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THE PROTECTIVE ACTION OF A SPECIFIC ENZYME AGAINST TYPE III PNEUMOCOCCUS INFECTION IN MICE
Abstract:
The bacterial enzyme which decomposes the purified capsular polysaccharide of Type III Pneumococcus in vitro also destroys the capsules of the living organisms growing in media and in the animal body. Potent preparations of this same enzyme protect mice against infection with virulent Type III Pneumococcus. The protective action is type-specific. The protective activity of the specific enzyme is destroyed by heat (70 degrees C. for 10 minutes). The enzyme remains in an effective concentration 24 to 48 hours after its injection into normal mice. The enzyme has been found to exert a favorable influence on the outcome of an infection already established at the time of treatment. A definite relationship has been found to exist between the activity of the enzyme in vitro and its protective power in the animal body. The mechanism of the protective action is discussed with special reference to the relation between the decapsulation of the bacteria by the enzyme and the phagocytic response of the host.
Insights
A bacterial enzyme effectively removes capsules from Type III Pneumococcus bacteria, protecting mice from infection. This enzyme
Area of Science:
- Microbiology
- Immunology
- Enzymology
Background:
- The capsule of Type III Pneumococcus is a key virulence factor.
- Bacterial enzymes can degrade capsular polysaccharides.
- Understanding enzyme-host interactions is crucial for developing antimicrobial strategies.
Purpose of the Study:
- To investigate the in vitro and in vivo effects of a bacterial enzyme on Type III Pneumococcus.
- To determine the enzyme's therapeutic potential against pneumococcal infections.
- To elucidate the mechanism of the enzyme's protective action.
Main Methods:
- Enzymatic degradation of purified capsular polysaccharide and whole bacterial cells.
- In vivo protection assays in mice infected with virulent Type III Pneumococcus.
- Assessment of enzyme stability and persistence in vivo.
- Correlation of in vitro enzyme activity with in vivo protective efficacy.
Main Results:
- The enzyme effectively decomposed Type III Pneumococcus capsules both in vitro and in vivo.
- Enzyme preparations demonstrated significant type-specific protection against pneumococcal infection in mice.
- Heat treatment inactivated the enzyme's protective activity.
- The enzyme remained active in mice for 24-48 hours post-injection and showed therapeutic benefit in established infections.
Conclusions:
- A specific bacterial enzyme can decapsulate Type III Pneumococcus, leading to type-specific protection.
- The enzyme's ability to degrade bacterial capsules correlates with its in vivo protective capacity.
- This enzyme holds promise as a therapeutic agent against Streptococcus pneumoniae infections, potentially by enhancing phagocytosis.
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