Experimental evidence for limited in vivo virulence of Mycobacterium africanum

Funding Information: The authors thank the excellent support from the i3S scientific platforms, namely Animal Facility and Translational Cytometry. Funding. This work was supported by Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 ? Operational Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through Funda??o para a Ci?ncia e a Tecnologia, Minist?rio da Ci?ncia, Tecnologia e Inova??o in the framework of the project ?Institute for Research and Innovation in Health Sciences? (POCI-01-0145-FEDER-007274), and by grants FCT ? Aga Khan Development Network (ref 333197025), POCI-01-0145-FEDER-028955 (to MS), PTDC/BIA-MIC/30692/2017, and UID/Multi/04413/2013 (to DM and MV). BC and KF were funded by FCT Ph.D. scholarships SFRH/BD/114403/2016 and SFRH/BD/114405/2016, respectively. The Gulbenkian Foundation is acknowledged for a field work research grant to BC, Bolsas de apoio ? investiga??o para estudantes de doutoramento dos PALOP, Ref. P-146397. DM and MS were supported by FCT through Estimulo Individual ao Emprego Cient?fico. Publisher Copyright: © Copyright © 2019 Cá, Fonseca, Sousa, Maceiras, Machado, Sanca, Rabna, Rodrigues, Viveiros and Saraiva.Tuberculosis remains a public health problem and a main cause of death to humans. Both Mycobacterium tuberculosis and Mycobacterium africanum cause tuberculosis. In contrast to M. tuberculosis, which is geographically spread, M. africanum is restricted to West Africa. Differences have also been found in the growth rate and type of disease caused by M. africanum, globally suggesting an attenuation of this bacteria. In this study, we used the mouse model of infection to follow the dynamics of M. africanum infection in terms of bacterial burdens and tissue pathology, as well as the immune response triggered. Our findings support a lower virulence of M. africanum as compared to M. tuberculosis, including in mice lacking IFN-γ, a major protective cytokine in tuberculosis. Furthermore, the lung immune response triggered by M. africanum infection in wild-type animals was characterized by a discrete influx of leukocytes and a modest transcriptional upregulation of inflammatory mediators. Our findings contribute to elucidate the pathogenesis of M. africanum, supporting the hypothesis that this is an attenuated member of the tuberculosis-causing bacteria. Understanding the biology of M. africanum and how it interacts with the host to establish infection will have implications for our knowledge of TB and for the development of novel and better tools to control this devastating disease.publishersversionpublishe

MCP1 SNPs and Pulmonary Tuberculosis in Cohorts from West Africa, the USA and Argentina: Lack of Association or Epistasis with IL12B Polymorphisms

The monocyte chemotactic protein-1 (MCP-1) is a chemokine that plays an important role in the recruitment of monocytes to M. tuberculosis infection sites, and previous studies have reported that genetic variants in MCP1 are associated with differential susceptibility to pulmonary tuberculosis (PTB). We examined eight MCP1 single nucleotide polymorphisms (SNPs) in a multi-ethnic, case-control design that included: 321 cases and 346 controls from Guinea-Bissau, 258 cases and 271 controls from The Gambia, 295 cases and 179 controls from the U.S. (African-Americans), and an additional set of 237 cases and 144 controls of European ancestry from the U.S. and Argentina. Two locus interactions were also examined for polymorphisms in MCP1 and interleukin 12B (IL12B), another gene implicated in PTB risk. Examination of previously associated MCP1 SNPs rs1024611 (−2581A/G), rs2857656 (−362G/C) and rs4586 (+900C/T) did not show evidence for association. One interaction between rs2857656 and IL12B SNP rs2288831 was observed among Africans but the effect was in the opposite direction in Guineans (OR = 1.90, p = 0.001) and Gambians (OR = 0.64, p = 0.024). Our data indicate that the effect of genetic variation within MCP1 is not clear cut and additional studies will be needed to elucidate its role in TB susceptibility

Emergence of multidrug-resistant Mycobacterium tuberculosis of the Beijing lineage in Portugal and Guinea-Bissau: a snapshot of moving clones by whole-genome sequencing.

The Beijing genotype comprises a highly disseminated strain type that is frequently associated with multidrug resistant (MDR) tuberculosis (TB) and increased transmissibility but, countries such as Portugal and Guinea-Bissau fall outside the regions phylogeographically associated with this specific genotype. Nevertheless, recent data shows that this genotype might be gradually emerging in these two countries as an underlying cause of primary MDR-TB. Here, we describe the emergence of Mycobacterium tuberculosis Beijing strains associated with MDR-TB in Portugal and Guinea-Bissau demonstrating the presence of the well described superclusters 100-32 and 94-32 in Portugal and Guinea-Bissau, respectively. Genome-wide analysis and comparison with a global genomic dataset of M. tuberculosis Beijing strains, revealed the presence of two genomic clusters encompassing isolates from Portugal and Guinea-Bissau, GC1 (n = 121) and GC2 (n = 39), both of which bore SNP signatures compatible with the 100-32/B0/W148 and 94-32/Central Asia Outbreak clades, respectively. Moreover, GC2 encompasses a cross-border cluster between Portugal, Guinea-Bissau and Brazil thus supporting migration-associated introduction of MDR-TB and subsequent clonal expansion at the community-level. The comparison with global Beijing datasets demonstrates the global reach of the disease and its complex dissemination across multiple countries while in parallel there are clear microevolutionary trajectories towards extensively drug resistant TB

The Guinea-Bissau Family of Mycobacterium tuberculosis Complex Revisited

The Guinea-Bissau family of strains is a unique group of the Mycobacterium tuberculosis complex that, although genotypically closely related, phenotypically demonstrates considerable heterogeneity. We have investigated 414 M. tuberculosis complex strains collected in Guinea-Bissau between 1989 and 2008 in order to further characterize the Guinea-Bissau family of strains. To determine the strain lineages present in the study sample, binary outcomes of spoligotyping were compared with spoligotypes existing in the international database SITVIT2. The major circulating M. tuberculosis clades ranked in the following order: AFRI (n = 195, 47.10%), Latin-American-Mediterranean (LAM) (n = 75, 18.12%), ill-defined T clade (n = 53, 12.8%), Haarlem (n = 37, 8.85%), East-African-Indian (EAI) (n = 25, 6.04%), Unknown (n = 12, 2.87%), Beijing (n = 7, 1.68%), X clade (n = 4, 0.96%), Manu (n = 4, 0.97%), CAS (n = 2, 0.48%). Two strains of the LAM clade isolated in 2007 belonged to the Cameroon family (SIT61). All AFRI isolates except one belonged to the Guinea-Bissau family, i.e. they have an AFRI_1 spoligotype pattern, they have a distinct RFLP pattern with low numbers of IS6110 insertions, and they lack the regions of difference RD7, RD8, RD9 and RD10, RD701 and RD702. This profile classifies the Guinea-Bissau family, irrespective of phenotypic biovar, as part of the M. africanum West African 2 lineage, or the AFRI_1 sublineage according to the spoligtyping nomenclature. Guinea-Bissau family strains display a variation of biochemical traits classically used to differentiate M. tuberculosis from M. bovis. Yet, the differential expression of these biochemical traits was not related to any genes so far investigated (narGHJI and pncA). Guinea-Bissau has the highest prevalence of M. africanum recorded in the African continent, and the Guinea-Bissau family shows a high phylogeographical specificity for Western Africa, with Guinea-Bissau being the epicenter. Trends over time however indicate that this family of strains is waning in most parts of Western Africa, including Guinea-Bissau (p = 0.048)

Tuberculosis across the seas: CPLP-TB - a joint effort in cataloguing mycobacterium tuberculosis genetic diversity in the lusophone space

The Community of Portuguese Language Speaking Countries (CPLP) comprises nine countries across four continents, accounting for 7.2% of the world’s land area, and where tuberculosis (TB) is still a cause of public health concern. A marked variation in TB incidence (23 to 551 cases per 100 000 habitants) can be observed across the different member-states and, despite of this, a considerable gap in the knowledge on the Mycobacterium tuberculosis population structure and country-level geospatial distribution still exists. To address this we have gathered a comprehensive set of molecular and phenotypic drug susceptibility data on approximately 1150 different clinical isolates, from different partners, across 5 distinct portuguesespeaking countries. This initial dataset comprises molecular genotypic data obtained by either 12, 15 or 24-loci Mycobacterial Interspersed Repetitive Unit – Variable Number of Tandem repeat (MIRU-VNTR) and/or Spoligotyping. The complete dataset therefore includes M. tuberculosis clinical isolates from Portugal (n≈370), Angola (n≈80), Guinea-Bissau (n≈13), Mozambique (n≈14) and Brazil (n≈680). To make this data available to the scientific community and public health authorities we have developed CPLP-TB, an online database coupled with webbased tools that enable exploratory data analysis. This new tool specifically directed at CPLP countries include advanced data analysis capability together with graphical visualization tools (e.g. dendrogram and choropleth mapping). As a public health tool, it is expected to contribute for a deeper knowledge on the combined population structure and strain circulation between countries, thus enabling the assessment of strain specific trends in a broader macroepidemiological context. Furthermore, this new tool provides a new framework for interlaboratory cooperation on TB molecular epidemiology.N/

Clonal expansion across the seas as seen through CPLP-TB database: A joint effort in cataloguing Mycobacterium tuberculosis genetic diversity in Portuguese-speaking countries.

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 analysed 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. The data herein presented reinforces Latin American and Mediterranean (LAM) strains as the hallmark of M. tuberculosis populational structure in the CPLP coupled with country-specific differential prevalence of minor clades. Moreover, using high-resolution typing by 24-loci MIRU-VNTR, six cross-border genetic clusters were detected, thus supporting recent clonal expansion across the Lusophone space. 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

uma nova ferramenta de vigilância transnacional da tuberculose no espaço lusófono

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.publishersversionpublishe