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Immunological heterogeneity among the M-associated protein antigens of group-A streptococci

J P Widdowson, W R Maxted, A M Pinney

    Journal of Medical Microbiology
    |February 1, 1976
    PubMed

    Insights

    Group-A streptococci share M-associated antigens, allowing classification into three categories based on antibody responses. This research aids in understanding streptococcal serotypes and their relation to rheumatic fever and infections.

    Area of Science:

    • Microbiology
    • Immunology
    • Infectious Diseases

    Background:

    • Group-A streptococci (GAS) possess M protein, crucial for virulence and serotyping.
    • Shared M-associated antigens among different GAS serotypes are key to understanding cross-reactivity.

    Purpose of the Study:

    • To categorize group-A streptococci based on M-associated antigens.
    • To investigate antibody cross-reactivity among different GAS serotypes.

    Main Methods:

    • Utilized human sera with antibodies to M-associated antigens.
    • Employed complement-fixation-inhibition tests and absorption studies.

    Main Results:

    • Group-A streptococci were divided into three categories based on M-associated antigens.
    • Opacity-factor-negative respiratory serotypes showed shared antigens with high antibody titers in rheumatic fever patients.
    • Opacity-factor-positive throat/skin serotypes and pyoderma serotypes exhibited varying antibody affinities and cross-reactivity.

    Conclusions:

    • M-associated antigens facilitate the classification of group-A streptococci into distinct categories.
    • Significant cross-reactivity exists between the M-associated antigens of different GAS categories.
    • Understanding these shared antigens is vital for diagnosing and potentially treating streptococcal infections and sequelae like rheumatic fever.

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