Formation of regular packets of Staphylococcus aureus cells

Area of Science:

• Microbiology
• Cell Biology
• Bacterial Morphology

Background:

• Staphylococcus aureus typically forms irregular, grape-like clusters.
• Bacterial cell division and separation are crucial for morphology.
• The mechanism of S. aureus cell arrangement is not fully understood.

Purpose of the Study:

• To investigate the fundamental division planes of Staphylococcus aureus.
• To understand the role of separation enzymes in S. aureus cell arrangement.
• To characterize the formation of regular cell packets in S. aureus.

Main Methods:

• Inducing loss of separation enzyme activity using detergents (sodium dodecyl sulfate, Triton X-100).
• Inducing loss of separation enzyme activity via genetic mutation.
• Microscopic analysis (scanning electron microscopy) of cell packet formation.

Main Results:

• Loss of separation enzyme activity leads to the formation of regularly arranged cell packets.
• These packets contain 8 to 64 spherical cells in a three-dimensional arrangement.
• Scanning electron microscopy revealed some irregularities in packet formation.
• S. aureus fundamentally divides along three perpendicular planes.

Conclusions:

• S. aureus cell division occurs along three fixed, orthogonal planes.
• Separation enzymes are responsible for translocating cells into grape-like clusters after division.
• Inhibition of separation enzymes results in the formation of ordered cell packets.