Understanding How Staph Adheres May Lead to Resistant Materials

Medical Design Briefs INSIDER

This scanning electron microscopy image reveals how Staphylococcus Aureus cells physically interact with a nanostructure. A bacterial cell (blue) is embedded inside the hollow nanopillar's hole and several cells cling to the nanopillar's curved walls. (Credit: Mofrad lab and the Nanomechanics Research Institute)

The bacterium Staphylococcus Aureus is a common source of serious infections after surgeries involving prosthetic joints and artificial heart valves. So a search for bacteria-resistant materials is as an important line of defense. A team of scientists at Lawrence Berkeley National Laboratory is examining how individual Staph cells adhere to metallic nanostructures since an infection can’t begin unless the bacteria first clings to a surface.

They found that bacterial adhesion and survival rates vary depending on the nanostructure’s shape. Their work could lead to a more nuanced understanding of what makes a surface less inviting to bacteria.

By understanding bacterial methods of adhesion, medical implant devices can be fabricated to contain surface features immune to bacteria adhesion, without chemical modifications, they said.

The scientists first used electron beam lithographic and electroplating techniques to fabricate nickel nanostructures of various shapes, then introduced Staph cells to these structures, gave them time to stick, and then rinsed the structures with deionized water to remove all but the most solidly bound bacteria.

Scanning electron microscopy revealed which shapes were the most effective at inhibiting bacterial adhesion. They observed higher bacteria survival rates on the tubular-shaped pillars, where individual cells were partially embedded into the holes. In contrast, pillars with no holes had the lowest survival rates.

The scientists also found that the cells adhere to a wide range of surfaces, not only horizontal ones, but to highly curved features as well. The cells can also suspend from overhangs of mushroom-shaped nanostructures.

Source