:

    • Temperature-sensitive (ts) mutants of foot-and-mouth disease virus (FMDV) are valuable tools for studying viral genetics and pathogenesis.
    • Understanding the virulence of FMDV mutants is crucial for developing effective control strategies and vaccines.

    Purpose of the Study:

    • To assess the virulence of FMDV ts mutants in a suckling mouse model.
    • To investigate the relationship between temperature sensitivity, reversion, and virulence.
    • To analyze the virulence of recombinants generated from FMDV ts mutants.

    Main Methods:

    • Isolation and characterization of temperature-sensitive mutants from two FMDV strains.
    • Virulence assessment of mutants and parent strains in suckling mice.
    • Genetic crosses to generate phenotypic revertants and wild-type recombinants.
    • Virulence evaluation of resulting recombinants.

    Main Results:

    • The majority of FMDV ts mutants exhibited reduced virulence compared to parental strains.
    • Two mutants maintained parental virulence levels; no correlation was found between cut-off temperature or revertant content and virulence.
    • Recombinants derived from genetic crosses showed significantly higher virulence than either parent virus.

    Conclusions:

    • FMDV temperature sensitivity does not directly correlate with reduced virulence.
    • Genetic recombination can restore or enhance FMDV virulence, even from attenuated mutants.
    • Complex genetic interactions influence FMDV virulence, highlighting challenges in predicting attenuation.

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