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Separating Bacteria by Capsule Amount Using a Discontinuous Density Gradient
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Separating Bacteria by Capsule Amount Using a Discontinuous Density Gradient

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Capsule genes of Streptococcus pneumoniae influence growth in vitro

Patrick Bättig1, Kathrin Mühlemann

  • 1Institute for Infectious Diseases, University of Bern, Bern, Switzerland.

FEMS Immunology and Medical Microbiology
|June 21, 2007
PubMed

Insights

The pneumococcal capsule

Area of Science:

  • Microbiology
  • Bacterial Genetics

Background:

  • The in vitro lag phase of Streptococcus pneumoniae growth is linked to serotype.
  • Pneumococcal capsule genes play a role in bacterial growth dynamics.

Purpose of the Study:

  • To investigate the specific role of capsule genes in bacterial growth using strain D39.
  • To determine how capsule gene deletions affect the lag phase of Streptococcus pneumoniae.

Main Methods:

  • Utilized strain D39 of Streptococcus pneumoniae.
  • Created partial and complete deletions of the capsule operon.
  • Assessed bacterial growth, specifically the lag phase, in Todd Hewitt broth with and without serum supplementation.

Main Results:

  • Complete deletion of the capsule operon significantly prolonged the lag phase (P=0.0002).
  • Partial deletions had varied effects on the lag phase.
  • Supplementation with 5% fetal bovine serum partially restored normal growth in mutants with extended lag phases.

Conclusions:

  • Pneumococcal capsule gene products demonstrably influence in vitro bacterial growth in strain D39.
  • The capsule's role in growth is complex and depends on the specific gene products and environmental conditions.

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