DISCRIMINATION OF MYCOBACTERIUM-AVIUM MYCOBACTERIUM-INTRACELLULARE STRAINS BY GENOMIC DNA-FINGERPRINTING WITH A 16S RIBOSOMAL-RNA GENE PROBE

Ribotyping was investigated as a means of distinguishing ten different serotyped reference strains and seven epidemiologically unrelated iso lates of Mycobacterium avium-Mycobacterium intracellulare using a labe lled 16S rDNA probe. Thirteen restriction enzymes were screened toward s an accurate discrimination of strains. Two selected restriction enzy mes (SacI and ClaI) enabled us to classify the 17 strains into ten rib otypes with an index of discrimination of 0.897. Typeability and repro ducibility of the method reached 100%. The patterns obtained exhibited polymorphism of RE fragments within and outside the 16S rRNA gene and may be useful for epidemiological studies.