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Antigenic and immunogenic activity of flagella and fimbriae preparations from uropathogenic Proteus mirabilis
C Legnani-Fajardo1, P Zunino, G Algorta
1Microbiology Division, Instituto de Investigaciones Biologicas Clemente Estable, Montevideo, Uruguay.
Abstract:
The antigenic and immunogenic activities of fimbriae and flagella from three uropathogenic strains of Proteus mirabilis were compared. Flagella were obtained by mechanical treatment and fimbriae were isolated from cells by heat shock, ammonium sulfate precipitation, sodium deoxycholate and urea treatment, and gel filtration. Both preparations inoculated to mice demonstrated high antigenicity. Titers up to 1:80,000 were determined by an enzyme-linked immunosorbent assay either against the homologous or heterologous strains. When immunized mice were challenged with homologous or heterologous hematogenous infecting doses, a good cross protection was achieved only when fimbriae were used as antigens. Cross-reactivity found between the three fimbriae antisera, and the presence of common proteins in sodium dodecyl sulfate polyacrylamide gel electrophoresis patterns of fimbriae, should validate the study of these proteins to determine the existence of a shared adhesin.
Insights
Fimbriae from Proteus mirabilis showed better cross-protection against urinary tract infections in mice than flagella. This suggests fimbriae proteins are key targets for developing shared vaccines against this pathogen.
Area of Science:
- Microbiology
- Immunology
- Urology
Background:
- Proteus mirabilis is a common cause of urinary tract infections (UTIs).
- Fimbriae and flagella are surface structures of bacteria involved in pathogenesis and immune response.
- Understanding the immunogenic properties of these structures is crucial for vaccine development.
Purpose of the Study:
- To compare the antigenic and immunogenic activities of fimbriae and flagella from uropathogenic Proteus mirabilis.
- To evaluate the protective efficacy of fimbriae and flagella against P. mirabilis infections.
- To investigate potential shared antigens among P. mirabilis fimbriae.
Main Methods:
- Isolation of flagella via mechanical treatment.
- Isolation of fimbriae using heat shock, precipitation, and gel filtration.
- Enzyme-linked immunosorbent assay (ELISA) for antigenicity assessment.
- Immunization of mice and subsequent challenge with P. mirabilis strains.
- Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) for protein analysis.
Main Results:
- Both fimbriae and flagella exhibited high antigenicity, with ELISA titers up to 1:80,000.
- Fimbriae, but not flagella, provided significant cross-protection against homologous and heterologous P. mirabilis infections in mice.
- Cross-reactivity was observed between antisera against different fimbriae strains.
- SDS-PAGE revealed common protein bands in fimbriae preparations.
Conclusions:
- Fimbriae are more effective than flagella in inducing protective immunity against Proteus mirabilis.
- The findings suggest the presence of a shared adhesin among P. mirabilis fimbriae, warranting further investigation.
- Fimbrial antigens represent promising candidates for developing broadly protective vaccines against uropathogenic P. mirabilis.