Epidemiologia molecular e perfil de resistência de Mycobacterium tuberculosis em regiões de fronteira do Brasil

Abstract

Brazil is one of the countries with the highest incidence rate of tuberculosis (TB) in the world. Border regions favor the dissemination of Mycobacterium tuberculosis (MTB) due to the presence of high-risk groups and constant population flow, these factors favor the emergence of TB drug-resistant cases. The objective of this study was to perform the molecular and epidemiological characterization of MTB isolated from two Brazilian states located in border regions (Roraima and Mato Grosso do Sul) to identify the variables associated with the disease transmission. In addition, the study evaluated the antimicrobial resistance profile and the molecular mechanisms involved. From January/2014 and April/2017 282 MTB strains were isolated. The epidemiological data were collected thought a questionnaire and Sistema de Informação de Agravos e Notificação. Drug susceptibility profiles were performed using phenotypic methods and GeneXpert®. Resistant strains were submitted to the investigation of mutational events in rpoB, katG, inhA, rrs, rpsL and gidB genes. The genetic similarity of the isolates and the recent transmission was assessed using IS6110-RFLP, Spoligotyping, MIRU-VNTR 24 loci and Genome Sequencing. In Roraima, the isolates presented high genetic diversity and the most prevalent lineages were LAM, H and T. MIRU-VNTR and RFLP-IS6110 presented transmission rates of 21.3% and 30%, respectively. Drug resistance was detected in 15.1% isolates, all with primary resistance. This was the first study to describe the molecular epidemiology and drug resistance profile in this state. In Mato Grosso do Sul, a high rate of recent resistant transmission was observed (30%); in addition, 78% of TB resistant cases were new cases - high rate of primary resistance. Alcoholism was associated with strains drug-resistant in genomically unique profiles. Incarceration is a major contributor to the spread of TB drug-resistant, considering that 40% of cases with identical profiles were related to prisoners or ex-prisoners. Prisoners had more chances to acquiring TB drug-resistant than the general population (OR=7.05). In conclusion borders regions are important in the dissemination of TB and although have common characteristics, they also have particularities, requiring the implementation of distinct epidemiological surveillance in these regions.