Dados do Trabalho

Título

Genotipagem por MIRU-VNTR 24-loci e Distribuição Geoespacial de Estirpes de Mycobacterium tuberculosis Monorresistentes a Isoniazida

Introdução

The increase in drug-resistant strains is one of the biggest challenges in controlling tuberculosis (TB). The resistance to isoniazid (INH), mono-resistance (mono-HR) or associated with another antimicrobial, is worrying, as it can significantly reduce the effectiveness of the treatment. Worldwide, it is estimated that 8% of TB cases are mono-HR, similar to what was found in the city of Rio de Janeiro (RJ). An aggravating factor is that the Xpert Ultra rapid molecular test does not identify this resistance, making adequate management of the disease difficult

Objetivo (s)

. This study seeks to evaluate the diversity of Mtb lineages circulating in RJ between 2015 and 2019, focusing on analyzing the transmission pattern of mono-HR strains.

Material e Métodos

All mono-HR Mtb strains cryopreserved at -80°C from respiratory specimens were subcultured in LJ medium. After this, mycobacterial DNA was extracted from the strains using the GenoLyse kit (Hain Lifescience) and subjected to genotyping by MIRU-VNTR 24-loci using the ABI3130 sequencing platform. The numerical profiles were added to a Microsof Excel spreadsheet, analyzed on the TBminer NG and MIRU-VNTRplus digital platforms for lineage identification and grouping analysis (clonal complex-CC), respectively. 

Resultados e Conclusão

. 142 mono-HR strains were detected, however, only 139 presented a profile with results for at least 13 loci. Of these, the lineage profile was: LAM 86 (61.87%), Haarlem 28 (20.14%), Cameroon 7 (5.04%), UgandaI 6 (4.32%), X 4 (2.88%), S 3 (2.16%), T1 3 (2.16%), EAI 1 (0.72%) and Ghana 1 (0.72%). Of the 139 samples, 71 (51.07%) were grouped into 14 CC and 67 (48.20%) exhibited unique profiles when considering a variation of up to 2-loci difference. These data suggest that mono-RH TB maybe being transmitted rather than occurring solely in intrahost events. The geospatial distribution showed that a cluster of mono-INH cases in the Complexo do Alemão region, and the distribution of cases based on the 14 CC demonstrated that CC-8 were observed in the Anchieta and Pavuna region, neighboring sub-districts, the CC -1, although widely distributed in RJ, was mainly clustered on Ilha do Governador. Most CC-1 cases are in homeless people

Palavras Chave

Tuberculosis; Isoniazid; monoresistance; transmission; Genotyping; MIRU-VNTR 24-loci; leishmaniose