Afb Mtb - Ethionamide Antibacterial Gradient Infected Tissue

Testing for drug susceptibility to ethionamide, a crucial part of second line anti-tuberculosis therapy, is problematic as the difference characterizing drug resistance or susceptibility is small. Moreover, the minimum inhibitory concentration (MIC) is very near to the therapeutic index. Inspite of the importance of ethionamide in the treatment of MDR-TB, there are only a few reports on the drug susceptibility testing of this agent. The gold standard of drug susceptibility testing against anti-tuberculosis agents is the proportion method that uses a single critical concentration of drugs to determine resistance or susceptibility. However, the thermolabile nature of ethionamide may play a role in reducing the potency of the drug during inspissation of the drug containing medium. Deterioration of the drug during prolonged incubation period required for M. tuberculosis can also be crucial.