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[The secreted proteolytic enzymes of Proteus mirabilis]

V M Bondarenko, L V Parkhomenko, V K Koval'chuk

    Zhurnal Mikrobiologii, Epidemiologii I Immunobiologii
    |March 1, 1993
    PubMed

    Insights

    Protease activity in Proteus mirabilis exacerbates infections, particularly after parenteral introduction. This leads to reduced blood antiprotease levels and bacterial spread, primarily to the urinary tract.

    Area of Science:

    • Microbiology
    • Immunology
    • Pathogenesis

    Background:

    • Proteus mirabilis is a common cause of urinary tract infections.
    • Bacterial proteases are virulence factors that can degrade host tissues.
    • The role of P. mirabilis protease activity in infection severity is not fully understood.

    Purpose of the Study:

    • To investigate the role of P. mirabilis protease activity in the aggravation of infectious processes.
    • To elucidate the mechanisms by which proteases contribute to bacterial dissemination and tissue damage.

    Main Methods:

    • Experiments were conducted on white mice using genetically linked pairs of P. mirabilis with and without protease activity.
    • Parenteral and intragastric administration routes were used to introduce bacteria.
    • Antiprotease capacity of blood, bacterial dissemination into organs, and gastrointestinal mucosal barrier integrity were assessed.

    Main Results:

    • P. mirabilis protease activity significantly aggravated infectious processes following parenteral introduction.
    • Protease activity led to decreased antiprotease capacity of the blood.
    • Bacteria disseminated into organs and tissues, with predominant colonization of the urinary tract.
    • Intragastric administration caused damage to the gastrointestinal epithelial barrier after preliminary destruction of mucin and sIgA.

    Conclusions:

    • Protease activity of P. mirabilis plays a crucial role in exacerbating infections, especially via parenteral routes.
    • Bacterial proteases contribute to infection by reducing blood antiprotease levels and promoting bacterial spread.
    • The integrity of the gastrointestinal mucosal barrier, including mucin and sIgA, is essential for preventing infection after oral administration.

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