Application of microplate almar blue assay for rapid detection of drug resistance of M. tuberculosis strains

ABSTRACT

Background: Recently, microplate almar blue assay has been used commonly in detecting gen related to tuberculosis drug resistance, which provides results after 5-7 days with lower cost compared to traditional methods. Objective: To evaluate the application of microplate almar blue assay for rapid detection of drug resistance of M. tuberculosis strains. Subject and Method: A microplate-based assay which uses Alamar blue reagent - an oxidation reduction dye (MABA), was used for the determination of the anti-tuberculosis drug (isoniazid-INH, rifampicine-RIF, streptomycine-STR and ethabuton=EMB) resistance of 96 M. tuberculosis strains isolated from Vietnamese patients in comparison to those obtained by conversional method. Result: MABA showed to have high sensitivity and specificity in testing the sensitivity to individual anti-tuberculosis drugs (from 82.4% for STR to 93.3% for - INH and from 82.5% for EMB to 98.4% for STR; respectively), as well as for the multi-drug resistant M.tuberculosis (86.4% of sensitivity), highly correlated with the result determined by proportion method. Conclusion: MABA reveals the advantage in shortening test time, in simple performance and lower cost compared with the conversional culture based methods.