HT-SPOTi: A Rapid Drug Susceptibility Test (DST) to Evaluate Antibiotic Resistance Profiles and Novel Chemicals for Anti-Infective Drug Discovery.

Antibiotic resistance is one of the major threats to global health and well-being. The past decade has seen an alarming rise in the evolution and spread of drug-resistant strains of pathogenic microbes. The emergence of extensively drug resistant (XDR) strains of Mycobacterium tuberculosis and antimicrobial resistance among the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter species) as well as fungal pathogens (such as certain species of Candida, Aspergillus, Cryptococcus, and Trichophyton) poses a significant 21st century scientific challenge. With an extremely limited arsenal of efficacious antibiotics, techniques that can (a) identify novel antimicrobials and (b) detect antimicrobial resistance are becoming increasingly important. In this article, we illustrate the HT-SPOTi, an assay that is principally based on the growth of an organism on agar medium containing a range of different concentrations of drugs or inhibitors. The simple methodology makes this assay ideal for evaluating novel antimicrobial compounds as well as profiling an organism's antibiotic resistance profile.