Related Experiment Videos
[The virulence of Streptococcus pneumoniae strains--the causative agents of pneumococcal infection at different
Abstract:
A total of 256 S. pneumoniae strains, the causative agents of infectious processes with different localization, were studied for their virulence (in experiments on mice), neuraminidase and aldolase-protease activity (APA). In pneumococcal strains isolated 18-20 hours after intraperitoneal infection their virulence for mice increased, on the average, 1,000-fold and the average level of extracellular and cellular neuraminidase and APA increased 2- to 5-fold in comparison with the initial values. Pneumococcal strains causing acute pneumococcal infections with different localization, or the aggravation of such infections, exhibited higher virulence for mice and higher levels of neuraminidase and APA, while the inflammatory process at the period of clinical remissions was mainly maintained by S. pneumoniae cultures with low virulence.
Insights
Virulence of Streptococcus pneumoniae strains increased significantly after infection in mice, correlating with higher neuraminidase and aldolase-protease activity (APA). Lower virulence strains were associated with infection remission.
Area of Science:
- Microbiology
- Pathogenesis
- Biochemistry
Context:
- Streptococcus pneumoniae is a major cause of infectious diseases.
- Understanding pneumococcal virulence factors is crucial for disease management.
Purpose:
- To investigate the relationship between virulence and enzymatic activity (neuraminidase and aldolase-protease activity - APA) in S. pneumoniae strains.
- To correlate enzymatic activity with disease severity and progression in a murine model.
Summary:
- A study of 256 S. pneumoniae strains demonstrated a 1,000-fold increase in mouse virulence and a 2- to 5-fold rise in neuraminidase and APA levels in strains isolated 18-20 hours post-infection.
- Strains causing acute or aggravated infections showed higher virulence and enzymatic activity.
- Conversely, S. pneumoniae with low virulence were primarily associated with maintaining the inflammatory process during clinical remissions.
Impact:
- This research highlights the role of neuraminidase and APA as key virulence factors in S. pneumoniae infections.
- Findings may inform the development of novel therapeutic strategies targeting these enzymes to combat pneumococcal diseases.