24-locus MIRU-VNTR genotyping is a useful tool to study the molecular epidemiology of tuberculosis among Warao Amerindians in Venezuela.
While the gold standard for molecular epidemiological studies on tuberculosis is changing towards MIRU-VNTR typing because this technique generates easily analyzed numerical results, it is less labor intensive and has a discriminative power comparable to that of IS6110-based RFLP, especially when 24 loci are analyzed; more extensive and representative validation studies are needed to confirm this. In this study we genotyped 41 Mycobacterium tuberculosis isolates, about 40% of the total case load of the study year, from the Warao people, an indigenous population who live in a geographically isolated area in Venezuela and have a high TB incidence of 450/100,000. IS6110-based RFLP analysis on these isolates indicates that 78% of the strains are in clusters, suggesting a very high transmission rate. We show that both the 15-locus MIRU-VNTR combined with spoligotyping, as well as the 24-locus MIRU-VNTR typing have sufficient discrimination power (an HGI of 0.93 and 0.95, respectively) to replace IS6110-based RFLP (HGI=0.93) and thus are useful tools to study the molecular epidemiology of tuberculosis in this high TB incidence population.
Laboratorio de Tuberculosis, Instituto de Biomedicina, al lado de Hospital Vargas, San José, Caracas, Venezuela.
Mailis
M
Maes
Kristin
K
Kremer
Dick
D
van Soolingen
Howard
H
Takiff
Jacobus H
JH
de Waard
D016172:DNA Fingerprinting; D005838:Genotype; D006801:Humans; D007199:Indians, South American; D018598:Minisatellite Repeats / Q000235:genetics*; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology* / Q000208:ethnology; D014687:Venezuela / Q000453:epidemiology