Advances in the screening of antimicrobial compounds using electrochemical biosensors: is there room for nanomaterials?

Abstract

The abusive use of antimicrobial compounds and the associated appearance of antimicrobial resistant strains are a major threat to human health. An improved antimicrobial administration involves a faster diagnosis and detection of resistances. Antimicrobial susceptibility testing (AST) are the reference techniques for this purpose, relying mainly in the use of culture techniques. The long time required for analysis and the lack of reproducibility of these techniques have fostered the development of high-throughput AST methods, including electrochemical biosensors. In this review, recent electrochemical methods used in AST have been revised, with particular attention on those used for the evaluation of new drug candidates. The role of nanomaterials in these biosensing platforms has also been questioned, inferring that it is of minor importance compared to other applications. Graphical Abstract

Combined electrical-electrochemical phenotypic profiling of antibiotic susceptibility of in vitro biofilm models

“…Recently, a bacterial metabolic perturbation has emerged as an indicator of antibiotic efficacy because bacterial metabolism plays an important role in reflecting their viability, growth, and reproduction, and antibiotics directly induce metabolic changes in biofilms. [43][44][45][46] Many reports demonstrated the interplay among action mechanisms of antibiotics, bacterial metabolism, and eventually their growth inhibition. 47,48 For the rapid phenotypic AST, such metabolic changes have recently been monitored by measuring redox interactions of labeled reporters which are involved in bacterial respiration, pH change, and enzyme production during bacterial metabolism.…”

“…46,[49][50][51] Although those label-based metabolic sensing techniques are successful as a rapid and user-friendly AST approach, there is a growing interest in developing a label-free AST technique because of its overwhelming advantages including simplified steps, reduced amounts of reagents, point-of-care realization, and costeffectiveness. 45,52 For the label-free metabolic sensing, our group demonstrated that the electrons metabolically produced from Pseudomonas aeruginosa can be a strong signal to monitor their growth and treatment efficacy, successfully providing a quantifiable MIC of three antibiotics (i.e., gentamicin, ciprofloxacin, and ampicillin), and characterized the bacterial antibiotic action mechanisms. [53][54][55] A microbial fuel cell (MFC) was created as a metabolic biosensor where the anode incubated the pathogen with antibiotics.…”