Biofilms: Problems and Solutions
Michigan State University
Microbiology and Molecular Genetics
An estimated 80% of all human infections are related to biofilm formation. Biofilms are communities of bacteria that adhere to a surface, such as damaged tissue or an implanted medical device, and secrete a protective extracellular matrix of proteins and polysaccharides. Bacteria in biofilms have a much higher tolerance to antibiotics than the motile counterparts and thus biofilm-based infections are difficult to eradicate. My project has 2 aims; identifying the problems of biofilms in wound healing and the solutions to kill them. Biofilms are believed to contribute to the slow healing and chronic wounds prevalent among diabetic patients. The first aim of my study is to examine the detrimental effects of biofilms in wound healing. This will be accomplished by using a diabetic mouse model. Each mouse will have two wounds, one infected with Pseudomonas aeruginosa biofilms and one without, and the rate of healing of infected and non-infected wounds will be compared. The second aim of this study is to find synergistic combinations of antibiotics and compounds that can overcome the antibiotic resistance mechanisms of the biofilms to kill them. This will be accomplished through use of an in vitro biofilm assay to measure the effectiveness of the potential treatments identified by a large-scale screen. The treatments are tested on biofilm-forming Pseudomonas aeruginosa which is the most common infection of cystic fibrosis patients and contributes to respiratory failure, the leading cause of death. Due to the decreased responsiveness of biofilms to antibiotics, the infection often becomes a lifelong infection and hardship. My pilot studies have already identified a synergistic treatment combination with greatly improved efficacy against these biofilms resulting in nearly 100% killing in the same conditions that the currently antibiotic treatment only kills 10%. This study has the potential to greatly improve treatment of biofilm-based infections, such as those of cystic fibrosis and diabetic patients.