From models to pathogens: how much have we learned about Streptococcus pneumoniae cell division?

Area of Science:

• Microbiology
• Bacterial Cell Biology
• Antimicrobial Drug Discovery

Background:

• Streptococcus pneumoniae is a significant human pathogen, causing serious infections and exhibiting multi-drug resistance.
• Bacterial cell division is a promising target for developing new antimicrobial interventions.
• Understanding the growth and division mechanisms of S. pneumoniae is crucial for therapeutic strategies.

Purpose of the Study:

• To review recent advances in understanding Streptococcus pneumoniae growth and division.
• To compare S. pneumoniae's cell division with well-studied model organisms like Escherichia coli and Bacillus subtilis.
• To elucidate the molecular machinery governing the ovococcal shape of S. pneumoniae.

Main Methods:

• Comparative analysis of peptidoglycan synthesis pathways in S. pneumoniae and model bacteria.
• Review of conserved and divergent proteins involved in bacterial elongation and division.
• Integration of data to propose a model for S. pneumoniae growth and division.

Main Results:

• Streptococcus pneumoniae utilizes peripheral and septal peptidoglycan synthesis, involving elongasome and divisome complexes, similar to rod-shaped bacteria.
• Many cell division proteins are conserved between S. pneumoniae and model rods, suggesting a shared fundamental mechanism.
• S. pneumoniae exhibits unique differences from model rods, supporting a model of a single, large midcell machinery for growth and division.
• The ovococcal shape likely evolved from a rod-shaped ancestor through gene reduction.

Conclusions:

• Streptococcus pneumoniae's growth and division are governed by a conserved, albeit potentially unified, machinery.
• The ovococcal morphology of S. pneumoniae may have evolved from rod-shaped ancestors.
• Targeting bacterial cell division in S. pneumoniae offers a viable strategy for novel antimicrobial drug development.