Dados do Trabalho

Título

Genetic diversity based on MIRU-VNTR of a newly Mycobacterium tuberculosis Central-Asia genotype Brazilian Amazonian Region

Introdução

The Mycobacterium tuberculosis (Mtb) Central Asian Strain (CAS) genotype is predominantly found in Afghanistan, Pakistan, North India, Nepal, the Middle East, Libya, Sudan, Ethiopia, Kenya, and Tanzania. The CAS lineage probably originated from the Beijing lineage which is predominant in Asia. Despite being rare in Brazil, through a largely based population study screened by Spoligotyping method, we observed the presence of six clinical Mtb isolates belonging to a newly designated SIT 2545 (CAS lineage), so far exclusive from the State of Para, Brazil, according to the international database SITVIT2.

Objetivo(s)

To access the Brazilian CAS lineage genetic diversity using MIRU-VNTR, the genotyping gold standard method to infer transmissibility and phylogeny.

Material e Métodos

From the stored six isolated DNA samples, we performed the manual duplex 24-loci MIRU-VNTR protocol using 2% agarose gel. The numerical data was added to a Microsoft Excel spreadsheet and the results were analyzed using the MIRU-VNTRplus webtool.

Resultados e Conclusão

Out of 24 loci, five loci (960, 3163b, 2461, 2996, and 3171) presented allelic variability classifying the cohort into two main groups: 1) orphan profile (isolate 431), and 2) a cluster harbording samples 1906, 1918, 2248, 2537, and 2224, being that the last one presented a single locus variation, suggesting that sample 431 do not belong to the same recent transmission chain. Compared to the international database, the six isolates were grouped into a monophyletic branch related to the clade of Delhi/CAS.
We confirmed CAS lineage using spoligotyping and MIRU-VNTR 24-loci, suggesting that the six samples do not belong to the same clone (recent transmission chain). As perspectives we will compare the genotyping and whole-genome sequencing analysis among this population to investigate the evolution of drug resistance, and cluster patterns for transmissibility assessment and discuss the ancestrality based on global phylogenomics.

Palavras-chave

Tuberculosis, Genotyping, Spoligotyping, MIRU-VNTR, Central-Asia.