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.
Maes
Mailis
M
Laboratorio de Tuberculosis, Instituto de Biomedicina, al lado de Hospital Vargas, San José, Caracas, Venezuela.
Kremer
Kristin
K
van Soolingen
Dick
D
Takiff
Howard
H
de Waard
Jacobus H
JH
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