Related Experiment Videos
[Toxicity and virulence of different strains of meningococcus]
Abstract:
With the aid of a modified Dubos and Schaedleder's method a determination was made on albino mice of the toxicity of 49 strains of meningococcus. The greatest toxicity was possessed by strains isolated from the cerebrospinal fluid of patients with cerebrospinal meningitis; standard strains were less toxic and strains isolated from healthy carriers were nontoxic. The living and the heated cultures of meningococci produced the same toxic action which was apparently associated with the thermostable antigens of the cell. The virulence studied in 24 strains of meningococcus on a model of 9-day chick embryos failed to correlate with the toxic properties of the strains.
Insights
Toxicity of meningococcus strains varied based on isolation source, with cerebrospinal fluid strains being most toxic. This toxicity is linked to heat-stable antigens, not virulence in chick embryos.
Area of Science:
- Microbiology
- Immunology
- Pathogen Toxin Research
Background:
- Neisseria meningitidis (meningococcus) is a significant cause of bacterial meningitis.
- Understanding meningococcal toxicity is crucial for developing effective treatments and vaccines.
- Previous studies have explored meningococcal virulence factors with varying results.
Purpose of the Study:
- To determine the toxicity of various meningococcus strains using a mouse model.
- To investigate the relationship between meningococcal toxicity and isolation source.
- To explore the correlation between toxicity and virulence in chick embryos.
Main Methods:
- A modified Dubos and Schaedleder's method was employed for toxicity determination.
- Albino mice were used to assess the toxicity of 49 meningococcus strains.
- The virulence of 24 strains was studied in a 9-day chick embryo model.
Main Results:
- Strains isolated from cerebrospinal fluid exhibited the highest toxicity.
- Standard strains showed moderate toxicity, while strains from healthy carriers were nontoxic.
- Both live and heated meningococcal cultures demonstrated similar toxicity, indicating a link to thermostable antigens.
- No correlation was found between meningococcal toxicity and virulence in the chick embryo model.
Conclusions:
- Meningococcal toxicity is strain-dependent and associated with isolation source.
- Thermostable antigens within the meningococcal cell appear to be the primary mediators of toxicity.
- Virulence in chick embryos does not reliably predict the toxic potential of meningococcus strains.