The Division of Tuberculosis Elimination (DTBE) Mycobacteriology
Laboratory Branch (MLB) provides services for the following tests
on mycobacterial cultures submitted from federal, state, local,
and territorial public health laboratories.
State or local TB control programs
Two genotyping laboratories, one in Michigan and one in California,
are under contract with CDC to provide genotyping services to
TB programs in the United States. Three genotyping methods to
identify TB strains:
- Mycobacterial interspersed repetitive unit (MIRU) analysis
- IS6110-based restriction fragment length polymorphism (RFLP)
For more information, view
the Guide to the Application of
Genotyping to Tuberculosis Prevention and Control.
DTBE epidemiologic investigations and surveillance activities
- The MLB provides support for DTBE epidemiologic investigations
and surveillance activities. TB genotyping results, when combined
with epidemiologic data, help to distinguish TB patients who are
involved in the same chain of recent transmission.
Genotyping of nontuberculous mycobacteria
- In support of epidemiological investigations involving nontuberculous mycobacteria, the MLB identifies strains by
analysis of DNA restriction patterns produced by pulsed-field gel electrophoresis (PFGE).
Drug susceptibility testing
The MLB performs drug susceptibility
testing for selected Mycobacterium species referred from
state or other authorized health facilities. Cultures of mycobacteria
are tested by the indirect proportion method with antituberculosis
drugs incorporated into 7H10 agar plates.
Identification of Mycobacterium species
The MLB identifies Mycobacterium species referred from state
or other authorized health facilities.
The primary method for identification
of Mycobacterium species is high
performance liquid chromatography (HPLC) analysis of species-specific mycolic acids.
Interim Laboratory Biosafety Guidance for Extensively Drug-Resistant (XDR)
Mycobacterium tuberculosis strains
Last Reviewed: 05/18/2008
Content Source: Division of Tuberculosis Elimination
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention