Microbial fuel cell-based diagnostic platform to reveal antibacterial effect of beta-lactam antibiotics

Beta-lactam antibiotics comprise the largest group of antibacterial agents. Due to their bactericidal properties and limited toxicity to humans they are preferred in antimicrobial therapy. In most cases, therapy is empiric since susceptibility testing in diagnostic laboratories takes a relatively long time. This paper presents a novel platform that is based on the microbial fuel cell (MFC) technology and focuses on the early antibiogram determination of isolates against a series of beta-lactam antibiotics. An advantage of the system is that it can be integrated into traditional microbiological diagnostic laboratory procedures. Tested bacterium suspensions are uploaded into the anodic chambers of each miniaturized MFC unit integrated into a panel system, containing different antibiotic solutions. Electronic signals gained in each MFC unit are continuously monitored and are proportional to the metabolic activity of the presenting test bacterium. Using this method, antibiotic susceptibility can be evaluated in 2-4h after inoculation. Hereby we demonstrate the efficacy of the platform in antibiogram determination by testing the susceptibilities of Escherichia coli strain ATCC 25922 and Staphylococcus aureus strain ATCC 29213 against 10 beta-lactam antibiotics (penicillin, ampicillin, ticarcillin, cefazolin, cefuroxime, cefoperazone, cefepime, cefoxitin, cefaclor, imipenem). This paper also presents the construction of the background instrumentation and the panel system into which a printed circuit board (PCB) based electrode was integrated. Our results suggest that MFC based biosensors have the potential to be used in diagnostics for antibiogram determination.