A. Introduction -- B. Molecular Detection of Drug Resistance (MDDR) service -- C. Use of the MDDR service by submitters -- D. References

..The ability to rapidly and accurately detect drug resistance in Mycobacterium tuberculosis complex (MTBC) is critical for the effective treatment of patients suffering from tuberculosis (TB) and relevant interventions of TB control programs. Efforts to treat patients and control the spread of TB can be hindered by the emergence of MTBC resistant to both first and second line anti-TB drugs. Additionally, the slow growth rate of MTBC and inherent difficulties associated with conventional drug susceptibility testing methods often serve as impediments to obtaining timely results. Since September 2009, the Laboratory Branch of the Division of Tuberculosis Elimination at U.S. CDC has offered a molecular testing service using conventional DNA sequencing for the identification of drug resistance associated mutations in isolates of MTBC. In June 2012, the service was expanded by incorporating pyrosequencing (PSQ) into the testing algorithm and by accepting nucleic acid amplification-positive (NAAT+) sputum sediments for testing to provide the ability for local providers and programs to potentially further reduce delayed diagnosis of MDR TB. The service allows rapid identification of multidrug-resistant (MDR) TB through the detection of genetic mutations associated with rifampin (RMP) and isoniazid (INH) resistance. In addition, when resistance to RMP is already known or detected in the MDDR service, genetic loci associated with resistance to ethambutol (EMB), pyrazinamide (PZA), and the most effective second-line drugs, fluoroquinolones (FQ) and the injectables amikacin (AMK), kanamycin (KAN), and capreomycin (CAP), are examined.

Stephen B. Thacker CDC Library collection