Biofilms play an important role in Staphylococcus aureus infection not only in terms of the disease process itself but also with respect to their negative impact on antimicrobial therapy. The latter is evident in the observation that the successful resolution of biofilm-associated staphylococcal infections often requires surgical intervention to debride infected tissues and/or remove infected implants even when the infection is caused by a strain that is not resistant to the antibiotic of choice. Based on this our goal is to develop and optimize an alternative therapeutic approach that will be effective irrespective of the metabolic or even resistance status of the offending bacterial strains. To this end, this proposal focuses on development and optimization of a nanotherapeutic protocol for the physical destruction of staphylococci contained with a biofilm. To accomplish this, Aim 1 will focus on identifying the most relevant surface-exposed proteins that are present on bacterial cells within the biofilms formed by diverse clinical isolates of S. aureus.
In Aim 2, we will generate antibodies to these proteins that can be used for the targeted delivery of gold-plated carbon nanotubes directly to the bacterial cell surface. We will then use laser irradiation to induce photothermal and photoacoustic effects capable of killing biofilm-associated staphylococci in a manner that is both highly specific and independent of the metabolic and resistance status of the offending bacterial strain. Finally, in Aim 3 we will employ a murine model of biofilm-associated infection to evaluate the therapeutic efficacy of our nanotherapeutic approach in vivo. Taken together, we are confident that the experiments we propose will lead to the development of an alternative therapy capable of significantly enhancing the ability to treat the growing problem of staphylococcal biofilm-associated infection, perhaps to the point that removal of infected devices and/or surgical debridement will become a therapeutic option rather than an imperative.
Biofilm-associated staphylococcal infections take a devastating economic and emotional toll. This is due to the fact that biofilm-associated bacteria exhibit a degree of intrinsic resistance to antimicrobial therapy that necessitates surgical intervention to remove all infected tissue and/or implanted medical devices. Our goal is to develop a therapeutic method that can be used to overcome this intrinsic resistance and thereby reduce the need for such extreme intervention. We are confident that the nanotherapeutic approach we propose will allow us to accomplish this important clinical objective.
