Pathogens electrogenicity as a tool for in-situ metabolic activity monitoring and drug assessment in biofilms

Abstract

Concerns regarding increased antibiotic resistance arising from the emergent properties of biofilms have spurred interest in the discovery of novel antibiotic agents and techniques to directly estimate metabolic activity in biofilms. Although a number of methods have been developed to quantify biofilm formation, real-time quantitative assessment of metabolic activity in label-free biofilms remains a challenge. Production of electrical current via extracellular electron transport (EET) has recently been found in pathogens and appears to correlate with their metabolic activity. Accordingly, monitoring the production of electrical currents as an indicator of cellular metabolic activity in biofilms represents a new direction for research aiming to assess and screen the effects of antimicrobials on biofilm activity. In this article, we reviewed EET-capable pathogens and the methods to monitor biofilm activity to discuss advantages of using the capability of pathogens to produce electrical currents and effective combination of these methods. Moreover, we discussed EET mechanisms by pathogenic and environmental bacteria and open questions for the physiological roles of EET in pathogen's biofilm. The present limitations and possible future directions of in situ biofilm metabolic activity assessment for large-scale screening of antimicrobials are also discussed.

Multivariate landscapes constructed by Bayesian estimation over five hundred microbial electrochemical time profiles

“… 42 Owing to the flexibility of the electrolyte, potential poising, and electrode material, the present method can be extended to many other applications in electromicrobiology—microbial fuel cells and microbial electrosynthesis, or metabolic activity sensor technologies for antibiotic drug discovery. 43 , 44 …”

Physiological Benefits of Oxygen-Terminating Extracellular Electron Transfer

“…In addition, a microbiome in oral plaque was proposed to mediate EET termination with oxygen as the electron acceptor ( 78 ). Although neither electron conduction nor oxygen-terminating EET has been demonstrated in oral plaque, some bacteria in plaque have cell-surface redox regents showing electrode-terminating EET capability ( 79 , 80 ).…”

“…Although neither electron conduction nor oxygen-terminating EET has been demonstrated in oral plaque, some bacteria in plaque have cell-surface redox regents showing electrode-terminating EET capability ( 79 , 80 ). Bacteria in the biofilm interior exhibited a lower redox potential than those in the biofilm periphery, showing that a thermodynamically favorable cascade connects an anoxic biofilm interior to the oxic periphery ( 78 , 81 ).…”

Architecting data-driven microbial electrochemistry from scratch

“…I was able to start my research 6 years ago with a budget from AMED with the hypothesis that pathogenic bacteria are power-generating bacteria and that their ability to transfer electrons is related to biofilms and diseases. 2 However, I have not been able to finish that research yet. It was a research plan with very challenging goals, but I am still convinced that the content is very important.…”