Discrimination of multidrug-resistant Mycobacterium tuberculosis IS6110 fingerprint subclusters by rpoB gene mutation analysis

The rpoB gene mutations in a 69-bp region of the gene, resulting in resista nce to rifampin, were used to discriminate between Mycobacterium tuberculos is IS6110 fingerprint subclusters, These subclusters exhibited identical IS 6110 fragments or had one or two additional fragments. In the two major sub clusters all the analyzed strains have the same variant rpoB allele but are different from each other, suggesting the occurrence of independent outbre aks.