Conspicuous multidrug-resistant Mycobacterium tuberculosis cluster strains do not trespass country borders in Latin America and Spain

Multidrug-resistant Mycobacterium tuberculosis strain diversity in Ibero-America was examined by comparing extant genotype collections in national or state tuberculosis networks. To this end, genotypes from over 1000 patients with multidrug-resistant tuberculosis diagnosed from 2004 through 2008 in Argentina, Brazil, Chile, Colombia, Venezuela and Spain were compared in a database constructed ad hoc. Most of the 116 clusters identified by IS6110 restriction fragment length polymorphism were small and restricted to individual countries. The three largest clusters, of 116, 49 and 25 patients, were found in Argentina and corresponded to previously documented locally-epidemic strains. Only 13 small clusters involved more than one country, altogether accounting for 41 patients, of whom 13 were, in turn, immigrants from Latin American countries different from those participating in the study (Peru, Ecuador and Bolivia). Most of these international clusters belonged either to the emerging RD(Rio) LAM lineage or to the Haarlem family of M. tuberculosis and four were further split by country when analyzed with spoligotyping and rifampin resistance-conferring mutations, suggesting that they did not represent ongoing transnational transmission events. The Beijing genotype accounted for 1.3% and 10.2% of patients with multidrug-resistant tuberculosis in Latin America and Spain, respectively, including one international cluster of two cases. In brief, Euro-American genotypes were widely predominant among multidrug-resistant M. tuberculosis strains in Ibero-America, reflecting closely their predominance in the general M. tuberculosis population in the region, and no evidence was found of acknowledged outbreak strains trespassing country borders.Fil: Ritacco, Gloria Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Dirección Nacional de Instituto de Investigación.Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"; ArgentinaFil: Iglesias, Maria Jose. Universidad de Zaragoza; EspañaFil: Ferrazoli, Lucilaine. Instituto Adolfo Lutz; BrasilFil: Monteserin, Johana. Dirección Nacional de Instituto de Investigación.Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dalla Costa, Elis R.. Centro de Desenvolvimento Científico e Tecnológico; BrasilFil: Cebollada, Alberto. Universidad de Zaragoza; EspañaFil: Morcillo, Nora Susana. Provincia de Buenos Aires. Ministerio de Salud. Hospital ; ArgentinaFil: Robledo, Jaime. No especifíca;Fil: de Waar, Jacobus H.. Instituto de Biomedicina; VenezuelaFil: Araya, Pamela. Instituto de Salud Pública de Chile; ChileFil: Aristimiño, Liselotte. Universidad Centroccidental Lisandro Alvarado (ucla);Fil: Diaz, Raúl. Instituto Pedro Khouri; CubaFil: Gavin, Patricia. Universidad de Zaragoza; EspañaFil: Imperiale, Belén Rocío. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Simonsen, Vera. Instituto Adolfo Lutz; BrasilFil: Zapata, Elsa M.. No especifíca;Fil: Jiménez, María S.. Instituto de Salud Carlos III. Centro Nacional de Microbiología; EspañaFil: Rossetti, Maria L.. No especifíca;Fil: Martin, Carlos. Universidad de Zaragoza; EspañaFil: Barrera, Lucía. Dirección Nacional de Instituto de Investigación.Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"; ArgentinaFil: Samper, Sofia. Hospital Universitario Miguel Servet; Españ

Correlations of mutations in katG, oxyR-ahpC and inhA genes and in vitro susceptibility in Mycobacterium tuberculosis clinical strains segregated by spoligotype families from tuberculosis prevalent countries in South America

Background Mutations associated with resistance to rifampin or streptomycin have been reported for W/Beijing and Latin American Mediterranean (LAM) strain families of Mycobacterium tuberculosis. A few studies with limited sample sizes have separately evaluated mutations in katG, ahpC and inhA genes that are associated with isoniazid (INH) resistance. Increasing prevalence of INH resistance, especially in high tuberculosis (TB) prevalent countries is worsening the burden of TB control programs, since similar transmission rates are noted for INH susceptible and resistant M. tuberculosis strains. Results We, therefore, conducted a comprehensive evaluation of INH resistant M. tuberculosis strains (n = 224) from three South American countries with high burden of drug resistant TB to characterize mutations in katG, ahpC and inhA gene loci and correlate with minimal inhibitory concentrations (MIC) levels and spoligotype strain family. Mutations in katG were observed in 181 (80.8%) of the isolates of which 178 (98.3%) was contributed by the katG S315T mutation. Additional mutations seen included oxyR-ahpC; inhA regulatory region and inhA structural gene. The S315T katG mutation was significantly more likely to be associated with MIC for INH ≥2 μg/mL. The S315T katG mutation was also more frequent in Haarlem family strains than LAM (n = 81) and T strain families. Conclusion Our data suggests that genetic screening for the S315T katG mutation may provide rapid information for anti-TB regimen selection, epidemiological monitoring of INH resistance and, possibly, to track transmission of INH resistant strains.Fil: Dalla Costa, Elis R. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Ribeiro, Marta O. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Silva, Márcia S. N. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Arnold, Liane S. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Rostirolla, Diana C. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Cafrune, Patricia I. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Espinoza, Roger C. Blufstein Clinic Laboratory; Perú.Fil: Palaci, Moises. Federal University of Espírito Santo; Brasil.Fil: Telles, Maria A. Adolfo Lutz Institute; Brasil.Fil: Ritacco, Viviana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Servicio de Micobacterias; Argentina.Fil: Suffys, Philip N. Oswaldo Cruz Institute; Brasil.Fil: Lopes, Maria L. Evandro Chagas Institute; Brasil.Fil: Campelo, Creuza L. LACEN Ceará; BrasilFil: Miranda, Silvana S. Federal University of Minas Gerais; Brasil.Fil: Kremer, Kristin. National Institute for Public Healthand the Environment (RIVM). Mycobacteria Reference Unit (CIb-LIS); Países Bajos.Fil: Almeida da Silva, Pedro E. Federal Foundation of Rio Grande; Brasil.Fil: de Souza Fonseca, Leila. Federal University of Rio de Janeiro. Tuberculosis Academic Program; Brasil.Fil: Ho, John L. Cornell University; Estados Unidos.Fil: Kritski, Afrânio L. Federal University of Rio de Janeiro. Tuberculosis Academic Program; Brasil.Fil: Rossetti, María L. R. State Foundation for Production and Research in Health (FEPPS); Brasil

Smear plus Detect-TB for a sensitive diagnosis of pulmonary tuberculosis: a cost-effectiveness analysis in an incarcerated population

Background: Prison conditions can favor the spread of tuberculosis (TB). This study aimed to evaluate in a Brazilian prison: the performance and accuracy of smear, culture and Detect-TB; performance of smear plus culture and smear plus Detect-TB, according to different TB prevalence rates; and the cost-effectiveness of these procedures for pulmonary tuberculosis (PTB) diagnosis. Methods: This paper describes a cost-effectiveness study. A decision analytic model was developed to estimate the costs and cost-effectiveness of five routine diagnostic procedures for diagnosis of PTB using sputum specimens: a) Smear alone, b) Culture alone, c) Detect-TB alone, d) Smear plus culture and e) Smear plus Detect-TB. The cost-effectiveness ratio of costs were evaluated per correctly diagnosed TB case and all procedures costs were attributed based on the procedure costs adopted by the Brazilian Public Health System. Results: A total of 294 spontaneous sputum specimens from patients suspected of having TB were analyzed. The sensibility and specificity were calculated to be 47% and 100% for smear; 93% and 100%, for culture; 74% and 95%, for Detect-TB; 96% and 100%, for smear plus culture; and 86% and 95%, for smear plus Detect-TB. The negative and positive predictive values for smear plus Detect-TB, according to different TB prevalence rates, ranged from 83 to 99% and 48 to 96%, respectively. In a cost-effectiveness analysis, smear was both less costly and less effective than the other strategies. Culture and smear plus culture were more effective but more costly than the other strategies. Smear plus Detect-TB was the most cost-effective method. Conclusions: The Detect-TB evinced to be sensitive and effective for the PTB diagnosis when applied with smear microscopy. Diagnostic methods should be improved to increase TB case detection. To support rational decisions about the implementation of such techniques, cost-effectiveness studies are essential, including in prisons, which are known for health care assessment problems

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

Colorimetric microwell plate reverse-hybridization assay for Mycobacterium tuberculosis detection

Direct smear examination using Ziehl-Neelsen staining for pulmonary tuberculosis (PTB) diagnosis is inexpensive and easy to use, but has the major limitation of low sensitivity. Rapid molecular methods are becoming more widely available in centralized laboratories, but they depend on timely reporting of results and strict quality assurance obtainable only from costly commercial kits available in high burden nations. This study describes a pre-commercial colorimetric method, Detect-TB, for detecting Mycobacterium tuberculosis DNA in which an oligonucleotide probe is fixed onto wells of microwell plates and hybridized with biotinylated polymerase chain reaction amplification products derived from clinical samples. The probe is capable of hybridising with the IS6110 insertion element and was used to specifically recognise the M. tuberculosis complex. When combined with an improved silica-based DNA extraction method, the sensitivity of the test was 50 colony-forming units of the M. tuberculosis reference strain H37Rv. The results that were in agreement with reference detection methods were observed in 95.2% (453/476) of samples included in the analysis. Sensitivity and specificity for 301 induced sputum samples and 175 spontaneous sputum samples were 85% and 98%, and 94% and 100%, respectively. This colorimetric method showed similar specificity to that described for commercially available kits and may provide an important contribution for PTB diagnosis