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09:11
Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination
Published on: September 25, 2014
Surface charge of Streptococcus pneumoniae predicts serotype distribution
Yuan Li1, Daniel M Weinberger, Claudette M Thompson
1Department of Epidemiology and Department of Immunology & Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA.
Infection and Immunity
|October 2, 2013
Summary
The surface charge of Streptococcus pneumoniae, influenced by its capsule, impacts resistance to immune cells. More negative charges correlate with higher prevalence in human populations.
Area of Science:
- Microbiology
- Immunology
- Genetics
Background:
- Streptococcus pneumoniae colonizes the nasopharynx, causing various infections.
- Pneumococcal capsule type influences surface charge, potentially affecting host interactions.
- Previous research suggests negative surface charge may aid immune evasion.
Purpose of the Study:
- To investigate the relationship between Streptococcus pneumoniae surface charge and its ability to colonize the human nasopharynx.
- To determine if surface charge influences resistance to phagocyte-mediated killing.
- To assess the correlation between surface charge and carriage prevalence in human populations.
Main Methods:
- Measured surface charge (zeta potential) of laboratory and clinical Streptococcus pneumoniae strains.
- Assessed resistance to nonopsonic killing by human neutrophils in vitro.
- Analyzed carriage prevalence data in human populations before and after PCV7 vaccination.
Main Results:
- A more negative surface charge correlated with increased resistance to neutrophil killing.
- Higher negative zeta potential was associated with greater pneumococcal carriage prevalence.
- Capsule type is the primary determinant of net surface charge, though exceptions exist.
Conclusions:
- Pneumococcal surface charge, mainly determined by capsule type, plays a role in resistance to host immune defenses and carriage prevalence.
- While surface charge is a significant factor, it is not the sole mechanism by which the pneumococcal capsule interacts with the host.
- Further research is needed to fully elucidate the complex interactions between pneumococcal capsule, surface charge, and host immunity.
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