The many facets of drug susceptibility testing for Mycobacterium tuberculosis

Although cases of tuberculosis are at an all-time low in the United States, they are still a major cause of morbidity and mortality in the rest of the world; drug-resistant tuberculosis is on the rise in many areas. There are many methods used to detect drug resistance, with varying degrees of reliability. Some important anti-tuberculosis drugs, such as pyrazinamide and the newest agent, bedaquiline (Sirturo; Johnson & Johnson), do not even have reliable methods yet. This article summarizes the epidemiology of tuberculosis and presents an appraisal of the currently available phenotypic and genotypic methods for detecting drug resistance.