RAPID, AMPLIFICATION-BASED FINGERPRINTING OF MYCOBACTERIUM-TUBERCULOSIS

Insertion element IS6110 occurs in multiple copies throughout the Myco bacterium tuberculosis genome, and the variability of its insertion si tes is the basis for the IS6110 restriction fragment length polymorphi sm (RFLP) method for typing. We describe a novel gene amplification me thod to assess the variability of the location of IS6110. A unilateral -nested polymerase chain reaction and hybridization procedure was used to measure the variability in the distances between IS6110 elements a nd copies of a major polymorphic tandem repeat sequence of M. tubercul osis. The pattern of amplicons produced could be used to cluster epide miologically related strains of M. tuberculosis into groups which corr elated with the groups formed using IS6110-RFLP typing. Reliable patte rns can be generated directly from sputum specimens as well as from M. tuberculosis cultures. We designated the novel method as IS6110-ampli printing.