By Aiddah Rotich

Faculty Mentor: Dr. Theresa Grana

Abstract

With the rise of global infections involving drug-resistant tuberculosis, first line drugs are at risk of becoming less effective in treatments leading to the need for new synthetic compounds. Therefore, a robust system of drug testing procedures is needed to test their efficacy against the airborne pathogen, M. tuberculosis. The focus of the project was adapting published assays and resources to test the effects of synthesized drugs on a model organism. Mycobacterium aurum, a surrogate organism with similar genome profile to M. tuberculosis, was used during compound testing. The ten synthesized compounds that were tested are sulfonamide derivatives made using eco-friendly synthesis pathways. The 96-well plate broth dilution assay was applied to one of the derivatives to determine its minimum inhibitory concentration. This assay involved adding growth media, standardized bacteria culture in log-phase growth and a binary dilution series of the drug from 2000ug/ml to 0.06ug/ml to a 96-well plate. A resazurin fluorescent dye, Alamar blue, was applied to all wells and cell viability measured at 570nm. A spot-on agar assay was then conducted using all the ten synthesized compounds with first line drugs Isoniazid and Rifampin used as positive controls. Each drug compound’s dilution series 1:2 ranged from 1000ug/ml – 7.8ug/ml and was plated on an agar plate. While inconsistent results were produced after application of the 96 well plate format, more promising results are to be obtained from the spot-on agar assay. Although both methods are listed as valid methods for novel compound testing, each have their limitations and challenges. Further adaptations of the 96-well assay along with repeated trials are needed to obtain significant and reliable results.