CDC | TB Topic - Laboratory Information

Tuberculosis

Laboratory Information

The Division of Tuberculosis Elimination (DTBE) Mycobacteriology Laboratory Branch (MLB) provides services for the following tests on mycobacterial cultures. Any local health department, licensed physician's office, licensed laboratory or licensed health care facility may submit cultures for testing but they must be routed through either their state health department or other authorized facility.

Genotyping

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:

Spoligotyping
Mycobacterial interspersed repetitive unit (MIRU) analysis
IS6110-based restriction fragment length polymorphism (RFLP) analysis

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.