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A Tuberculose (TB) permanece um grave problema de saúde pública na Comunidade dos Países de Língua Portuguesa (CPLP). Apesar da ampla variância da incidência da TB nos seus estados-membro e de um fluxo migratório contínuo entre os países que integram este grupo, existe uma enorme lacuna no que diz respeito ao conhecimento da estrutura populacional conjunta do Mycobacterium tuberculosis e circulação de estirpes entre estes países. Para fazer face a esta necessidade, foi agregado e analisado o maior conjunto de dados respeitante à diversidade genotípica e resistência fenotípica na CPLP que compreende um total de 1447 isolados clínicos, incluindo 423 isolados multirresistentes de cinco países da CPLP. Por forma a tornar estes dados disponíveis para a comunidade científica e autoridades de saúde pública, foi desenvolvida a CPLP-TB (disponível em http://cplp-tb.ff.ulisboa.pt), uma base de dados disponível online e provida de aplicativos para análise exploratória do conteúdo. Como ferramenta de saúde pública, espera-se que venha a contribuir para um conhecimento mais aprofundado da estrutura populacional do M. tuberculosis e circulação de estirpes na CPLP de forma a apoiar a avaliação de risco e tendências específicas para diversos clones. Tuberculosis (TB) remains a major health problem within the Community of Portuguese Language Speaking Countries (CPLP). Despite the marked variation in TB incidence across its member-states and continued human migratory flux between countries, a considerable gap in the knowledge on the Mycobacterium tuberculosis population structure and strain circulation between the countries still exists. To address this, we have assembled and analyzed the largest CPLP M . tuberculosis molecular and drug susceptibility dataset, comprised by a total of 1447 clinical isolates, including 423 multidrug-resistant isolates, from five CPLP countries. To make this data available to the scientific community and public health authorities we developed CPLP-TB (available at http://cplp-tb.ff.ulisboa.pt), an online database coupled with web-based tools for exploratory data analysis. As a public health tool, it is expected to contribute to improved knowledge on the M. tuberculosis population structure and strain circulation within the CPLP, thus supporting the risk assessment of strain-specific trends. publishersversion published

Rifampicin is one of the most important chemotherapeutic agents used in the treatment of tuberculosis. M. tuberculosis clinical strains resistant to rifampicin harbor mainly mutation in an 81-base pair region of rpoB. These mutations mainly consist of single amino acid substitutions. However insertions also can be related with rifampicin resistance strains. Herein, we described an insertion of 12 nucleotides in clinical isolates of M. tuberculosis resistant to rifampicin, all obtained from inmates. To evaluate the importance this insertion in surviving and drug resistance, it were carried out fitness experimental assays as well as in silico studies of 3D structural models, molecular docking simulations and virtual screening. The medical records of the seven patients showed all were previously treated to tuberculosis. Growth curves shown that the insertion determines a biological cost when compared to wild type rpoB and katG; or the double mutated rpoB S531L and katG S315T. From docking and molecular dynamics simulations it can be inferred that the insertion does not affect the process of synthesis of RNA transcripts. On the other hand, in the mutant RNAP-RIF complex rifampicin confirmed a low affinity interaction for the mutant form. Interesting, virtual screening for potential inhibitors for wtRNAP and mRNAP using a library of 1446 compounds approved by the FDA showed that the best ligands were mainly compounds with antibiotic activity, although the targets involved in the pharmacological action are other than RNAP. In conclusion, seven strains of M. tuberculosis RIF resistant that present an insertion of four amino acids in RNA polymerase showed by growth curve assays, a biological cost. Further, bioinformatics tools had characterized the putative drug resistance dynamic as well as the maintenance of RNA polymerase activity.