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The changing pathogenicity of Mycoplasma pneumoniae with passage in vitro. Correlates of virulence

A M Collier, P C Hu, W A Clyde

    Diagnostic Microbiology and Infectious Disease
    |July 1, 1985
    PubMed

    Insights

    An avirulent strain of Mycoplasma pneumoniae lost its ability to cause pneumonia in hamsters. This suggests changes in its respiratory epithelium attachment mechanism, not detectable by standard protein analysis.

    Area of Science:

    • Microbiology
    • Pathogenesis
    • Molecular Biology

    Background:

    • Mycoplasma pneumoniae is a significant respiratory pathogen.
    • Virulent strains attach to respiratory epithelium, causing disease.
    • Avirulent strains may offer insights into virulence factors.

    Purpose of the Study:

    • To investigate the molecular basis for the loss of virulence in an avirulent Mycoplasma pneumoniae strain.
    • To understand the mechanism of attachment to respiratory epithelium.

    Main Methods:

    • Isolation of an avirulent Mycoplasma pneumoniae strain via broth passage.
    • Inoculation of hamsters to assess virulence (pneumonia production).
    • Protein analysis using gel electrophoresis.

    Main Results:

    • The avirulent strain failed to induce pneumonia in hamsters.
    • The primary defect in the avirulent strain was the loss of attachment to respiratory epithelium.
    • Gel electrophoresis did not reveal significant differences in surface proteins between virulent and avirulent strains.

    Conclusions:

    • The loss of virulence is linked to impaired epithelial attachment.
    • Alterations in the binding protein's function, not its electrophoretic mobility, likely explain avirulence.
    • Monoclonal antibody analysis of antigenic determinants is recommended to understand attachment mechanisms.

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