RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM ANALYSIS OF EPIDEMIOLOGICALLY RELATED MYCOBACTERIUM-TUBERCULOSIS ISOLATES

Restriction fragment length polymorphism (RFLP) analysis of a large nu mber of Japanese isolates of Mycobacterium tuberculosis, containing is olates from small outbreaks of M. tuberculosis infection, and clinical isolates of M. bovis BCG, was carried out using a DNA probe derived f rom the insertion sequence IS 986. Clinical isolates of M. tuberculosi s had a high degree of RFLP. The occurrences of the IS element varied from 1 to 19, the majority of isolates having 8 to 15 copies. Very sim ilar fingerprints, however, were seen among strains isolated in the Ka nto district. In particular, 3 strains were of the same pattern with o r without an additional band. Similarity of the banding patterns of st rains islated in the same district was observed in other areas. Six gr oups of strains, each group arising from a suspected common source of infection, were analyzed. Of these, 5 showed identical fingerprints wi thin each group, but one showed different fingerprints. RFLP patterns of three strains isolated from individuals with lymphadenitis develope d about two months after BCG vaccination, and one strain isolated from a bladder cancer patient with BCG instillation therapy were identical to those of BCG-Tokyo which had been used for the vaccination and the rapy. These results confirm that RFLP analysis using IS 986 is a suita ble tool for epidemiology of tuberculosis.