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Streptococcus pneumoniae produces a second haemolysin that is distinct from pneumolysin
J R Canvin1, J C Paton, G J Boulnois
1Department of Microbiology and Immunology, University of Leicester, U.K.
Microbial Pathogenesis
|March 1, 1997
Summary
Pneumococci, commonly alpha-haemolytic, can produce beta-haemolysis. This study confirms a second pneumococcal haemolysin, separate from pneumolysin, is responsible for this effect.
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Molecular Biology
Background:
- Streptococcus pneumoniae (pneumococci) are typically characterized as alpha-haemolytic.
- However, under specific conditions, pneumococci can exhibit beta-haemolytic activity on blood agar.
Purpose of the Study:
- To investigate the mechanism behind the observed beta-haemolysis in pneumococci.
- To determine if pneumolysin is responsible for beta-haemolysis or if another factor is involved.
Main Methods:
- Utilized wild-type pneumococcal strains and a genetically modified strain lacking pneumolysin production.
- Assessed beta-haemolysis zones on blood-containing media.
- Tested the effect of anti-pneumolysin antibody and cholesterol on haemolytic activity.
Main Results:
- All tested pneumococcal strains, including the wild-type, produced beta-haemolysis.
- The observed beta-haemolysis was not neutralized by anti-pneumolysin antibodies.
- Beta-haemolysis was effectively inactivated by cholesterol.
Conclusions:
- Pneumococci produce a distinct second haemolysin, independent of pneumolysin.
- This novel haemolysin contributes to the beta-haemolytic phenotype observed in certain conditions.