Antibiotic resistance of S. aureus on a ‘bifunctional’ surface: An in vitro coculture study

Abstract

There is significant interest in anti-infective biomaterials that have dual properties of promoting tissue integration and inhibiting bacterial adhesion to prevent device associated infection. However, it is also known that bacteria such as S. aureus have abundant surface pathogen-associated molecular patterns can readily interact with mammalian cells such as osteoblasts. Using tissue culture plastic, we found that S. aureus were electrostatically repelled from this surface and that when they were inoculated onto this surface pre-seeded with MC3T3-E1, they formed aggregates that adhered strongly to these osteoblastic cells. Importantly, the bacteria in the aggregates were more resistant to gentamicin compared to those in bacterial monoculture. This finding thus suggested that the bacteria repelled from such a surface might end up establishing biofilm-like community on adjacent mammalian cells or tissue and that anti-infective biomaterials should actively kill bacteria.