Author: Janvi Patel
Patel, Janvi, 2025 Dual Therapy Approaches for Antibiotic Potentiation Against Biofilm Threats, Flinders University, College of Medicine and Public Health
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Bacterial biofilms, complex communities settle in their own self-produced extracellular matrix, are a major cause of chronic and persistent infections in chronic wound and on medical devices due to their remarkable resistance to antibiotics and the immune system. This resistance is because of the biofilm matrix defense, slow bacterial growth, and the persister cells, with a minimum inhibitory concentration as much as 1000 times higher than that required for planktonic bacteria. Antibiotic resistant pathogens leading chronic infection is an indication of the necessity of new therapeutic approaches. In this study, the limitation will be met through the investigation of dual therapeutic approach that combine the use of antibiotics with the application of biofilms dispersal agents in D- amino acids (DAAs) and quaternary ammonium compounds (QACs) to enhance the sensitivity of the biofilm coated bacteria as well as the effectiveness of the treatment. The test hypothesis is that QACs and DAAs by interference with biofilm matrix and increasing bacterial susceptibility, will increase the effectiveness of antibiotics against clinically relevant bacteria such as Staphylococcus aureus and Escherichia coli. Methods used in vitro inhibition and dispersion of biofilms through the use of crystal violet staining and minimum biofilm eradication concentration (MBEC) testing, using antibiotics alone and in combination. The results indicated that the removal of biofilms by QACs alone had varying effects. However, QACs showed a strong synergistic effect by considerably reducing the quantity of antibiotic required to kill biofilm bacteria when paired with antibiotics at lower, sub-eradication concentrations. Because of their solubility and strain-specific difficulties, DAAs had little antibiofilm activity under the testing conditions. These findings suggest that dual therapy approaches hold great promise for addressing biofilm medicated resistance in chronic wound therapy. Future research direction includes in vivo confirmation, optimization of delivery system for instance in the format of alginate hydrogels, and mechanism-based investigations so further define the mechanisms of disruption of biofilms and antibiotic enhancement.
Keywords: Bacterial biofilm, Antibacterial, Antibiotics, MBEC, QACs, DAAs.
Subject: Medical Biotechnology thesis
Thesis type: Masters
Completed: 2025
School: College of Medicine and Public Health
Supervisor: Dr. Andrew Hayles