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[Pathogenicity of K. ozaenae for mice and chick embryos]
Abstract:
The authors tested the virulence of K. ozaenae--its old museum strains, the freshly isolated ones and those passaged on meat-peptone agar; experiments were carried out on mice and chick embryos. To mice the culture was administered intraperitoneally, subcutaneously, intranasally, and to embryos--into the allantoic cavity and on the chorioallantoic membrane. Irrespective of the method of administration, the freshly isolated strains were highly virulent both for mice and for chick embryos. The virulence of such strains decreased in the process of passaging on the nutrient medium. Old museum strains were of low virulence for albino mice and avirulent for chick embryos. In comparing the virulent and avirulent strains there were found no differences in the antigenic structure and toxicity of the Boiven complex, cytoplasm, membrane, capsular polysaccharide or whole virulent and avirulent bacteria killed by heating.
Insights
Freshly isolated Klebsiella ozaenae strains are highly virulent in mice and chick embryos. Virulence decreases with laboratory passaging, while old museum strains show low or no virulence, with no identified antigenic or toxic differences.
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Infectious Diseases
Context:
- Klebsiella ozaenae is a bacterium with clinical significance.
- Understanding bacterial virulence is crucial for developing effective treatments.
- The study investigates factors influencing K. ozaenae virulence.
Purpose:
- To evaluate the virulence of different Klebsiella ozaenae strains.
- To compare the pathogenicity of freshly isolated, passaged, and museum strains.
- To identify potential differences in virulent and avirulent strains.
Summary:
- Freshly isolated K. ozaenae strains demonstrated high virulence in murine and embryonated chick models via various administration routes.
- Passaging on nutrient media led to a decrease in virulence.
- Old museum strains exhibited significantly reduced virulence in mice and were avirulent in chick embryos.
- No differences were observed in antigenic structure or toxicity (Boiven complex, cytoplasm, membrane, capsular polysaccharide) between virulent and avirulent strains.
Impact:
- Findings highlight the impact of laboratory conditions on bacterial virulence.
- Suggests that virulence factors may not be linked to major antigenic or toxic components.
- Informs future research on K. ozaenae pathogenicity and strain characterization.