New research by mechanical engineers at Purdue University, West Lafayette, IN, aims at fighting bacterial biofilms that can foul medical devices, catheters, prosthetic valves, and other devices. Combating biofilms using antibiotics and toxic chemicals can lead to the growth of antibiotic-resistant strains.

This graphic illustrates how swimming microorganisms cause the stretching of polymers in a mucus-like substance, attracting the motile cells to surfaces in biofilms. (Credit: Gaojin Li and Arezoo Ardekani)
The engineers’ findings reveal specifics about interactions that induce bacteria to swim close to surfaces, where they remain long enough to attach and form biofilms. The researchers studied the motion of motile organisms using a swimming model called a squirmer, which allows them to simulate three modes of propulsion employed by the microorganisms.

They discovered that most bacteria are “pushers”, which swim closer to surfaces in the presence of the extracellular polymeric substance. This knowledge could lead to methods that hinder the ability of bacteria to stick to surfaces.

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