MDDR in M. tuberculosis complex
Molecular Detection of Drug Resistance (MDDR) is Polymerase Chain Reaction (PCR) testing provided by the Centers for Disease Control and Prevention (CDC) aimed at the detection of genetic markers of drug resistance for Mycobacterium tuberculosis complex (MTBC). Results are available in days as compared to weeks for conventional drug susceptibility testing.
Deoxyribonucleic Acid (DNA) analysis for drug resistant mutations.
Specimen Requirements for Submission
- High-risk of Rifampin resistance of Multi-Drug Resistant Tuberculosis (MDR-TB) (including previously treated Tuberculosis (TB) case, drug resistant TB contact, foreign-born from area with high rates of MDR-TB).
- Known Rifampin resistant isolates.
- High profile patients (e.g. daycare workers, healthcare provider).
- Adverse reactions (e.g. patients allergic to Rifampin).
- Mixed or non-viable cultures.
Submit reference isolates of TB using a Category A mailer provided by the MSPHL in accordance with the Infectious Substance, Category A shipping guidelines.
Only isolates of M. tuberculosis complex can be submitted for MDDR testing.
Test Request Form(s)
Refer to the CDC Result Report
Leaked during transport
No name on specimen
Most results are reported within 24 – 48 hours after CDC receives the specimen.
Limitations of MDDR: Potential to identify mutations that do not confer phenotypic resistance. Not all genetic loci associated with resistance are known, therefore, a susceptible molecular result does not rule out resistance.