Typing Method for the QUB11a Locus of Mycobacterium tuberculosis: IS6110 Insertions and Tandem Repeat Analysis

Abstract EN

QUB11a is used as a locus for variable number of tandem repeats (VNTR) analysis of Mycobacterium tuberculosis Beijing lineage.

However, amplification of QUB11a occasionally produces large fragments (>1,400 bp) that are not easily measured by capillary electrophoresis because of a lack of the typical stutter peak patterns that are used for counting repeat numbers.

IS6110 insertion may complicate VNTR analysis of large QUB11a fragments in M.

tuberculosis.

We established a method for determining both tandem repeat numbers and IS6110 insertion in the QUB11a locus of M.

tuberculosis using capillary electrophoresis analysis and BsmBI digestion.

All 29 large QUB11a fragments (>1,200 bp) investigated contained IS6110 insertions and varied in the number of repeats (18 patterns) and location of IS6110 insertions.

This method allows VNTR analysis with high discrimination.