Olaifa, Kayode William2024-08-022024-08-022022Olaifa, K. (2022). Electroanalysis of microbial biofilms and antibiofilm drug testing. Nazarbayev University School of Engineering and Digital Scienceshttps://nur.nu.edu.kz/handle/123456789/8188Microbial biofilms are responsible for about 80% of infectious diseases in humans, resulting in high morbidity and mortality rates. Biofilm confers protection to the microbial cells from stressors, including antimicrobial treatments. Biofilms are more difficult to remove/kill, thus, contributing to antimicrobial resistance phenomenon. Unfortunately, existing methodologies routinely employed for microbial biofilms and evaluation of anti-biofilm compounds are flawed with varying limitations. Therefore, an urgent need for the design/development and adoption of new diagnostic platforms is exigent. Additionally, the need for new therapeutic options cannot be overemphasized. In this work, a bioelectrochemical platform that uses simple, low-cost, and commercially available screen-printed electrodes was implemented for real-time evaluation of selected antimicrobials against clinically relevant biofilm-forming species. We also adopted a drug repurposing strategy against a model resistant bacterial strain using the developed bioelectrochemical platform. Finally, attempt was made to detect a model fungal pathogen in human urine samples also via the developed platform. In general, both biochemical and electroanalytic methods suggests that complete inhibition of biofilm formation would require concentrations higher than that needed for planktonic cells. Further optimization of the methodology on C. albicans biofilms indicated that the antifungal activity of the tested compounds is in the order of complex Ag3>Amphotericin B>Fluconazole, while the conventional XTT indicated the order of Amphotericin B > Fluconazole >complex Ag3. This variability further reiterates the necessity for a multi-method approach to validate the antibiofilm efficacy of any compound. However, this study demonstrated, for the first time, the real-time antibiofilm assessment of selected antimicrobials using electroanalytical approach and offers consistent findings as early as 10 h following inoculationenAttribution-NonCommercial-ShareAlike 3.0 United StatesType of access: OpenPhD thesis