April 07, 2015
The bacterium Staphylococcus Aureus (S.aureus), also known as Staph, is a common source of post-surgery infections involving prosthetic joints and artificial heart valves. The bacteria adhere to medical equipment and if they get inside the body a serious and even life-threatening infection may result. The emergence of drug-resistant strains of S.aureus makes matters worse.
Staphylococcus cells first need to adhere to a surface that is going into a surgical site. This is why a team of researchers led by Berkeley Lab (Lawrence Berkeley National Laboratory) scientists are exploring how surface features facilitate bacterial adhesion.
The scientists used electron beam lithographic and electro-plating techniques to fabricate nanocrystalline nickel nano-structures of various shapes and sizes, not much bigger than the staph cells themselves. They investigated for the first time how individual S.aureus bacteria cells adhere and found that adhesion and survival rates vary depending on the nanostructure’s shape. The bacteria seem to sense the nanotopography of the surface and form stronger adhesions on specific nanostructures.
“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,” says Mohammad Mofrad, a faculty scientist in Berkeley Lab’s Physical Biosciences Division and a professor of Bioengineering and Mechanical Engineering at UC Berkeley.