Molecular typing of Mycobacterium tuberculosis based on variable number of tandem DNA repeats used alone and in association with spoligotyping.
Fingerprinting based on variable numbers of tandem DNA repeats (VNTR), a recently described methodology, was evaluated for molecular typing of Mycobacterium tuberculosis in an insular setting. In this study, VNTR fingerprinting was used alone or as a second-line test in association with spoligotyping, double-repetitive-element PCR (DRE-PCR), and IS6110 restriction fragment length polymorphism (RFLP) analysis, and the discriminatory power for each method or the combination of methods was compared by calculating the Hunter-Gaston discriminative index (HGI). The results obtained showed that in 6 out of 12 (50%) cases, VNTR-defined clusters were further subdivided by spoligotyping, compared to 7 out of 18 (39%) cases where spoligotyping-defined clusters were further subdivided by VNTR. When used alone, VNTR was the least discriminatory method (HGI = 0.863). Although VNTR was significantly more discriminatory when used in association with spoligotyping (HGI = 0.982), the combination of spoligotyping and DRE-PCR (HGI = 0.992) was still the most efficient among rapid, PCR-based methodologies, giving results comparable to IS6110 RFLP analysis. Nonetheless, VNTR typing may provide additional phylogenetical information that may be helpful to trace the molecular evolution of tubercle bacilli.
Filliol
I
I
Unité de la Tuberculose et des Mycobactéries, Institut Pasteur, F-97165 Pointe-à-Pitre Cedex, Guadeloupe.
Ferdinand
S
S
Negroni
L
L
Sola
C
C
Rastogi
N
N
D015373:Bacterial Typing Techniques; D016172:DNA Fingerprinting / Q000379:methods*; D004269:DNA, Bacterial / Q000032:analysis; D006801:Humans; D018598:Minisatellite Repeats / Q000235:genetics*; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics*; D009838:Oligodeoxyribonucleotides / Q000032:analysis*; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D014376:Tuberculosis / Q000382:microbiology*
D004269:DNA, Bacterial; D009838:Oligodeoxyribonucleotides