Reproducibility of 15-Loci MIRU-VNTR Method in Mycobacterium tuberculosis Genotyping

Abstract

Background: Mycobacterium tuberculosis genotyping is an essential step for understanding the epidemiology of tuberculosis. Mycobacterial-interspersed-repetitive-units (MIRU)-variable-number-of-tandem-repeats (VNTR) typing is an important method for this purpose. Objectives: The study aimed to determine the reproducibility of 15-loci MIRU-VNTR method. Methods: DNA extraction and 15-loci MIRU-VNTR were carried out for genotyping of 60 M. tuberculosis isolates collected from different clinical samples of 27 M. tuberculosis patients, each with two to four clinical isolates of M. tuberculosis. The similarity of M. tuberculosis isolates of the same patient was investigated by MIRU-VNTRplus. Results: The patterns of MIRU-VNTR were identical in 43 M. tuberculosis isolates collected from 20 tuberculosis patients, giving the repeatability of 71.6% for the test. In 12 isolates of M. tuberculosis belonging to five patients, the variable-number tandem repeat (VNTR) in only one locus was different. In three M. tuberculosis isolates of one patient, two different genotypes were identified. Conclusions: This study confirms the high reproducibility of 15-loci MIRU-VNTR, except for limited cases.

Distribution of Mycobacterium tuberculosis lineages in South America

“…The most advanced technique in the analysis of MTB from clinical samples is WGS, which allows the study of genome microevolution and the preparation of genomic libraries to identify epidemiological events of interest, with greater discrimination when detecting outbreaks, virulence, pathogenesis, transmission chains and mutations associated with resistance to first-and second-line antituberculosis drugs (Guthrie et al, 2019;Meehan et al, 2019). MIRU-VNTR is also a highly stable, fast, reproducible and highly discriminatory technique, which is why it is considered for epidemiological studies, population genetics and phylogenetic studies of pathogens belonging to the Mycobacterium tuberculosis complex (MTBC) (Babai Kochkaksaraei et al, 2019;Jiménez et al, 2017). These two molecular techniques are the most widely used for studying the genotyping of MTB, and MIRU-VNTR is used more often in developing countries of South America than WGS.…”