Guide to the Application of Genotyping to Tuberculosis Prevention
Introduction to Tuberculosis Genotyping
Overview of the CDC Tuberculosis Genotyping Program
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. TB programs that have been approved
to participate in the CDC Tuberculosis Genotyping Program may submit
to a genotyping laboratory one isolate from each culture-positive
patient with TB within their jurisdictions. In rare circumstances,
TB programs may submit additional isolates from the same patient.
These circumstances are described in Chapter 5, Developing a
TB Genotyping Program. The genotyping laboratories will analyze
isolates from current patients, but TB programs may request permission
to submit selected isolates collected in the past. Although the
implementation of universal genotyping (i.e., submitting one isolate
from every culture-positive patient with TB) has substantial benefits,
a TB program does not have to submit a particular number or percentage
of isolates to participate in the program.
The genotyping laboratories will use three genotyping methods:
spoligotyping, mycobacterial interspersed repetitive units
(MIRU) analysis, and IS6110-based restriction fragment
length polymorphism (RFLP) analysis. Spoligotyping and MIRU
analysis are based on the polymerase chain reaction (PCR).
Together, these methods will be referred to as PCR genotyping tests.
The genotyping laboratories will analyze all the submitted isolates
by both PCR genotyping tests. Under certain circumstances and upon
the request of the TB program, isolates that have matching genotypes
by both spoligotyping and MIRU analysis can be tested by RFLP analysis.
Genotyping results, under most circumstances, will be reported to
the TB program but not to the submitting laboratories. The genotyping
services are free to TB programs, but neither CDC nor the genotyping
laboratories will pay the packaging and shipping costs.
Released October 2008
Centers for Disease Control and Prevention
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
Division of Tuberculosis Elimination - http://www.cdc.gov/tb
Please send comments/suggestions/requests
CDC/Division of Tuberculosis Elimination
Communications, Education, and Behavioral Studies Branch
1600 Clifton Rd., NE - Mailstop E-10, Atlanta, GA 30333