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Biological activities of partially purified elastase produced by Flavobacterium meningosepticum
Abstract:
Injection of viable cells of Flavobacterium meningosepticum at doses of 10(6) colony-forming units/eye caused ophthalmia in rabbits' corneas. Elastase, free of protease activity, was partially purified from broth cultures of F. meningosepticum ATCC12535 and TMS516. The optimum pH of the elastase activity was about 8.0. The activity was suppressed by Ni, Zn, Co, EDTA, and o-phenanthroline, and accelerated by Cu and Fe. The minimum dose of the elastase causing ophthalmia in the eyes of rabbits was 5 micrograms/eye (0.065 elastase units). The minimum lethal dose of the elastase for suckling mice by intracerebral injection was 0.4 micrograms (0.0052 elastase units)/suckling mouse, and its minimum lethal dose for adult mice by intraperitoneal injection was 740 micrograms/mouse (9.52 elastase units).
Insights
Flavobacterium meningosepticum causes eye inflammation. Its purified elastase enzyme also induced ophthalmia in rabbits and proved lethal in mice at specific doses, highlighting its pathogenic potential.
Area of Science:
- Microbiology
- Ophthalmology
- Enzymology
Background:
- Flavobacterium meningosepticum is a Gram-negative bacterium known to cause infections.
- Bacterial enzymes can play a significant role in pathogenesis.
Purpose of the Study:
- To investigate the role of Flavobacterium meningosepticum in causing ophthalmia.
- To characterize the elastase enzyme produced by F. meningosepticum and assess its pathogenic potential.
Main Methods:
- Injection of viable F. meningosepticum cells into rabbit eyes.
- Partial purification of elastase from bacterial broth cultures.
- Determination of optimal pH and effects of metal ions on elastase activity.
- Dose-response studies to determine the minimum ophthalmia-inducing and lethal doses of elastase in rabbits and mice.
Main Results:
- F. meningosepticum cells induced ophthalmia in rabbit corneas.
- Partially purified elastase, free of protease activity, caused ophthalmia at 5 micrograms/eye.
- The elastase exhibited optimal activity at pH 8.0, with its activity modulated by various metal ions.
- Minimum lethal doses for the elastase were determined for suckling mice (0.4 micrograms/mouse) and adult mice (740 micrograms/mouse).
Conclusions:
- Elastase produced by F. meningosepticum is a virulence factor contributing to ophthalmia.
- The purified elastase exhibits dose-dependent toxicity in animal models, indicating its pathogenic significance.