Genetic variation and evolutionary origin of the direct repeat locus of Mycobacterium tuberculosis complex bacteria.

ABSTRACT: The direct repeat region in Mycobacterium tuberculosis complex strains is composed of multiple direct variant repeats (DVRs), each of which is composed of a 36-bp direct repeat (DR) plus a nonrepetitive spacer sequence of similar size. It has been shown previously that clinical isolates show extensive polymorphism in the DR region by the variable presence of DVRs, and this polymorphism has been used in the epidemiology of tuberculosis. In an attempt to better understand the evolutionary scenario leading to polymorphic DR loci and to improve strain differentiation by spoligotyping, we characterized and compared the DNA sequences of the complete DR region and its flanking DNA of M. tuberculosis complex strains. We identified 94 different spacer sequences among 26 M. tuberculosis complex stra

SUBMITTER: van Embden JD 

PROVIDER: S-EPMC111299 | biostudies-literature | 2000 May

REPOSITORIES: biostudies-literature