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[Virulence of Streptococcus pneumoniae strains isolated in acute and chronic inflammatory lung diseases]
Abstract:
The virulence of 139 Str. pneumoniae strains was studied. The cultures differing in virulence were found to have the same specific prominence. In most serotypes the LD50 for mice was within greater than 3-5 lg/ml and greater than or equal to 6 lg/ml. Highly virulent cultures comprised a comparatively small number of serotypes. More than half of pneumococcal strains isolated in acute pneumonia possessed the moderate level of pathogenicity for white mice. During the acute phase of inflammatory pulmonary diseases Str. pneumoniae strains with high and moderate virulence prevailed, and at the period of clinical remission those with low virulence.
Insights
This study investigated Streptococcus pneumoniae virulence in 139 strains. Most strains showed moderate pathogenicity, with highly virulent strains being less common, especially during disease remission.
Area of Science:
- Microbiology
- Infectious Diseases
- Pathogenesis
Context:
- Streptococcus pneumoniae is a leading cause of bacterial pneumonia.
- Understanding pneumococcal virulence is crucial for disease management and vaccine development.
- This study analyzed the virulence of 139 clinical isolates of Streptococcus pneumoniae.
Purpose:
- To assess the virulence levels of clinical Streptococcus pneumoniae strains.
- To correlate strain virulence with specific serotypes and disease phases.
- To identify factors contributing to pneumococcal pathogenicity.
Summary:
- The study found that virulence varied among Streptococcus pneumoniae strains, with no specific prominence linked to differing virulence levels.
- Most serotypes exhibited LD50 values for mice between 3-5 lg/ml and ≥6 lg/ml.
- Highly virulent strains were rare, and over half of strains from acute pneumonia cases showed moderate pathogenicity.
- During acute inflammatory pulmonary disease, high and moderate virulence strains predominated, while low virulence strains were more prevalent during clinical remission.
Impact:
- Findings highlight the prevalence of moderately virulent Streptococcus pneumoniae strains in acute pneumonia.
- The study demonstrates a shift in pneumococcal virulence profiles during different disease stages.
- This research contributes to understanding pneumococcal epidemiology and guides strategies for combating pneumococcal infections.