Electrochemical impedance-based evaluation of antibiotic susceptibility in bacterial cells and biofilms grown on gold electrodes

Abstract

Catastrophic problem of antibiotic resistance is prevalent across the globe as it is triggered by bacterial survival mechanisms like exopolysaccharide layer (EPS) that serves as a protective slimy coating over bacteria, protecting it from environmental stress like drought, chemical stress and antibiotic effects and allowing it to survive and adapt to any environment. These biofilms are found in hospital-acquired infections seen in catheters of UTIs, valve insertions, implants, and incorrect antibiotic prescription, this is largely attributed to the ability of the exopolysaccharide layer in biofilm to confer antibiotic resistance. While traditional lab tests take 24-48 hours to identify fully developed biofilms, impedance can detect biofilms from early adhesion stages, the moment bacterial cells adhere to the surface, drastically decreasing time required for diagnosis. The rationale of this project focuses on mitigating biofilm's ability to develop as a biomedical diagnostic device in the detection and monitoring of bacterial cells. A hypothesis emphasizes speed and accuracy using real-time Electrochemical impedance (EIS) on gold screen-printed electrodes (Au-SPEs) to determine Minimum inhibition concentration (MIC) is 0.001mg/ml and Minimum biofilm eradication concentration (MBEC) is 5 mg/ml. Biofilm-forming bacterial cells using the electrochemical technique of impedance spectroscopy (EIS) and cyclic voltammetry (CV). This is a non-faradic, label-free antimicrobial testing method that rapidly tracks impedance changes or biofilm resistance during antibiotic exposure by analyzing impedance plots and peak variations across various antibiotic ranges. It also analyses method of inoculating bacterial biofilms in broth and its efficiency against antibiotics. The outcome focuses on developing a superior technique for monitoring biofilm maturation and the efficiency of antibiotics against antibiotic-resistant biofilms in medical settings.