Restriction fragment length polymorphism analysis of Mycobacterium tuberculosis isolated from patients with pulmonary tuberculosis in northern Tanzania.

Isolates of Mycobacterium tuberculosis from 88 patients with pulmonary tuberculosis in northern Tanzania were subjected to IS6110 restriction fragment length polymorphism (RFLP) analysis. Of 88 isolates, 73 fell into 11 groups of which 9 contained 2-5 isolates. Of 2 large homology groups one, group H (20 isolates), was isolated only from patients resident in the Kilimanjaro region, whereas 79% of isolates from other groups came from this region. A significant association (P = 0.023) was found between another group, M (24 isolates) and isolation from patients of the Masai tribe. The data from this pilot study support the idea that IS6110 RFLP analysis provides information which may be of value in the control of tuberculosis in Africa.

Insertion sequence typing of Mycobacterium tuberculosis: characterization of a widespread subtype with a single copy of IS6110.

DNA fingerprinting with the insertion sequence IS6110 (also known as IS986) has become established as a major tool for investigating the spread of tuberculosis. Most strains of Mycobacterium tuberculosis have multiple copies of IS6110, but a small minority carry a single copy only. We have examined selected strains from Malaysia, Tanzania and Oman, in comparison with M. bovis isolates and BCG strains carrying one or two copies of IS6110. The insertion sequence appears to be present in the same position in all these strains, which suggests that in these organisms the element is defective in transposition and that the loss of transposability may have occurred at an early stage in the evolution of the M. tuberculosis complex.