Bacteria regulate collective behaviour by mechanosensing cell-cell collisions.

Pseudomonas aeruginosa uses mechanosensing of cell-cell collisions to regulate collective motion, with collision-induced reversals decreasing alignment at high density.

• Why it matters: Understanding how bacteria coordinate collective behaviors is crucial for insights into their navigation and adaptation in complex environments, yet the regulatory mechanisms remain unclear.
• What they did: The study employed live imaging, single-cell tracking, and simulations to show that collision-induced reversals modulate collective order, enabling adaptive surface exploration and preventing trapping at boundaries.
• The result: Findings suggest bacterial organization is a feedback-regulated state, providing a navigational advantage in structured environments, and highlight mechanosensing as a key regulator of collective behavior.