Send to

Choose Destination
See comment in PubMed Commons below
J Clin Microbiol. 2010 Feb;48(2):575-8. doi: 10.1128/JCM.01604-09. Epub 2009 Dec 23.

Comparison of restriction fragment length polymorphism with the polymorphic guanine-cytosine-rich sequence and spoligotyping for differentiation of Mycobacterium tuberculosis isolates with five or fewer copies of IS6110.

Author information

  • 1Francis J. Curry National Tuberculosis Center, Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, Department of Medicine, University of California, San Francisco, San Francisco, California 94110, USA.


The use of IS6110 as a marker for molecular epidemiological studies is limited when a Mycobacterium tuberculosis isolate has five or fewer copies of IS6110. Restriction fragment length polymorphism analysis with a highly polymorphic GC-rich repetitive sequence located in the plasmid pTBN12 (PGRS RFLP) and spoligotyping (based on the polymorphism of the DR region) are two frequently used secondary typing methods. The aim of this study was to compare the performance of these two methods in a population-based study in San Francisco. We included all patients with culture-positive tuberculosis from 1999 to 2007 with IS6110 RFLP results presenting five or fewer bands. PGRS RFLP and spoligotyping were performed using standardized methods. We determined the concordance between the two methods regarding cluster status and the risk factors for an isolate to be in a cluster with each of the methods. Our data indicate that both methods had similar discriminatory power and that the risk factors associated with clustering by either method were the same. Although the cluster/unique status was concordant in 84% of the isolates, patients were clustered differently depending on the method. Therefore, the methods are not interchangeable, and the same method should be used for longitudinal studies.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk