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Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
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Published on: February 23, 2014

MUTATIONS TO PENICILLIN RESISTANCE IN THE ENTEROBACTERIACEAE THAT AFFECT SENSITIVITY TO SERUM AND VIRULENCE FOR THE

R J ROANTREE, J P STEWARD

    Journal of Bacteriology
    |March 1, 1965
    PubMed

    Insights

    Mutations conferring penicillin resistance in Enterobacteriaceae can alter serum sensitivity and reduce virulence. Some penicillin-resistant mutants sensitive to serum showed decreased virulence in mice, with one strain eliciting protective immunity.

    Area of Science:

    • Microbiology
    • Bacterial genetics

    Background:

    • Enterobacteriaceae are a family of Gram-negative bacteria.
    • Penicillin resistance is a significant factor in bacterial infections.
    • Serum sensitivity can impact bacterial virulence.

    Purpose of the Study:

    • To investigate mutations affecting penicillin resistance in Enterobacteriaceae.
    • To determine the relationship between penicillin resistance, serum sensitivity, and virulence.
    • To explore the potential for developing attenuated bacterial strains for immunization.

    Main Methods:

    • Utilized the gradient plate technique to derive penicillin-resistant mutants from Escherichia coli and Salmonella strains.
    • Assessed serum sensitivity of the derived mutants.
    • Evaluated the virulence of penicillin-resistant mutants in mouse models.
    • Investigated host immune response to specific mutant strains.

    Main Results:

    • Penicillin-resistant mutants were successfully generated.
    • Many mutants exhibited increased sensitivity to serum.
    • Penicillin-resistant mutants often displayed reduced virulence in mice.
    • A subset of mutants sensitive to human serum remained virulent in mice, lacking mouse bactericidal antibodies.
    • Immunization with these specific mutants conferred protection.

    Conclusions:

    • Penicillin resistance mutations in Enterobacteriaceae can pleiotropically affect serum sensitivity and virulence.
    • Serum sensitivity is linked to virulence, with increased sensitivity often correlating with decreased virulence.
    • Attenuated bacterial strains, identified through specific mutation profiles, hold potential for vaccine development.
    Keywords:
    AMPICILLINANTIGEN-ANTIBODY REACTIONSESCHERICHIA COLIEXPERIMENTAL LAB STUDYMICEMUTATIONPENICILLIN GPENICILLIN RESISTANCEPHARMACOLOGYSALMONELLASALMONELLA TYPHIMURIUMVIRULENCE

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