[Application of RFLP to typing strains of Mycobacterium tuberculosis].

BACKGROUND

Typing of Mycobacterium tuberculosis strains using RFLP (Restriction Fragments Length Polymorphism) had been shown to be useful for the detection of tuberculosis outbreaks in different countries.

METHODS

A non-radioactive hybridization technique with the insertion sequence IS6110 has been used for typing M. tuberculosis strains. This technique detects polymorphism in the genome of M. tuberculosis following digestion with the restriction enzyme PvuII, and hybridisation with IS6110.

RESULTS

One hundred and fourteen strains of M. tuberculosis isolated from Hospital Clínico Universitario (HCU) of Zaragoza, have been typed. Identical banding patterns were obtained in successive isolates from the same patient (at different times or from different culture sites) as was the case with some strains isolated in the same geographical location. The latter may be interpreted as a possible outbreak or perhaps a higher prevalence of a particular strain type in certain areas.

CONCLUSIONS

The high level of polymorphism observed in the strains of M. tuberculosis isolated in HCU of Zaragoza, allows their typing using RFLP. The standardised use of this technique in different Spanish hospitals may allow the detection of outbreaks, which is of special interest for multiresistant strains of M. tuberculosis.