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[Immunochemical study of the meningococcal cell wall]
Abstract:
Meningococcus strains--standard and those isolated from the cerebrospinal fluid of patients suffering from the cerebrospinal meningitis were grown on fluid and solid protein-free nutrient media. Electron microscopic study showed that in the strains isolated from patients the wall was much thicker than in the standard strains. The cell wall preparations were obtained by its solution at pH 9.0 and separation from the microbial residue. In the cultures grown on the solid medium the cell was dissolved already in its washing at pH 7.2. It was revealed in gel filtration that the cell wall preparations consisted of three fractions. The fraction with the mol wt of from 2 to 3 million possessed a complex protein-polysaccharide nature, contained all the antigens of the group and intergroup specificity, was nontoxic for mice and antigenic for rabbits. Two other fractions whose mol wt was below 67000 contained no antigens.
Insights
Meningococcus strains from meningitis patients had thicker cell walls than standard strains. A large, protein-polysaccharide fraction contained all antigens, while smaller fractions lacked them.
Area of Science:
- Microbiology
- Immunology
- Biochemistry
Background:
- Neisseria meningitidis causes bacterial meningitis.
- Understanding meningococcal cell wall structure is crucial for vaccine development.
Purpose of the Study:
- To compare the cell wall structure of standard Meningococcus strains with those isolated from meningitis patients.
- To characterize the antigenic properties of Meningococcus cell wall components.
Main Methods:
- Culturing Meningococcus strains on fluid and solid media.
- Electron microscopy for cell wall thickness assessment.
- Gel filtration and antigenicity testing for cell wall fraction characterization.
Main Results:
- Meningococcus strains from patients exhibited significantly thicker cell walls compared to standard strains.
- Cell wall preparations yielded three fractions via gel filtration.
- A high molecular weight fraction (2-3 million Da) contained group and intergroup antigens, was non-toxic, and antigenic.
- Lower molecular weight fractions (<67,000 Da) lacked detectable antigens.
Conclusions:
- Differences in cell wall thickness may correlate with pathogenicity in Meningococcus.
- The high molecular weight protein-polysaccharide fraction is a promising candidate for meningococcal vaccines due to its antigenicity and low toxicity.