Genes y determinantes de virulencia de Mycobacterium tuberculosis que contribuyen a la evasión de la respuesta inmune / Mycobacterium tuberculosis genes and virulence determinants that contribute to the immune response evasion

La tuberculosis pulmonar es un problema de salud pública a nivel mundial. La Organización Mundial de la Salud en el año 2018 reportó alrededor de 10 millones de enfermos y 1,5 millones de muertes. Mycobacterium tuberculosis es un patógeno intracelular y el agente causal de la enfermedad. Estudios experimentales de virulencia han permitido determinar un conjunto de genes de virulencia, que le confieren la capacidad de resistir el ambiente hostil en el macrófago, superar la actividad de la respuesta inmune y persistir en el hospedero. El objetivo de la publicación es presentar una revisión de las investigaciones de los últimos 20 años que han demostrado los genes o factores de virulencia de M. tuberculosis que contribuyen a la evasión de la respuesta inmune. Según los resultados de las investigaciones, existen múltiples factores y genes de virulencia que participan en la evasión de la respuesta inmune innata como ESAT-6, PknG, PhoP, ManLAM, SapM, katG, tpx, nuoG, sodA/secA2, pknE y Rv3654c/Rv3655c, mientras existen elementos capaces de modular la respuesta inmune adaptativa. La comprensión de la interacción entre los genes de virulencia y la actividad del sistema inmune, son importantes para estudiar nuevos métodos de diagnóstico, el diseño de nuevas vacunas y por ende, mejorar las medidas de control, prevención y tratamiento de la tuberculosis(AU)

Pulmonary tuberculosis is a public health problem worldwide. The World Health Organization in 2018 reported about 10 million patients and 1.5 million deaths. Mycobacterium tuberculosis, an intracellular pathogen, is the causative agent of the disease. Experimental virulence studies have allowed to determine a set of virulence genes that confer the ability to resist the hostile environment in the macrophage, overcome the activity of the immune response and persist in the host. The objective of the publication is to present a review of the last 20 years investigations that have shown the genes or virulence factors of M. tuberculosis that contribute to the evasion of the immune response. According to the results of the investigations, there are multiple virulence factors and genes that participate in the evasion of the innate immune response such as ESAT-6, PknG, PhoP, ManLAM, SapM, katG, tpx, nuoG, sodA/secA2, pknE and Rv3654c/Rv3655c, while there are elements capable of modulating the adaptive immune response. The understanding of the interaction between the virulence genes and the activity of the immune system, are important to study new diagnostic methods, the design of new vaccines and therefore, to improve the control, prevention and treatment measures of tuberculosis(AU)

Identificación y estudio de susceptibilidad antimicrobiana en cepas de mycobacterium spp. aisladas en un hospital de alta complejidad / Identification and study of antimicrobial susceptibility of isolated mycobacterium spp. strains in a hospital of high complexity

El género Mycobacterium se encuentra asociado a una cantidad importante de patologías, donde la tuberculosis destaca dentro de los principales problemas de salud pública a nivel mundial y nacional. Esta se agudiza con el incremento en la resistencia antimicrobiana y, por ello, la pesquisa de micobacterias contempla un pilar fundamental en el diagnóstico de patologías infecciosas de importancia clínica. Por lo tanto, el objetivo fue describir las principales especies de micobacterias aisladas y su patrón de susceptibilidad a partir de muestras clínicas procesadas en el Hospital Dr. Hernán Henríquez Aravena durante el año 2012. Se realizó un estudio descriptivo retrospectivo, en donde se utilizaron los resultados de 7023 baciloscopías procesadas en el Laboratorio Clínico del Hospital Dr. Hernán Henríquez Aravena de Temuco el año 2012. Todas las baciloscopías fueron analizadas y solicitadas según criterios establecidos por el Instituto de Salud Pública de Chile, comprendiendo muestras de expectoración y no expectoración. De las 7023 baciloscopías realizadas, 100 resultaron ser positivas para Mycobacterium. De 21 cepas enviadas al Instituto de Salud Pública de Chile para identificación, 19 cepas corresponden al complejo Mycobacterium tuberculosis y dos a Mycobacterium avium intracelular. En el estudio de sensibilidad, se encontró resistencia a estreptomicina e isoniazida en 13,3 % de las expectoraciones. De acuerdo a lo establecido por la literatura, más del 90 % pertenecen a Mycobacterium tuberculosis, mientras que, de las micobacterias no tuberculosas sólo se aislaron Mycobacterium avium intracelular. Los antimicrobianos con mayores niveles de resistencia son estreptomicina e isoniazida.

The genus Mycobacterium is associated with a significant number of pathologies, where tuberculosis stands out among the main public health problems worldwide and nationally. This is exacerbated by the increase in antimicrobial resistance and, therefore, the research of mycobacteria contemplates a fundamental pillar in the diagnosis of infectious pathologies of clinical importance. Therefore, the aim was to describe the main species of isolated mycobacteria and their susceptibility pattern from clinical samples processed at the Dr. Hernán Henríquez Aravena Hospital during 2012. A retrospective descriptive study was carried out, where the results of 7023 sputum microscopy processed in the Clinical Laboratory of the Dr. Hernán Henríquez Aravena Hospital in Temuco in 2012. All sputum microscopy was analyzed and requested according to criteria established by the Instituto de Salud Pública of Chile, including expectoration and non-sputum samples. Of the 7023-sputum microscopy performed, 100 were positive for Mycobacterium. Of 21 strains sent to the Instituto de Salud Pública of Chile for identification, 19 strains correspond to the Mycobacterium tuberculosis complex and two to intracellular Mycobacterium avium. In the sensitivity study, resistance to streptomycin and isoniazid was found in 13.3 % of the expectorations. According to what is established by the literature, more than 90 % belong to Mycobacterium tuberculosis, while only intracellular Mycobacterium avium was isolated from non-tuberculous mycobacteria. Antimicrobials with higher levels of resistance are streptomycin and isoniazid.

Fast detection of Mycobacterium tuberculosis in culture-positive sputum samples by nitrate reductase activity

ABSTRACT Microscopy and bacterial culture are the main tools in the diagnosis of tuberculosis. Since the slow growth of Mycobacterium tuberculosis impairs rapid diagnosis strategies, especially in countries where the latter are the only available resources, the ongoing development of new and inexpensive tools based on mycobacterial metabolism optimizing growth detection with preliminary identification is greatly welcome. When compared to the other species from the M. tuberculosis complex, M. tuberculosis is a strong nitrate reducer. Current assay compares the nitrate reductase activity of M. tuberculosis from pulmonary specimens cultivated in nitrate-supplemented media. Fifty-five sputum samples were decontaminated and inoculated in conventional (Middlebrook 7H9, Ogawa Kudoh-OK) and in nitrate-supplemented media (Middlebrook 7H9-N, Ogawa Kudoh-N). An aliquot from the media directly reacted with Griess reagent (7H9-N and OK-N) every five days, or transferred to a nitrate substrate solution (7H9, OK). Nitrate to nitrite reduction was considered positive, revealed by the pink color, indicating bacterial growth. As reference method, the Mycobacteria Growth Indicator Tube (MGIT) was used for sensitivity calculations and statistical analysis. 7H9-N and OK-N assays proved to perform better in detecting M. tuberculosis than conventional assays (7H9 and OK). Indeed, broth nitrate-supplemented medium (7H9-N) was comparable to MGIT to detect M. tuberculosis, except in growth detection time. Results show that 7H9-N may be used as an alternative tool particularly in low-income countries since it is a simple and cheap technique, and does not restrict diagnosis to single-source products.

Type-2 diabetes alters the basal phenotype of human macrophages and diminishes their capacity to respond, internalise, and control Mycobacterium tuberculosis

BACKGROUND Type 2 diabetes (T2D) is a risk factor for the development of tuberculosis (TB), although the associated mechanisms are not known. OBJECTIVES To study the association between T2D and the basal phenotype of macrophages, and their immune response to Mycobacterium tuberculosis (Mtb) infection. METHODS We evaluated the influence of T2D on the response of monocyte-derived macrophages (MDM) to Mtb in patients with T2D (n = 10) compared to healthy subjects (n = 9), before and after infection with Mtb clinical isolates bearing different degrees of virulence. The levels of cell surface markers for activation secreted cytokines and chemokines, bacterial association, and intracellular bacterial growth were evaluated. FINDINGS The expression levels of HLA-DR, CD80, and CD86 were low while those of of PD-L1 were high in uninfected MDMs derived from patients with diabetes; as a result of Mtb infection, changes were only observed in the expression levels of PD-L1. The levels of cytokines (e.g., IL-6, IL-1β, IL-10, and IL-12) and chemokines (e.g., MCP-1, MIG, and RANTES) are perturbed in MDMs derived from patients with diabetes, both before infection and in response to Mtb infection. In response to the more virulent Mtb strains, the levels of association and bacterial clearance were diminished in MDMs derived from patients with diabetes. CONCLUSIONS T2D affects the basal activation state of the macrophages and its capacity to respond and control Mtb infection.

Construction of Mycobacterium tuberculosis cdd knockout and evaluation of invasion and growth in macrophages

Cytidine deaminase (MtCDA), encoded by cdd gene (Rv3315c), is the only enzyme identified in nucleotide biosynthesis pathway of Mycobacterium tuberculosis that is able to recycle cytidine and deoxycytidine. An M. tuberculosis knockout strain for cdd gene was obtained by allelic replacement. Evaluation of mRNA expression validated cdd deletion and showed the absence of polar effect. MudPIT LC-MS/MS data indicated thymidine phosphorylase expression was decreased in knockout and complemented strains. The cdd disruption does not affect M. tuberculosis growth both in Mid- dlebrook 7H9 and in RAW 264.7 cells, which indicates that cdd is not important for macrophage invasion and virulence.

Tuberculosis among prison staff in Rio Grande do Sul / Tuberculosis entre los profesionales de las prisiones en Rio Grande do Sul / Tuberculose entre profissionais de penitenciárias do Rio Grande do Sul

ABSTRACT Objective: to evaluate the risk of infection and illness caused by Mycobacterium tuberculosis among health care and security staff in prisons in two regions of Rio Grande do Sul (RS). Method: cross-sectional study involving prison staff. An interview and sputum smear microscopy and culture were performed. Latent infection was evaluated according to the result of the tuberculin test (TT), self-referred. Results: among staff who had a TT, 10 (83.3%) in the central region and 2 (16.7%) in the southern region were considered reactors. Length of employment among prison officers who reacted to TT was 15.3 years, and among health care workers, 4.1 years (p = 0.01). No cases of active tuberculosis (TB) were identified. Conclusion: prevalence of latent TB was 27.9%. Length of employment between different professional categories and their working regions was considered a risk factor for latent TB.

RESUMEN Objetivo: evaluar el riesgo de infección y de la enfermedad por Mycobacterium tuberculosis entre los profesionales de la salud y seguridad en los centros penitenciarios en dos regiones del estado de Rio Grande do Sul (RS). Método: estudio transversal con la participación de profesionales de la prisión. Se llevó a cabo una entrevista, la baciloscopia y cultivo de esputo. La infección latente se evaluó de acuerdo con el resultado de la prueba de la tuberculina (TST) mediante auto-reporte. Resultados: entre los trabajadores que realizaron la TST en la región central, 10 (83,3%) fueron considerados reactores; y 2 (16,7%) en la región Sur. El tiempo de trabajo entre los agentes de la prisión con reacción a la TST fue de 15,3 años, y entre los trabajadores de la salud fue de 4,1 años (p = 0,01). No hubo casos identificados de la tuberculosis (TB) activa. Conclusión: la prevalencia de la TB latente fue del 27,9%. El tiempo de trabajo entre las diferentes categorías profesionales y la región en la que trabajan fueron considerados factores de riesgo para la TB latente.

RESUMO Objetivo: avaliar o risco de infecção e adoecimento por Mycobacterium tuberculosis entre profissionais de saúde e de segurança em casas penitenciárias de duas regiões do Rio Grande do Sul (RS). Método: estudo transversal, envolvendo profissionais de penitenciárias. Foi realizada uma entrevista, baciloscopia e cultura de escarro. A infecção latente foi avaliada de acordo com o resultado do teste tuberculínico (TT), auto-referido. Resultados: entre os trabalhadores que realizaram o TT na região central, 10 (83,3%) foram considerados reatores; e na região sul, 2 (16,7%). O tempo de trabalho entre os agentes penitenciários reatores ao TT foi 15,3 anos e entre os trabalhadores da saúde 4,1 anos (p = 0,01). Não foram identificados casos de Tuberculose (TB) ativa. Conclusão: a prevalência de TB latente foi 27,9%. O tempo de trabalho entre as diferentes categorias profissionais e a região em que trabalham foram considerados fator de risco para TB latente.

Análisis genómico comparativo de cepas peruanas de Mycobacterium tuberculosis / Comparative genomic analysis of peruvian strains of Mycobacterium tuberculosis

RESUMEN Objetivos. Analizar comparativamente tres secuencias genómicas de Mycobacterium tuberculosis(MTB): INS-SEN,cepa sensible; INS-MDR, cepa multidrogorresistente e INS-XDR, cepa extensamente resistente, procedentes de la Ciudad de Lima, Perú. Materiales y métodos. Se identificaron los polimorfismos de un solo nucleótido (SNPs) específicos en las cepas INS-SEN, INS-MDR y INS-XDR mediante el criterio de inclusión/exclusión. Se compararon los tres genomas de MTB y se construyó una filogenia molecular con 27 cepas de MTB de otros estudios, disponibles de la base de datos Genbank. Los SNPs específicos en cada genoma fueron organizados en clústers de grupos ortólogos (COGs). Resultados. El análisis de genomas permitió identificar un conjunto de SNPs asociados a determinantes de virulencia (familia de proteínas mce, policetidos, phiRv1, transposasas, metiltransferasas y relacionados a síntesis de vitaminas) principalmente. Se observa una estrecha relación entre la cepa INS-MDR y INS-XDR, con solo un 6,1% de SNPs diferentes, sin embargo, la cepa INS-SEN presenta un 50,2 y 50,3% de SNPs diferentes a las cepas MDR y XDR, respectivamente. La filogenia molecular agrupó a las cepas peruanas dentro del linaje LAM y cercanamente a las cepas F11 y KZN de Sudáfrica. Conclusiones . Se evidenció una alta similitud (99,9%) de la cepa INS-SEN con la cepa sudafricana F11, de gran alcance mundial, mientras los análisis de las cepas INS-MDR e INS-XDR demuestran una probable expansión de la familia KZN, cepa de Sudáfrica con alta virulencia y patogenicidad.

ABSTRACT Objectives. To comparatively analyze three genomic sequences of Mycobacterium tuberculosis(MTB), including sensitive (INS-SEN), multi-drug-resistant (INS-MDR), and extremely drug-resistant (INS-XDR) strains, collected in Lima, Peru. Materials and Methods. Specific single nucleotide polymorphisms (SNPs) were identified in the INS SEN, INS-MDR, and INS-XDR strains according to the inclusion/exclusion criteria. The three MTB genomes were compared and a molecular phylogeny was constructed with 27 MTB strains from other studies available from the Genbank database. Results. The specific SNPs in each genome were organized in clusters of orthologous groups (COGs). The genomic analysis allowed for the identification of a set of SNPs associated mainly with virulence determinants (family of mce proteins, polyketides, phiRv1, transposase, and methyltransferases, and other related to vitamin synthesis). A close correlation between the INS-MDR and INS-XDR strains was observed, with only a 6.1% difference in SNPs; however, the INS-SEN strain had 50.2% and 50.3% different SNPs from the MDR and XDR strains, respectively. The molecular phylogeny grouped the Peruvian strains within the LAM lineage and closely to the F11 and KZN strains from South Africa. Conclusions. High similarity (99.9%) was noted between the INS-SEN strain and the F11 South African strain with broadglobal scope, while the analysis of the INS-MDR and INS-XDR strains showed a likely expansion of the KZN family, a South African strain with high virulence and pathogenicity.

Zoonotic tuberculosis: A comprehensive one health approach

The objective of this report is to provide information on Mycobacterium tuberculosis complex infections in animals and in humans. Included is information on the susceptibility of different species as well as information on etiology, epidemiology, pathogenesis, diagnosis, prevention and control of this disease. The term One Health has been adopted to describe the unified human medical and veterinary interdisciplinary/multidisciplinary collaborative approach to zoonoses and will be critical for future endeavors in the control of the global TB epidemic. This unified paradigm is ideally suited for control of bovine TB and many other international public health and clinical health issues. Sharing resources and increasing interaction between public health and veterinary medical scientists can raise awareness of ‘shared risk' of bovine TB between humans and animals and, in resource-limited situations, can maximize use of existing infrastructure and reduce unnecessary duplication of effort in disease control programs.

El objetivo de este artículo es proporcionar información sobre las infecciones por el Complejo Mycobacterium tuberculosis en animales y en humanos. Se incluye información sobre la susceptibilidad de diferentes especies, así como sobre la etiología, epidemiología, patogenia, diagnóstico, prevención y control de esta enfermedad. La expresión UNA SALUD ha sido adoptada para describir el enfoque unificado de la medicina humana y la veterinaria, de colaboración interdisciplinaria/multidisciplinaria en las zoonosis, que puede resultar fundamental para el control de la endemia mundial de tuberculosis. Este paradigma unificado es especialmente relevante para el control de la tuberculosis bovina. Compartir recursos y lograr una mayor interacción entre la investigación en salud pública y en medicina veterinaria puede elevar la conciencia de “riesgo compartido” de la tuberculosis bovina en humanos y animales y, en situaciones de recursos limitados, puede maximizar el uso de la infraestructura existente y reducir la duplicación innecesaria de esfuerzos en los programas de control de la infección y enfermedad.

Morbi-mortalidad en pacientes con infección por Mycobacterium tuberculosis comprobada, y co-infección VIH-Tuberculosis en Hospital Roosevelt en Guatemala / Morbi-mortality in patients with proved Mycobacterium tuberculosis infections, co-infected and no co-infected with HIV, at Roosevelt Hospital in Guatemala

Tuberculosis (TB) es la enfermedad oportunista más importante relacionada con VIH, provocando manifestaciones clínicas graves y con frecuencia diseminadas, y afección extrapulmonar. En Guatemala es la principal causa de muerte en pacientes con Sida. OBJETIVO: Determinar la morbi-mortalidad en pacientes hospitalizados con Tuberculosis en Hospital Roosevelt. MÉTODOS: Se incluyeron pacientes con diagnóstico comprobado por tests microbiológicos positivos para Mycobacterium tuberculosis, mayores de 12 años de edad, ingresados en los servicios de Medicina interna durante el año 2013. Se consideraron positivos los pacientes con frotes de ZN, prueba de PCR-RT (GeneXpert de Cepheid). Se colectaron los datos clínicos y epidemiológicos de los pacientes con un instrumento estandarizado de manera prospectiva, generándose una base de datos en Excel 2010 y realizando el análisis estadístico con: SPSS21...(AU)

Introduction: Tuberculosis (TB) is the main opportunistic infection related to HIV, causing complex and serious disease, frequently, extra-pulmonary in HIV patients. In Guatemala it represents the main cause of death in AIDS patients and with an increased incidence in patients with other co-morbidities. OBJECTIVE: To determine the morbi-mortalily in admitted patients in internal medicine wards with tuberculosis at Roosevelt Hospital in Guatemala City. METHODOLOGY: Patients with proved infection by clinical and/or culture/PCR-RT positive to Mycobacterium tuberculosis were included, older than 12 years old, admitted to the internal medicine guards, which presented positive culture and/or ZN smears and/or PCR-RT (GeneXpert, Cepheid) positive tests in 2013. Clinical and epidemiological data were collected in a prospective manner, with a standardized instrument, generating an Excel 2010 data base that was analyzed by SPSS21. RESULTS: 200 patients were included, 61% males with man: woman ratio of 1.5:1. 48% presented HIV coinfection. 54% of the patients aged: 25 to 44 years old. 43% residents outside Guatemala City. The extra pulmonary TB was present in 65%. The highest mortality was observed in TB-HIV co-infected patients: 30.2% versus 10. % in lung cases (p=0.001). 2.1% died in the first 24 hours after admission, 13.5% between 1-7 days; 14.6% after 7 days of hospital stay, (p=0.002). Regarding the CD4 count, the higher mortality index was shown in the cases <100cel/mL 28.12%, versus 2.08% in > 100 (p=0.0001). CONCLUSSIONS: In a reference center like Roosevelt Hospital, the coinfection HIV-TB represents 48% of the TB cases. Mortality was higher in extrapulmonary TB and HIV patients with <100 CD4 counts

Historia natural de la tuberculosis, fisiopatogenia de la infección y la enfermedad en el niño / Natural history of tuberculosis, infection and disease pathogenesis in children

The multiple manifestations of tuberculosis (TB) are a result of the relationships between Mycobacterium tuberculosis, the host and the environmental, social and cultural conditions. In TB pathogenesis, three factors must be considered: the virulence of the bacillus, the potential of cellular destruction and caseous necrosis, and the immune response and hypersensitivity to the infection.

La expresión múltiple de la tuberculosis se debe a la relación entre el Mycobacterium tuberculosis, el huésped y las condiciones medioambientales, sociales y culturales. En la patogenia de la tuberculosis se deben tener en cuenta tres factores: la virulencia del bacilo, la capacidad de producir destrucción celular y necrosis caseosa y la respuesta inmunitaria e hipersensibilidad a la infección.

Whole-body magnetic resonance imaging in children: state of the art / Ressonância magnética de corpo inteiro em pediatria: estado da arte

Whole-body imaging in children was classically performed with radiography, positron-emission tomography, either combined or not with computed tomography, the latter with the disadvantage of exposure to ionizing radiation. Whole-body magnetic resonance imaging (MRI), in association with the recently developed metabolic and functional techniques such as diffusion-weighted imaging, has brought the advantage of a comprehensive evaluation of pediatric patients without the risks inherent to ionizing radiation usually present in other conventional imaging methods. It is a rapid and sensitive method, particularly in pediatrics, for detecting and monitoring multifocal lesions in the body as a whole. In pediatrics, it is utilized for both oncologic and non-oncologic indications such as screening and diagnosis of tumors in patients with genetic syndromes, evaluation of disease extent and staging, evaluation of therapeutic response and post-therapy follow-up, evaluation of non neoplastic diseases such as multifocal osteomyelitis, vascular malformations and syndromes affecting multiple regions of the body. The present review was aimed at describing the major indications of whole-body MRI in pediatrics added of technical considerations.

A avaliação de corpo inteiro em crianças era classicamente realizada com radiografias simples, cintilografia e tomografia por emissão de pósitrons combinada ou não à tomografia computadorizada, estes com a desvantagem de exposição à radiação ionizante. A ressonância magnética de corpo inteiro (RMCI), associada ao desenvolvimento de técnicas metabólicas e funcionais como difusão, trouxe a vantagem de uma avaliação global do paciente pediátrico sem os riscos da radiação ionizante habitualmente presente nos métodos radiológicos convencionais. A RMCI é um método rápido e sensível, com aplicação especial na área de pediatria na detecção e no monitoramento de lesões multifocais no corpo como um todo. Em pediatria, esta técnica é utilizada tanto em oncologia - no diagnóstico e rastreamento de tumores em pacientes portadores de síndromes genéticas, na avaliação da extensão de doenças e estadiamento oncológico, na avaliação da resposta terapêutica e no seguimento pós-terapêutico - como em lesões não neoplásicas - osteomielite multifocal, malformações vasculares e síndromes que comprometam múltiplas regiões do corpo. Esta revisão tem como objetivo mostrar as principais indicações do exame na população pediátrica e técnica de realização.

Multidrug Resistant Tuberculosis: Trends and Control.

Multidrug resistant tuberculosis (MDR-TB) has been an area of growing concern and is posing a threat to the control of tuberculosis (TB). The exact magnitude of problem of resistance to anti-tuberculosis drugs worldwide was not known till the 1994-97 global project on anti-tuberculosis drug resistance surveillance initiated by the World Health Organization (WHO) and International Union Against Tuberculosis and Lung Diseases (IUATLD). The Global Tuberculosis Report 2014 estimated that an 3.5% of newly diagnosed and 20.5% of previously treated TB cases had MDR-TB. It has been estimated that 480,000 cases emerged and 210,000 deaths occurred due to MDR-TB globally in 2013. In India, estimates showed that the prevalence of MDR-TB among new and previously treated patients was 2.2% and 15%, respectively. It is estimated that 99,000 cases of MDR-TB emerge every year of which 62,000 were among notified cases of TB in 2013. The MDR-TB is a human-made problem and results largely from poorly managed cases of TB. Adequate, timely diagnosis and optimal treatment of MDR-TB will help curb the epidemic. Efforts must be focused on the effective use of anti-tuberculosis drugs in every new patient, so as to prevent the emergence of MDR-TB.

Suppression of Eis and expression of Wag31 and GroES in Mycobacterium tuberculosis cytosol under anaerobic culture conditions.

A major impediment in chemotherapy of Tuberculosis (TB) is the persistence of M. tuberculosis in a latent or dormant state, possibly perpetuated by paucity of oxygen within the lung granuloma. Proteome analysis of the anaerobically persisting microbe could therefore provide novel targets for drugs against latent TB infection (LTBI). An Indian clinical isolate of M. tuberculosis was cultured under aerobic and anaerobic conditions following Wayne’s hypoxia model and its cytosolic proteins were resolved by two-dimensional gel electrophoresis (2DE). Peptide mass fingerprinting of 32 differentially expressed spots using MALDI TOF-TOF MS-MS resulted in identification of 23 proteins. Under the anaerobic culture conditions, expression of 12 of these proteins was highly suppressed (>2 fold reduction in spot volumes), with 4 of them (GrpE, CanB, MoxR1 and Eis) appearing as completely suppressed since corresponding spots were not detectable in the anaerobic sample. On the other hand, 4 proteins were highly expressed, with two of them (Wag31 and GroES) being uniquely expressed under anaerobic conditions. Suppression of Eis could make the anaerobically persisting bacilli susceptible to the aminoglycoside antibiotics which are known to be acetylated and inactivated by Eis. Although all 4 over-expressed proteins can be considered as putative drug targets for LTBI, Wag31 appears particularly interesting in view of its role in the cell wall biogenesis.

Polaciúria incapacitante para a vida usual. Relato de tuberculose da bexiga. A tuberculose permanece no rol do diagnóstico diferencial da maioria das doenças / Incapacitating pollakiuria affecting daily life. A case report of tuberculosis of the bladder. Tuberculosis remains on the list of the differential diagnoses for most diseases

A tuberculose (TB) é dos mais graves problemas de saúde humano e associa-se a pobreza, incipiência do sistema de saúde, deficiência de gestão que dificulta a diminuição de doenças de determinismo social, epidemia do vírus da imunodeficiência humana e imunodeficiência adquirida e multirresistência do M. tuberculosis. O acometimento extrapulmonar ocorre em 15% dos casos de TB e pode evoluir com amesma sintomatologia geral do acometimento pulmonar, com variações na dependência de sua localização e gravidade. Este relato apresenta paciente com hematúria e polaciúria incapacitante para a vida social, associada inicialmente à neoplasia, e determinada pela TB geniturinária, com diagnóstico após histopatologia de espécime clínico obtido da bexiga, em que o tempo longo para o diagnóstico foi determinante para grave sequela. Objetiva alertar para a TB como doença permanente no Brasil ea necessidade de ser considerada sempre como diagnóstico diferencial de doenças pulmonares ou extrapulmonares.

Tuberculosis (TB) is among the most serious human health concerns and is associated with poverty, limited availability of health care services and bad management, all of which negatively affect the possibility of reducing socially-determined diseases, such as HIV/AIDS epidemics and multidrug resistant M. tuberculosis. Extrapulmonary involvement occurs in 15% of TB cases and can develop with the same overall symptomatology of exclusively pulmonary involvement, with smaller variations depending on location and severity. This report presents a patient with hematuria and pollakiuria with incapacitating effects on social life, initially thought of as a malignancy and later identified as genitourinary TB. Diagnosis was based on histopathology of clinical specimens from the bladder. Time elapsed between onset and diagnosis led to considerable sequelae. This report aims at raising awareness of TB as a permanent concern in Brazil and of the need to always considered it as a differential diagnosis of pulmonary or extrapulmonary disease.

Revisiting the Rich's formula: an update about granulomas in human tuberculosis

The formula proposed by Rich in 1951 explained the formation in a tuberculous lesion in a period that was unknown cellular functions, cytokines and other immunological aspects involved in granuloma formation by tuberculosis; its components are assembled conceptually to explain the pathogenic mechanisms involved in the granulomatous lesion in tuberculosis. In this manuscript, we report an update of Rich's formula based on the new and old concepts about pathogenic mechanisms involved in the granulomatous lesion in tuberculosis. Current knowledge allows us to conclude that the balance between the characteristics of the bacillus and host protective response is necessary to indicate the outcome of pathogenesis, infection or active disease and the necrosis degree of the tuberculosis lesion.

Reativação de tuberculose no tratamento com imunobiológicos / Reactivation of tuberculosis in treatment with immunobiological

O uso de agentes biológicos vem se mostrando uma boa opção no tratamento da psoríase de difícil controle. Os inibidores do fator de necrose tumoral alfa (TNF-alfa) demonstraram resultados positivos tanto em índices de resposta terapêutica quanto em velocidade de início de ação. No entanto, pelo fato de o TNF-alfa ter uma importante participação na formação do granuloma e, consequentemente na defesa contra o Mycobacterium tuberculosis, tal tratamento pode resultar na reativação de doença latente. Assim sendo, o screening para tuberculose é necessário antes e durante o uso destas drogas na prática clínica.

The use of biologics agents has been a good option in the trteatment of resistant psoriasis. The tumor necrosis factor-alpha (TNF-alpha) blockers demonstrated positives results, both in efficacy and onset of action. However TNF-alpha plays an important role in host defense against tuberculosis, this treatment can result in reactivation of latent disease. Thus, screening for tuberculosis is necessary before and during the use of these drugs in clinical practice.

Caracterização dos perfis genéticos e de resistência a fármacos de isolados de mycobacterium tuberculosis associados com casos de tuberculose multirresistente na Bahia, Brasil / Characterization of genetic profiles and drug resistance of Mycobacterium tuberculosis isolates associated with cases of multidrug-resistant tuberculosis in Bahia, Brazil

A resistência aos fármacos utilizados no tratamento da tuberculose (TB) é um importante desafio no combate à doença. A rifampicina e a isoniazida são dois fármacos de primeira linha essenciais para a cura da doença, a qual tem como agente o M. tuberculosis. Pacientes com TB cujos isolados de M. tuberculosis apresentem resistência in vitro simultânea a estes dois fármacos desenvolvem a TB multirresistente (TBMR). A resistência do M. tuberculosis está relacionada com mutações em genes importantes para a sobrevivência do bacilo. O tratamento da TBMR é mais longo e utiliza fármacos anti-TB de segunda linha, os quais são de maior toxicidade, predispondo os pacientes à não adesão aos esquemas de tratamento. O paciente com TBMR, quando não devidamente tratado, pode selecionar cepas resistentes aos fármacos anti-TB de segunda linha, proporcionando o surgimento da TB extensivamente resistente (TBXDR). Por sua vez, estas cepas podem ser transmitidas em comunidades, constituindo um grave problema de saúde pública. Segundo a Organização Mundial de Saúde, a TBXDR tem sido documentada em alguns países, mas no Brasil estes dados são escassos. A caracterização genética de cepas de M. tuberculosis envolvidas com os casos TBMR/TBXDR pode facilitar a identificação de vias de transmissão. OBJETIVO: Pesquisar casos de TBXDR na Bahia e caracterizar perfis genéticos de isolados de M. tuberculosis de pacientes com TB multirresistente, associando o perfil genético encontrado com as características sócio-demográficas e clínicas dos pacientes envolvidos. MATERIAIS E MÉTODOS: Isolados de M. tuberculosis obtidos de pacientes com diagnóstico de TBMR entre 2008-2011 residentes no Estado da Bahia (Brasil) foram submetidos ao teste de sensibilidade utilizando fármacos anti-TB de primeira e segunda linha e genotipados pela técnica do Número Variável de Repetições em Tandem de Unidades Repetitivas Inter-espaçadas Micobacterianas (MIRU-VNTR) para obtenção de perfis genéticos que foram associados com perfis da base de dados internacional MIRU-VNTRplus. Isolados com perfis genéticos não associáveis a linhagens com o uso desta técnica foram adicionalmente genotipados por Spoligotyping e ambas as informações foram consideradas para assimilação de linhagens utilizando esta mesma base de dados. Informações clínico-epidemiológicas foram obtidas do banco de dados “Sistema TBMR” do Ministério da Saúde. RESULTADOS: Foram analisados 392 isolados. Destes, 35% foram excluídos por ausência de crescimento ou contaminação e 12% constituíam amostras em duplicata, resultando em 206 pacientes com TBMR no estudo. Comprovou-se a ocorrência da TBXDR em 7% (14/206) dos pacientes; destes, dois não possuíam registro anterior para qualquer tratamento anti-TB. Os pacientes estudados foram provenientes de 45 municípios do Estado. A capital, Salvador, concentrou 71% dos casos TBMR e 76% dos TBXDR. Dos casos TBXDR, 36% (5/14) apresentaram isolados resistentes a todos os fármacos testados. Observou-se associação de resistência combinada entre estreptomicina e etambutol (8/14, 57%) e o perfil TBXDR (RP 4,0; IC95% 1,2-13,8; P=0,01). Dos casos TBXDR, 71% (10/14) desenvolveram uma ou mais comorbidades (P=0,04), sendo o transtorno mental uma comorbidade significativa neste grupo (21%; 3/14; P=0,04). Encontrou-se 56 perfis genéticos, 38 únicos e 18 agrupados em clusters (contendo de 2 a 11 isolados). Quase a totalidade (92%) dos casos TBXDR esteve agrupada em clusters, diferindo dos casos não-TBXDR (P=0,049). Os perfis genéticos estiveram principalmente associados a seis famílias: LAM (70%), Cameroon (16%), Haarlem (10%) e as famílias X, S, Uganda I, que combinadas perfizeram 4%. Os casos TBXDR foram representados pelas famílias LAM (45%, ST’s 376, ST42, ST20), Cameroon (36%, ST61 único) e Haarlem (18%, ST50). CONCLUSÕES: A Bahia apresentou casos de TBXDR e as famílias de M.tuberculosis envolvidas com estes casos foram LAM, Cameroon e Haarlem. A genotipagem auxiliou na descoberta de casos epidemiologicamente relacionados.

Description of Pediatric Tuberculosis Evaluated in a Referral Center in Istanbul Turkey

PURPOSE: Diagnosis of tuberculosis (TB) in children is more challenging than in adults. This study aimed to describe demographical, clinical and laboratory findings of children diagnosed with tuberculosis in Turkey, including the issues of contact tracing, culture positivity and forms of the disease. MATERIALS AND METHODS: Clinical and laboratory data of 51 children with a mean age of 8.0+/-4.6 years who were diagnosed with TB were retrospectively reviewed. Main diagnostic tools included tuberculin skin test, chest X-ray, sputum/gastric aspirate culture with sensitivity testing, and direct microscopy for acid-fast bacilli on available samples. Clinical characteristics and outcomes of the patients were examined. RESULTS: Thirty-six (70.6%) children were diagnosed with intra-thoracic and 15 (29.4%) with extra-thoracic tuberculosis. Twenty-eight of the patients had a positive Bacillus Calmette-Guerin vaccine scar (28/51, 54.9%) and 23/51 (45.1%) had a positive tuberculin skin test. An adult TB contact was identified in 27 (52.9%) of the cases. On direct microscopy, acid-fast bacilli were found in nine (17.6%) patients and positive culture for Mycobacterium tuberculosis was found in 19 (37.3%). Drug resistance to isoniazid was detected in four (7.8%). One patient with nephrotic syndrome and miliary tuberculosis died during follow-up. All other patients responded well to the treatment. CONCLUSION: Focusing on active contact tracing among all household contacts of tuberculous cases may be helpful in early identification and controlling childhood disease, even in regions with low disease prevalence. Adopting a suspicious and proactive approach in this particular age group is warranted.

Factores de virulencia de Mycobacterium tuberculosis / Virulence factors of Mycobacterium tuberculosis

Mycobacterium tuberculosis, the etiological agent of human tuberculosis, causes annually three million deaths and latently infects about two billion people. Immunodeficiency caused by malnutrition, senescence or co-infection with HIVenhances the risk of developing active tuberculosis, either from a primary infection or by reactivation of a latent infection. The increasing appearance of multidrug-resistant strains to existing drugs is worrisome, since it leaves patients practically without treatment options. The understanding of the mechanisms of transmission, pathogenesis and virulence of M. tuberculosis is important. The analysis of its genome shows the presence of alternative sigma factors, transcriptional repressors and activators, two component signaling systems, metabolic enzymes and cellular secretory systems, that are associated with virulence in a series of pathogenic micro-organisms. Environmental stimuli such as pH, temperature, osmolality, oxygen availability are processed, activating or repressing virulence genes. The molecular mechanisms of action of these genes have been elucidated in in vitro and in vivo models.

Mycobacterium indicus pranii as stand-alone or adjunct immunotherapeutic in treatment of experimental animal tuberculosis.

Background & objectives: Mycobacterium w (M.w) is a saprophytic cultivable mycobacterium and shares several antigens with M. tuberculosis. It has shown good immunomodulation in leprosy patients. Hence in the present study, the efficacy of M.w immunotherapy, alone or in combination with multi drug chemotherapeutic regimens was investigated against drug sensitive M. tuberculosis H37Rv and three clinical isolates with variable degree of drug resistance in mice. Methods: BALB/c mice were infected with M. tuberculosis H37Rv (susceptible to all first and second line drugs) and three clinical isolates taken from the epository of the Institute. The dose of 200 bacilli was used for infection via respiratory route in an aerosol chamber. Chemotherapy (5 days/wk) was given one month after infection and the vaccinated group was given a dose of 1×107 bacilli by subcutaneous route. Bacterial load was measured at 4 and 6 wk after initiation of chemotherapy. Results: M.w when given along with chemotherapy (4 and 6 wk) led to a greater reduction in the bacterial load in lungs and other organs of TB infected animals compared to. However, the reduction was significantly (P<0.05) more in terms of colony forming units (cfu) in both organs (lungs and spleen). Conclusion: M.w (as immunomodulator) has beneficial therapeutic effect as an adjunct to chemotherapy.