Researchers explore how Staphylococcus cells adhere to nanostructures

A team of researchers investigated for the first time how individual Staphylococcus aureus cells adhere to metallic nanostructures of various shapes and sizes, according to a study recently published in Biomaterials.

Researchers with the University of California at Berkeley and the University of Waterloo in Canada found that bacterial adhesion and survival rates vary depending on the shape of the nanostructure. The scientists used electron beam lithographic and electroplating techniques to fabricate nickel nanostructures of various shapes, introduced S. aureus cells to the structures and then rinsed the structures to remove all but the most solidly bound bacteria.

Scanning electronic microscopy revealed higher bacteria survival rates on tubular-shaped pillars where individual cells were partially embedded in the holes. Pillars with no holes had the lowest survival rates of bacteria.

"By understanding the preferences of bacteria during adhesion, medical implant devices can be fabricated to contain surface features immune to bacteria adhesion, without the requirement of any chemical modifications," Mohammad Mofrad, a faculty scientist in Berkeley Lab's Physical Biosciences Division, said.

The researchers also found that S. aureus cells can adhere not only to horizontal surfaces but also to highly curved features. The cells were also able to suspend from the overhangs of mushroom-shaped nanostructures.

"The bacteria seem to sense the nanotopography of the surface and form stronger adhesions on specific nanostructures," Zeinab Jahed, the lead author of the study, said.