Molecular characterization of Sardinian Mycobacterium tuberculosis isolates by IS6110 restriction fragment length polymorphism, MIRU-VNTR and rep-PCR

New Microbiol. 2010 Apr;33(2):155-62.

Abstract

An evaluation of the utility of rep PCR typing compared to the 15 loci discriminatory set of MIRU-VNTR was undertaken. Twenty-nine isolates of Mycobacterium tuberculosis from patients were examined. Genomic DNA was extracted from the isolates by standard method. The number of copies of tandem repeats of the 15 MIRU-VNTR loci was determined by PCR amplification and agarose gel electrophoresis of the amplicons. M. tuberculosis outbreak-related strains were distinguished from other isolates. MIRU-VNTR typing identified 4 major clusters of strains. The same isolates clustered together after RFLP typing, but rep-PCR identified only 3 of them. The concordance between RFLP and MIRU-VNTR typing was complete, with the exception of two isolates with identical RFLP patterns that differed in the number of tandem repeat copies at two MIRU-VNTR alleles. A further isolate, even sharing the same RFLP pattern, differed by one repeat from the rest of its cluster. We also tested the use of an automated rep-PCR for clinical laboratory applications but it failed to identify the link between two pairs of epidemiologically related strains clustered by the other 2 techniques. For superior discrimination, ease of comparison of results and lower cost, MIRU-VNTR typing should be the favored PCR-based typing tool.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Typing Techniques / methods*
  • DNA Transposable Elements / genetics*
  • Humans
  • Italy / epidemiology
  • Minisatellite Repeats / genetics*
  • Molecular Epidemiology
  • Mycobacterium tuberculosis* / classification
  • Mycobacterium tuberculosis* / genetics
  • Mycobacterium tuberculosis* / isolation & purification
  • Polymerase Chain Reaction / methods*
  • Polymorphism, Restriction Fragment Length
  • Tuberculosis* / diagnosis
  • Tuberculosis* / epidemiology
  • Tuberculosis* / microbiology

Substances

  • DNA Transposable Elements