Phenotypic and genomic comparison of Mycobacterium aurum and surrogate model species to Mycobacterium tuberculosis: implications for drug discovery.

Science.gov (United States)

Namouchi, Amine; Cimino, Mena; Favre-Rochex, Sandrine; Charles, Patricia; Gicquel, Brigitte

2017-07-13

Tuberculosis (TB) is caused by Mycobacterium tuberculosis and represents one of the major challenges facing drug discovery initiatives worldwide. The considerable rise in bacterial drug resistance in recent years has led to the need of new drugs and drug regimens. Model systems are regularly used to speed-up the drug discovery process and circumvent biosafety issues associated with manipulating M. tuberculosis. These include the use of strains such as Mycobacterium smegmatis and Mycobacterium marinum that can be handled in biosafety level 2 facilities, making high-throughput screening feasible. However, each of these model species have their own limitations. We report and describe the first complete genome sequence of Mycobacterium aurum ATCC23366, an environmental mycobacterium that can also grow in the gut of humans and animals as part of the microbiota. This species shows a comparable resistance profile to that of M. tuberculosis for several anti-TB drugs. The aims of this study were to (i) determine the drug resistance profile of a recently proposed model species, Mycobacterium aurum, strain ATCC23366, for anti-TB drug discovery as well as Mycobacterium smegmatis and Mycobacterium marinum (ii) sequence and annotate the complete genome sequence of this species obtained using Pacific Bioscience technology (iii) perform comparative genomics analyses of the various surrogate strains with M. tuberculosis (iv) discuss how the choice of the surrogate model used for drug screening can affect the drug discovery process. We describe the complete genome sequence of M. aurum, a surrogate model for anti-tuberculosis drug discovery. Most of the genes already reported to be associated with drug resistance are shared between all the surrogate strains and M. tuberculosis. We consider that M. aurum might be used in high-throughput screening for tuberculosis drug discovery. We also highly recommend the use of different model species during the drug discovery screening process.

Mycobacterium tuberculosis Metabolism

Science.gov (United States)

Warner, Digby F.

2015-01-01

Metabolism underpins the physiology and pathogenesis of Mycobacterium tuberculosis. However, although experimental mycobacteriology has provided key insights into the metabolic pathways that are essential for survival and pathogenesis, determining the metabolic status of bacilli during different stages of infection and in different cellular compartments remains challenging. Recent advances—in particular, the development of systems biology tools such as metabolomics—have enabled key insights into the biochemical state of M. tuberculosis in experimental models of infection. In addition, their use to elucidate mechanisms of action of new and existing antituberculosis drugs is critical for the development of improved interventions to counter tuberculosis. This review provides a broad summary of mycobacterial metabolism, highlighting the adaptation of M. tuberculosis as specialist human pathogen, and discusses recent insights into the strategies used by the host and infecting bacillus to influence the outcomes of the host–pathogen interaction through modulation of metabolic functions. PMID:25502746

Characterization of drug susceptibility of Mycobacterium tuberculosis isolated from new cases of tuberculosis concurrent with HIV infection

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G. V. Panov

2015-01-01

Full Text Available The paper characterizes drug susceptibility in Mycobacterium tuberculosis isolated from new cases of tuberculosis concurrent with HIV infection. The investigators have studied the spectrum of drug resistance in Mycobacterium tuberculosis isolated from new cases of tuberculosis concurrent with and without HIV infection (172 and 309 clinical isolates, respectively. There are differences in the rate of primary drug resistance to antituberculosis drugs in patients with and without HIV infection (59 and 43.5% of the cases, respectively. The HIV-infected have also shown high rifampicin resistance rates in Mycobacterium tuberculosis (41.7%. The reasons for these differences are as yet unknown and call for further investigation.

Rapid Detection of Cell-Free Mycobacterium tuberculosis DNA in Tuberculous Pleural Effusion.

Science.gov (United States)

Che, Nanying; Yang, Xinting; Liu, Zichen; Li, Kun; Chen, Xiaoyou

2017-05-01

Tuberculous pleurisy is one of the most common types of extrapulmonary tuberculosis, but its diagnosis remains difficult. In this study, we report for the first time on the detection of cell-free Mycobacterium tuberculosis DNA in pleural effusion and an evaluation of a newly developed molecular assay for the detection of cell-free Mycobacterium tuberculosis DNA. A total of 78 patients with pleural effusion, 60 patients with tuberculous pleurisy, and 18 patients with alternative diseases were included in this study. Mycobacterial culture, the Xpert MTB/RIF assay, the adenosine deaminase assay, the T-SPOT.TB assay, and the cell-free Mycobacterium tuberculosis DNA assay were performed on all the pleural effusion samples. The cell-free Mycobacterium tuberculosis DNA assay and adenosine deaminase assay showed significantly higher sensitivities of 75.0% and 68.3%, respectively, than mycobacterial culture and the Xpert MTB/RIF assay, which had sensitivities of 26.7% and 20.0%, respectively ( P pleural effusion showed the highest sensitivity of 95.0% but the lowest specificity of 38.9%. The cell-free Mycobacterium tuberculosis DNA assay detected as few as 1.25 copies of IS 6110 per ml of pleural effusion and showed good accordance of the results between repeated tests ( r = 0.978, P = 2.84 × 10 -10 ). These data suggest that the cell-free Mycobacterium tuberculosis DNA assay is a rapid and accurate molecular test which provides direct evidence of Mycobacterium tuberculosis etiology. Copyright © 2017 American Society for Microbiology.

The draft genome of Mycobacterium aurum, a potential model organism for investigating drugs against Mycobacterium tuberculosis and Mycobacterium leprae

KAUST Repository

Phelan, Jody; Maitra, Arundhati; McNerney, Ruth; Nair, Mridul; Gupta, Antima; Coll, Francesc; Pain, Arnab; Bhakta, Sanjib; Clark, Taane G.

2015-01-01

Mycobacterium aurum (M. aurum) is an environmental mycobacteria that has previously been used in studies of anti-mycobacterial drugs due to its fast growth rate and low pathogenicity. The M. aurum genome has been sequenced and assembled into 46 contigs, with a total length of 6.02 Mb containing 5684 annotated protein-coding genes. A phylogenetic analysis using whole genome alignments positioned M. aurum close to Mycobacterium vaccae and Mycobacterium vanbaalenii, within a clade related to fast-growing mycobacteria. Large-scale genomic rearrangements were identified by comparing the M. aurum genome to those of Mycobacterium tuberculosis and Mycobacterium leprae. M. aurum orthologous genes implicated in resistance to anti-tuberculosis drugs in M. tuberculosis were observed. The sequence identity at the DNA level varied from 68.6% for pncA (pyrazinamide drug-related) to 96.2% for rrs (streptomycin, capreomycin). We observed two homologous genes encoding the catalase-peroxidase enzyme (katG) that is associated with resistance to isoniazid. Similarly, two embB homologues were identified in the M. aurum genome. In addition to describing for the first time the genome of M. aurum, this work provides a resource to aid the use of M. aurum in studies to develop improved drugs for the pathogenic mycobacteria M. tuberculosis and M. leprae.

The draft genome of Mycobacterium aurum, a potential model organism for investigating drugs against Mycobacterium tuberculosis and Mycobacterium leprae

KAUST Repository

Phelan, Jody

2015-06-04

Mycobacterium aurum (M. aurum) is an environmental mycobacteria that has previously been used in studies of anti-mycobacterial drugs due to its fast growth rate and low pathogenicity. The M. aurum genome has been sequenced and assembled into 46 contigs, with a total length of 6.02 Mb containing 5684 annotated protein-coding genes. A phylogenetic analysis using whole genome alignments positioned M. aurum close to Mycobacterium vaccae and Mycobacterium vanbaalenii, within a clade related to fast-growing mycobacteria. Large-scale genomic rearrangements were identified by comparing the M. aurum genome to those of Mycobacterium tuberculosis and Mycobacterium leprae. M. aurum orthologous genes implicated in resistance to anti-tuberculosis drugs in M. tuberculosis were observed. The sequence identity at the DNA level varied from 68.6% for pncA (pyrazinamide drug-related) to 96.2% for rrs (streptomycin, capreomycin). We observed two homologous genes encoding the catalase-peroxidase enzyme (katG) that is associated with resistance to isoniazid. Similarly, two embB homologues were identified in the M. aurum genome. In addition to describing for the first time the genome of M. aurum, this work provides a resource to aid the use of M. aurum in studies to develop improved drugs for the pathogenic mycobacteria M. tuberculosis and M. leprae.

The draft genome of Mycobacterium aurum , a potential model organism for investigating drugs against Mycobacterium tuberculosis and Mycobacterium leprae

Directory of Open Access Journals (Sweden)

Jody Phelan

2015-01-01

Full Text Available Mycobacterium aurum (M. aurum is an environmental mycobacteria that has previously been used in studies of anti-mycobacterial drugs due to its fast growth rate and low pathogenicity. The M. aurum genome has been sequenced and assembled into 46 contigs, with a total length of 6.02 Mb containing 5684 annotated protein-coding genes. A phylogenetic analysis using whole genome alignments positioned M. aurum close to Mycobacterium vaccae and Mycobacterium vanbaalenii, within a clade related to fast-growing mycobacteria. Large-scale genomic rearrangements were identified by comparing the M. aurum genome to those of Mycobacterium tuberculosis and Mycobacterium leprae. M. aurum orthologous genes implicated in resistance to anti-tuberculosis drugs in M. tuberculosis were observed. The sequence identity at the DNA level varied from 68.6% for pncA (pyrazinamide drug-related to 96.2% for rrs (streptomycin, capreomycin. We observed two homologous genes encoding the catalase-peroxidase enzyme (katG that is associated with resistance to isoniazid. Similarly, two emb B homologues were identified in the M. aurum genome. In addition to describing for the first time the genome of M. aurum , this work provides a resource to aid the use of M. aurum in studies to develop improved drugs for the pathogenic mycobacteria M. tuberculosis and M. leprae.

SUSCEPTIBILITY OF RIFAMPICIN-ISONIAZID RESISTANT MYCOBACTERIUM TUBERCULOSIS ISOLATES AGAINST LEVOFLOXACIN

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A. H. Kurniawan

2016-01-01

Full Text Available Background: Tuberculosis (TB is a high burden disease in Indonesia with multidrug-resistant (MDR TB incidence started to increase. Treatment success of MDR-TB globally was low in number than it was targeted which was especially caused by fluoroquinolone resistance. One of the fluoroquinolone is levofloxacin, an antibiotic that has been widely used irrationally as antimicrobial treatment. Therefore, this study investigated the sensitivity and MBC of MDR Mycobacterium tuberculosis isolates against Levofloxacin. Method: The susceptibility test for MDR-Mycobacterium tuberculosis on levofloxacin by standard method with levofloxacin were on concentrations 0,5 μg/ml, 1 μg/ml, and 2 μg/ml. Sample of 8 strains MDR-Mycobacterium tuberculosis were cultured with each concentrations on Middlebrook 7H9 for 1 week incubation. Next, each of the incubated concentration was subcultured on solid media Middlebrook 7H10 for 3 weeks incubation. Colonized agar plates after 3 weeks incubation were confirmed with acid-fast stain. Results: On MB 7H10 with levofloxacin concentration 2 μg/ml showed bactericidal effect 100% by no MDR Mycobacterium tuberculosis colony grew (0/8 while the MB 7H10 with levofloxacin concentration 1 μg/ml and 0,5 μg/ml showed the bactericidal effect 37,5% and 25% respectively. The colonized agar plate implied that the MDR Mycobacterium tuberculosis with levofloxacin concentration 1 μg/ml (5/8 and 0,5 μg/ml (6/8 grew well. Conclusion: Levofloxacin concentration 2 μg/ml was susceptible on MDR Mycobacterium tuberculosis. The concentration 2 μg/ml of levofloxacin could be considered as MBC.

Evaluation of Genetic Pattern of Non-Tuberculosis Mycobacterium Using VNTR Method

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Noorozi J

2011-06-01

Full Text Available Background and Objectives: Epidemiological studies of Non-tuberculosis Mycobacterium is important because of the drug resistance pattern and worldwide dissemination of these organisms. One of genetic fingerprinting methods for epidemiological studies is VNTR (Variable Number Tandem Repeat. In this study genetic pattern of atypical Mycobacterium was evaluated by VNTR method for epidemiologic studies. Methods: 48 pulmonary and non pulmonary specimens separated from patients with the symptoms of pulmonary tuberculosis (PTB and identified as Non-tuberculosis Mycobacteriumby phenotypic and PCR-RFLP methods were selected for this study. Clinical samples and their standard strains were evaluated according to VNTR pattern using the 7 genetic loci including ETR-B. ETR-F. ETR-C. MPTR-A. ETR-A. ETR-E. ETR-D.Results: The results of VNTR method showed that none of the 7 loci had any polymorphism in the standard strains of atypical mycobacterium. Some of these variable number tandem repeat in 42 clinical samples of non-tuberculosis Mycobacterium were polymorphic while the PCR product (for any loci was not found in the remaining 6 specimens. Conclusion: Although the used genetic loci of this study were suitable for epidemiological studies of Mycobacterium tuberculosis, these loci were not able to determine the diversity of genetics of non-tuberculosis Mycobacterium Therefore, it seems necessary that other loci be studied using VNTR method.

Management of latent Mycobacterium tuberculosis infection: WHO guidelines for low tuberculosis burden countries

NARCIS (Netherlands)

Getahun, Haileyesus; Matteelli, Alberto; Abubakar, Ibrahim; Aziz, Mohamed Abdel; Baddeley, Annabel; Barreira, Draurio; den Boon, Saskia; Borroto Gutierrez, Susana Marta; Bruchfeld, Judith; Burhan, Erlina; Cavalcante, Solange; Cedillos, Rolando; Chaisson, Richard; Chee, Cynthia Bin-Eng; Chesire, Lucy; Corbett, Elizabeth; Dara, Masoud; Denholm, Justin; de Vries, Gerard; Falzon, Dennis; Ford, Nathan; Gale-Rowe, Margaret; Gilpin, Chris; Girardi, Enrico; Go, Un-Yeong; Govindasamy, Darshini; D Grant, Alison; Grzemska, Malgorzata; Harris, Ross; Horsburgh, C. Robert; Ismayilov, Asker; Jaramillo, Ernesto; Kik, Sandra; Kranzer, Katharina; Lienhardt, Christian; LoBue, Philip; Lönnroth, Knut; Marks, Guy; Menzies, Dick; Migliori, Giovanni Battista; Mosca, Davide; Mukadi, Ya Diul; Mwinga, Alwyn; Nelson, Lisa; Nishikiori, Nobuyuki; Oordt-Speets, Anouk; Rangaka, Molebogeng Xheedha; Reis, Andreas; Rotz, Lisa; Sandgren, Andreas; Sañé Schepisi, Monica; Schünemann, Holger J.; Sharma, Surender Kumar; Sotgiu, Giovanni; Stagg, Helen R.; Sterling, Timothy R.; Tayeb, Tamara; Uplekar, Mukund; van der Werf, Marieke J.; Vandevelde, Wim; van Kessel, Femke; van't Hoog, Anna; Varma, Jay K.; Vezhnina, Natalia; Voniatis, Constantia; Vonk Noordegraaf-Schouten, Marije; Weil, Diana; Weyer, Karin; Wilkinson, Robert John; Yoshiyama, Takashi; Zellweger, Jean Pierre; Raviglione, Mario

2015-01-01

Latent tuberculosis infection (LTBI) is characterised by the presence of immune responses to previously acquired Mycobacterium tuberculosis infection without clinical evidence of active tuberculosis (TB). Here we report evidence-based guidelines from the World Health Organization for a public health

Comparative genomics of archived pyrazinamide resistant Mycobacterium tuberculosis complex isolates from Uganda

Science.gov (United States)

Bovine tuberculosis is a ‘neglected zoonosis’ and its contribution to the proportion of Mycobacterium tuberculosis complex infections in humans is unknown. A retrospective study on archived Mycobacterium tuberculosis complex (MTC) isolates from a reference laboratory in Uganda was undertaken to iden...

Tuberculosis patients co-infected with Mycobacterium bovis and Mycobacterium tuberculosis in an urban area of Brazil.

Science.gov (United States)

Silva, Marcio Roberto; Rocha, Adalgiza da Silva; da Costa, Ronaldo Rodrigues; de Alencar, Andrea Padilha; de Oliveira, Vania Maria; Fonseca Júnior, Antônio Augusto; Sales, Mariana Lázaro; Issa, Marina de Azevedo; Filho, Paulo Martins Soares; Pereira, Omara Tereza Vianello; dos Santos, Eduardo Calazans; Mendes, Rejane Silva; Ferreira, Angela Maria de Jesus; Mota, Pedro Moacyr Pinto Coelho; Suffys, Philip Noel; Guimarães, Mark Drew Crosland

2013-05-01

In this cross-sectional study, mycobacteria specimens from 189 tuberculosis (TB) patients living in an urban area in Brazil were characterised from 2008-2010 using phenotypic and molecular speciation methods (pncA gene and oxyR pseudogene analysis). Of these samples, 174 isolates simultaneously grew on Löwenstein-Jensen (LJ) and Stonebrink (SB)-containing media and presented phenotypic and molecular profiles of Mycobacterium tuberculosis, whereas 12 had molecular profiles of M. tuberculosis based on the DNA analysis of formalin-fixed paraffin wax-embedded tissue samples (paraffin blocks). One patient produced two sputum isolates, the first of which simultaneously grew on LJ and SB media and presented phenotypic and molecular profiles of M. tuberculosis, and the second of which only grew on SB media and presented phenotypic profiles of Mycobacterium bovis. One patient provided a bronchial lavage isolate, which simultaneously grew on LJ and SB media and presented phenotypic and molecular profiles of M. tuberculosis, but had molecular profiles of M. bovis from paraffin block DNA analysis, and one sample had molecular profiles of M. tuberculosis and M. bovis identified from two distinct paraffin blocks. Moreover, we found a low prevalence (1.6%) of M. bovis among these isolates, which suggests that local health service procedures likely underestimate its real frequency and that it deserves more attention from public health officials.

Tuberculosis patients co-infected with Mycobacterium bovis and Mycobacterium tuberculosis in an urban area of Brazil

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Marcio Roberto Silva

2013-05-01

Full Text Available In this cross-sectional study, mycobacteria specimens from 189 tuberculosis (TB patients living in an urban area in Brazil were characterised from 2008-2010 using phenotypic and molecular speciation methods (pncA gene and oxyR pseudogene analysis. Of these samples, 174 isolates simultaneously grew on Löwenstein-Jensen (LJ and Stonebrink (SB-containing media and presented phenotypic and molecular profiles of Mycobacterium tuberculosis, whereas 12 had molecular profiles of M. tuberculosis based on the DNA analysis of formalin-fixed paraffin wax-embedded tissue samples (paraffin blocks. One patient produced two sputum isolates, the first of which simultaneously grew on LJ and SB media and presented phenotypic and molecular profiles of M. tuberculosis, and the second of which only grew on SB media and presented phenotypic profiles of Mycobacterium bovis. One patient provided a bronchial lavage isolate, which simultaneously grew on LJ and SB media and presented phenotypic and molecular profiles of M. tuberculosis, but had molecular profiles of M. bovis from paraffin block DNA analysis, and one sample had molecular profiles of M. tuberculosis and M. bovis identified from two distinct paraffin blocks. Moreover, we found a low prevalence (1.6% of M. bovis among these isolates, which suggests that local health service procedures likely underestimate its real frequency and that it deserves more attention from public health officials.

The draft genome of Mycobacterium aurum, a potential model organism for investigating drugs against Mycobacterium tuberculosis and Mycobacterium leprae.

Science.gov (United States)

Phelan, Jody; Maitra, Arundhati; McNerney, Ruth; Nair, Mridul; Gupta, Antima; Coll, Francesc; Pain, Arnab; Bhakta, Sanjib; Clark, Taane G

2015-09-01

Mycobacterium aurum (M. aurum) is an environmental mycobacteria that has previously been used in studies of anti-mycobacterial drugs due to its fast growth rate and low pathogenicity. The M. aurum genome has been sequenced and assembled into 46 contigs, with a total length of 6.02Mb containing 5684 annotated protein-coding genes. A phylogenetic analysis using whole genome alignments positioned M. aurum close to Mycobacterium vaccae and Mycobacterium vanbaalenii, within a clade related to fast-growing mycobacteria. Large-scale genomic rearrangements were identified by comparing the M. aurum genome to those of Mycobacterium tuberculosis and Mycobacterium leprae. M. aurum orthologous genes implicated in resistance to anti-tuberculosis drugs in M. tuberculosis were observed. The sequence identity at the DNA level varied from 68.6% for pncA (pyrazinamide drug-related) to 96.2% for rrs (streptomycin, capreomycin). We observed two homologous genes encoding the catalase-peroxidase enzyme (katG) that is associated with resistance to isoniazid. Similarly, two embB homologues were identified in the M. aurum genome. In addition to describing for the first time the genome of M. aurum, this work provides a resource to aid the use of M. aurum in studies to develop improved drugs for the pathogenic mycobacteria M. tuberculosis and M. leprae. Copyright © 2015 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

Supplementary Material for: Whole genome sequencing reveals genomic heterogeneity and antibiotic purification in Mycobacterium tuberculosis isolates

KAUST Repository

Black, PA; Vos, M. de; Louw, GE; Merwe, RG van der; Dippenaar, A.; Streicher, EM; Abdallah, AM; Sampson, SL; Victor, TC; Dolby, T.; Simpson, JA; Helden, PD van; Warren, RM; Pain, Arnab

2015-01-01

Abstract Background Whole genome sequencing has revolutionised the interrogation of mycobacterial genomes. Recent studies have reported conflicting findings on the genomic stability of Mycobacterium tuberculosis during the evolution of drug

Risk factors for Mycobacterium tuberculosis infection among children in Greenland

DEFF Research Database (Denmark)

Søborg, Bolette; Andersen, Aase Bengaard; Melbye, Mads

2011-01-01

To examine the risk factors for Mycobacterium tuberculosis infection (MTI) among Greenlandic children for the purpose of identifying those at highest risk of infection.......To examine the risk factors for Mycobacterium tuberculosis infection (MTI) among Greenlandic children for the purpose of identifying those at highest risk of infection....

Peritoneal tuberculosis due to Mycobacterium caprae

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T. Nebreda

2016-01-01

Full Text Available The incidence of tuberculosis in humans due to Mycobacterium caprae is very low and is almost confined to Europe. We report a case of a previously healthy 41-year-old Moroccan with a 6 month history of abdominal pain, weight loss, fatigue and diarrhea. A diagnosis of peritoneal tuberculosis due to M. caprae was made.

Detection of Mycobacterium Tuberculosis by using PCR

International Nuclear Information System (INIS)

Suhadi, F; Dadang-Sudrajat; Maria-Lina, R.

1996-01-01

Polymerase Chain Reaction (PCR) procedure using three primary set derived from repetitive DNA sequence specific to mycobacteria was used to diagnose pathogenic Mycobacterium tuberculosis. The assay was specific for M. tuberculosis and could be used to detect the amount DNA less than 10 -9 g

Modelling the Transitional Dynamics of Mycobacterium Tuberculosis ...

African Journals Online (AJOL)

The World Health Organization's targets of eliminating Tuberculosis (TB) by 2050 is challenged by the emergence and spread of drug resistance TB. However, the traditional mechanism of resistance is that of acquired resistance, whereby the mycobacterium Tuberculosis (MTB) strain develops mutations under selective ...

Extra pulmonary tuberculosis: Rapid identification of Mycobacterium tuberculosis grown in Mycobacterium growth indicator tube 960 and Lowenstein-Jensen media, employing Standard diagnostics Bioline Mycobacterium tuberculosis protein 64 antigen detection kit

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G Kandhakumari

2015-01-01

Full Text Available Background: Investigation of extra pulmonary tuberculosis (EPTB in and around Pondicherry is being carried out since August 2011 in our tertiary care super specialty hospital. Objectives: To compare the rapid Kit SD Bio-Line MPT 64 Ag with conventional and time consuming biochemical tests. Confirmation of Mycobacterium tuberculosis at a reasonable time frame is the main thrust. Materials and Methods: Thirty three Mycobacterium tuberculosis and four Non-Tuberculous Mycobacteria (NTM grown in MGIT960 system/Lowenstein-Jensen media (LJ were examined by the rapid MPT 64 antigen detection as well as a battery of conventional tests like niacin, nitrate reduction, paraminobenzoic acid susceptibility and cord formation. Results and Conclusion: . Both the rapid kit and conventional tests correctly identified 33 M.tuberculosis isolates. Keeping conventional identification as reference, sensitivity and specificity for rapid kit was 100%. Rapid kit which takes only 15 minutes is accurate, cost effective, and facilitates early treatment for these EPTB patients, whose clinical specimens are paucibacillary.

Multiplexed Quantitation of Intraphagocyte Mycobacterium tuberculosis Secreted Protein Effectors

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Fadel Sayes

2018-04-01

Full Text Available Summary: The pathogenic potential of Mycobacterium tuberculosis largely depends on ESX secretion systems exporting members of the multigenic Esx, Esp, and PE/PPE protein families. To study the secretion and regulation patterns of these proteins while circumventing immune cross-reactions due to their extensive sequence homologies, we developed an approach that relies on the recognition of their MHC class II epitopes by highly discriminative T cell receptors (TCRs of a panel of T cell hybridomas. The latter were engineered so that each expresses a unique fluorescent reporter linked to specific antigen recognition. The resulting polychromatic and multiplexed imaging assay enabled us to measure the secretion of mycobacterial effectors inside infected host cells. We applied this novel technology to a large panel of mutants, clinical isolates, and host-cell types to explore the host-mycobacteria interplay and its impact on the intracellular bacterial secretome, which also revealed the unexpected capacity of phagocytes from lung granuloma to present mycobacterial antigens via MHC class II. : Sayes et al. develop an approach to express distinct fluorescent reporters that is based on the recognition of specific Mycobacterium tuberculosis MHC class II epitopes by highly discriminative T cell hybridomas. This multiplexed technology allows the study of secretion, subcellular location, and regulation patterns of these instrumental protein members. Keywords: mycobacterium tuberculosis, type VII secretion systems, intracellular bacteria, T-cell hybridomas, mycobacterial virulence factors, bacterial antigen presentation, lentiviral vectors, reporter T cells, in vivo antigen presentation, protein localization

Comparative Mycobacteriology of the Mycobacterium tuberculosis complex

OpenAIRE

Gordon, Stephen V.; Behr, Marcel A.

2015-01-01

The Mycobacterium tuberculosis complex (MTBC) is a group of highly genetically related pathogens that cause tuberculosis (TB) in mammalian species. However, the very name of the complex underlines the fact that our knowledge of these pathogens is dominated by studies on the human pathogen, M. tuberculosis. Of course this is entirely justified; M. tuberculosis is a major global pathogen that exacts a horrendous burden in terms of mortality and morbidity so it is appropriate that it is...

Coinfección por Mycobacterium malmoense y Mycobacterium tuberculosis en paciente con el síndrome de inmunodeficiencia humana

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Lilian María Mederos Cuervo

Full Text Available Se presenta un caso de coinfección por Mycobacterium malmoense y Mycobacterium tuberculosis en un paciente cubano con síndrome de inmunodeficiencia adquirida (sida, que producía enfermedad respiratoria y hepática respectivamente. Los cultivos realizados a partir de las muestras de esputo demostraron la presencia de una cepa micobacteriana no pigmentada de crecimiento lento perteneciente al grupo III de Runyon e identificada como Mycobacterium malmoense. A partir de los cultivos del tejido hepático extraído laparoscópicamente se aisló una cepa posteriormente identificada como Mycobacterium tuberculosis. El estudio anatomopatológico confirmó el diagnóstico de tuberculosis, el paciente recibió tratamiento específico y evolucionó clínicamente bien. Se reporta un caso infrecuente de coinfección por Mycobacterium, el cual describe el primer reporte de tuberculosis hepática en una paciente con sida en Cuba.

Diffuse Type Primary Mycobacterium Tuberculosis of the Breast: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun A; Kang, Bong Joo; Kim, Sung Hun; Kim, Hnana; Lee, Ah Won [Seoul St. Mary' s Hospital, The Catholic University of Korea, Seoul (Korea, Republic of)

2011-12-15

Tuberculous mastitis is a rare manifestation of mycobacterium tuberculosis infection. It mimics inflammatory breast cancer or other pyogenic inflammations. In most of the tuberculous mastitis reports, coexisting or prior tuberculosis infection and secondary infection of the breast by direct spread via axillary or cervical lymphadenopathy, or hematogenous spread have been noted. We describe the mammographic and ultrasonographic findings of a case of diffuse type mycobacterium tuberculosis of the breast showing diffuse edema which was confirmed as tuberculosis through biopsy and had no evidence of old or concurrent pulmonary tuberculosis on chest computed tomography

Safety assessment in primary Mycobacterium tuberculosis smear ...

African Journals Online (AJOL)

Introduction Tuberculosis (TB) is caused by Mycobacterium tuberculosis and is transmitted mainly through aerosolization of infected sputum which puts laboratory workers at risk in spite of the laboratory workersf risk of infection being at 3 to 9 times higher than the general public. Laboratory safety should therefore be ...

Immunological crossreactivity of the Mycobacterium leprae CFP-10 with its homologue in Mycobacterium tuberculosis

NARCIS (Netherlands)

Geluk, A.; van Meijgaarden, K. E.; Franken, K. L. M. C.; Wieles, B.; Arend, S. M.; Faber, W. R.; Naafs, B.; Ottenhoff, T. H. M.

2004-01-01

Mycobacterium tuberculosis culture filtrate protein-10 (CFP-10) (Rv3874) is considered a promising antigen for the immunodiagnosis of tuberculosis (TB) together with early secreted antigens of M. tuberculosis (ESAT-6). Both ESAT-6 and CFP-10 are encoded by the RD1 region that is deleted from all

Targeting phenotypically tolerant Mycobacterium tuberculosis

Science.gov (United States)

Gold, Ben; Nathan, Carl

2016-01-01

While the immune system is credited with averting tuberculosis in billions of individuals exposed to Mycobacterium tuberculosis, the immune system is also culpable for tempering the ability of antibiotics to deliver swift and durable cure of disease. In individuals afflicted with tuberculosis, host immunity produces diverse microenvironmental niches that support suboptimal growth, or complete growth arrest, of M. tuberculosis. The physiological state of nonreplication in bacteria is associated with phenotypic drug tolerance. Many of these host microenvironments, when modeled in vitro by carbon starvation, complete nutrient starvation, stationary phase, acidic pH, reactive nitrogen intermediates, hypoxia, biofilms, and withholding streptomycin from the streptomycin-addicted strain SS18b, render M. tuberculosis profoundly tolerant to many of the antibiotics that are given to tuberculosis patients in a clinical setting. Targeting nonreplicating persisters is anticipated to reduce the duration of antibiotic treatment and rate of post-treatment relapse. Some promising drugs to treat tuberculosis, such as rifampicin and bedaquiline, only kill nonreplicating M. tuberculosis in vitro at concentrations far greater than their minimal inhibitory concentrations against replicating bacilli. There is an urgent demand to identify which of the currently used antibiotics, and which of the molecules in academic and corporate screening collections, have potent bactericidal action on nonreplicating M. tuberculosis. With this goal, we review methods of high throughput screening to target nonreplicating M. tuberculosis and methods to progress candidate molecules. A classification based on structures and putative targets of molecules that have been reported to kill nonreplicating M. tuberculosis revealed a rich diversity in pharmacophores. However, few of these compounds were tested under conditions that would exclude the impact of adsorbed compound acting during the recovery phase of

Microevolution of Mycobacterium tuberculosis in a tuberculosis patient.

NARCIS (Netherlands)

Al-Hajoj, S.A.; Akkerman, O.; Parwati, I.; Al-Gamdi, S.; Rahim, Z.; Soolingen, D. van; Ingen, J. van; Supply, P.; Zanden, A.G. van der

2010-01-01

Five Mycobacterium tuberculosis isolates were obtained from three body sites from a Dutch patient. The isolates displayed a single genotype by 24-locus MIRU-VNTR typing (except for a single locus not amplified from one isolate) but were differentiated by small variations in IS6110 fingerprints,

Lymphatic endothelial cells are a replicative niche for Mycobacterium tuberculosis

Science.gov (United States)

Lerner, Thomas R.; de Souza Carvalho-Wodarz, Cristiane; Repnik, Urska; Russell, Matthew R.G.; Borel, Sophie; Diedrich, Collin R.; Rohde, Manfred; Wainwright, Helen; Collinson, Lucy M.; Wilkinson, Robert J.; Griffiths, Gareth; Gutierrez, Maximiliano G.

2016-01-01

In extrapulmonary tuberculosis, the most common site of infection is within the lymphatic system, and there is growing recognition that lymphatic endothelial cells (LECs) are involved in immune function. Here, we identified LECs, which line the lymphatic vessels, as a niche for Mycobacterium tuberculosis in the lymph nodes of patients with tuberculosis. In cultured primary human LECs (hLECs), we determined that M. tuberculosis replicates both in the cytosol and within autophagosomes, but the bacteria failed to replicate when the virulence locus RD1 was deleted. Activation by IFN-γ induced a cell-autonomous response in hLECs via autophagy and NO production that restricted M. tuberculosis growth. Thus, depending on the activation status of LECs, autophagy can both promote and restrict replication. Together, these findings reveal a previously unrecognized role for hLECs and autophagy in tuberculosis pathogenesis and suggest that hLECs are a potential niche for M. tuberculosis that allows establishment of persistent infection in lymph nodes. PMID:26901813

Anti-mycobacterium tuberculosis activity of polyherbal medicines used for the treatment of tuberculosis in Eastern Cape, South Africa.

Science.gov (United States)

Famewo, Elizabeth B; Clarke, Anna M; Wiid, Ian; Ngwane, Andile; van Helden, Paul; Afolayan, Anthony J

2017-09-01

The emergence of drug-resistant strains of Mycobacterium tuberculosis has become a global public health problem. Polyherbal medicines offer great hope for developing alternative drugs for the treatment of tuberculosis. To evaluate the anti-tubercular activity of polyherbal medicines used for the treatment of tuberculosis. The remedies were screened against Mycobacterium tuberculosis H37Rv using Middlebrook 7H9 media and MGIT BACTEC 960 system. They were liquid preparations from King Williams Town site A (KWTa), King Williams Town site B (KWTb), King Williams Town site C (KWTc), Hogsback first site (HBfs), Hogsback second site (HBss), Hogsback third site (HBts), East London (EL), Alice (AL) and Fort Beaufort (FB). The susceptibility testing revealed that all the remedies contain anti-tubercular activity with KWTa, KWTb, KWTc, HBfs, HBts, AL and FB exhibiting more activity at a concentration below 25 µl/ml. Furthermore, MIC values exhibited inhibitory activity with the most active remedies from KWTa, HBfs and HBts at 1.562 µg/ml. However, isoniazid showed more inhibitory activity against M. tuberculosis at 0.05 µg/ml when compare to the polyherbal remedies. This study has indicated that these remedies could be potential sources of new anti-mycobacterial agents against M. tuberculosis . However, the activity of these preparations and their active principles still require in vivo study in order to assess their future as new anti-tuberculosis agents.

Adaptation and evolution of drug-resistant Mycobacterium tuberculosis

NARCIS (Netherlands)

Bergval, I.L.

2013-01-01

Many studies have been conducted on drug resistance and the evolution of Mycobacterium tuberculosis. Notwithstanding, many molecular mechanisms facilitating the emergence, adaptation and spread of drug-resistant tuberculosis have yet to be discovered. This thesis reports studies of the adaptive

Proteogenomic Investigation of Strain Variation in Clinical Mycobacterium tuberculosis Isolates

KAUST Repository

Heunis, Tiaan

2017-08-18

Mycobacterium tuberculosis consists of a large number of different strains that display unique virulence characteristics. Whole-genome sequencing has revealed substantial genetic diversity among clinical M. tuberculosis isolates, and elucidating the phenotypic variation encoded by this genetic diversity will be of utmost importance to fully understand M. tuberculosis biology and pathogenicity. In this study we integrated whole-genome sequencing and mass spectrometry (GeLC-MS/MS) to reveal strain-specific characteristics in the proteomes of two clinical M. tuberculosis Latin American-Mediterranean isolates. Using this approach we identified 59 peptides containing single amino acid variants, which covered ~9% of all total coding nonsynonymous single nucleotide variants detected by whole-genome sequencing. Furthermore, we identified 29 distinct peptides that mapped to a hypothetical protein not present in the M. tuberculosis H37Rv reference proteome. Here we provide evidence for the expression of this protein in the clinical M. tuberculosis SAWC3651 isolate. The strain-specific databases enabled confirmation of genomic differences (i.e. large genomic regions of difference and nonsynonymous single nucleotide variants) in these two clinical M. tuberculosis isolates and allowed strain differentiation at the proteome level. Our results contribute to the growing field of clinical microbial proteogenomics and can improve our understanding of phenotypic variation in clinical M. tuberculosis isolates.

Proteogenomic Investigation of Strain Variation in Clinical Mycobacterium tuberculosis Isolates

KAUST Repository

Heunis, Tiaan; Dippenaar, Anzaan; Warren, Robin M.; van Helden, Paul D.; van der Merwe, Ruben G.; Gey van Pittius, Nicolaas C.; Pain, Arnab; Sampson, Samantha L.; Tabb, David L.

2017-01-01

Mycobacterium tuberculosis consists of a large number of different strains that display unique virulence characteristics. Whole-genome sequencing has revealed substantial genetic diversity among clinical M. tuberculosis isolates, and elucidating the phenotypic variation encoded by this genetic diversity will be of utmost importance to fully understand M. tuberculosis biology and pathogenicity. In this study we integrated whole-genome sequencing and mass spectrometry (GeLC-MS/MS) to reveal strain-specific characteristics in the proteomes of two clinical M. tuberculosis Latin American-Mediterranean isolates. Using this approach we identified 59 peptides containing single amino acid variants, which covered ~9% of all total coding nonsynonymous single nucleotide variants detected by whole-genome sequencing. Furthermore, we identified 29 distinct peptides that mapped to a hypothetical protein not present in the M. tuberculosis H37Rv reference proteome. Here we provide evidence for the expression of this protein in the clinical M. tuberculosis SAWC3651 isolate. The strain-specific databases enabled confirmation of genomic differences (i.e. large genomic regions of difference and nonsynonymous single nucleotide variants) in these two clinical M. tuberculosis isolates and allowed strain differentiation at the proteome level. Our results contribute to the growing field of clinical microbial proteogenomics and can improve our understanding of phenotypic variation in clinical M. tuberculosis isolates.

Proteogenomic Investigation of Strain Variation in Clinical Mycobacterium tuberculosis Isolates.

Science.gov (United States)

Heunis, Tiaan; Dippenaar, Anzaan; Warren, Robin M; van Helden, Paul D; van der Merwe, Ruben G; Gey van Pittius, Nicolaas C; Pain, Arnab; Sampson, Samantha L; Tabb, David L

2017-10-06

Mycobacterium tuberculosis consists of a large number of different strains that display unique virulence characteristics. Whole-genome sequencing has revealed substantial genetic diversity among clinical M. tuberculosis isolates, and elucidating the phenotypic variation encoded by this genetic diversity will be of the utmost importance to fully understand M. tuberculosis biology and pathogenicity. In this study, we integrated whole-genome sequencing and mass spectrometry (GeLC-MS/MS) to reveal strain-specific characteristics in the proteomes of two clinical M. tuberculosis Latin American-Mediterranean isolates. Using this approach, we identified 59 peptides containing single amino acid variants, which covered ∼9% of all coding nonsynonymous single nucleotide variants detected by whole-genome sequencing. Furthermore, we identified 29 distinct peptides that mapped to a hypothetical protein not present in the M. tuberculosis H37Rv reference proteome. Here, we provide evidence for the expression of this protein in the clinical M. tuberculosis SAWC3651 isolate. The strain-specific databases enabled confirmation of genomic differences (i.e., large genomic regions of difference and nonsynonymous single nucleotide variants) in these two clinical M. tuberculosis isolates and allowed strain differentiation at the proteome level. Our results contribute to the growing field of clinical microbial proteogenomics and can improve our understanding of phenotypic variation in clinical M. tuberculosis isolates.

A Mycobacterium tuberculosis cluster demonstrating the use of genotyping in urban tuberculosis control

NARCIS (Netherlands)

G. de Vries (Gerard); R.M. van Hest (Reinier); C.C.A. Burdo (Conny); D. van Soolingen (Dick); J.H. Richardus (Jan Hendrik)

2009-01-01

textabstractBackground: DNA fingerprinting of Mycobacterium tuberculosis isolates offers better opportunities to study links between tuberculosis (TB) cases and can highlight relevant issues in urban TB control in low-endemic countries. Methods: A medium-sized molecular cluster of TB cases with

Mycobacterium tuberculosis infection in cattle from the Eastern Cape Province of South Africa.

Science.gov (United States)

Hlokwe, Tiny Motlatso; Said, Halima; Gcebe, Nomakorinte

2017-10-10

Mycobacterium tuberculosis is the main causative agent of tuberculosis (TB) in human and Mycobacterium bovis commonly causes tuberculosis in animals. Transmission of tuberculosis caused by both pathogens can occur from human to animals and vice versa. In the current study, M. tuberculosis, as confirmed by polymerase chain reaction (PCR) using primers targeting 3 regions of difference (RD4, RD9 and RD12) on the genomes, was isolated from cattle originating from two epidemiologically unrelated farms in the Eastern Cape (E.C) Province of South Africa. Although the isolates were genotyped with variable number of tandem repeat (VNTR) typing, no detailed epidemiological investigation was carried out on the respective farms to unequivocally confirm or link humans as sources of TB transmission to cattle, a move that would have embraced the 'One Health' concept. In addition, strain comparison with human M. tuberculosis in the database from the E.C Province and other provinces in the country did not reveal any match. This is the first report of cases of M. tuberculosis infection in cattle in South Africa. The VNTR profiles of the M. tuberculosis strains identified in the current study will form the basis for creating M. tuberculosis VNTR database for animals including cattle for future epidemiological studies. Our findings however, call for urgent reinforcement of collaborative efforts between the veterinary and the public health services of the country.

Tuberculosis relapse in Vietnam is significantly associated with Mycobacterium tuberculosis Beijing genotype infections

NARCIS (Netherlands)

Huyen, Mai N. T.; Buu, Tran N.; Tiemersma, Edine; Lan, Nguyen T. N.; Dung, Nguyen H.; Kremer, Kristin; Soolingen, Dick V.; Cobelens, Frank G. J.

2013-01-01

In Vietnam, the Mycobacterium tuberculosis Beijing genotype is associated with multi-drug resistance and is emerging. A possible explanation for this genotype's success is an increased rate of relapse. In a prospective cohort study, isolates from patients with smear-positive tuberculosis were

Mycobacterium tuberculosis, Beijing genotype strains not associated with radiological presentation of pulmonary tuberculosis

NARCIS (Netherlands)

Borgdorff, Martien W.; van Deutekom, Henk; de Haas, Petra E. W.; Kremer, Kristin; van Soolingen, Dick

2004-01-01

Mycobacterium tuberculosis strains of the Beijing genotype have been involved in various outbreaks of multidrug-resistant tuberculosis. Some studies suggest that the infection with the Beijing genotype is associated with a different host immune response. Since this might also lead to a different

Highly structured genetic diversity of the Mycobacterium tuberculosis population in Djibouti.

Science.gov (United States)

Godreuil, S; Renaud, F; Choisy, M; Depina, J J; Garnotel, E; Morillon, M; Van de Perre, P; Bañuls, A L

2010-07-01

Djibouti is an East African country with a high tuberculosis incidence. This study was conducted over a 2-month period in Djibouti, during which 62 consecutive patients with pulmonary tuberculosis (TB) were included. Genetic characterization of Mycobacterium tuberculosis, using mycobacterial interspersed repetitive-unit variable-number tandem-repeat typing and spoligotyping, was performed. The genetic and phylogenetic analysis revealed only three major families (Central Asian, East African Indian and T). The high diversity and linkage disequilibrium within each family suggest a long period of clonal evolution. A Bayesian approach shows that the phylogenetic structure observed in our sample of 62 isolates is very likely to be representative of the phylogenetic structure of the M. tuberculosis population in the total number of TB cases.

Collectin CL-LK Is a Novel Soluble Pattern Recognition Receptor for Mycobacterium tuberculosis

DEFF Research Database (Denmark)

Troegeler, Anthony; Lugo-Villarino, Geanncarlo; Hansen, Søren

2015-01-01

Understanding the molecular components of immune recognition of the tuberculosis (TB) bacillus, Mycobacterium tuberculosis, can help designing novel strategies to combat TB. Here, we identify collectin CL-LK as a novel soluble C-type lectin able to bind M. tuberculosis, and characterize mycobacte......Understanding the molecular components of immune recognition of the tuberculosis (TB) bacillus, Mycobacterium tuberculosis, can help designing novel strategies to combat TB. Here, we identify collectin CL-LK as a novel soluble C-type lectin able to bind M. tuberculosis, and characterize...

Benzothiazinones kill Mycobacterium tuberculosis by blocking arabinan synthesis

DEFF Research Database (Denmark)

Makarov, Vadim; Manina, Giulia; Mikusova, Katarina

2009-01-01

New drugs are required to counter the tuberculosis (TB) pandemic. Here, we describe the synthesis and characterization of 1,3-benzothiazin-4-ones (BTZs), a new class of antimycobacterial agents that kill Mycobacterium tuberculosis in vitro, ex vivo, and in mouse models of TB. Using genetics...

Characterization of a Mycobacterium leprae antigen related to the secreted Mycobacterium tuberculosis protein MPT32

NARCIS (Netherlands)

Wieles, B.; van Agterveld, M.; Janson, A.; Clark-Curtiss, J.; Rinke de Wit, T.; Harboe, M.; Thole, J.

1994-01-01

Secreted proteins may serve as major targets in the immune response to mycobacteria. To identify potentially secreted Mycobacterium leprae antigens, antisera specific for culture filtrate proteins of Mycobacterium tuberculosis were used to screen a panel of recombinant antigens selected previously

Triple valve endocarditis by mycobacterium tuberculosis. A case report

Directory of Open Access Journals (Sweden)

Shaikh Quratulain

2012-09-01

Full Text Available Abstract Background Granulomas caused by Mycobacterium Tuberculosis have been observed at autopsy in the heart, pre-dominantly in the myocardium and endocardium, but rarely involving the coronary vessels and valvular structures. Mycobacterium tuberculosis valvular endocarditis is extremely rare, with most reports coming from autopsy series. Case presentation We report the case of a 17 year old immunocompetent girl who presented with history of fever, malaise, foot gangrene and a left sided hemiparesis. On investigation she was found to have infective endocarditis involving the aortic, mitral and tricuspid valves. She had developed a right middle cerebral artery stroke. She underwent dual valve replacement and tricuspid repair. The vegetations showed granulomatous inflammation but blood cultures and other biological specimen cultures were negative for any organisms. She was started on antituberculous treatment and anticoagulation. Conclusion This is the first reported case of triple valve endocarditis by Mycobacterium Tuberculosis in an immunocompetent host. Especially important is the fact that the right heart is involved which has been historically described in the setting of intravenous drug abuse. This implies that Tuberculosis should be considered in cases of culture negative endocarditis in endemic areas like Pakistan even in immunocompetent hosts.

Advances in the Laboratory Diagnosis of Mycobacterium Tuberculosis

African Journals Online (AJOL)

Mycobacterium tuberculosis (MTB), the agent of human tuberculosis remains a leading cause of mortality globally. Its resurgence during the last two decades is a reflection of its opportunistic relationship with HIV. The challenges associated with the disease are enormous and often debilitating. The role of clinical and ...

Comparative Genomics and Proteomic Analysis of Four Non-tuberculous Mycobacterium Species and Mycobacterium tuberculosis Complex : Occurrence of Shared Immunogenic Proteins

NARCIS (Netherlands)

Gcebe, Nomakorinte; Michel, Anita; Gey van Pittius, Nicolaas C; Rutten, Victor

2016-01-01

The Esx and PE/PPE families of proteins are among the most immunodominant mycobacterial antigens and have thus been the focus of research to develop vaccines and immunological tests for diagnosis of bovine and human tuberculosis, mainly caused by Mycobacterium bovis and Mycobacterium tuberculosis,

Total hip replacement infected with Mycobacterium tuberculosis complicated by Addison disease and psoas muscle abscess: a case report

Directory of Open Access Journals (Sweden)

De Nardo Pasquale

2012-01-01

Full Text Available Abstract Introduction Prosthetic joint infection due to Mycobacterium tuberculosis is occasionally encountered in clinical practice. To the best of our knowledge, this is the first report of a prosthetic joint infection due to Mycobacterium tuberculosis complicated by psoas abscesses and secondary Addison disease. Case presentation A 67-year-old immunocompetent Caucasian woman underwent total left hip arthroplasty because of osteoarthritis. After 18 months, she underwent arthroplasty revision for a possible prosthetic infection. Periprosthetic tissue specimens for bacteria were negative, and empirical antibiotic therapy was unsuccessful. She was then admitted to our department because of complications arising 22 months after arthroplasty. A physical examination revealed a sinus tract overlying her left hip and skin and mucosal pigmentation. Her levels of C-reactive protein, basal cortisol, adrenocorticotropic hormone, and sodium were out of normal range. Results of the tuberculin skin test and QuantiFERON-TB Gold test were positive. Computed tomography revealed a periprosthetic abscess and the inclusion of the left psoas muscle. Results of microbiological tests were negative, but polymerase chain reaction of a specimen taken from the hip fistula was positive for Mycobacterium tuberculosis. Our patient's condition was diagnosed as prosthetic joint infection and muscle psoas abscess due to Mycobacterium tuberculosis and secondary Addison disease. She underwent standard treatment with rifampicin, ethambutol, isoniazid, and pyrazinamide associated with hydrocortisone and fludrocortisone. At 15 months from the beginning of therapy, she was in good clinical condition and free of symptoms. Conclusions Prosthetic joint infection with Mycobacterium tuberculosis is uncommon. A differential diagnosis of tuberculosis should be considered when dealing with prosthetic joint infection, especially when repeated smears and histology examination from infected

Buoyant density of Mycobacterium tuberculosis: implications for sputum processing

NARCIS (Netherlands)

den Hertog, A. L.; Klatser, P. R.; Anthony, R. M.

2009-01-01

A tuberculosis (TB) research laboratory in the Netherlands. The concentration of Mycobacterium tuberculosis cells from sputum is almost universally performed by centrifugation after chemical liquefaction. These methods are thus dependent on the effective sedimentation of mycobacterial cells, and the

Intraocular manifestations of mycobacterium tuberculosis: A review of the literature

Directory of Open Access Journals (Sweden)

Lauren A. Dalvin

2017-05-01

Full Text Available Mycobacterium tuberculosis: is most commonly associated with pulmonary infection. However, tuberculosis (TB can also affect the eye. TB can affect nearly any tissue in the eye, and a high index of suspicion is required for accurate diagnosis, as many of the intraocular manifestations of TB can mimic other, more common diseases. Correct diagnosis is critical because systemic anti-tuberculosis treatment may be required, and vision loss or even loss of the affected eye can occur without proper treatment. Thus, it is important for ophthalmologists and infectious disease specialists to work together to accurately diagnose and treat intraocular TB. This article reports the various known presentations of intraocular TB and reviews important elements of diagnosis and treatment. Keywords: Mycobacterium, Tuberculosis, Choroidal granuloma, Retinal vasculitis

Diversity and evolution of drug resistance mechanisms in Mycobacterium tuberculosis

Directory of Open Access Journals (Sweden)

Al-Saeedi M

2017-10-01

Full Text Available Mashael Al-Saeedi, Sahal Al-Hajoj Department of Infection and Immunity, Mycobacteriology Research Section, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia Abstract: Despite the efficacy of antibiotics to protect humankind against many deadly pathogens, such as Mycobacterium tuberculosis, nothing can prevent the emergence of drug-resistant strains. Several mechanisms facilitate drug resistance in M. tuberculosis including compensatory evolution, epistasis, clonal interference, cell wall integrity, efflux pumps, and target mimicry. In this study, we present recent findings relevant to these mechanisms, which can enable the discovery of new drug targets and subsequent development of novel drugs for treatment of drug-resistant M. tuberculosis. Keywords: Mycobacterium tuberculosis, antibiotic resistance, compensatory evolution, epistasis, efflux pumps, fitness cost

21 CFR 866.3370 - Mycobacterium tuberculosis immunofluorescent reagents.

Science.gov (United States)

2010-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents... used to identify Mycobacterium tuberculosis directly from clinical specimens. The identification aids...

Comparison of antigen-specific T-cell responses of tuberculosis patients using complex or single antigens of Mycobacterium tuberculosis

DEFF Research Database (Denmark)

Mustafa, A S; Amoudy, H A; Wiker, H G

1998-01-01

GroES, rPstS, rGroEL and rDnaK) antigens of Mycobacterium tuberculosis. The responses of PBMC to these defined antigens were compared with the corresponding results obtained with complex antigens, such as whole-cell M. tuberculosis, M. tuberculosis culture filtrate (MT-CF) and cell wall antigens, as well...... as the vaccine strain, Mycobacterium bovis bacillus Calmette-Guerin (BCG). In addition, M. tuberculosis and MT-CF-induced T-cell lines were tested in the same assays against the panel of purified and complex antigens. The compiled data from PBMC and T-cell lines tested for antigen-induced proliferation and IFN...

Immune responses to the Mycobacterium tuberculosis-specific antigen ESAT-6 signal subclinical infection among contacts of tuberculosis patients

DEFF Research Database (Denmark)

Doherty, T Mark; Demissie, Abebech; Olobo, Joseph

2002-01-01

Diagnosis of latent Mycobacterium tuberculosis infection is considered essential for tuberculosis control but is hampered by the lack of specific reagents. We report that strong recognition of tuberculosis complex-specific antigen ESAT-6 by healthy household contacts of tuberculosis patients...

Revisiting host preference in the Mycobacterium tuberculosis complex: experimental infection shows M. tuberculosis H37Rv to be avirulent in cattle.

Directory of Open Access Journals (Sweden)

Adam O Whelan

Full Text Available Experiments in the late 19th century sought to define the host specificity of the causative agents of tuberculosis in mammals. Mycobacterium tuberculosis, the human tubercle bacillus, was independently shown by Smith, Koch, and von Behring to be avirulent in cattle. This finding was erroneously used by Koch to argue the converse, namely that Mycobacterium bovis, the agent of bovine tuberculosis, was avirulent for man, a view that was subsequently discredited. However, reports in the literature of M. tuberculosis isolation from cattle with tuberculoid lesions suggests that the virulence of M. tuberculosis for cattle needs to be readdressed. We used an experimental bovine infection model to test the virulence of well-characterized strains of M. tuberculosis and M. bovis in cattle, choosing the genome-sequenced strains M. tuberculosis H37Rv and M. bovis 2122/97. Cattle were infected with approximately 10(6 CFU of M. tuberculosis H37Rv or M. bovis 2122/97, and sacrificed 17 weeks post-infection. IFN-gamma and tuberculin skin tests indicated that both M. bovis 2122 and M. tuberculosis H37Rv were equally infective and triggered strong cell-mediated immune responses, albeit with some indication of differential antigen-specific responses. Postmortem examination revealed that while M. bovis 2122/97-infected animals all showed clear pathology indicative of bovine tuberculosis, the M. tuberculosis-infected animals showed no pathology. Culturing of infected tissues revealed that M. tuberculosis was able to persist in the majority of animals, albeit at relatively low bacillary loads. In revisiting the early work on host preference across the M. tuberculosis complex, we have shown M. tuberculosis H37Rv is avirulent for cattle, and propose that the immune status of the animal, or genotype of the infecting bacillus, may have significant bearing on the virulence of a strain for cattle. This work will serve as a baseline for future studies into the genetic basis

Dehalogenation of Haloalkanes by Mycobacterium tuberculosis H37Rv and Other Mycobacteria

Science.gov (United States)

Jesenská, Andrea; Sedlác̆ek, Ivo; Damborský, Jir̆í

2000-01-01

Haloalkane dehalogenases convert haloalkanes to their corresponding alcohols by a hydrolytic mechanism. To date, various haloalkane dehalogenases have been isolated from bacteria colonizing environments that are contaminated with halogenated compounds. A search of current databases with the sequences of these known haloalkane dehalogenases revealed the presence of three different genes encoding putative haloalkane dehalogenases in the genome of the human parasite Mycobacterium tuberculosis H37Rv. The ability of M. tuberculosis and several other mycobacterial strains to dehalogenate haloaliphatic compounds was therefore studied. Intact cells of M. tuberculosis H37Rv were found to dehalogenate 1-chlorobutane, 1-chlorodecane, 1-bromobutane, and 1,2-dibromoethane. Nine isolates of mycobacteria from clinical material and four strains from a collection of microorganisms were found to be capable of dehalogenating 1,2-dibromoethane. Crude extracts prepared from two of these strains, Mycobacterium avium MU1 and Mycobacterium smegmatis CCM 4622, showed broad substrate specificity toward a number of halogenated substrates. Dehalogenase activity in the absence of oxygen and the identification of primary alcohols as the products of the reaction suggest a hydrolytic dehalogenation mechanism. The presence of dehalogenases in bacterial isolates from clinical material, including the species colonizing both animal tissues and free environment, indicates a possible role of parasitic microorganisms in the distribution of degradation genes in the environment. PMID:10618227

Antibacterial Activity of Medicinal Aqueous Plant Extracts against Mycobacterium tuberculosis

Directory of Open Access Journals (Sweden)

Muna Mohammed Buzayan

2012-09-01

Full Text Available Tuberculosis (TB remains a serious health problem in many regions of the world, and the development of resistance to antibiotics by this microbe created the need for new drugs to replace those which have lost effectiveness. This study assesses the medicinal anti-Mycobacterium tuberculosis properties of natural products obtained from plants collected from Eastern Libya. In this study aqueous extracts of nine different plants were assayed for their Mycobacterium tuberculosis inhibitory activity using the BACTEC MGIT960 susceptibility test method. The aqueous extracts of Ceratonia siliqua L, Helichrysum stoechas (L. Moench and Thymus algeriensis did not show any activity against M. tuberculosis in different concentrations. The aqueous extract of Marrubium vulgare L. from Syria showed high activity against M. tuberculosis. Marrubium alysson L., Marrubium vulgare L., Pistacia lentiscus L, Quercus coccifera L, Thymus capitatus (L. Hoffm. & Link, showed varying degrees of activity against M. tuberculosis. The results of this study show that aqueous extracts from six different medicinal plants have different effects against M. tuberculosis in vitro.

Mycobacterium tuberculosis Genotype and Case Notification Rates, Rural Vietnam, 2003-2006

NARCIS (Netherlands)

Buu, T.N.; Huyen, M.N.T.; Lan, N.N.T.; Quy, H.T.; Hen, N.V.; Zignol, M.; Borgdorff, M.W.; van Soolingen, D.; Cobelens, F.G.J.

2009-01-01

Tuberculosis case notification rates (CNRs) for young adults in Vietnam are increasing. To determine whether this finding could reflect emergence of Mycobacterium tuberculosis Beijing genotype, we studied all new sputum smear-positive pulmonary tuberculosis patients registered for treatment in 3

Siderocalin inhibits the intracellular replication of Mycobacterium tuberculosis in macrophages

DEFF Research Database (Denmark)

Johnson, Erin E; Srikanth, Chittur V; Sandgren, Andreas

2010-01-01

Siderocalin is a secreted protein that binds to siderophores to prevent bacterial iron acquisition. While it has been shown to inhibit the growth of Mycobacterium tuberculosis (M.tb) in extracellular cultures, its effect on this pathogen within macrophages is not clear. Here, we show that sideroc......Siderocalin is a secreted protein that binds to siderophores to prevent bacterial iron acquisition. While it has been shown to inhibit the growth of Mycobacterium tuberculosis (M.tb) in extracellular cultures, its effect on this pathogen within macrophages is not clear. Here, we show...... findings are consistent with an important role for siderocalin in protection against M.tb infection and suggest that exogenously administered siderocalin may have therapeutic applications in tuberculosis....

Characterization of Mycobacterium tuberculosis nicotinamidase/pyrazinamidase.

Science.gov (United States)

Zhang, Hua; Deng, Jiao-Yu; Bi, Li-Jun; Zhou, Ya-Feng; Zhang, Zhi-Ping; Zhang, Cheng-Gang; Zhang, Ying; Zhang, Xian-En

2008-02-01

The nicotinamidase/pyrazinamidase (PncA) of Mycobacterium tuberculosis is involved in the activation of the important front-line antituberculosis drug pyrazinamide by converting it into the active form, pyrazinoic acid. Mutations in the pncA gene cause pyrazinamide resistance in M. tuberculosis. The properties of M. tuberculosis PncA were characterized in this study. The enzyme was found to be a 20.89 kDa monomeric protein. The optimal pH and temperature of enzymatic activity were pH 7.0 and 40 degrees C, respectively. Inductively coupled plasma-optical emission spectrometry revealed that the enzyme was an Mn(2+)/Fe(2+)-containing protein with a molar ratio of [Mn(2+)] to [Fe(2+)] of 1 : 1; furthermore, the external addition of either type of metal ion had no apparent effect on the wild-type enzymatic activity. The activity of the purified enzyme was determined by HPLC, and it was shown that it possessed similar pyrazinamidase and nicotinamidase activity, by contrast with previous reports. Nine PncA mutants were generated by site-directed mutagenesis. Determination of the enzymatic activity and metal ion content suggested that Asp8, Lys96 and Cys138 were key residues for catalysis, and Asp49, His51, His57 and His71 were essential for metal ion binding. Our data show that M. tuberculosis PncA may bind metal ions in a manner different from that observed in the case of Pyrococcus horikoshii PncA.

The Use Of Rap-PCR In Studying Mycobacterium tuberculosis ...

African Journals Online (AJOL)

Mycobacterium tuberculosis is the second leading cause of death from infectious agent. This study sought to detect M. tuberculosis genes, which were specifically expressed, or upregulated during intracellular infection of. J774 murine macrophages; as such genes may be potential targets for novel drug action. J774 murine ...

In vitro and in vivo activities of the nitroimidazole TBA-354 against Mycobacterium tuberculosis.

Science.gov (United States)

Upton, A M; Cho, S; Yang, T J; Kim, Y; Wang, Y; Lu, Y; Wang, B; Xu, J; Mdluli, K; Ma, Z; Franzblau, S G

2015-01-01

Nitroimidazoles are a promising new class of antitubercular agents. The nitroimidazo-oxazole delamanid (OPC-67683, Deltyba) is in phase III trials for the treatment of multidrug-resistant tuberculosis, while the nitroimidazo-oxazine PA-824 is entering phase III for drug-sensitive and drug-resistant tuberculosis. TBA-354 (SN31354[(S)-2-nitro-6-((6-(4-trifluoromethoxy)phenyl)pyridine-3-yl)methoxy)-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazine]) is a pyridine-containing biaryl compound with exceptional efficacy against chronic murine tuberculosis and favorable bioavailability in preliminary rodent studies. It was selected as a potential next-generation antituberculosis nitroimidazole following an extensive medicinal chemistry effort. Here, we further evaluate the pharmacokinetic properties and activity of TBA-354 against Mycobacterium tuberculosis. TBA-354 is narrow spectrum and bactericidal in vitro against replicating and nonreplicating Mycobacterium tuberculosis, with potency similar to that of delamanid and greater than that of PA-824. The addition of serum protein or albumin does not significantly alter this activity. TBA-354 maintains activity against Mycobacterium tuberculosis H37Rv isogenic monoresistant strains and clinical drug-sensitive and drug-resistant isolates. Spontaneous resistant mutants appear at a frequency of 3 × 10(-7). In vitro studies and in vivo studies in mice confirm that TBA-354 has high bioavailability and a long elimination half-life. In vitro studies suggest a low risk of drug-drug interactions. Low-dose aerosol infection models of acute and chronic murine tuberculosis reveal time- and dose-dependent in vivo bactericidal activity that is at least as potent as that of delamanid and more potent than that of PA-824. Its superior potency and pharmacokinetic profile that predicts suitability for once-daily oral dosing suggest that TBA-354 be studied further for its potential as a next-generation nitroimidazole. Copyright © 2015, American

Diagnosis of intestinal tuberculosis using a monoclonal antibody to Mycobacterium tuberculosis

Institute of Scientific and Technical Information of China (English)

Yasushi Ihama; Akira Hokama; Kenji Hibiya; Kazuto Kishimoto; Manabu Nakamoto; Tetsuo Hirata; Nagisa Kinjo

2012-01-01

AIM:To investigate the utility of immunohistochemical (IHC) staining with an antibody to Mycobacterium tuberculosis (M.tuberculosis) for the diagnosis of intestinal tuberculosis (TB).METHODS:We retrospectively identified 10 patients (4 males and 6 females; mean age =65.1 ± 13.6 years)with intestinal TB.Clinical characteristics,including age,gender,underlying disease,and symptoms were obtained.Chest radiograph and laboratory tests,including sputum Ziehl-Neelsen (ZN) staining,M.tuberculosis culture,and sputum polymerase chain reaction (PCR)for tubercle bacilli DNA,as well as Tuberculin skin test (TST) and QuantiFERON-TB gold test (QFT),were examined.Colonoscopic records recorded on the basis of Sato's classification were also reviewed,in addition to data from intestinal biopsies examined for histopathological findings,including hematoxylin and eosin staining,and ZN staining,as well as M.tuberculosis culture,and PCR for tubercle bacilli DNA.For the present study,archived formalin-fixed paraffin-embedded (FFPE) intestinal tissue samples were immunohistochemically stained using a commercially available species-specific monoclonal antibody to the 38-kDa antigen of the M.tuberculosis complex.These sections were also stained with the pan-macrophage marker CD68 antibody.RESULTS:From the clinical data,we found that no patients were immunocompromised,and that the main symptoms were diarrhea and weight loss.Three patients displayed active pulmonary TB,six patients (60％) had a positive TST,and 4 patients (40％) had a positive QFT.Colonoscopic findings revealed that all patients had type 1 findings (linear ulcers in a circumferential arrangement or linear ulcers arranged circumferentially with mucosa showing multiple nodules),all of which were located in the right hemicolon and/or terminal ileum.Seven patients (70％) had concomitant healed lesions in the ileocecal area.No acid-fast bacilli were detected with ZN staining of the intestinal tissue samples,and both M.tuberculosis

Immune responses to the Mycobacterium tuberculosis-specific antigen ESAT-6 signal subclinical infection among contacts of tuberculosis patients

DEFF Research Database (Denmark)

Doherty, T Mark; Demissie, Abebech; Olobo, Joseph

2002-01-01

Diagnosis of latent Mycobacterium tuberculosis infection is considered essential for tuberculosis control but is hampered by the lack of specific reagents. We report that strong recognition of tuberculosis complex-specific antigen ESAT-6 by healthy household contacts of tuberculosis patients...... correlates with the subsequent development of active tuberculosis during a 2-year follow-up period....

Detection of Mycobacterium bovis and Mycobacterium tuberculosis from Cattle: Possible Public Health Relevance

DEFF Research Database (Denmark)

Thakur, Aneesh; Sharma, Mandeep; Katoch, Vipin C.

2012-01-01

Mycobacterium bovis and Mycobacterium tuberculosis infect both animals and humans. The disease epidemiology by these agents differs in developed and developing countries due to the differences in the implementation of the prevention and control strategies. The present study describes the detectio...

Microbe Profile: Mycobacterium tuberculosis: Humanity's deadly microbial foe.

Science.gov (United States)

Gordon, Stephen V; Parish, Tanya

2018-04-01

Mycobacterium tuberculosis is an expert and deadly pathogen, causing the disease tuberculosis (TB) in humans. It has several notable features: the ability to enter non-replicating states for long periods and cause latent infection; metabolic remodelling during chronic infection; a thick, waxy cell wall; slow growth rate in culture; and intrinsic drug resistance and antibiotic tolerance. As a pathogen, M. tuberculosis has a complex relationship with its host, is able to replicate inside macrophages, and expresses diverse immunomodulatory molecules. M. tuberculosis currently causes over 1.8 million deaths a year, making it the world's most deadly human pathogen.

DIGITAL DETECTION SYSTEM DESIGN OF MYCOBACTERIUM TUBERCULOSIS THROUGH EXTRACTION OF SPUTUM IMAGE USING NEURAL NETWORK METHOD

Directory of Open Access Journals (Sweden)

Franky Arisgraha

2012-01-01

Full Text Available Tuberculosis (TBC is an dangerous disease and many people has been infected. One of many important steps to control TBC effectively and efficiently is by increasing case finding using right method and accurate diagnostic. One of them is to detect Mycobacterium Tuberculosis inside sputum. Conventional detection of Mycobacterium Tuberculosis inside sputum can need a lot of time, so digitally detection method of Mycobacterium Tuberculosis was designed as an effort to get better result of detection. This method was designed by using combination between digital image processing method and Neural Network method. From testing report that was done, Mycobacterium can be detected with successful value reach 77.5% and training error less than 5%.

Beijing Lineage of MDR Mycobacterium tuberculosis in Bulgaria, 2007-2011

NARCIS (Netherlands)

Panaiotov, Stefan; Bachiyska, Elizabeta; Yordanova, Stanislava; Atanasova, Yuliana; Brankova, Nadia; Levterova, Viktoria; Sengstake, Sarah; Anthony, Richard; Bergval, Indra; Sola, Christophe; Kantardjiev, Todor

2014-01-01

To assess the spread of the Mycobacterium tuberculosis Beijing genotype among patients with multidrug-resistant and extensively resistant tuberculosis in Bulgaria, we genotyped 188 (72%) of 261 microbiologically confirmed resistant isolates obtained during 2007-2011. The estimated prevalence of the

Comprehensive Definition of the SigH Regulon of Mycobacterium tuberculosis Reveals Transcriptional Control of Diverse Stress Responses.

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Jared D Sharp

Full Text Available Expression of SigH, one of 12 Mycobacterium tuberculosis alternative sigma factors, is induced by heat, oxidative and nitric oxide stresses. SigH activation has been shown to increase expression of several genes, including genes involved in maintaining redox equilibrium and in protein degradation. However, few of these are known to be directly regulated by SigH. The goal of this project is to comprehensively define the Mycobacterium tuberculosis genes and operons that are directly controlled by SigH in order to gain insight into the role of SigH in regulating M. tuberculosis physiology. We used ChIP-Seq to identify in vivo SigH binding sites throughout the M. tuberculosis genome, followed by quantification of SigH-dependent expression of genes linked to these sites and identification of SigH-regulated promoters. We identified 69 SigH binding sites, which are located both in intergenic regions and within annotated coding sequences in the annotated M. tuberculosis genome. 41 binding sites were linked to genes that showed greater expression following heat stress in a SigH-dependent manner. We identified several genes not previously known to be regulated by SigH, including genes involved in DNA repair, cysteine biosynthesis, translation, and genes of unknown function. Experimental and computational analysis of SigH-regulated promoter sequences within these binding sites identified strong consensus -35 and -10 promoter sequences, but with tolerance for non-consensus bases at specific positions. This comprehensive identification and validation of SigH-regulated genes demonstrates an extended SigH regulon that controls an unexpectedly broad range of stress response functions.

Comprehensive Definition of the SigH Regulon of Mycobacterium tuberculosis Reveals Transcriptional Control of Diverse Stress Responses.

Science.gov (United States)

Sharp, Jared D; Singh, Atul K; Park, Sang Tae; Lyubetskaya, Anna; Peterson, Matthew W; Gomes, Antonio L C; Potluri, Lakshmi-Prasad; Raman, Sahadevan; Galagan, James E; Husson, Robert N

2016-01-01

Expression of SigH, one of 12 Mycobacterium tuberculosis alternative sigma factors, is induced by heat, oxidative and nitric oxide stresses. SigH activation has been shown to increase expression of several genes, including genes involved in maintaining redox equilibrium and in protein degradation. However, few of these are known to be directly regulated by SigH. The goal of this project is to comprehensively define the Mycobacterium tuberculosis genes and operons that are directly controlled by SigH in order to gain insight into the role of SigH in regulating M. tuberculosis physiology. We used ChIP-Seq to identify in vivo SigH binding sites throughout the M. tuberculosis genome, followed by quantification of SigH-dependent expression of genes linked to these sites and identification of SigH-regulated promoters. We identified 69 SigH binding sites, which are located both in intergenic regions and within annotated coding sequences in the annotated M. tuberculosis genome. 41 binding sites were linked to genes that showed greater expression following heat stress in a SigH-dependent manner. We identified several genes not previously known to be regulated by SigH, including genes involved in DNA repair, cysteine biosynthesis, translation, and genes of unknown function. Experimental and computational analysis of SigH-regulated promoter sequences within these binding sites identified strong consensus -35 and -10 promoter sequences, but with tolerance for non-consensus bases at specific positions. This comprehensive identification and validation of SigH-regulated genes demonstrates an extended SigH regulon that controls an unexpectedly broad range of stress response functions.

Variable host-pathogen compatibility in Mycobacterium tuberculosis.

NARCIS (Netherlands)

Gagneux, Sebastien; DeRiemer, Kathryn; Van, Tran; Kato-Maeda, Midori; Jong, Bouke C de; Narayanan, Sujatha; Nicol, Mark; Niemann, Stefan; Kremer, Kristin; Gutierrez, M Cristina; Hilty, Markus; Hopewell, Philip C; Small, Peter M

2006-01-01

Mycobacterium tuberculosis remains a major cause of morbidity and mortality worldwide. Studies have reported human pathogens to have geographically structured population genetics, some of which have been linked to ancient human migrations. However, no study has addressed the potential evolutionary

Beta-lactamases of Mycobacterium tuberculosis and Mycobacterium kansasii.

Science.gov (United States)

Segura, C; Salvadó, M

1997-09-01

Re-emergence of infectious diseases caused by mycobacteria as well as the emergence of multiresistant strains of Mycobacterium has promoted the research on the use of beta-lactames in the treatment of such diseases. Mycobacteria produce beta-lactamases: M. tuberculosis produces a wide-spectrum beta-lactamase whose behaviour mimicks those of Gram-negative bacteria. M. kansasii produces also beta-lactamase which can be inhibited by clavulanic acid. An overview on beta-lactamases from both species is reported.

Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection

DEFF Research Database (Denmark)

Brock, I; Weldingh, K; Leyten, EM

2004-01-01

Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection.Brock I, Weldingh K, Leyten EM, Arend SM, Ravn P, Andersen P. Department of Infectious Disease Immunology, Statens Serum Institute, Artillerivej 5, DK-2300 Copenhagen S, Denmark. The currently used...... method for immunological detection of tuberculosis infection, the tuberculin skin test, has low specificity. Antigens specific for Mycobacterium tuberculosis to replace purified protein derivative are therefore urgently needed. We have performed a rigorous assessment of the diagnostic potential of four...... recently identified antigens (Rv2653, Rv2654, Rv3873, and Rv3878) from genomic regions that are lacking from the Mycobacterium bovis bacillus Calmette-Guerin (BCG) vaccine strains as well as from the most common nontuberculous mycobacteria. The fine specificity of potential epitopes in these molecules...

Multidrug-Resistant Mycobacterium tuberculosis of the Latin American Mediterranean Lineage, Wrongly Identified as Mycobacterium pinnipedii (Spoligotype International Type 863 [SIT863]), Causing Active Tuberculosis in South Brazil

KAUST Repository

Dalla Costa, Elis R.; Vasconcelos, Sidra E. G.; Esteves, Leonardo S.; Gomes, Harrison M.; Gomes, Lia L.; Almeida da Silva, Pedro; Perdigã o, Joã o; Portugal, Isabel; Viveiros, Miguel; McNerney, Ruth; Pain, Arnab; Clark, Taane G.; Rastogi, Nalin; Unis, Gisela; Rossetti, Maria Lucia R.; Suffys, Philip Noel

2015-01-01

We recently detected the spoligotype patterns of strains of Mycobacterium pinnipedii, a species of the Mycobacterium tuberculosis complex, in sputum samples from nine cases with pulmonary tuberculosis residing in Porto Alegre, South Brazil. Because this species is rarely encountered in humans, we further characterized these nine isolates by additional genotyping techniques, including 24-locus mycobacterial interspersed repetitive-unit–variable-number tandem-repeat (MIRU-VNTR) typing, verification of the loci TbD1, RD9, pks15/1, RDRio, and fbpC, the insertion of IS6110 at a site specific to the M. tuberculosis Latin American Mediterranean (LAM) lineage, and whole-genome sequencing. The combined analysis of these markers revealed that the isolates are in fact M. tuberculosis and more specifically belong to the LAM genotype. Most of these isolates (n = 8) were shown to be multidrug resistant (MDR), which prompted us to perform partial sequencing of the rpoA, rpoB, rpoC, katG, and inhA genes. Seven isolates (77.8%) carried the S315T mutation in katG, and one of these (11%) also presented the C(−17)T single-nucleotide polymorphism (SNP) in inhA. Interestingly, six of the MDR isolates also presented an undescribed insertion of 12 nucleotides (CCA GAA CAA CCC) in codon 516 of rpoB. No putative compensatory mutation was found in either rpoA or rpoC. This is the first report of an M. tuberculosis LAM family strain with a convergent M. pinnipedii spoligotype. These spoligotypes are observed in genotype databases at a modest frequency, highlighting that care must be taken when identifying isolates in the M. tuberculosis complex on the basis of single genetic markers.

Multidrug-Resistant Mycobacterium tuberculosis of the Latin American Mediterranean Lineage, Wrongly Identified as Mycobacterium pinnipedii (Spoligotype International Type 863 [SIT863]), Causing Active Tuberculosis in South Brazil

KAUST Repository

Dalla Costa, Elis R.

2015-09-23

We recently detected the spoligotype patterns of strains of Mycobacterium pinnipedii, a species of the Mycobacterium tuberculosis complex, in sputum samples from nine cases with pulmonary tuberculosis residing in Porto Alegre, South Brazil. Because this species is rarely encountered in humans, we further characterized these nine isolates by additional genotyping techniques, including 24-locus mycobacterial interspersed repetitive-unit–variable-number tandem-repeat (MIRU-VNTR) typing, verification of the loci TbD1, RD9, pks15/1, RDRio, and fbpC, the insertion of IS6110 at a site specific to the M. tuberculosis Latin American Mediterranean (LAM) lineage, and whole-genome sequencing. The combined analysis of these markers revealed that the isolates are in fact M. tuberculosis and more specifically belong to the LAM genotype. Most of these isolates (n = 8) were shown to be multidrug resistant (MDR), which prompted us to perform partial sequencing of the rpoA, rpoB, rpoC, katG, and inhA genes. Seven isolates (77.8%) carried the S315T mutation in katG, and one of these (11%) also presented the C(−17)T single-nucleotide polymorphism (SNP) in inhA. Interestingly, six of the MDR isolates also presented an undescribed insertion of 12 nucleotides (CCA GAA CAA CCC) in codon 516 of rpoB. No putative compensatory mutation was found in either rpoA or rpoC. This is the first report of an M. tuberculosis LAM family strain with a convergent M. pinnipedii spoligotype. These spoligotypes are observed in genotype databases at a modest frequency, highlighting that care must be taken when identifying isolates in the M. tuberculosis complex on the basis of single genetic markers.

Extracellular Sphingomyelinase Rv0888 of Mycobacterium tuberculosis Contributes to Pathological Lung Injury of Mycobacterium smegmatis in Mice via Inducing Formation of Neutrophil Extracellular Traps.

Science.gov (United States)

Dang, Guanghui; Cui, Yingying; Wang, Lei; Li, Tiantian; Cui, Ziyin; Song, Ningning; Chen, Liping; Pang, Hai; Liu, Siguo

2018-01-01

Mycobacterium tuberculosis is the causative agent of tuberculosis (TB), which mainly causes pulmonary injury and tubercles. Although macrophages are generally considered to harbor the main cells of M. tuberculosis , new evidence suggests that neutrophils are rapidly recruited to the infected lung. M. tuberculosis itself, or its early secreted antigenic target protein 6 (ESAT-6), can induce formation of neutrophil extracellular traps (NETs). However, NETs trap mycobacteria but are unable to kill them. The role of NETs' formation in the pathogenesis of mycobacteria remains unclear. Here, we report a new M. tuberculosis extracellular factor, bifunctional enzyme Rv0888, with both nuclease and sphingomyelinase activities. Rv0888 sphingomyelinase activity can induce NETs' formation in vitro and in the lung of the mice and enhance the colonization ability of Mycobacterium smegmatis in the lungs of mice. Mice infected by M. smegmatis harboring Rv0888 sphingomyelinase induced pathological injury and inflammation of the lung, which was mainly mediated by NETs, induced by Rv0888 sphingomyelinase, associated protein (myeloperoxidase) triggered caspase-3. In summary, the study sheds new light on the pathogenesis of mycobacteria and reveals a novel target for TB treatment.

Identification of a novel 27-kDa protein from Mycobacterium tuberculosis culture fluid by a monoclonal antibody specific for the Mycobacterium tuberculosis complex

NARCIS (Netherlands)

Rambukkana, A.; Das, P. K.; Kolk, A. H.; Burggraaf, J. D.; Kuijper, S.; Harboe, M.

1993-01-01

Mycobacterium tuberculosis antigens inducing species-specific immune responses are likely to be particularly important for serodiagnosis or for skin testing of tuberculosis. In the present study, we describe the characterization of two novel monoclonal antibodies (MoAbs) A3h4 (IgG2a) and B5g1 (IgM)

Bioaktivitas Ekstrak Metanol Daun Pegagan (Centella Asiatica L. Terhadap Pertumbuhan Bakteri Mycobacterium Tuberculosis

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Yusran Yusran

2016-01-01

Full Text Available Plants gotu kola (Centella Asiatica L .Urban is a wild plant that efficacious as remedies traditional cure disease tuberculosis (TB.TB is disease contagious infection caused by bacteria mycobacterium tuberculosis. Research aims to understand the ability extract methanol leaves gotu kola red and leaves gotu kola green and determines the concentration optimal extract methanol leaves gotu kola red and leaves gotu kola green and to know the comparison between extract methanol leaves gotu kola red with an extract methanol leaves gotu kola green in inhibits the activity of mycobacterium tuberculosis.Extraction done with the methods maceration use methanol and continued with evaporation until obtained extract viscous .Testing antibacterial activity done in a microscopic observation drug susceptibility ( mods use plate petri dish 24 hole with the variation of concentration ie 20%,40%, 60%, 80% and 100%.The results of testing show that extracts methanol leaves gotu kola red and leaves gotu kola green positive capable of inhibiting the growth of bacteria mycobacterium tuberculosis with inhibition optimal in concentration 80 % and 100 % characterized by the absence of growth bacteria colonies which are (- or 0 %.Extract methanol leaves gotu kola green capable of inhibiting the growth of bacteria mycobacterium tuberculosis better than extract methanol leaves gotu kola red seen in concentration 40% and 60%.

Proteasomal control of cytokinin synthesis protects Mycobacterium tuberculosis against nitric oxide

Science.gov (United States)

Samanovic, Marie I.; Tu, Shengjiang; Novák, Ondřej; Iyer, Lakshminarayan M.; McAllister, Fiona E.; Aravind, L.; Gygi, Steven P.; Hubbard, Stevan R.; Strnad, Miroslav; Darwin, K. Heran

2015-01-01

Summary One of several roles of the Mycobacterium tuberculosis proteasome is to defend against host-produced nitric oxide (NO), a free radical that can damage numerous biological macromolecules. Mutations that inactivate proteasomal degradation in Mycobacterium tuberculosis result in bacteria that are hypersensitive to NO and attenuated for growth in vivo, but it was not known why. To elucidate the link between proteasome function, NO-resistance, and pathogenesis, we screened for suppressors of NO hypersensitivity in a mycobacterial proteasome ATPase mutant and identified mutations in Rv1205. We determined that Rv1205 encodes a pupylated proteasome substrate. Rv1205 is a homologue of the plant enzyme LONELY GUY, which catalyzes the production of hormones called cytokinins. Remarkably, we report for the first time that an obligate human pathogen secretes several cytokinins. Finally, we determined that the Rv1205-dependent accumulation of cytokinin breakdown products is likely responsible for the sensitization of Mycobacterium tuberculosis proteasome-associated mutants to NO. PMID:25728768

Inactivation of Mycobacterium paratuberculosis and Mycobacterium tuberculosis in fresh soft cheese by gamma radiation

International Nuclear Information System (INIS)

Badr, Hesham M.

2011-01-01

The effectiveness of gamma irradiation on the inactivation of Mycobacterium paratuberculosis, Mycobacterium bovis and Mycobacterium tuberculosis in fresh soft cheese that prepared from artificially inoculated milk samples was studied. Irradiation at dose of 2 kGy was sufficient for the complete inactivation of these mycobacteria as they were not detected in the treated samples during storage at 4±1 o C for 15 days. Moreover, irradiation of cheese samples, that were prepared from un-inoculated milk, at this effective dose had no significant effects on their gross composition and contents from riboflavin, niacin and pantothenic acid, while significant decreases in vitamin A and thiamin were observed. In addition, irradiation of cheese samples had no significant effects on their pH and nitrogen fractions contents, except for the contents of ammonia, which showed a slight, but significant, increases due to irradiation. The analysis of cheese fats indicated that irradiation treatment induced significant increase in their oxidation parameters and contents from free fatty acids; however, the observed increases were relatively low. On the other hand, irradiation of cheese samples induced no significant alterations on their sensory properties. Thus, irradiation dose of 2 kGy can be effectively applied to ensure the safety of soft cheese with regards to these harmful mycobacteria. - Highlights: → We examined the effectiveness of gamma irradiation on inactivation of Mycobacterium paratuberculosis, Mycobacterium bovis and Mycobacterium tuberculosis in fresh soft cheese. → Irradiation at dose of 2 kGy was sufficient for complete inactivation of these mycobacteria. → Irradiation of cheese samples induced no significant alterations on their sensory properties.

Inactivation of Mycobacterium paratuberculosis and Mycobacterium tuberculosis in fresh soft cheese by gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Badr, Hesham M., E-mail: heshambadr_aea@yahoo.co.uk [Atomic Energy Authority, Nuclear Research Center, Abou Zaabal, P.O. Box 13759 Cairo (Egypt)

2011-11-15

The effectiveness of gamma irradiation on the inactivation of Mycobacterium paratuberculosis, Mycobacterium bovis and Mycobacterium tuberculosis in fresh soft cheese that prepared from artificially inoculated milk samples was studied. Irradiation at dose of 2 kGy was sufficient for the complete inactivation of these mycobacteria as they were not detected in the treated samples during storage at 4{+-}1 {sup o}C for 15 days. Moreover, irradiation of cheese samples, that were prepared from un-inoculated milk, at this effective dose had no significant effects on their gross composition and contents from riboflavin, niacin and pantothenic acid, while significant decreases in vitamin A and thiamin were observed. In addition, irradiation of cheese samples had no significant effects on their pH and nitrogen fractions contents, except for the contents of ammonia, which showed a slight, but significant, increases due to irradiation. The analysis of cheese fats indicated that irradiation treatment induced significant increase in their oxidation parameters and contents from free fatty acids; however, the observed increases were relatively low. On the other hand, irradiation of cheese samples induced no significant alterations on their sensory properties. Thus, irradiation dose of 2 kGy can be effectively applied to ensure the safety of soft cheese with regards to these harmful mycobacteria. - Highlights: > We examined the effectiveness of gamma irradiation on inactivation of Mycobacterium paratuberculosis, Mycobacterium bovis and Mycobacterium tuberculosis in fresh soft cheese. > Irradiation at dose of 2 kGy was sufficient for complete inactivation of these mycobacteria. > Irradiation of cheese samples induced no significant alterations on their sensory properties.

Mycobacterium malmesburyense sp. nov., a non-tuberculous species of the genus Mycobacterium revealed by multiple gene sequence characterization.

Science.gov (United States)

Gcebe, Nomakorinte; Rutten, Victor; Pittius, Nicolaas Gey van; Naicker, Brendon; Michel, Anita

2017-04-01

Non-tuberculous mycobacteria (NTM) are ubiquitous in the environment, and an increasing number of NTM species have been isolated and characterized from both humans and animals, highlighting the zoonotic potential of these bacteria. Host exposure to NTM may impact on cross-reactive immune responsiveness, which may affect diagnosis of bovine tuberculosis and may also play a role in the variability of the efficacy of Mycobacterium bovis BCG vaccination against tuberculosis. In this study we characterized 10 NTM isolates originating from water, soil, nasal swabs of cattle and African buffalo as well as bovine tissue samples. These isolates were previously identified during an NTM survey and were all found, using 16S rRNA gene sequence analysis to be closely related to Mycobacterium moriokaense. A polyphasic approach that included phenotypic characterization, antibiotic susceptibility profiling, mycolic acid profiling and phylogenetic analysis of four gene loci, 16S rRNA, hsp65, sodA and rpoB, was employed to characterize these isolates. Sequence data analysis of the four gene loci revealed that these isolates belong to a unique species of the genus Mycobacterium. This evidence was further supported by several differences in phenotypic characteristics between the isolates and the closely related species. We propose the name Mycobacterium malmesburyense sp. nov. for this novel species. The type strain is WCM 7299T (=ATCC BAA-2759T=CIP 110822T).

Structural studies on Mycobacterium tuberculosis RecA

Indian Academy of Sciences (India)

Structures of crystals of Mycobacterium tuberculosis RecA, grown and analysed under different conditions, provide insights into hitherto underappreciated details of molecular structure and plasticity. In particular, they yield information on the invariant and variable features of the geometry of the P-loop, whose binding to ATP ...

Dendritic Cells Activate and Mature after Infection with Mycobacterium tuberculosis

Directory of Open Access Journals (Sweden)

Mamo Gezahagne

2011-07-01

Full Text Available Abstract Background Dendritic cells (DCs can take up an array of different antigens, including microorganisms which they can process and present more effectively than any other antigen presenting cell. However, whether the interaction between the human DC and Mycobacterium tuberculosis represents a defense mechanism by the invaded host, or helping the invader to evade the defense mechanism of the host is still not clearly understood. Findings To analyze the interactions between M. tuberculosis and immune cells, human peripheral blood monocyte-derived immature DCs were infected with M. tuberculosis H37Rv wild type strain and flow cytometry was used to analyse cell surface expression markers. The ability of the M. tuberculosis infected DC to induce T cell proliferation using 5 and 6-carboxyfluorescein diacetate succinimidyl ester (CFSE dilution technique was also investigated. DCs were found to internalize the mycobacteria and show dose dependent infection and necrosis with different multiplicity of infection. Flow cytometry analysis of cell surface expression markers CD40, CD54, CD80, CD83, CD86 and HLA DR in infected DC revealed significant (p M. tuberculosis in comparison to immature DC with no stimulation. Lipopolysaccharide (LPS from Salmonella abortus equi, a known DC maturation agent, was used as a positive control and showed a comparable up regulation of cell surface markers as observed with M. tuberculosis infected DC. It was revealed that the M. tuberculosis infected DC induced T cell proliferation. Conclusion These data clearly demonstrate that M. tuberculosis induces activation and maturation of human monocyte-derived immature DC as well as induces T cell proliferation in vitro.

DNA repair in Mycobacterium tuberculosis revisited.

Science.gov (United States)

Dos Vultos, Tiago; Mestre, Olga; Tonjum, Tone; Gicquel, Brigitte

2009-05-01

Our understanding of Mycobacterium tuberculosis DNA repair mechanisms is still poor compared with that of other bacterial organisms. However, the publication of the first complete M. tuberculosis genome sequence 10 years ago boosted the study of DNA repair systems in this organism. A first step in the elucidation of M. tuberculosis DNA repair mechanisms was taken by Mizrahi and Andersen, who identified homologs of genes involved in the reversal or repair of DNA damage in Escherichia coli and related organisms. Genes required for nucleotide excision repair, base excision repair, recombination, and SOS repair and mutagenesis were identified. Notably, no homologs of genes involved in mismatch repair were identified. Novel characteristics of the M. tuberculosis DNA repair machinery have been found over the last decade, such as nonhomologous end joining, the presence of Mpg, ERCC3 and Hlr - proteins previously presumed to be produced exclusively in mammalian cells - and the recently discovered bifunctional dCTP deaminase:dUTPase. The study of these systems is important to develop therapeutic agents that can counteract M. tuberculosis evolutionary changes and to prevent adaptive events resulting in antibiotic resistance. This review summarizes our current understanding of the M. tuberculosis DNA repair system.

Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection

DEFF Research Database (Denmark)

Brock, I; Weldingh, K; Leyten, EM

2004-01-01

Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection.Brock I, Weldingh K, Leyten EM, Arend SM, Ravn P, Andersen P. Department of Infectious Disease Immunology, Statens Serum Institute, Artillerivej 5, DK-2300 Copenhagen S, Denmark. The currently used...... method for immunological detection of tuberculosis infection, the tuberculin skin test, has low specificity. Antigens specific for Mycobacterium tuberculosis to replace purified protein derivative are therefore urgently needed. We have performed a rigorous assessment of the diagnostic potential of four...... selected and combined the specific peptide stretches from the four proteins not recognized by M. bovis BCG-vaccinated individuals. These peptide stretches were tested with peripheral blood mononuclear cells obtained from patients with microscopy- or culture-confirmed tuberculosis and from healthy M. bovis...

Efficacy of amikacin and ciprofloxacin against clinical isolates of mycobacterium tuberculosis

International Nuclear Information System (INIS)

Satti, M.; Faqir, F.; Sattar, A.; Abbasi, S.; Butt, T.; Karamat, K.A.; Abidi, M.

2010-01-01

Background: Tuberculosis was a leading cause of death at the turn of the 20 century and continues to be one of the medical scourges of mankind. Before the availability of antimicrobial drugs the cornerstone of treatment was rest in the open air in sanatoria. The major breakthrough in treatment of tuberculosis came with the discovery of Streptomycin. Later, INH, Ethambutol, Pyrazinamide, Rifampicin were added to the arsenal. Objective of this study was to determine the sensitivity of clinical isolates of Mycobacterium tuberculosis against two second-line anti-tuberculosis drugs, Amikacin and Ciprofloxacin. Methods: This cross-sectional study was conducted at Department of Microbiology, Armed Forces Institute of Pathology (AFIP) Rawalpindi. All routine clinical samples received for acid fast bacilli (AFB) in the Department of Microbiology, AFIP, Rawalpindi were processed by modified Petroff's technique and inoculated on Lowenstein Jensen (LJ) medium and Bactec 460 Mycobacterium tuberculosis culture system. After identification of M. tuberculosis sensitivity was performed against first-line anti-tuberculosis drugs. Then susceptibility of M. tuberculosis isolates against Amikacin and Ciprofloxacin was performed on LJ medium. H37Rv was used as control strain. Results: Results were interpreted using resistance ratio method. Out of 100 M. tuberculosis isolates, 98% were sensitive to Amikacin and 97% to Ciprofloxacin. Conclusion: Amikacin and Ciprofloxacin are very effective second line anti-tuberculosis drugs against tuberculosis isolates in our set-up. (author)

Drug susceptibility testing of Mycobacterium tuberculosis to fluoroquinolones

DEFF Research Database (Denmark)

Johansen, I S; Larsen, A R; Sandven, P

2003-01-01

In the first attempt to establish a quality assurance programme for susceptibility testing of Mycobacterium tuberculosis to fluoroquinolones, 20 strains with different fluoroquinolone susceptibility patterns were distributed by the Supranational Reference Laboratory in Stockholm to the other...

Bloodstream Infections with Mycobacterium tuberculosis among HIV patients

Centers for Disease Control (CDC) Podcasts

This podcast looks at bloodstream infections with Mycobacterium tuberculosis and other pathogens among outpatients infected with HIV in Southeast Asia. CDC health scientist Kimberly McCarthy discusses the study and why bloodstream infections occur in HIV-infected populations.

Mycobacterium tuberculosis: nepřekonatelný nepřítel

Czech Academy of Sciences Publication Activity Database

Machová, Iva; Pichová, Iva

2014-01-01

Roč. 24, č. 4 (2014), s. 98-100 ISSN 1210-1737 R&D Projects: GA MŠk LO1302; GA MŠk(CZ) 7E11070 EU Projects: European Commission(XE) 241587 - SYSTEMTB Institutional support: RVO:61388963 Keywords : Mycobacterium tuberculosis * tuberculosis * latent infection * resistance * metabolism * drugs Subject RIV: CE - Biochemistry

Characterization of extensively drug-resistant Mycobacterium tuberculosis in Nepal.

Science.gov (United States)

Poudel, Ajay; Maharjan, Bhagwan; Nakajima, Chie; Fukushima, Yukari; Pandey, Basu D; Beneke, Antje; Suzuki, Yasuhiko

2013-01-01

The emergence of extensively drug-resistant tuberculosis (XDR-TB) has raised public health concern for global control of TB. Although molecular characterization of drug resistance-associated mutations in multidrug-resistant isolates in Nepal has been made, mutations in XDR isolates and their genotypes have not been reported previously. In this study, we identified and characterized 13 XDR Mycobacterium tuberculosis isolates from clinical isolates in Nepal. The most prevalent mutations involved in rifampicin, isoniazid, ofloxacin, and kanamycin/capreomycin resistance were Ser531Leu in rpoB gene (92.3%), Ser315Thr in katG gene (92.3%), Asp94Gly in gyrA gene (53.9%) and A1400G in rrs gene (61.5%), respectively. Spoligotyping and multilocus sequence typing revealed that 69% belonged to Beijing family, especially modern types. Further typing with 26-loci variable number of tandem repeats suggested the current spread of XDR M. tuberculosis. Our result highlights the need to reinforce the TB policy in Nepal with regard to control and detection strategies. Copyright © 2012 Elsevier Ltd. All rights reserved.

Polymorphisms in Isoniazid and Prothionamide Resistance Genes of the Mycobacterium tuberculosis Complex

KAUST Repository

Projahn, M.; Koser, C. U.; Homolka, S.; Summers, D. K.; Archer, John A.C.; Niemann, S.

2011-01-01

Sequence analyses of 74 strains that encompassed major phylogenetic lineages of the Mycobacterium tuberculosis complex revealed 10 polymorphisms in mshA (Rv0486) and four polymorphisms in inhA (Rv1484) that were not responsible for isoniazid or prothionamide resistance. Instead, some of these mutations were phylogenetically informative. This genetic diversity must be taken into consideration for drug development and for the design of molecular tests for drug resistance.

Polymorphisms in Isoniazid and Prothionamide Resistance Genes of the Mycobacterium tuberculosis Complex

KAUST Repository

Projahn, M.

2011-06-27

Sequence analyses of 74 strains that encompassed major phylogenetic lineages of the Mycobacterium tuberculosis complex revealed 10 polymorphisms in mshA (Rv0486) and four polymorphisms in inhA (Rv1484) that were not responsible for isoniazid or prothionamide resistance. Instead, some of these mutations were phylogenetically informative. This genetic diversity must be taken into consideration for drug development and for the design of molecular tests for drug resistance.

Whole genome sequencing reveals genomic heterogeneity and antibiotic purification in Mycobacterium tuberculosis isolates

KAUST Repository

Black, PA

2015-10-24

Background Whole genome sequencing has revolutionised the interrogation of mycobacterial genomes. Recent studies have reported conflicting findings on the genomic stability of Mycobacterium tuberculosis during the evolution of drug resistance. In an age where whole genome sequencing is increasingly relied upon for defining the structure of bacterial genomes, it is important to investigate the reliability of next generation sequencing to identify clonal variants present in a minor percentage of the population. This study aimed to define a reliable cut-off for identification of low frequency sequence variants and to subsequently investigate genetic heterogeneity and the evolution of drug resistance in M. tuberculosis. Methods Genomic DNA was isolated from single colonies from 14 rifampicin mono-resistant M. tuberculosis isolates, as well as the primary cultures and follow up MDR cultures from two of these patients. The whole genomes of the M. tuberculosis isolates were sequenced using either the Illumina MiSeq or Illumina HiSeq platforms. Sequences were analysed with an in-house pipeline. Results Using next-generation sequencing in combination with Sanger sequencing and statistical analysis we defined a read frequency cut-off of 30 % to identify low frequency M. tuberculosis variants with high confidence. Using this cut-off we demonstrated a high rate of genetic diversity between single colonies isolated from one population, showing that by using the current sequencing technology, single colonies are not a true reflection of the genetic diversity within a whole population and vice versa. We further showed that numerous heterogeneous variants emerge and then disappear during the evolution of isoniazid resistance within individual patients. Our findings allowed us to formulate a model for the selective bottleneck which occurs during the course of infection, acting as a genomic purification event. Conclusions Our study demonstrated true levels of genetic diversity

Combating highly resistant emerging pathogen Mycobacterium abscessus and Mycobacterium tuberculosis with novel salicylanilide esters and carbamates.

Science.gov (United States)

Baranyai, Zsuzsa; Krátký, Martin; Vinšová, Jarmila; Szabó, Nóra; Senoner, Zsuzsanna; Horváti, Kata; Stolaříková, Jiřina; Dávid, Sándor; Bősze, Szilvia

2015-08-28

In the Mycobacterium genus over one hundred species are already described and new ones are periodically reported. Species that form colonies in a week are classified as rapid growers, those requiring longer periods (up to three months) are the mostly pathogenic slow growers. More recently, new emerging species have been identified to lengthen the list, all rapid growers. Of these, Mycobacterium abscessus is also an intracellular pathogen and it is the most chemotherapy-resistant rapid-growing mycobacterium. In addition, the cases of multidrug-resistant Mycobacterium tuberculosis infection are also increasing. Therefore there is an urgent need to find new active molecules against these threatening strains. Based on previous results, a series of salicylanilides, salicylanilide 5-chloropyrazinoates and carbamates was designed, synthesized and characterised. The compounds were evaluated for their in vitro activity on M. abscessus, susceptible M. tuberculosis H37Rv, multidrug-resistant (MDR) M. tuberculosis MDR A8, M. tuberculosis MDR 9449/2006 and on the extremely-resistant Praha 131 (XDR) strains. All derivatives exhibited a significant activity with minimum inhibitory concentrations (MICs) in the low micromolar range. Eight salicylanilide carbamates and two salicylanilide esters exhibited an excellent in vitro activity on M. abscessus with MICs from 0.2 to 2.1 μM, thus being more effective than ciprofloxacin and gentamicin. This finding is potentially promising, particularly, as M. abscessus is a threateningly chemotherapy-resistant species. M. tuberculosis H37Rv was inhibited with MICs from 0.2 μM, and eleven compounds have lower MICs than isoniazid. Salicylanilide esters and carbamates were found that they were effective also on MDR and XDR M. tuberculosis strains with MICs ≥1.0 μM. The in vitro cytotoxicity (IC50) was also determined on human MonoMac-6 cells, and selectivity index (SI) of the compounds was established. In general, salicylanilide

Mycobacterium tuberculosis Isolates from Single Outpatient Clinic in Panama City Exhibit Wide Genetic Diversity

Science.gov (United States)

Sambrano, Dilcia; Correa, Ricardo; Almengor, Pedro; Domínguez, Amada; Vega, Silvio; Goodridge, Amador

2014-01-01

Understanding Mycobacterium tuberculosis biodiversity and transmission is significant for tuberculosis control. This short report aimed to determine the genetic diversity of M. tuberculosis isolates from an outpatient clinic in Panama City. A total of 62 M. tuberculosis isolates were genotyped by 12 loci mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) and Spoligotyping. Forty-five (72.6%) of the isolates showed unique MIRU-VNTR genotypes, and 13 (21%) of the isolates were grouped into four clusters. Four isolates showed polyclonal MIRU-VNTR genotypes. The MIRU-VNTR Hunter-Gaston discriminatory index reached 0.988. The Spoligotyping analysis revealed 16 M. tuberculosis families, including Latin American-Mediterranean, Harlem, and Beijing. These findings suggest a wide genetic diversity of M. tuberculosis isolates at one outpatient clinic. A detailed molecular epidemiology survey is now warranted, especially following second massive immigration for local Panama Canal expansion activities. PMID:24865686

Role of Granulocyte-Macrophage Colony-Stimulating Factor Production by T Cells during Mycobacterium tuberculosis Infection.

Science.gov (United States)

Rothchild, Alissa C; Stowell, Britni; Goyal, Girija; Nunes-Alves, Cláudio; Yang, Qianting; Papavinasasundaram, Kadamba; Sassetti, Christopher M; Dranoff, Glenn; Chen, Xinchun; Lee, Jinhee; Behar, Samuel M

2017-10-24

response to Mycobacterium tuberculosis While gamma interferon (IFN-γ) is a key effector function of T cells during infection, a failed phase IIb clinical trial and other studies have revealed that IFN-γ production alone is not sufficient to control M. tuberculosis In this study, we demonstrate that CD4 + , CD8 + , and nonconventional T cells produce GM-CSF during Mycobacterium tuberculosis infection in mice and in the peripheral blood of infected humans. Under conditions where other sources of GM-CSF are absent, T cell production of GM-CSF is protective and is required for control of infection. GM-CSF activation of macrophages to limit bacterial growth requires host expression of the transcription factor PPARγ. The identification of GM-CSF production as a T cell effector function may inform future host-directed therapy or vaccine designs. Copyright © 2017 Rothchild et al.

Evidence of presence of Mycobacterium tuberculosis in bovine tissue samples by multiplex PCR: possible relevance to reverse zoonosis.

Science.gov (United States)

Mittal, M; Chakravarti, S; Sharma, V; Sanjeeth, B S; Churamani, C P; Kanwar, N S

2014-04-01

Bovine tuberculosis, caused by Mycobacterium bovis, remains one of the most important zoonotic health concerns worldwide. The transmission of Mycobacterium tuberculosis from humans to animals also occurs especially in countries where there is close interaction of humans with the animals. In the present study, thirty bovine lung tissue autopsy samples from an organized dairy farm located in North India were screened for the presence of Mycobacterium tuberculosis complex by smear microscopy, histopathological findings and PCR. Differential diagnosis of M. tuberculosis and M. bovis was made based on the deletion of mce-3 operon in M. bovis. The present study found eight of these samples positive for M. tuberculosis by multiplex PCR. Sequencing was performed on two PCR-positive representative samples and on annotation, and BLAST analysis confirmed the presence of gene fragment specific to Mycobacterium tuberculosis. The presence of M. tuberculosis in all the positive samples raises the possibility of human-to-cattle transmission and possible adaptation of this organism in bovine tissues. This study accentuates the importance of screening and differential diagnosis of Mycobacterium tuberculosis complex in humans and livestock for adopting effective TB control and eradication programmes. © 2014 Blackwell Verlag GmbH.

Sulfonamide-Based Inhibitors of Aminoglycoside Acetyltransferase Eis Abolish Resistance to Kanamycin in Mycobacterium tuberculosis

Energy Technology Data Exchange (ETDEWEB)

Garzan, Atefeh; Willby, Melisa J.; Green, Keith D.; Gajadeera, Chathurada S.; Hou, Caixia; Tsodikov, Oleg V.; Posey, James E.; Garneau-Tsodikova, Sylvie

2016-12-08

A two-drug combination therapy where one drug targets an offending cell and the other targets a resistance mechanism to the first drug is a time-tested, yet underexploited approach to combat or prevent drug resistance. By high-throughput screening, we identified a sulfonamide scaffold that served as a pharmacophore to generate inhibitors of Mycobacterium tuberculosis acetyltransferase Eis, whose upregulation causes resistance to the aminoglycoside (AG) antibiotic kanamycin A (KAN) in Mycobacterium tuberculosis. Rational systematic derivatization of this scaffold to maximize Eis inhibition and abolish the Eis-mediated KAN resistance of M. tuberculosis yielded several highly potent agents. A crystal structure of Eis in complex with one of the most potent inhibitors revealed that the inhibitor bound Eis in the AG-binding pocket held by a conformationally malleable region of Eis (residues 28–37) bearing key hydrophobic residues. These Eis inhibitors are promising leads for preclinical development of innovative AG combination therapies against resistant TB.

Comparison of the UDP-N-Acetylmuramate:l-Alanine Ligase Enzymes from Mycobacterium tuberculosis and Mycobacterium leprae

OpenAIRE

Mahapatra, Sebabrata; Crick, Dean C.; Brennan, Patrick J.

2000-01-01

In the peptidoglycan of Mycobacterium leprae, l-alanine of the side chain is replaced by glycine. When expressed in Escherichia coli, MurC (UDP-N-acetyl-muramate:l-alanine ligase) of M. leprae showed Km and Vmax for l-alanine and glycine similar to those of Mycobacterium tuberculosis MurC, suggesting that another explanation should be sought for the presence of glycine.

Comparison of antigen-specific T-cell responses of tuberculosis patients using complex or single antigens of Mycobacterium tuberculosis

DEFF Research Database (Denmark)

Mustafa, A S; Amoudy, H A; Wiker, H G

1998-01-01

We have screened peripheral blood mononuclear cells (PBMC) from tuberculosis (TB) patients for proliferative reactivity and interferon-gamma (IFN-gamma) secretion against a panel of purified recombinant (r) and natural (n) culture filtrate (rESAT-6, nMPT59, nMPT64 and nMPB70) and somatic-derived (r......GroES, rPstS, rGroEL and rDnaK) antigens of Mycobacterium tuberculosis. The responses of PBMC to these defined antigens were compared with the corresponding results obtained with complex antigens, such as whole-cell M. tuberculosis, M. tuberculosis culture filtrate (MT-CF) and cell wall antigens, as well...... as the vaccine strain, Mycobacterium bovis bacillus Calmette-Guerin (BCG). In addition, M. tuberculosis and MT-CF-induced T-cell lines were tested in the same assays against the panel of purified and complex antigens. The compiled data from PBMC and T-cell lines tested for antigen-induced proliferation and IFN...

JST Thesaurus Headwords and Synonyms: Mycobacterium tuberculosis [MeCab user dictionary for science technology term[Archive

Lifescience Database Archive (English)

Full Text Available MeCab user dictionary for science technology term Mycobacterium tuberculosis 名詞 一般 * * * * 結核...菌 ケッカクキン ケッカクキン Thesaurus2015 200906007893342100 C LS07 UNKNOWN_2 Mycobacterium tuberculosis

Molecular identification of Mycobacterium tuberculosis complex isolates from Kermanshah Province, Iran

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Roghieh Moghaddam

2016-01-01

Full Text Available Tuberculosis is one of the most important zoonotic diseases in the world. Rapid diagnosis of the disease and identification of species is extremely important for proper treatment of the disease as some species of the complex are resistant to the first-line of tuberculosis drugs. The aim of present study was molecular identification of Mycobacterium tuberculosis (MTB complex isolates from Kermanshah Province, Iran, which were submitted to the Tuberculosis Reference Laboratory at Razi Vaccine and Serum Research Institute (Tehran, Iran. To identify the genus Mycobacterium, all isolates were subjected to 16S rRNA polymerase chain reaction (PCR, and PCR-IS6110 was subsequently used to confirm that the isolates belonged to MTB complex. Finally, region of difference (RD typing was used to identify the species in the complex. The results of 16S rRNA and IS6110 PCR analysis showed the presence of 543-bp and 245-bp bands, respectively. Furthermore, 146bp, 172bp, 235bp, and 369bp at RD1, RD4, RD9, and RD12, respectively, were observed during RD typing. Thus, based on the results, all isolates were identified as MTB. It is worth mentioning that most tuberculosis cases are identified on the basis of acid-fast bacilli detection, and antibiotic therapy is immediately initiated subsequently. Moreover, it should be noted that some of these acid-fast positive cases might not be of genus Mycobacterium, and thus, the antibiotics prescribed might threaten the health of the patients. Additionally, if the identified bacilli are not within MTB complex, the drug therapy would differ. However, Mycobacterium bovis, which is a member of MTB complex and is resistant to pyrazinamide, requires exact strain identification. Based on the findings, individual isolates should be identified by RD typing methods, which could clearly discriminate the species from each other.

Integration of published information into a resistance-associated mutation database for Mycobacterium tuberculosis.

Science.gov (United States)

Salamon, Hugh; Yamaguchi, Ken D; Cirillo, Daniela M; Miotto, Paolo; Schito, Marco; Posey, James; Starks, Angela M; Niemann, Stefan; Alland, David; Hanna, Debra; Aviles, Enrique; Perkins, Mark D; Dolinger, David L

2015-04-01

Tuberculosis remains a major global public health challenge. Although incidence is decreasing, the proportion of drug-resistant cases is increasing. Technical and operational complexities prevent Mycobacterium tuberculosis drug susceptibility phenotyping in the vast majority of new and retreatment cases. The advent of molecular technologies provides an opportunity to obtain results rapidly as compared to phenotypic culture. However, correlations between genetic mutations and resistance to multiple drugs have not been systematically evaluated. Molecular testing of M. tuberculosis sampled from a typical patient continues to provide a partial picture of drug resistance. A database of phenotypic and genotypic testing results, especially where prospectively collected, could document statistically significant associations and may reveal new, predictive molecular patterns. We examine the feasibility of integrating existing molecular and phenotypic drug susceptibility data to identify associations observed across multiple studies and demonstrate potential for well-integrated M. tuberculosis mutation data to reveal actionable findings. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Distinct Spatiotemporal Dynamics of Peptidoglycan Synthesis between Mycobacterium smegmatis and Mycobacterium tuberculosis

Directory of Open Access Journals (Sweden)

Helene Botella

2017-09-01

Full Text Available Peptidoglycan (PG, a polymer cross-linked by d-amino acid-containing peptides, is an essential component of the bacterial cell wall. We found that a fluorescent d-alanine analog (FDAA incorporates chiefly at one of the two poles in Mycobacterium smegmatis but that polar dominance varies as a function of the cell cycle in Mycobacterium tuberculosis: immediately after cytokinesis, FDAAs are incorporated chiefly at one of the two poles, but just before cytokinesis, FDAAs are incorporated comparably at both. These observations suggest that mycobacterial PG-synthesizing enzymes are localized in functional compartments at the poles and septum and that the capacity for PG synthesis matures at the new pole in M. tuberculosis. Deeper knowledge of the biology of mycobacterial PG synthesis may help in discovering drugs that disable previously unappreciated steps in the process.

Rapid drug susceptibility test of mycobacterium tuberculosis by bioluminescence sensor

Science.gov (United States)

Lu, Bin; Xu, Shunqing; Chen, Zifei; Zhou, Yikai

2001-09-01

With the persisting increase of drug-resistant stains of M. Tuberculosis around the world, rapid and sensitive detection of antibiotic of M. Tuberculosis is becoming more and more important. In the present study, drug susceptibility of M. tuberculosis were detected by recombination mycobacteriophage combined with bioluminescence sensor. It is based on the use of recombination mycobacteriophage which can express firefly luciferase when it infects viable mycobacteria, and can effectively produce quantifiable photon. Meanwhile, in mycobacterium cells treated with active antibiotic, no light is observed. The emitted light is recorded by a bioluminscence sensor, so the result of drug-resistant test can be determined by the naked eye. 159 stains of M. tuberculosis were applied to this test on their resistant to rifampin, streptomycin and isoniazid. It is found that the agreement of this assay with Liewenstein- Jensen slat is: rifampin 95.60 percent, isoniazid 91.82 percent, streptomycin 88.68 percent, which showed that it is a fast and practical method to scene and detect drug resistant of mycobacterium stains.

Progenitor “Mycobacterium canettii” clone responsible for lymph node tuberculosis epidemic, Djibouti.

Science.gov (United States)

Blouin, Yann; Cazajous, Géraldine; Dehan, Céline; Soler, Charles; Vong, Rithy; Hassan, Mohamed Osman; Hauck, Yolande; Boulais, Christian; Andriamanantena, Dina; Martinaud, Christophe; Martin, Émilie; Pourcel, Christine; Vergnaud, Gilles

2014-01-01

“Mycobacterium canettii,” an opportunistic human pathogen living in an unknown environmental reservoir, is the progenitor species from which Mycobacterium tuberculosis emerged. Since its discovery in 1969, most of the ≈70 known M. canettii strains were isolated in the Republic of Djibouti, frequently from expatriate children and adults. We show here, by whole-genome sequencing, that most strains collected from February 2010 through March 2013, and associated with 2 outbreaks of lymph node tuberculosis in children, belong to a unique epidemic clone within M. canettii. Evolution of this clone, which has been recovered regularly since 1983, may mimic the birth of M. tuberculosis. Thus, recognizing this organism and identifying its reservoir are clinically important.

[A study on genotype of 271 mycobacterium tuberculosis isolates in 6 prefectures in Yunnan Province].

Science.gov (United States)

Chen, L Y; Yang, X; Ru, H H; Yang, H J; Yan, S Q; Ma, L; Chen, J O; Yang, R; Xu, L

2018-01-06

Objective: To understand the characteristics of genotypes of Mycobacterium tuberculosis isolates in Yunnan province, and provide the molecular epidemiological evidence for prevention and control of tuberculosis in Yunnan Province. Methods: Mycobacterium Tuberculosis isolates were collected from 6 prefectures of Yunnan province in 2014 and their Genetypes of Mycobacterium tuberculosis isolates were obtained using spoligotyping and multiple locus variable numbers of tandem repeats analysis (MLVA). The results of spoligotyping were entered into the SITVITWEB database to obtain the Spoligotyping International Type (SIT) patterns and the sublineages of MTB isolates. The genoyping patterns were clustered with BioNumerics (version 5.0). Results: A total of 271 MTB isolates represented patients were collected from six prefectures in Yunnan province. Out of these patients, 196 (72.3%) were male. The mean age of the patients was (41.9±15.1) years. The most MTB isolates were from Puer, totally 94 iusolates(34.69%). Spoligotyping analysis revealed that 151 (55.72%) MTB isolates belonged to the Beijing genotype, while the other 120 (44.28%) were from non-Beijing genotype; 40 genotypes were consisted of 24 unique genotypes and 16 clusters. The 271 isolates were differentiated into 30 clusters (2 to 17 isolates per cluster) and 177 unique genotypes, showing a clustering rate of 23.62%. Beijing genotype strains showed higher clustering rate than non-Beijing genotype strains (29.14% vs 16.67%). The HGI of 12-locus VNTR in total MTB strains, Beijing genotype strains and non-Beijing genotype was 0.993, 0.982 and 0.995 respectively. Conclusion: The Beijing genotype was the predominant genotype in Yunnan Province, the characteristics of Mycobacterium tuberculosis showed high genetic diversity. The genotyping data reflect the potential recent ongoing transmission in some area, which highlights the urgent need for early diagnosis and treatment of the infectious TB cases, to cut off the

Comparison of the UDP-N-Acetylmuramate:l-Alanine Ligase Enzymes from Mycobacterium tuberculosis and Mycobacterium leprae

Science.gov (United States)

Mahapatra, Sebabrata; Crick, Dean C.; Brennan, Patrick J.

2000-01-01

In the peptidoglycan of Mycobacterium leprae, l-alanine of the side chain is replaced by glycine. When expressed in Escherichia coli, MurC (UDP-N-acetyl-muramate:l-alanine ligase) of M. leprae showed Km and Vmax for l-alanine and glycine similar to those of Mycobacterium tuberculosis MurC, suggesting that another explanation should be sought for the presence of glycine. PMID:11073931

Cellular immune responses to ESAT-6 discriminate between patients with pulmonary disease due to Mycobacterium avium complex and those with pulmonary disease due to Mycobacterium tuberculosis

DEFF Research Database (Denmark)

Lein, A D; von Reyn, C F; Ravn, P

1999-01-01

ESAT-6 (for 6-kDa early secreted antigenic target) is a secreted antigen found almost exclusively in organisms of the Mycobacterium tuberculosis complex. We compared in vitro gamma interferon (IFN-gamma) responses by peripheral blood mononuclear cells to this antigen in patients with pulmonary...... disease due to either Mycobacterium avium complex (MAC) or Mycobacterium tuberculosis with those in healthy, skin test-negative, control subjects. Significant IFN-gamma responses to ESAT-6 were detected in 16 (59%) of 27 M. tuberculosis pulmonary disease patients, 0 (0%) of 8 MAC disease patients, and 0...... (0%) of 8 controls. Significant IFN-gamma responses to M. tuberculosis purified protein derivative were detected in 23 (85%) of 27 M. tuberculosis disease patients, 2 (25%) of 8 MAC disease patients, and 5 (63%) of 8 healthy controls. M. avium sensitin was recognized in 24 (89%) of 27 M. tuberculosis...

Mycobacterium tuberculosis bacteremia detected by the Isolator lysis-centrifugation blood culture system.

OpenAIRE

Kiehn, T E; Gold, J W; Brannon, P; Timberger, R J; Armstrong, D

1985-01-01

Mycobacterium tuberculosis was detected by the Isolator lysis-centrifugation blood culture system from the blood of a patient with tuberculosis of the breast. The organism also grew on conventional laboratory media inoculated with pleural fluid from the patient.

Beijing/W genotype Mycobacterium tuberculosis and drug resistance.

NARCIS (Netherlands)

Glynn, Judith R; Kremer, Kristin; Borgdorff, Martien W; Rodriguez, Mar Pujades; Soolingen, Dick van

2006-01-01

Beijing/W genotype Mycobacterium tuberculosis is widespread, may be increasing, and may have a predilection for drug resistance. Individual-level data on >29,000 patients from 49 studies in 35 countries were combined to assess the Beijing genotype's prevalence worldwide, trends over time and with

Modern lineages of Mycobacterium tuberculosis in Addis Ababa ...

African Journals Online (AJOL)

Background: The genotyping of Mycobacterium tuberculosis strains is important to have unique insights into the dissemination dynamics and evolutionary genetics of this pathogen and for TB control as it allows the detection of suspected outbreaks and the tracing of transmission chains. Objective: To characterize M.

Mycobacterium tuberculosis effectors interfering host apoptosis signaling.

Science.gov (United States)

Liu, Minqiang; Li, Wu; Xiang, Xiaohong; Xie, Jianping

2015-07-01

Tuberculosis remains a serious human public health concern. The coevolution between its pathogen Mycobacterium tuberculosis and human host complicated the way to prevent and cure TB. Apoptosis plays subtle role in this interaction. The pathogen endeavors to manipulate the apoptosis via diverse effectors targeting key signaling nodes. In this paper, we summarized the effectors pathogen used to subvert the apoptosis, such as LpqH, ESAT-6/CFP-10, LAMs. The interplay between different forms of cell deaths, such as apoptosis, autophagy, necrosis, is also discussed with a focus on the modes of action of effectors, and implications for better TB control.

Identification of the Mycobacterium marinum Apa antigen O-mannosylation sites reveals important glycosylation variability with the M. tuberculosis Apa homologue.

Science.gov (United States)

Coddeville, Bernadette; Wu, Sz-Wei; Fabre, Emeline; Brassart, Colette; Rombouts, Yoann; Burguière, Adeline; Kremer, Laurent; Khoo, Kay-Hooi; Elass-Rochard, Elisabeth; Guérardel, Yann

2012-10-22

The 45/47 kDa Apa, an immuno-dominant antigen secreted by Mycobacterium tuberculosis is O-mannosylated at multiple sites. Glycosylation of Apa plays a key role in colonization and invasion of the host cells by M. tuberculosis through interactions of Apa with the host immune system C-type lectins. Mycobacterium marinum (M.ma) a fish pathogen, phylogenetically close to M. tuberculosis, induces a granulomatous response with features similar to those described for M. tuberculosis in human. Although M.ma possesses an Apa homologue, its glycosylation status is unknown, and whether this represents a crucial element in the pathophysiology induced by M.ma remains to be addressed. To this aim, we have identified two concanavalin A-reactive 45/47 kDa proteins from M.ma, which have been further purified by a two-step anion exchange chromatography process. Advanced liquid chromatography-nanoESI mass spectrometry-based proteomic analyses of peptides, derived from either tryptic digestion alone or in combination with the Asp-N endoproteinase, established that M.ma Apa possesses up to seven distinct O-mannosylated sites with mainly single mannose substitutions, which can be further extended at the Ser/Thr/Pro rich region near the N-terminus. This opens the way to further studies focussing on the involvement and biological functions of Apa O-mannosylation using the M.ma/zebrafish model. Copyright © 2012 Elsevier B.V. All rights reserved.

Molecular Epidemiology of Mycobacterium Tuberculosis Strains in ...

African Journals Online (AJOL)

Doroudchi M, Kremer K, Basiri EA, Kadivar MR,. Van Soolingen D, Ghaderi AA. IS6110‑RFLP and spoligotyping of Mycobacterium tuberculosis isolates in Iran. Scand J Infect. Dis 2000;32:663‑8. 13. Farnia P, Masjedi MR, Mirsaeidi M, Mohammadi F,. Jallaledin‑Ghanavi, Vincent V, et al. Prevalence of Haarlem I and Beijing ...

Delayed bactericidal response of Mycobacterium tuberculosis to bedaquiline involves remodelling of bacterial metabolism

DEFF Research Database (Denmark)

Koul, A.; Vranckx, L.; Dhar, N.

2014-01-01

Bedaquiline (BDQ), an ATP synthase inhibitor, is the first drug to be approved for treatment of multidrug-resistant tuberculosis in decades. Though BDQ has shown excellent efficacy in clinical trials, its early bactericidal activity during the first week of chemotherapy is minimal. Here, using...... microfluidic devices and time-lapse microscopy of Mycobacterium tuberculosis, we confirm the absence of significant bacteriolytic activity during the first 3-4 days of exposure to BDQ. BDQ-induced inhibition of ATP synthesis leads to bacteriostasis within hours after drug addition. Transcriptional...... and proteomic analyses reveal that M. tuberculosis responds to BDQ by induction of the dormancy regulon and activation of ATP-generating pathways, thereby maintaining bacterial viability during initial drug exposure. BDQ-induced bacterial killing is significantly enhanced when the mycobacteria are grown on non...

Horizontal acquisition of a hypoxia-responsive molybdenum cofactor biosynthesis pathway contributed to Mycobacterium tuberculosis pathoadaptation.

Science.gov (United States)

Levillain, Florence; Poquet, Yannick; Mallet, Ludovic; Mazères, Serge; Marceau, Michael; Brosch, Roland; Bange, Franz-Christoph; Supply, Philip; Magalon, Axel; Neyrolles, Olivier

2017-11-01

The unique ability of the tuberculosis (TB) bacillus, Mycobacterium tuberculosis, to persist for long periods of time in lung hypoxic lesions chiefly contributes to the global burden of latent TB. We and others previously reported that the M. tuberculosis ancestor underwent massive episodes of horizontal gene transfer (HGT), mostly from environmental species. Here, we sought to explore whether such ancient HGT played a part in M. tuberculosis evolution towards pathogenicity. We were interested by a HGT-acquired M. tuberculosis-specific gene set, namely moaA1-D1, which is involved in the biosynthesis of the molybdenum cofactor. Horizontal acquisition of this gene set was striking because homologues of these moa genes are present all across the Mycobacterium genus, including in M. tuberculosis. Here, we discovered that, unlike their paralogues, the moaA1-D1 genes are strongly induced under hypoxia. In vitro, a M. tuberculosis moaA1-D1-null mutant has an impaired ability to respire nitrate, to enter dormancy and to survive in oxygen-limiting conditions. Conversely, heterologous expression of moaA1-D1 in the phylogenetically closest non-TB mycobacterium, Mycobacterium kansasii, which lacks these genes, improves its capacity to respire nitrate and grants it with a marked ability to survive oxygen depletion. In vivo, the M. tuberculosis moaA1-D1-null mutant shows impaired survival in hypoxic granulomas in C3HeB/FeJ mice, but not in normoxic lesions in C57BL/6 animals. Collectively, our results identify a novel pathway required for M. tuberculosis resistance to host-imposed stress, namely hypoxia, and provide evidence that ancient HGT bolstered M. tuberculosis evolution from an environmental species towards a pervasive human-adapted pathogen.

Virulence factors of the Mycobacterium tuberculosis complex

Science.gov (United States)

Forrellad, Marina A.; Klepp, Laura I.; Gioffré, Andrea; Sabio y García, Julia; Morbidoni, Hector R.; Santangelo, María de la Paz; Cataldi, Angel A.; Bigi, Fabiana

2013-01-01

The Mycobacterium tuberculosis complex (MTBC) consists of closely related species that cause tuberculosis in both humans and animals. This illness, still today, remains to be one of the leading causes of morbidity and mortality throughout the world. The mycobacteria enter the host by air, and, once in the lungs, are phagocytated by macrophages. This may lead to the rapid elimination of the bacillus or to the triggering of an active tuberculosis infection. A large number of different virulence factors have evolved in MTBC members as a response to the host immune reaction. The aim of this review is to describe the bacterial genes/proteins that are essential for the virulence of MTBC species, and that have been demonstrated in an in vivo model of infection. Knowledge of MTBC virulence factors is essential for the development of new vaccines and drugs to help manage the disease toward an increasingly more tuberculosis-free world. PMID:23076359

Phenotypic assays for Mycobacterium tuberculosis infection.

Science.gov (United States)

Song, Ok-Ryul; Deboosere, Nathalie; Delorme, Vincent; Queval, Christophe J; Deloison, Gaspard; Werkmeister, Elisabeth; Lafont, Frank; Baulard, Alain; Iantomasi, Raffaella; Brodin, Priscille

2017-10-01

Tuberculosis (TB) is still a major global threat, killing more than one million persons each year. With the constant increase of Mycobacterium tuberculosis strains resistant to first- and second-line drugs, there is an urgent need for the development of new drugs to control the propagation of TB. Although screenings of small molecules on axenic M. tuberculosis cultures were successful for the identification of novel putative anti-TB drugs, new drugs in the development pipeline remains scarce. Host-directed therapy may represent an alternative for drug development against TB. Indeed, M. tuberculosis has multiple specific interactions within host phagocytes, which may be targeted by small molecules. In order to enable drug discovery strategies against microbes residing within host macrophages, we developed multiple fluorescence-based HT/CS phenotypic assays monitoring the intracellular replication of M. tuberculosis as well as its intracellular trafficking. What we propose here is a population-based, multi-parametric analysis pipeline that can be used to monitor the intracellular fate of M. tuberculosis and the dynamics of cellular events such as phagosomal maturation (acidification and permeabilization), zinc poisoning system or lipid body accumulation. Such analysis allows the quantification of biological events considering the host-pathogen interplay and may thus be derived to other intracellular pathogens. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

(1H-NMR spectroscopy revealed Mycobacterium tuberculosis caused abnormal serum metabolic profile of cattle.

Directory of Open Access Journals (Sweden)

Yingyu Chen

Full Text Available To re-evaluate virulence of Mycobacterium tuberculosis (M. tb in cattle, we experimentally infected calves with M. tb andMycobacterium bovisvia intratracheal injection at a dose of 2.0×10(7 CFU and observed the animals for 33 weeks. The intradermal tuberculin test and IFN-γin vitro release assay showed that both M. tb and M. bovis induced similar responses. Immunohistochemical staining of pulmonary lymph nodes indicated that the antigen MPB83 of both M. tb and M. bovis were similarly distributed in the tissue samples. Histological examinations showed all of the infected groups exhibited neutrophil infiltration to similar extents. Although the infected cattle did not develop granulomatous inflammation, the metabolic profiles changed significantly, which were characterized by a change in energy production pathways and increased concentrations of N-acetyl glycoproteins. Glycolysis was induced in the infected cattle by decreased glucose and increased lactate content, and enhanced fatty acid β-oxidation was induced by decreased TG content, and decreased gluconeogenesis indicated by the decreased concentration of glucogenic and ketogenic amino acids promoted utilization of substances other than glucose as energy sources. In addition, an increase in acute phase reactive serum glycoproteins, together with neutrophil infiltration and increased of IL-1β production indicated an early inflammatory response before granuloma formation. In conclusion, this study indicated that both M. tb and M.bovis were virulent to cattle. Therefore, it is likely that cattle with M. tb infections would be critical to tuberculosis transmission from cattle to humans. Nuclear magnetic resonance was demonstrated to be an efficient method to systematically evaluate M. tb and M. bovi sinfection in cattle.

Genome sequencing and annotation of multidrug resistant Mycobacterium tuberculosis (MDR-TB PR10 strain

Directory of Open Access Journals (Sweden)

Mohd Zakihalani A. Halim

2016-03-01

Full Text Available Here, we report the draft genome sequence and annotation of a multidrug resistant Mycobacterium tuberculosis strain PR10 (MDR-TB PR10 isolated from a patient diagnosed with tuberculosis. The size of the draft genome MDR-TB PR10 is 4.34 Mbp with 65.6% of G + C content and consists of 4637 predicted genes. The determinants were categorized by RAST into 400 subsystems with 4286 coding sequences and 50 RNAs. The whole genome shotgun project has been deposited at DDBJ/EMBL/GenBank under the accession number CP010968. Keywords: Mycobacterium tuberculosis, Genome, MDR, Extrapulmonary

Molecular epidemiology and evolutionary genetics of Mycobacterium tuberculosis in Taipei

OpenAIRE

Su Ih-Jen; Lee Shi-Yi; Tsai Wen-Shing; Sun Jun-Ren; Chang Jia-Ru; Lin Chih-Wei; Tseng Fan-Chen; Dou Horng-Yunn; Lu Jang-Jih

2008-01-01

Abstract Background The control of tuberculosis in densely populated cities is complicated by close human-to-human contacts and potential transmission of pathogens from multiple sources. We conducted a molecular epidemiologic analysis of 356 Mycobacterium tuberculosis (MTB) isolates from patients presenting pulmonary tuberculosis in metropolitan Taipei. Classical antibiogram studies and genetic characterization, using mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (M...

Drug Susceptibility of Mycobacterium tuberculosis Beijing Genotype and Association with MDR TB

Science.gov (United States)

ten Kate, Marian T.; de Knegt, Gerjo J.; Kremer, Kristin; Aarnoutse, Rob E.; Boeree, Martin J.; Verbrugh, Henri A.; van Soolingen, Dick; Bakker-Woudenberg, Irma A.J.M.

2012-01-01

To determine differences in the ability of Mycobacterium tuberculosis strains to withstand antituberculosis drug treatment, we compared the activity of antituberculosis drugs against susceptible Beijing and East-African/Indian genotype M. tuberculosis strains. Beijing genotype strains showed high rates of mutation within a wide range of drug concentrations, possibly explaining this genotype’s association with multidrug-resistant tuberculosis. PMID:22469099

Mycobacterium Tuberculosis Pyomyositis in an Infant

Science.gov (United States)

Malik, ZA; Shehab, M

2013-01-01

Mycobacterium tuberculosis is endemic to many parts of the world. It may have variable clinical presentations, especially in the pediatric age group. Presented here is the case of a 9-month old infant who was referred for infectious disease opinion when his thigh induration failed to improve after surgical drainage and a course of oral antibiotic therapy. Mycobacterial PCR on the operative sample fluid was found to be positive; and mycobacterial culture grew M. tuberculosis. He received 9 months of treatment with anti-TB medications, with excellent results and complete recovery. This is the first report of TB pyomyositis in an infant; and highlights the need to have a high index of suspicion for unusual organisms when conventional therapy fails to demonstrate expected results. PMID:23919207

Mechanish of dTTP Inhibition of the Bifunctional dCTP Deaminase:dUTPase Encoded by Mycobacterium tuberculosis

DEFF Research Database (Denmark)

Helt, Signe Smedegaard; Thymark, Majbritt; Harris, Pernille

2008-01-01

Recombinant deoxycytidine triphosphate (dCTP) deaminase from Mycobacterium tuberculosis was produced in Escherichia coli and purified. The enzyme proved to be a bifunctional dCTP deaminase:deoxyuridine triphosphatase. As such, the M. tuberculosis enzyme is the second bifunctional enzyme to be cha......Recombinant deoxycytidine triphosphate (dCTP) deaminase from Mycobacterium tuberculosis was produced in Escherichia coli and purified. The enzyme proved to be a bifunctional dCTP deaminase:deoxyuridine triphosphatase. As such, the M. tuberculosis enzyme is the second bifunctional enzyme...

Evaluation of rapid immuno chromatographic assay kit using monoclonal mpt64 antibodies for identification of mycobacterium tuberculosis complex

International Nuclear Information System (INIS)

Satti, L.; Ikram, A.; Malik, N.

2010-01-01

To evaluate the performance of rapid immuno chromatographic kit MPT64 Ag for the identification of Mycobacterium tuberculosis complex from various Mycobacterium tuberculosis culture positive specimens. Department of Microbiology, Armed Forces Institute of Pathology Rawalpindi, from August 2008 through March 2009. Eighty four Mycobacterium tuberculosis positive cultures on I BACTEC 460 and MGIT 960, one ATCC 25177 MTB strain, three institutional control MTB strains, two institutional control MOTT strains and 20 different bacterial isolates were tested. Tests were performed according to the instructional manual. Out of total 84 tested samples, MPT64 showed positive result in 80 cultures. Only four positive cultures did not display any band on MPT64 kit. These four strains were reconfirmed as Mycobacterium tuberculosis by PCR method. MOTT control strains and all the 20 bacterial isolates were negative for band. The sensitivity and specificity of ICT assay in our study was 95.2% and 100% respectively. Rapid MPT64 Kit is a good diagnostic tool to differentiate between Mycobacterium tuberculosis complex and MOTT with 100% specificity. The technique is simple and can provide prompt information to the clinicians to initiate early and appropriate antituberculosis therapy. (author)

In vitro efficacy of ethionamide and clarithromycin in mycobacterium tuberculosis isolates

International Nuclear Information System (INIS)

Satti, M.S.; Abbasi, S.; Rafi, S.; Butt, T.; Karamat, K.A.

2010-01-01

To determine the sensitivity of clinical isolates of Mycobacterium tuberculosis isolates against ethionamide, and clarithromycin. Department of Microbiology, Armed Forces institute of Pathology (AFIP) Rawalpindi from June 2003 to June 2004. Materials and Methods: All routine clinical samples received for acid fast bacilli (AFB) culture and yielding positive growth on Lowenstien Jensen medium and Bactec 460 were include in the study. The isolates were from sputum (n=70), bronchioalveolar lavage (n=10), fine needle aspiration (n=6), lymph nodes (n=7), pleural fluid (n=4), endometrium (n=3). After the identification of M. tuberculosis (MTB) sensitivity was performed against first-line antituberculosis drugs. Then susceptibility of M. tuberculosis isolates against ethionamide and clarithromycih was performed on LJ medium. Mycobacterium H37Rv was used as control strain. Results were interpreted using resistance ratio method. Out of 100 M. tuberculosis isolates, sensitivity to ethionamide was 93% and 9% to clarithromycih. Clarithromycin when used alone is ineffective as antituberculosis drug but its efficacy in combination needs to be tested. However ethionamide may be used as an alternative antituberculosis drug. (author)

Identification and characterization of the ESAT-6 homologue of Mycobacterium leprae and T-cell cross-reactivity with Mycobacterium tuberculosis

NARCIS (Netherlands)

Geluk, Annemieke; van Meijgaarden, Krista E.; Franken, Kees L. M. C.; Subronto, Yanri W.; Wieles, Brigitte; Arend, Sandra M.; Sampaio, Elizabeth P.; de Boer, Tjitske; Faber, William R.; Naafs, Ben; Ottenhoff, Tom H. M.

2002-01-01

In this paper we describe identification and characterization of Mycobacterium leprae ESAT-6 (L-ESAT-6), the homologue of M. tuberculosis ESAT-6 (T-ESAT-6). T-ESAT-6 is expressed by all pathogenic strains belonging to the M. tuberculosis complex but is absent from virtually all other mycobacterial

Molecular Strain Typing of Mycobacterium tuberculosis: a Review of Frequently Used Methods

Science.gov (United States)

2016-01-01

Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, remains one of the most serious global health problems. Molecular typing of M. tuberculosis has been used for various epidemiologic purposes as well as for clinical management. Currently, many techniques are available to type M. tuberculosis. Choosing the most appropriate technique in accordance with the existing laboratory conditions and the specific features of the geographic region is important. Insertion sequence IS6110-based restriction fragment length polymorphism (RFLP) analysis is considered the gold standard for the molecular epidemiologic investigations of tuberculosis. However, other polymerase chain reaction-based methods such as spacer oligonucleotide typing (spoligotyping), which detects 43 spacer sequence-interspersing direct repeats (DRs) in the genomic DR region; mycobacterial interspersed repetitive units–variable number tandem repeats, (MIRU-VNTR), which determines the number and size of tandem repetitive DNA sequences; repetitive-sequence-based PCR (rep-PCR), which provides high-throughput genotypic fingerprinting of multiple Mycobacterium species; and the recently developed genome-based whole genome sequencing methods demonstrate similar discriminatory power and greater convenience. This review focuses on techniques frequently used for the molecular typing of M. tuberculosis and discusses their general aspects and applications. PMID:27709842

Associations between Mycobacterium tuberculosis Strains and Phenotypes

Science.gov (United States)

Brown, Timothy; Nikolayevskyy, Vladyslav; Velji, Preya

2010-01-01

To inform development of tuberculosis (TB) control strategies, we characterized a total of 2,261 Mycobacterium tuberculosis complex isolates by using multiple phenotypic and molecular markers, including polymorphisms in repetitive sequences (spoligotyping and variable-number tandem repeats [VNTRs]) and large sequence and single-nucleotide polymorphisms. The Beijing family was strongly associated with multidrug resistance (p = 0.0001), and VNTR allelic variants showed strong associations with spoligotyping families: >5 copies at exact tandem repeat (ETR) A, >2 at mycobacterial interspersed repetitive unit 24, and >3 at ETR-B associated with the East African–Indian and M. bovis strains. All M. tuberculosis isolates were differentiated into 4 major lineages, and a maximum parsimony tree was constructed suggesting a more complex phylogeny for M. africanum. These findings can be used as a model of pathogen global diversity. PMID:20113558

Identification of two proteins that interact with the Erp virulence factor from Mycobacterium tuberculosis by using the bacterial two-hybrid system

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Cataldi Angel A

2009-01-01

Full Text Available Abstract Background The exported repetitive protein (erp gene encodes a secreted 36-kDa protein with a central domain containing several proline-glycine-leucine-threonine-serine (PGLTS repeats. It has been demonstrated that erp is a virulence-associated factor since the disruption of this gene impairs the growth of Mycobacterium bovis and Mycobacterium tuberculosis in mice. Results In order to elucidate the function of Erp we searched for Erp-binding proteins from M. tuberculosis by using a bacterial two-hybrid system. Our results indicate that Erp interacts specifically with two putative membrane proteins, Rv1417 and Rv2617c. Further analysis revealed that the latter two interact with each other, indicating that Rv1417, Rv2617c and Erp are connected through multiple interactions. While Rv1417 is disseminated in several Actinomycetales genera, orthologues of Rv2617c are exclusively present in members of the M. tuberculosis complex (MTC. The central and amino-terminal regions of Erp were determined to be involved in the interaction with Rv1417 and Rv2627c. Erp forms from Mycobacterium smegmatis and Mycobacterium leprae were not able to interact with Rv2617c in two-hybrid assays. Immunolocalization experiments showed that Rv1417 and Rv2617c are found on the cell membrane and Erp on the bacterial cell wall. Finally, comparative genomics and expression studies revealed a possible role of Rv1417 in riboflavin metabolism. Conclusion We identified interactive partners of Erp, an M. tuberculosis protein involved in virulence, which will be the focus of future investigation to decipher the function of the Erp family protein.

Study on drug resistance of mycobacterium tuberculosis in patients with pulmonary tuberculosis by drug resistance gene detecting

International Nuclear Information System (INIS)

Wang Wei; Li Hongmin; Wu Xueqiong; Wang Ansheng; Ye Yixiu; Wang Zhongyuan; Liu Jinwei; Chen Hongbing; Lin Minggui; Wang Jinhe; Li Sumei; Jiang Ping; Feng Bai; Chen Dongjing

2004-01-01

To investigate drug resistance of mycobacterium tuberculosis in different age group, compare detecting effect of two methods and evaluate their the clinical application value, all of the strains of mycobacterium tuberculosis were tested for resistance to RFP, INH SM PZA and EMB by the absolute concentration method on Lowenstein-Jensen medium and the mutation of the rpoB, katG, rpsL, pncA and embB resistance genes in M. tuberculosis was tested by PCR-SSCP. In youth, middle and old age group, the rate of acquired drug resistance was 89.2%, 85.3% and 67.6% respectively, the gene mutation rate was 76.2%, 81.3% and 63.2% respectively. The rate of acquired drug resistance and multiple drug resistance in youth group was much higher than those in other groups. The gene mutation was correlated with drug resistance level of mycobacterium tuberculosis. The gene mutation rate was higher in strains isolated from high concentration resistance than those in strains isolated from low concentration resistance. The more irregular treatment was longer, the rate of drug resistance was higher. Acquired drug resistance varies in different age group. It suggested that surveillance of drug resistence in different age group should be taken seriously, especially in youth group. PCR - SSCP is a sensitive and specific method for rapid detecting rpoB, katG, rpsL, pncA and embB genes mutations of MTB. (authors)

A robust SNP barcode for typing Mycobacterium tuberculosis complex strains

KAUST Repository

Coll, Francesc; McNerney, Ruth; Guerra-Assunç ã o, José Afonso; Glynn, Judith R.; Perdigã o, Joã o; Viveiros, Miguel; Portugal, Isabel; Pain, Arnab; Martin, Nigel; Clark, Taane G.

2014-01-01

Strain-specific genomic diversity in the Mycobacterium tuberculosis complex (MTBC) is an important factor in pathogenesis that may affect virulence, transmissibility, host response and emergence of drug resistance. Several systems have been proposed

T-cell recognition of Mycobacterium tuberculosis culture filtrate fractions in tuberculosis patients and their household contacts

DEFF Research Database (Denmark)

Demissie, A; Ravn, P; Olobo, J

1999-01-01

We examined the immune responses of patients with active pulmonary tuberculosis (TB) and their healthy household contacts to short-term culture filtrate (ST-CF) of Mycobacterium tuberculosis or molecular mass fractions derived from it. Our goal was to identify fractions strongly recognized......, to secreted mycobacterial antigens is suggestive of an early stage of infection by M. tuberculosis, which could in time result in overt disease or containment of the infection. This possibility is currently being investigated by follow-up studies of the household contacts....

Protective and therapeutic efficacy of Mycobacterium smegmatis expressing HBHA-hIL12 fusion protein against Mycobacterium tuberculosis in mice.

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Shanmin Zhao

Full Text Available Tuberculosis (TB remains a major worldwide health problem. The only vaccine against TB, Mycobacterium bovis Bacille Calmette-Guerin (BCG, has demonstrated relatively low efficacy and does not provide satisfactory protection against the disease. More efficient vaccines and improved therapies are urgently needed to decrease the worldwide spread and burden of TB, and use of a viable, metabolizing mycobacteria vaccine may be a promising strategy against the disease. Here, we constructed a recombinant Mycobacterium smegmatis (rMS strain expressing a fusion protein of heparin-binding hemagglutinin (HBHA and human interleukin 12 (hIL-12. Immune responses induced by the rMS in mice and protection against Mycobacterium tuberculosis (MTB were investigated. Administration of this novel rMS enhanced Th1-type cellular responses (IFN-γ and IL-2 in mice and reduced bacterial burden in lungs as well as that achieved by BCG vaccination. Meanwhile, the bacteria load in M. tuberculosis infected mice treated with the rMS vaccine also was significantly reduced. In conclusion, the rMS strain expressing the HBHA and human IL-12 fusion protein enhanced immunogencity by improving the Th1-type response against TB, and the protective effect was equivalent to that of the conventional BCG vaccine in mice. Furthermore, it could decrease bacterial load and alleviate histopathological damage in lungs of M. tuberculosis infected mice.

Deciphering the biology of Mycobacterium tuberculosis from thecomplete genome sequence

DEFF Research Database (Denmark)

Cole, S.T.; Krogh, Anders Stærmose

1998-01-01

Countless millions of people have died from tuberculosis, a chronic infectious disease caused by the tubercle bacillus. The complete genome sequence of the best-characterized strain of Mycobacterium tuberculosis, H37Rv, has been determined and analysed in order to improve our understanding....... tuberculosis differs radically from other bacteria in that a very large portion of its coding capacity is devoted to the production of enzymes involved in lipogenesis and lipolysis, and to two new families of glycine-rich proteins with a repetitive structure that may represent a source of antigenic variation....

The transmission of Mycobacterium tuberculosis in high burden settings

NARCIS (Netherlands)

Yates, Tom A.; Khan, Palwasha Y.; Knight, Gwenan M.; Taylor, Jonathon G.; McHugh, Timothy D.; Lipman, Marc; White, Richard G.; Cohen, Ted; Cobelens, Frank G.; Wood, Robin; Moore, David A. J.; Abubakar, Ibrahim

2016-01-01

Unacceptable levels of Mycobacterium tuberculosis transmission are noted in high burden settings and a renewed focus on reducing person-to-person transmission in these communities is needed. We review recent developments in the understanding of airborne transmission. We outline approaches to measure

Uracil excision repair in Mycobacterium tuberculosis cell-free extracts.

Science.gov (United States)

Kumar, Pradeep; Bharti, Sanjay Kumar; Varshney, Umesh

2011-05-01

Uracil excision repair is ubiquitous in all domains of life and initiated by uracil DNA glycosylases (UDGs) which excise the promutagenic base, uracil, from DNA to leave behind an abasic site (AP-site). Repair of the resulting AP-sites requires an AP-endonuclease, a DNA polymerase, and a DNA ligase whose combined activities result in either short-patch or long-patch repair. Mycobacterium tuberculosis, the causative agent of tuberculosis, has an increased risk of accumulating uracils because of its G + C-rich genome, and its niche inside host macrophages where it is exposed to reactive nitrogen and oxygen species, two major causes of cytosine deamination (to uracil) in DNA. In vitro assays to study DNA repair in this important human pathogen are limited. To study uracil excision repair in mycobacteria, we have established assay conditions using cell-free extracts of M. tuberculosis and M. smegmatis (a fast-growing mycobacterium) and oligomer or plasmid DNA substrates. We show that in mycobacteria, uracil excision repair is completed primarily via long-patch repair. In addition, we show that M. tuberculosis UdgB, a newly characterized family 5 UDG, substitutes for the highly conserved family 1 UDG, Ung, thereby suggesting that UdgB might function as backup enzyme for uracil excision repair in mycobacteria. Copyright © 2011 Elsevier Ltd. All rights reserved.

Tracing Mycobacterium tuberculosis transmission by whole genome sequencing in a high incidence setting

DEFF Research Database (Denmark)

Bjorn-Mortensen, K; Soborg, B; Koch, A

2016-01-01

In East Greenland, a dramatic increase of tuberculosis (TB) incidence has been observed in recent years. Classical genotyping suggests a genetically similar Mycobacterium tuberculosis (Mtb) strain population as cause, however, precise transmission patterns are unclear. We performed whole genome...

Different Transcriptional Profiles of Human Monocyte-Derived Dendritic Cells Infected with Distinct Strains of Mycobacterium tuberculosis and Mycobacterium bovis Bacillus Calmette-Guérin

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Nunzia Sanarico

2011-01-01

Full Text Available In order to analyze dendritic cells (DCs activation following infection with different mycobacterial strains, we studied the expression profiles of 165 genes of human monocyte-derived DCs infected with H37Rv, a virulent Mycobacterium tuberculosis (MTB laboratory strain, CMT97, a clinical MTB isolate, Mycobacterium bovis bacillus Calmette-Guérin (BCG, Aventis Pasteur, and BCG Japan, both employed as vaccine against tuberculosis. The analysis of the gene expression reveals that, despite a set of genes similarly modulated, DCs response resulted strain dependent. In particular, H37Rv significantly upregulated EBI3 expression compared with BCG Japan, while it was the only strain that failed to release a significant IL-10 amount. Of note, BCG Japan showed a marked increase in CCR7 and TNF-α expression regarding both MTB strains and it resulted the only strain failing in exponential intracellular growth. Our results suggest that DCs display the ability to elicit a tailored strain-specific immune response.

Functional drug screening reveals anticonvulsants as enhancers of mTOR-independent autophagic killing of Mycobacterium tuberculosis through inositol depletion.

Science.gov (United States)

Schiebler, Mark; Brown, Karen; Hegyi, Krisztina; Newton, Sandra M; Renna, Maurizio; Hepburn, Lucy; Klapholz, Catherine; Coulter, Sarah; Obregón-Henao, Andres; Henao Tamayo, Marcela; Basaraba, Randall; Kampmann, Beate; Henry, Katherine M; Burgon, Joseph; Renshaw, Stephen A; Fleming, Angeleen; Kay, Robert R; Anderson, Karen E; Hawkins, Phillip T; Ordway, Diane J; Rubinsztein, David C; Floto, Rodrigo Andres

2015-02-01

Mycobacterium tuberculosis (MTB) remains a major challenge to global health made worse by the spread of multidrug resistance. We therefore examined whether stimulating intracellular killing of mycobacteria through pharmacological enhancement of macroautophagy might provide a novel therapeutic strategy. Despite the resistance of MTB to killing by basal autophagy, cell-based screening of FDA-approved drugs revealed two anticonvulsants, carbamazepine and valproic acid, that were able to stimulate autophagic killing of intracellular M. tuberculosis within primary human macrophages at concentrations achievable in humans. Using a zebrafish model, we show that carbamazepine can stimulate autophagy in vivo and enhance clearance of M. marinum, while in mice infected with a highly virulent multidrug-resistant MTB strain, carbamazepine treatment reduced bacterial burden, improved lung pathology and stimulated adaptive immunity. We show that carbamazepine induces antimicrobial autophagy through a novel, evolutionarily conserved, mTOR-independent pathway controlled by cellular depletion of myo-inositol. While strain-specific differences in susceptibility to in vivo carbamazepine treatment may exist, autophagy enhancement by repurposed drugs provides an easily implementable potential therapy for the treatment of multidrug-resistant mycobacterial infection. © 2014 The Authors. Published under the terms of the CC BY 4.0 license.

Unraveling Mycobacterium tuberculosis genomic diversity and evolution in Lisbon, Portugal, a highly drug resistant setting

KAUST Repository

Perdigão, João

2014-11-18

Background Multidrug- (MDR) and extensively drug resistant (XDR) tuberculosis (TB) presents a challenge to disease control and elimination goals. In Lisbon, Portugal, specific and successful XDR-TB strains have been found in circulation for almost two decades. Results In the present study we have genotyped and sequenced the genomes of 56 Mycobacterium tuberculosis isolates recovered mostly from Lisbon. The genotyping data revealed three major clusters associated with MDR-TB, two of which are associated with XDR-TB. Whilst the genomic data contributed to elucidate the phylogenetic positioning of circulating MDR-TB strains, showing a high predominance of a single SNP cluster group 5. Furthermore, a genome-wide phylogeny analysis from these strains, together with 19 publicly available genomes of Mycobacterium tuberculosis clinical isolates, revealed two major clades responsible for M/XDR-TB in the region: Lisboa3 and Q1 (LAM). The data presented by this study yielded insights on microevolution and identification of novel compensatory mutations associated with rifampicin resistance in rpoB and rpoC. The screening for other structural variations revealed putative clade-defining variants. One deletion in PPE41, found among Lisboa3 isolates, is proposed to contribute to immune evasion and as a selective advantage. Insertion sequence (IS) mapping has also demonstrated the role of IS6110 as a major driver in mycobacterial evolution by affecting gene integrity and regulation. Conclusions Globally, this study contributes with novel genome-wide phylogenetic data and has led to the identification of new genomic variants that support the notion of a growing genomic diversity facing both setting and host adaptation.

Molecular Identification of Mycobacterium Tuberculosis and Analysis of Its Resistance to Rifampin in Sputa from Tuberculosis Suspected Patients

International Nuclear Information System (INIS)

Syaifudin, M.

2010-01-01

An accurate identification of different species of Mycobacterium provides to allow appropriate treatment for Mycobacterium tuberculosis infection. Beside that, drug resistance of M. tuberculosis strains to rifampin is not clearly understood in contributing to the spread of tuberculosis in Indonesia. To assess the molecular mechanism of rifampin resistance, a number of clinical specimens of M. tuberculosis were analyzed their molecular nature of a part of the rpoB gene using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) methods. DNA's extracted from sputum samples were amplified and 32 P-labeled by PCR with the specific primers and the product was analyzed their mutation conferring resistance by MDE gel electrophoresis. Of the 70 specimens tested, 57 specimens were positive for M. tuberculosis organism only, three specimens contained a mixture of M. tuberculosis and non tuberculosis mycobacteria (NTM), and 10 specimens were negative approved by Duplex PCR. Of these sixty DNA positive samples (thus the sensitivity of PCR was 85.71%), 5 (8.3%) of them suspected to contain mutations in rpoB which were associated with rifampin resistance. Even though the frequency of mutation was low, the results from our study clearly indicate that the molecular mechanism of rifampin resistance in M. tuberculosis isolates from Indonesia involves alterations in the rpoB gene. Molecular diagnosis by PCR which is fast and easy to perform is useful for early and rapid detection of TB in sputum specimen. (author)

Sensitivity Pattern of Second Line Anti-Tuberculosis Drugs against Clinical Isolates of Multidrug Resistant Mycobacterium Tuberculosis

International Nuclear Information System (INIS)

Ghafoor, T.; Ikram, A.; Abbasi, S. A.; Zaman, G.; Ayyub, M.; Palomino, J. C.; Vandamme, P.; Martin, A.

2015-01-01

Objective:To determine the current sensitivity pattern of second line anti-tuberculosis drugs against clinical isolates of Multidrug Resistant Mycobacterium tuberculosis (MDR-TB). Study Design: A cross-sectional study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from November 2011 to April 2013. Methodology: Samples received during the study period were processed on BACTEC MGIT 960 system for Mycobacterium tuberculosis (MTB) culture followed by first line drugs susceptibility testing of culture proven MTB isolates. On the basis of resistance to rifampicin and isoniazid, 100 clinical isolates of MDR-TB were further subjected to susceptibility testing against amikacin (AMK), capreomycin (CAP), ofloxacin (OFL) and ethionamide (ETH) as per standard BACTEC MGIT 960 instructions. Results: Out of 100 MDR-TB isolates, 62% were from male patients and 38% from female patients. 97% were sensitive to AMK, 53% to OFL, 87% to CAP; and 87% were sensitive to ETH. Conclusion: The majority of the MDR-TB isolates showed excellent sensitivity against AMK, CAP and ETH. However, sensitivity of MDR-TB isolates against fluoroquinolones like OFL was not encouraging. (author)

Spoligotyping of Mycobacterium tuberculosis isolates from tuberculosis diagnosed patients at Dilla University Referral Hospital and other private clinics, Southern Ethiopia

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Gebremedhin Gebrezgabiher

2015-04-01

Full Text Available Objective: To assess Mycobacterium tuberculosis (M. tuberculosis strains exsisting in Gedeo zone and the surrounding areas of the Southern Ethiopia using spoligotyping. Methods: A cross sectional study was carried out from February, 2012 to June, 2013 and 97 (76 sputum and 21 fine needle aspirate samples were taken from tuberculosis diagnosed patients at Dilla University Referral Hospital and other private clinics. Culturing, region of difference (RD9 deletion typing and spoligotyping techniques were employed to isolate M. tuberculosis strains. Results: Growth of mycobacteria was observed in 35.1% (34/97. Speciation of isolates showed that 91.2% (31/34 of the isolates were M. tuberculosis. Further characterization led to the identification of 23 different spoligotype patterns of M. tuberculosis of which 61% and 39% displayed unique and cluster patterns, respectively. The most dominant shared type was spoligotype international type 53. Of the 23 strains, 12 have not been registered in the international spoligotyping database (SpolDB4. Seventy one percent of the strains belonged to the Euro-American lineage. Conclusions: This study revealed the existence of both genetically diverse and clustered M. tuberculosis strains from tuberculosis patients in the area, suggesting reactivation of infection and recent transmission, respectively. Molecular epidemiology of M. tuberculosis should be done nationwide in order to set appropriate control measures.

Interaction of Mycobacterium tuberculosis with human respiratory mucosa.

Science.gov (United States)

Middleton, A M; Chadwick, M V; Nicholson, A G; Dewar, A; Groger, R K; Brown, E J; Ratliff, T L; Wilson, R

2002-01-01

Endobronchial infection is associated with pulmonary tuberculosis in the majority of cases. We have investigated the adherence of Mycobacterium tuberculosis to the human respiratory mucosa. Organ cultures constructed with human tissue were infected with M. tuberculosis in the presence or absence of mycobacterial fibronectin attachment cell surface proteins and examined by scanning electron microscopy. M. tuberculosis adhered mainly to extracellular matrix (ECM) in areas of mucosal damage, but not to ciliated mucosa, intact extruded cells, basement membrane or collagen fibres. Bacteria also adhered to fibrous but not globular mucus and occasionally to healthy unciliated mucosa, open tight junctions and to extruded cells that had degenerated, exposing their contents. There was a significant reduction (pprotein (FAP) and M. bovis antigen 85B protein, in a concentration dependent manner. The combined effect of FAP and antigen 85B protein was significantly greater than either protein alone. Bacterial adherence to fibrous mucus was not influenced by fibronectin. We conclude that M. tuberculosis adheres to ECM in areas of mucosal damage at least in part via FAP and antigen 85B protein.

Active nuclear transcriptome analysis reveals inflammasome-dependent mechanism for early neutrophil response to Mycobacterium marinum.

Science.gov (United States)

Kenyon, Amy; Gavriouchkina, Daria; Zorman, Jernej; Napolitani, Giorgio; Cerundolo, Vincenzo; Sauka-Spengler, Tatjana

2017-07-26

The mechanisms governing neutrophil response to Mycobacterium tuberculosis remain poorly understood. In this study we utilise biotagging, a novel genome-wide profiling approach based on cell type-specific in vivo biotinylation in zebrafish to analyse the initial response of neutrophils to Mycobacterium marinum, a close genetic relative of M. tuberculosis used to model tuberculosis. Differential expression analysis following nuclear RNA-seq of neutrophil active transcriptomes reveals a significant upregulation in both damage-sensing and effector components of the inflammasome, including caspase b, NLRC3 ortholog (wu: fb15h11) and il1β. Crispr/Cas9-mediated knockout of caspase b, which acts by proteolytic processing of il1β, results in increased bacterial burden and less infiltration of macrophages to sites of mycobacterial infection, thus impairing granuloma development. We also show that a number of immediate early response genes (IEGs) are responsible for orchestrating the initial neutrophil response to mycobacterial infection. Further perturbation of the IEGs exposes egr3 as a key transcriptional regulator controlling il1β transcription.

Whole genome sequencing of Mycobacterium tuberculosis SB24 isolated from Sabah, Malaysia

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Noraini Philip

2016-09-01

Full Text Available Mycobacterium tuberculosis (M. tuberculosis is the causative agent of tuberculosis (TB that causes millions of death every year. We have sequenced the genome of M. tuberculosis isolated from cerebrospinal fluid (CSF of a patient diagnosed with tuberculous meningitis (TBM. The isolated strain was referred as M. tuberculosis SB24. Genomic DNA of the M. tuberculosis SB24 was extracted and subjected to whole genome sequencing using PacBio platform. The draft genome size of M. tuberculosis SB24 was determined to be 4,452,489 bp with a G + C content of 65.6%. The whole genome shotgun project has been deposited in NCBI SRA under the accession number SRP076503.

Mycobacterium tuberculosis whole genome sequencing and protein structure modelling provides insights into anti-tuberculosis drug resistance

KAUST Repository

Phelan, Jody; Coll, Francesc; McNerney, Ruth; Ascher, David B.; Pires, Douglas E. V.; Furnham, Nick; Coeck, Nele; Hill-Cawthorne, Grant A.; Nair, Mridul; Mallard, Kim; Ramsay, Andrew; Campino, Susana; Hibberd, Martin L.; Pain, Arnab; Rigouts, Leen; Clark, Taane G.

2016-01-01

of 144 Mycobacterium tuberculosis clinical isolates from The Special Programme for Research and Training in Tropical Diseases (TDR) collection sourced from 20 countries in four continents. A genome-wide approach was applied to 127 isolates to identify

Transmission of Mycobacterium tuberculosis Undetected by Tuberculin Skin Testing

Czech Academy of Sciences Publication Activity Database

Anderson, S. T.; Williams, A. J.; Brown, J. R.; Newton, S. M.; Šimšová, Marcela; Nicol, M. P.; Šebo, Peter; Levin, M.; Wilkinson, R. J.; Wilkinson, K. A.

2006-01-01

Roč. 173, - (2006), s. 1038-1042 ISSN 1073-449X R&D Projects: GA AV ČR IAA5020406 Institutional research plan: CEZ:AV0Z50200510 Keywords : adenylate cyclase * diagnostic tests and procedures * mycobacterium tuberculosis Subject RIV: EE - Microbiology, Virology Impact factor: 9.091, year: 2006

Differential expression of miRNAs by macrophages infected with virulent and avirulent Mycobacterium tuberculosis.

Science.gov (United States)

Das, Kishore; Saikolappan, Sankaralingam; Dhandayuthapani, Subramanian

2013-12-01

MicroRNAs (miRNAs) are small non-coding RNAs which post-transcriptionally regulate a wide range of biological processes that include cellular differentiation, development, immunity and apoptosis. There is a growing body of evidences that bacteria modulate immune responses by altering the expression of host miRNAs. Since macrophages are immune cells associated with innate and adaptive immunity, we investigated whether Mycobacterium tuberculosis infection affects miRNAs of macrophages. THP-1 macrophages infected with virulent (H37Rv) and avirulent (H37Ra) strains of M. tuberculosis were analyzed for changes in miRNAs' expression using microarray. This revealed that nine miRNA genes (miR-30a, miR-30e, miR-155, miR-1275, miR-3665, miR-3178, miR-4484, miR-4668-5p and miR-4497) were differentially expressed between THP-1cells infected with M. tuberculosis H37Rv and M. tuberculosis H37Ra strains. Additional characterization of these genes is likely to provide insights into their role in the pathogenesis of tuberculosis. Copyright © 2013 Elsevier Ltd. All rights reserved.

First insights into circulating Mycobacterium tuberculosis complex lineages and drug resistance in Guinea

Science.gov (United States)

Ejo, Mebrat; Gehre, Florian; Barry, Mamadou Dian; Sow, Oumou; Bah, Nene Mamata; Camara, Mory; Bah, Boubacar; Uwizeye, Cecile; Nduwamahoro, Elie; Fissette, Kristina; Rijk, Pim De; Merle, Corinne; Olliaro, Piero; Burgos, Marcos; Lienhardt, Christian; Rigouts, Leen; de Jong, Bouke C.

2015-01-01

In this study we assessed first-line anti-tuberculosis drug resistance and the genotypic distribution of Mycobacterium tuberculosis complex (MTBC) isolates that had been collected from consecutive new tuberculosis patients enrolled in two clinical trials conducted in Guinea between 2005 and 2010. Among the total 359 MTBC strains that were analyzed in this study, 22.8% were resistant to at least one of the first line anti-tuberculosis drugs, including 2.5% multidrug resistance and 17.5% isoniazid resistance, with or without other drugs. In addition, further characterization of isolates from a subset of the two trials (n = 184) revealed a total of 80 different spoligotype patterns, 29 “orphan” and 51 shared patterns. We identified the six major MTBC lineages of human relevance, with predominance of the Euro-American lineage. In total, 132 (71.7%) of the strains were genotypically clustered, and further analysis (using the DESTUS model) suggesting significantly faster spread of LAM10_CAM family (p = 0.00016). In conclusion, our findings provide a first insight into drug resistance and the population structure of the MTBC in Guinea, with relevance for public health scientists in tuberculosis control programs. PMID:26004194

MenA Is a Promising Drug Target for Developing Novel Lead Molecules to Combat Mycobacterium tuberculosis

OpenAIRE

Kurosu, Michio; Crick, Dean C.

2009-01-01

Potent inhibitors of MenA (1,4-dihydroxy-2-naphtoate prenyltrasferase) in Mycobacterium tuberculosis are identified, and are also effective in inhibiting growth of Mycobacterium tuberculosis at low concentrations. The MenA inhibitors possess common chemical structural features of ((alkylamino)alkoxyphenyl)(phenyl)methanones. Significantly, the MenA inhibitors can be synthesized in a few steps with high overall yields. The representative MenA inhibitors are highly effective in killing nonrepli...

Mycobacterium tuberculosis infection of domesticated Asian elephants, Thailand.

OpenAIRE

2011-01-01

Four Asian elephants were confirmed to be infected with Mycobacterium tuberculosis by bacterial culture, other diagnostic procedures, and sequencing of 16S–23S rDNA internal transcribed spacer region, 16S rRNA, and gyrase B gene sequences. Genotyping showed that the infectious agents originated from 4 sources in Thailand. To identify infections, a combination of diagnostic assays is essential.

Bloodstream Infections with Mycobacterium tuberculosis among HIV patients

Centers for Disease Control (CDC) Podcasts

2010-09-23

This podcast looks at bloodstream infections with Mycobacterium tuberculosis and other pathogens among outpatients infected with HIV in Southeast Asia. CDC health scientist Kimberly McCarthy discusses the study and why bloodstream infections occur in HIV-infected populations.  Created: 9/23/2010 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 9/23/2010.

High genetic diversity among Mycobacterium tuberculosis strains in Tehran, Iran

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Taher Azimi

2018-05-01

Full Text Available Introduction: Tuberculosis (TB still remains an important public health problem in Iran. The genotyping of Mycobacterium tuberculosis isolates is expected to lead to a better understanding of M. tuberculosis transmission in Tehran, the most populated city of Iran. Materials and Methods: A total of 2300 clinical specimens were obtained from TB suspected patients who were referred to a TB center in Tehran from Jan 2014 to Dec 2016. Identification was performed using both conventional and molecular methods. The presence of resistance to rifampicin was examined by the GeneXpert MTB/RIF. The standard 15-locus mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR typing method was applied to genotype of clinical isolates. Results: Of 2300 specimens, 80 isolates were identified as M. tuberculosis by using biochemical and molecular tests. Of 80 M. tuberculosis isolates, 76 (95% had unique genotypic profiles and 4 (5% shared a profile with one or more other strains. Based on single loci variation (SLV 4 clonal complexes were observed. NEW-1 was found to be the most predominant lineage (22.5% followed by West African (1.25%, Central Asian (CAS/Delhi (1.25%, Bovis (1.25%, H37Rv (1.25% and multiple matches (1.25%. Loci MIRU10, MIRU26, MTUB21 and QUB26 were found as highly discriminative. No mutation was detected in the hotspot region of rifampicin by using GeneXpert MTB/RIF. Conclusions: Our study findings show that there was considerable genotypic diversity among M. tuberculosis isolates in Tehran. The 15-locus MIRU-VNTR showed high HGDI and could be used as a first-line genotyping method for epidemiological studies. Keywords: Mycobacterium tuberculosis, Genotyping, MIRU-VNTR, Tehran, Iran

Mycobacterium tuberculosis and Mycobacterium marinum non-homologous end-joining proteins can function together to join DNA ends in Escherichia coli.

Science.gov (United States)

Wright, Douglas G; Castore, Reneau; Shi, Runhua; Mallick, Amrita; Ennis, Don G; Harrison, Lynn

2017-03-01

Mycobacterium tuberculosis and Mycobacterium smegmatis express a Ku protein and a DNA ligase D and are able to repair DNA double strand breaks (DSBs) by non-homologous end-joining (NHEJ). This pathway protects against DNA damage when bacteria are in stationary phase. Mycobacterium marinum is a member of this mycobacterium family and like M. tuberculosis is pathogenic. M. marinum lives in water, forms biofilms and infects fish and frogs. M. marinum is a biosafety level 2 (BSL2) organism as it can infect humans, although infections are limited to the skin. M. marinum is accepted as a model to study mycobacterial pathogenesis, as M. marinum and M. tuberculosis are genetically closely related and have similar mechanisms of survival and persistence inside macrophage. The aim of this study was to determine whether M. marinum could be used as a model to understand M. tuberculosis NHEJ repair. We identified and cloned the M. marinum genes encoding NHEJ proteins and generated E. coli strains that express the M. marinum Ku (Mm-Ku) and ligase D (Mm-Lig) individually or together (LHmKumLig strain) from expression vectors integrated at phage attachment sites in the genome. We demonstrated that Mm-Ku and Mm-Lig are both required to re-circularize Cla I-linearized plasmid DNA in E. coli. We compared repair of strain LHmKumLig with that of an E. coli strain (BWKuLig#2) expressing the M. tuberculosis Ku (Mt-Ku) and ligase D (Mt-Lig), and found that LHmKumLig performed 3.5 times more repair and repair was more accurate than BWKuLig#2. By expressing the Mm-Ku with the Mt-Lig, or the Mt-Ku with the Mm-Lig in E. coli, we have shown that the NHEJ proteins from M. marinum and M. tuberculosis can function together to join DNA DSBs. NHEJ repair is therefore conserved between the two species. Consequently, M. marinum is a good model to study NHEJ repair during mycobacterial pathogenesis. © The Author 2016. Published by Oxford University Press on behalf of the UK Environmental Mutagen

Attenuated Mycobacterium tuberculosis SO2 vaccine candidate is unable to induce cell death.

Directory of Open Access Journals (Sweden)

Adriana Aporta

Full Text Available It has been proposed that Mycobacterium tuberculosis virulent strains inhibit apoptosis and trigger cell death by necrosis of host macrophages to evade innate immunity, while non-virulent strains induce typical apoptosis activating a protective host response. As part of the characterization of a novel tuberculosis vaccine candidate, the M. tuberculosis phoP mutant SO2, we sought to evaluate its potential to induce host cell death. The parental M. tuberculosis MT103 strain and the current vaccine against tuberculosis Bacillus Calmette-Guérin (BCG were used as comparators in mouse models in vitro and in vivo. Our data reveal that attenuated SO2 was unable to induce apoptotic events neither in mouse macrophages in vitro nor during lung infection in vivo. In contrast, virulent MT103 triggers typical apoptotic events with phosphatidylserine exposure, caspase-3 activation and nuclear condensation and fragmentation. BCG strain behaved like SO2 and did not induce apoptosis. A clonogenic survival assay confirmed that viability of BCG- or SO2-infected macrophages was unaffected. Our results discard apoptosis as the protective mechanism induced by SO2 vaccine and provide evidence for positive correlation between classical apoptosis induction and virulent strains, suggesting apoptosis as a possible virulence determinant during M. tuberculosis infection.

Evolutionary history and global spread of the Mycobacterium tuberculosis Beijing lineage.

OpenAIRE

Merker Matthias; Blin Camille; Mona Stefano; Duforet-Frebourg Nicolas; Lecher Sophie; Willery Eve; Blum Michael G B; Rüsch-Gerdes Sabine; Mokrousov Igor; Aleksic Eman; Allix-Béguec Caroline; Antierens Annick; Augustynowicz-Kopec Ewa; Ballif Marie; Barletta Francesca

2015-01-01

International audience; Mycobacterium tuberculosis strains of the Beijing lineage are globally distributed and are associated with the massive spread of multidrug-resistant (MDR) tuberculosis in Eurasia. Here we reconstructed the biogeographical structure and evolutionary history of this lineage by genetic analysis of 4,987 isolates from 99 countries and whole-genome sequencing of 110 representative isolates. We show that this lineage initially originated in the Far East, from where it radiat...

Detection of 123 bp fragment of insertion element IS6110 Mycobacterium tuberculosis for diagnosis of extrapulmonary tuberculosis

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A K Maurya

2012-01-01

Full Text Available Purpose: Extrapulmonary tuberculosis (EPTB is emerging problem in developing and developed countries. The diagnosis of EPTB in its different clinical presentations remains a true challenge. IS6110-based polymerase chain reaction (PCR is used for rapid identification and positivity rate of the Mycobacterium tuberculosis complex in clinical isolates of different sites of EPTB. The present study was carried out to study the prevalence of M. tuberculosis complex in clinical isolates of EPTB at tertiary care centres in Lucknow. Materials and Methods: Seven hundred fifty-six specimens were collected from the suspected cases of EPTB which were processed for Mycobacteria by Ziehl Neelson (ZN staining and BACTEC culture. All the specimens were also processed for IS6110-based PCR amplification with primers targeting 123 bp fragment of insertion element IS6110 of the M. tuberculosis complex. Results: Of these 756 specimens, 71(9.3% were positive for acid fast bacilli (AFB by ZN staining, 227(30.1% were positive for mycobacteria by BACTEC culture and IS6110 PCR were positive for M. tuberculosis complex in 165 (20.7% isolates. We found a significant difference in sensitivities of different tests (P<0.05. Conclusions: This study reveals the positivity of M. tuberculosis complex in clinical isolates of EPTB case in tertiary care hospitals in Northern India. 72.7% of M. tuberculosis complex was confirmed by IS6110-PCR in culture isolates from different sites of EPTB. The high prevalence of the M. tuberculosis complex was seen in lymph node aspirate and synovial fluid. However, utility of PCR may play a potentially significant role in strengthening the diagnosis of EPTB especially targeting IS6110.

Phosphorylation of Mycobacterium tuberculosis ParB participates in regulating the ParABS chromosome segregation system.

Science.gov (United States)

Baronian, Grégory; Ginda, Katarzyna; Berry, Laurence; Cohen-Gonsaud, Martin; Zakrzewska-Czerwińska, Jolanta; Jakimowicz, Dagmara; Molle, Virginie

2015-01-01

Here, we present for the first time that Mycobacterium tuberculosis ParB is phosphorylated by several mycobacterial Ser/Thr protein kinases in vitro. ParB and ParA are the key components of bacterial chromosome segregation apparatus. ParB is a cytosolic conserved protein that binds specifically to centromere-like DNA parS sequences and interacts with ParA, a weak ATPase required for its proper localization. Mass spectrometry identified the presence of ten phosphate groups, thus indicating that ParB is phosphorylated on eight threonines, Thr32, Thr41, Thr53, Thr110, Thr195, and Thr254, Thr300, Thr303 as well as on two serines, Ser5 and Ser239. The phosphorylation sites were further substituted either by alanine to prevent phosphorylation or aspartate to mimic constitutive phosphorylation. Electrophoretic mobility shift assays revealed a drastic inhibition of DNA-binding by ParB phosphomimetic mutant compared to wild type. In addition, bacterial two-hybrid experiments showed a loss of ParA-ParB interaction with the phosphomimetic mutant, indicating that phosphorylation is regulating the recruitment of the partitioning complex. Moreover, fluorescence microscopy experiments performed in the surrogate Mycobacterium smegmatis ΔparB strain revealed that in contrast to wild type Mtb ParB, which formed subpolar foci similar to M. smegmatis ParB, phoshomimetic Mtb ParB was delocalized. Thus, our findings highlight a novel regulatory role of the different isoforms of ParB representing a molecular switch in localization and functioning of partitioning protein in Mycobacterium tuberculosis.

Phosphorylation of Mycobacterium tuberculosis ParB participates in regulating the ParABS chromosome segregation system.

Directory of Open Access Journals (Sweden)

Grégory Baronian

Full Text Available Here, we present for the first time that Mycobacterium tuberculosis ParB is phosphorylated by several mycobacterial Ser/Thr protein kinases in vitro. ParB and ParA are the key components of bacterial chromosome segregation apparatus. ParB is a cytosolic conserved protein that binds specifically to centromere-like DNA parS sequences and interacts with ParA, a weak ATPase required for its proper localization. Mass spectrometry identified the presence of ten phosphate groups, thus indicating that ParB is phosphorylated on eight threonines, Thr32, Thr41, Thr53, Thr110, Thr195, and Thr254, Thr300, Thr303 as well as on two serines, Ser5 and Ser239. The phosphorylation sites were further substituted either by alanine to prevent phosphorylation or aspartate to mimic constitutive phosphorylation. Electrophoretic mobility shift assays revealed a drastic inhibition of DNA-binding by ParB phosphomimetic mutant compared to wild type. In addition, bacterial two-hybrid experiments showed a loss of ParA-ParB interaction with the phosphomimetic mutant, indicating that phosphorylation is regulating the recruitment of the partitioning complex. Moreover, fluorescence microscopy experiments performed in the surrogate Mycobacterium smegmatis ΔparB strain revealed that in contrast to wild type Mtb ParB, which formed subpolar foci similar to M. smegmatis ParB, phoshomimetic Mtb ParB was delocalized. Thus, our findings highlight a novel regulatory role of the different isoforms of ParB representing a molecular switch in localization and functioning of partitioning protein in Mycobacterium tuberculosis.

Genome-wide analysis of multi- and extensively drug-resistant Mycobacterium tuberculosis

KAUST Repository

Coll, Francesc; Phelan, Jody; Hill-Cawthorne, Grant A.; Nair, Mridul; Mallard, Kim; Ali, Shahjahan; Abdallah, Abdallah; Alghamdi, Saad; Alsomali, Mona; Ahmed, Abdallah O.; Portelli, Stephanie; Oppong, Yaa; Alves, Adriana; Bessa, Theolis Barbosa; Campino, Susana; Caws, Maxine; Chatterjee, Anirvan; Crampin, Amelia C.; Dheda, Keertan; Furnham, Nicholas; Glynn, Judith R.; Grandjean, Louis; Minh Ha, Dang; Hasan, Rumina; Hasan, Zahra; Hibberd, Martin L.; Joloba, Moses; Jones-Ló pez, Edward C.; Matsumoto, Tomoshige; Miranda, Anabela; Moore, David J.; Mocillo, Nora; Panaiotov, Stefan; Parkhill, Julian; Penha, Carlos; Perdigã o, Joã o; Portugal, Isabel; Rchiad, ‍ Zineb; Robledo, Jaime; Sheen, Patricia; Shesha, Nashwa Talaat; Sirgel, Frik A.; Sola, Christophe; Oliveira Sousa, Erivelton; Streicher, Elizabeth M.; Helden, Paul Van; Viveiros, Miguel; Warren, Robert M.; McNerney, Ruth; Pain, Arnab; Clark, Taane G.

2018-01-01

To characterize the genetic determinants of resistance to antituberculosis drugs, we performed a genome-wide association study (GWAS) of 6,465 Mycobacterium tuberculosis clinical isolates from more than 30 countries. A GWAS approach within a mixed

Organization of the origins of replication of the chromosomes of Mycobacterium smegmatis, Mycobacterium leprae and Mycobacterium tuberculosis and isolation of a functional origin from M. smegmatis.

Science.gov (United States)

Salazar, L; Fsihi, H; de Rossi, E; Riccardi, G; Rios, C; Cole, S T; Takiff, H E

1996-04-01

The genus Mycobacterium is composed of species with widely differing growth rates ranging from approximately three hours in Mycobacterium smegmatis to two weeks in Mycobacterium leprae. As DNA replication is coupled to cell duplication, it may be regulated by common mechanisms. The chromosomal regions surrounding the origins of DNA replication from M. smegmatis, M. tuberculosis, and M. leprae have been sequenced, and show very few differences. The gene order, rnpA-rpmH-dnaA-dnaN-recF-orf-gyrB-gyrA, is the same as in other Gram-positive organisms. Although the general organization in M. smegmatis is very similar to that of Streptomyces spp., a closely related genus, M. tuberculosis and M. leprae differ as they lack an open reading frame, between dnaN and recF, which is similar to the gnd gene of Escherichia coli. Within the three mycobacterial species, there is extensive sequence conservation in the intergenic regions flanking dnaA, but more variation from the consensus DnaA box sequence was seen than in other bacteria. By means of subcloning experiments, the putative chromosomal origin of replication of M. smegmatis, containing the dnaA-dnaN region, was shown to promote autonomous replication in M. smegmatis, unlike the corresponding regions from M. tuberculosis or M. leprae.

Metabolic principles of persistence and pathogenicity in Mycobacterium tuberculosis.

Science.gov (United States)

Ehrt, Sabine; Schnappinger, Dirk; Rhee, Kyu Y

2018-04-24

Metabolism was once relegated to the supply of energy and biosynthetic precursors, but it has now become clear that it is a specific mediator of nearly all physiological processes. In the context of microbial pathogenesis, metabolism has expanded outside its canonical role in bacterial replication. Among human pathogens, this expansion has emerged perhaps nowhere more visibly than for Mycobacterium tuberculosis, the causative agent of tuberculosis. Unlike most pathogens, M. tuberculosis has evolved within humans, which are both host and reservoir. This makes unrestrained replication and perpetual quiescence equally incompatible strategies for survival as a species. In this Review, we summarize recent work that illustrates the diversity of metabolic functions that not only enable M. tuberculosis to establish and maintain a state of chronic infection within the host but also facilitate its survival in the face of drug pressure and, ultimately, completion of its life cycle.

Siderocalin inhibits the intracellular replication of Mycobacterium tuberculosis in macrophages

DEFF Research Database (Denmark)

Johnson, Erin E; Srikanth, Chittur V; Sandgren, Andreas

2010-01-01

Siderocalin is a secreted protein that binds to siderophores to prevent bacterial iron acquisition. While it has been shown to inhibit the growth of Mycobacterium tuberculosis (M.tb) in extracellular cultures, its effect on this pathogen within macrophages is not clear. Here, we show that sideroc...

Structure of Mycobacterium tuberculosis RuvA, a protein involved in recombination

International Nuclear Information System (INIS)

Prabu, J. Rajan; Thamotharan, S.; Khanduja, Jasbeer Singh; Alipio, Emily Zabala; Kim, Chang-Yub; Waldo, Geoffrey S.; Terwilliger, Thomas C.; Segelke, Brent; Lekin, Tim; Toppani, Dominique; Hung, Li-Wei; Yu, Minmin; Bursey, Evan; Muniyappa, K.; Chandra, Nagasuma R.; Vijayan, M.

2006-01-01

RuvA, a protein from M. tuberculosis H37Rv involved in recombination, has been cloned, expressed, purified and analysed by X-ray crystallography. The process of recombinational repair is crucial for maintaining genomic integrity and generating biological diversity. In association with RuvB and RuvC, RuvA plays a central role in processing and resolving Holliday junctions, which are a critical intermediate in homologous recombination. Here, the cloning, purification and structure determination of the RuvA protein from Mycobacterium tuberculosis (MtRuvA) are reported. Analysis of the structure and comparison with other known RuvA proteins reveal an octameric state with conserved subunit–subunit interaction surfaces, indicating the requirement of octamer formation for biological activity. A detailed analysis of plasticity in the RuvA molecules has led to insights into the invariant and variable regions, thus providing a framework for understanding regional flexibility in various aspects of RuvA function

Added value of IP-10 as a read-out of Mycobacterium tuberculosis

DEFF Research Database (Denmark)

Jenum, Synne; Dhanasekaran, Sivmakumaran; Ritz, Christian

2016-01-01

We have explored the added value of IFNγ-inducible protein 10 as a read-out of Mycobacterium tuberculosis specific immunity in young Indian children where the sensitivity of the IGRA for tuberculosis (TB) is poor. Reduced frequency of indeterminate results and an increased sensitivity for TB, sug...

Pulmonary Mycobacterium tuberculosis (Beijing strain infection in a stray dog : clinical communication

Directory of Open Access Journals (Sweden)

S.D.C. Parsons

2008-05-01

Full Text Available Mycobacterium tuberculosis infection in dogs is rarely reported and has not previously been documented in South Africa. A case of a stray Maltese crossbreed dog with extensive multifocal pulmonary tuberculosis due to M. tuberculosis is described. Pulmonary granulomas in this case were poorly encapsulated and contained large numbers of acid-fast bacteria, highlighting the potential for infected companion animals to excrete the pathogen. Treatment of canine tuberculosis is generally not advised, and for this reason, euthanasia of diseased animals must be advocated in most instances. Physicians and veterinarians must be aware that companion animals with active disease caused by M. tuberculosis could act as a potential source of infection.

Characterization of Mycobacterium tuberculosis Complex DNAs from Egyptian Mummies by Spoligotyping

Science.gov (United States)

Zink, Albert R.; Sola, Christophe; Reischl, Udo; Grabner, Waltraud; Rastogi, Nalin; Wolf, Hans; Nerlich, Andreas G.

2003-01-01

Bone and soft tissue samples from 85 ancient Egyptian mummies were analyzed for the presence of ancient Mycobacterium tuberculosis complex DNA (aDNA) and further characterized by spoligotyping. The specimens were obtained from individuals from different tomb complexes in Thebes West, Upper Egypt, which were used for upper social class burials between the Middle Kingdom (since ca. 2050 BC) and the Late Period (until ca. 500 BC). A total of 25 samples provided a specific positive signal for the amplification of a 123-bp fragment of the repetitive element IS6110, indicating the presence of M. tuberculosis DNA. Further PCR-based tests for the identification of subspecies failed due to lack of specific amplification products in the historic tissue samples. Of these 25 positive specimens, 12 could be successfully characterized by spoligotyping. The spoligotyping signatures were compared to those in an international database. They all show either an M. tuberculosis or an M. africanum pattern, but none revealed an M. bovis-specific pattern. The results from a Middle Kingdom tomb (used exclusively between ca. 2050 and 1650 BC) suggest that these samples bear an M. africanum-type specific spoligotyping signature. The samples from later periods provided patterns typical for M. tuberculosis. This study clearly demonstrates that spoligotyping can be applied to historic tissue samples. In addition, our results do not support the theory that M. tuberculosis originated from the M. bovis type but, rather, suggest that human M. tuberculosis may have originated from a precursor complex probably related to M. africanum. PMID:12517873

Nitazoxanide stimulates autophagy and inhibits mTORC1 signaling and intracellular proliferation of Mycobacterium tuberculosis.

Directory of Open Access Journals (Sweden)

Karen K Y Lam

Full Text Available Tuberculosis, caused by Mycobacterium tuberculosis infection, is a major cause of morbidity and mortality in the world today. M. tuberculosis hijacks the phagosome-lysosome trafficking pathway to escape clearance from infected macrophages. There is increasing evidence that manipulation of autophagy, a regulated catabolic trafficking pathway, can enhance killing of M. tuberculosis. Therefore, pharmacological agents that induce autophagy could be important in combating tuberculosis. We report that the antiprotozoal drug nitazoxanide and its active metabolite tizoxanide strongly stimulate autophagy and inhibit signaling by mTORC1, a major negative regulator of autophagy. Analysis of 16 nitazoxanide analogues reveals similar strict structural requirements for activity in autophagosome induction, EGFP-LC3 processing and mTORC1 inhibition. Nitazoxanide can inhibit M. tuberculosis proliferation in vitro. Here we show that it inhibits M. tuberculosis proliferation more potently in infected human THP-1 cells and peripheral monocytes. We identify the human quinone oxidoreductase NQO1 as a nitazoxanide target and propose, based on experiments with cells expressing NQO1 or not, that NQO1 inhibition is partly responsible for mTORC1 inhibition and enhanced autophagy. The dual action of nitazoxanide on both the bacterium and the host cell response to infection may lead to improved tuberculosis treatment.

Nitazoxanide stimulates autophagy and inhibits mTORC1 signaling and intracellular proliferation of Mycobacterium tuberculosis.

Science.gov (United States)

Lam, Karen K Y; Zheng, Xingji; Forestieri, Roberto; Balgi, Aruna D; Nodwell, Matt; Vollett, Sarah; Anderson, Hilary J; Andersen, Raymond J; Av-Gay, Yossef; Roberge, Michel

2012-01-01

Tuberculosis, caused by Mycobacterium tuberculosis infection, is a major cause of morbidity and mortality in the world today. M. tuberculosis hijacks the phagosome-lysosome trafficking pathway to escape clearance from infected macrophages. There is increasing evidence that manipulation of autophagy, a regulated catabolic trafficking pathway, can enhance killing of M. tuberculosis. Therefore, pharmacological agents that induce autophagy could be important in combating tuberculosis. We report that the antiprotozoal drug nitazoxanide and its active metabolite tizoxanide strongly stimulate autophagy and inhibit signaling by mTORC1, a major negative regulator of autophagy. Analysis of 16 nitazoxanide analogues reveals similar strict structural requirements for activity in autophagosome induction, EGFP-LC3 processing and mTORC1 inhibition. Nitazoxanide can inhibit M. tuberculosis proliferation in vitro. Here we show that it inhibits M. tuberculosis proliferation more potently in infected human THP-1 cells and peripheral monocytes. We identify the human quinone oxidoreductase NQO1 as a nitazoxanide target and propose, based on experiments with cells expressing NQO1 or not, that NQO1 inhibition is partly responsible for mTORC1 inhibition and enhanced autophagy. The dual action of nitazoxanide on both the bacterium and the host cell response to infection may lead to improved tuberculosis treatment.

[Increased IL-4 production in response to virulent Mycobacterium tuberculosis in tuberculosis patients with advanced disease].

Science.gov (United States)

Ordway, Diane J; Martins, Marta S; Costa, Leonor M; Freire, Mónica S; Arroz, Maria J; Dockrell, Hazel M; Ventura, Fernando A

2005-01-01

The study was designed to compare immune responses to Mycobacterium tuberculosis bacilli and antigens in healthy Portuguese subjects and pulmonary tuberculosis patients (TB), and to correlate immune status with clinical severity of tuberculosis disease. PBMC were cultured and stimulated with live and killed M. tuberculosis H37Rv and purified protein derivative (PPD) and lymphoproliferation and production of IFN-gamma and IL-5/IL-4 by these cultures were evaluated by the use of ELISA and multi-parameter flow cytometry. PBMC from 30 tuberculosis patients demonstrated significantly reduced amounts of proliferation and IFN-gamma when stimulated with live M. tuberculosis compared the control group. Of 15 tuberculosis patients tested for intracellular IL-4 following stimulation with M. tuberculosis, 7 showed greatly increased IL-4 production in CD8+ and gammadelta+ T cells. Tuberculosis patients demonstrated an increase of intracellular IL-4 after PBMC were stimulated with live M. tuberculosis in the CD4+ phenotype, but more notably in CD8+ and gammadelta TCR+ subsets. Increased production of IL-4 in tuberculosis patients was primarily in individuals with advanced involvement of lung parenchymal with high bacterial loads in sputum. These results suggest that an alteration in type 1 and type 2 cytokine balance can occur in patients with tuberculosis at an advanced clinical stage of disease.

Supplementary Material for: Whole genome sequencing reveals genomic heterogeneity and antibiotic purification in Mycobacterium tuberculosis isolates

KAUST Repository

Black, PA

2015-01-01

Abstract Background Whole genome sequencing has revolutionised the interrogation of mycobacterial genomes. Recent studies have reported conflicting findings on the genomic stability of Mycobacterium tuberculosis during the evolution of drug resistance. In an age where whole genome sequencing is increasingly relied upon for defining the structure of bacterial genomes, it is important to investigate the reliability of next generation sequencing to identify clonal variants present in a minor percentage of the population. This study aimed to define a reliable cut-off for identification of low frequency sequence variants and to subsequently investigate genetic heterogeneity and the evolution of drug resistance in M. tuberculosis. Methods Genomic DNA was isolated from single colonies from 14 rifampicin mono-resistant M. tuberculosis isolates, as well as the primary cultures and follow up MDR cultures from two of these patients. The whole genomes of the M. tuberculosis isolates were sequenced using either the Illumina MiSeq or Illumina HiSeq platforms. Sequences were analysed with an in-house pipeline. Results Using next-generation sequencing in combination with Sanger sequencing and statistical analysis we defined a read frequency cut-off of 30 % to identify low frequency M. tuberculosis variants with high confidence. Using this cut-off we demonstrated a high rate of genetic diversity between single colonies isolated from one population, showing that by using the current sequencing technology, single colonies are not a true reflection of the genetic diversity within a whole population and vice versa. We further showed that numerous heterogeneous variants emerge and then disappear during the evolution of isoniazid resistance within individual patients. Our findings allowed us to formulate a model for the selective bottleneck which occurs during the course of infection, acting as a genomic purification event. Conclusions Our study demonstrated true levels of genetic

Evaluation of the Mycobacterium tuberculosis SO2 vaccine using a natural tuberculosis infection model in goats.

Science.gov (United States)

Bezos, J; Casal, C; Álvarez, J; Roy, A; Romero, B; Rodríguez-Bertos, A; Bárcena, C; Díez, A; Juste, R; Gortázar, C; Puentes, E; Aguiló, N; Martín, C; de Juan, L; Domínguez, L

2017-05-01

The development of new vaccines against animal tuberculosis (TB) is a priority for improving the control and eradication of this disease, particularly in those species not subjected to compulsory eradication programmes. In this study, the protection conferred by the Mycobacterium tuberculosis SO 2 experimental vaccine was evaluated using a natural infection model in goats. Twenty-six goats were distributed in three groups: (1) 10 goats served as a control group; (2) six goats were subcutaneously vaccinated with BCG; and (3) 10 goats were subcutaneously vaccinated with SO 2 . Four months after vaccination, all groups were merged with goats infected with Mycobacterium bovis or Mycobacterium caprae, and tested over a 40 week period using a tuberculin intradermal test and an interferon-γ assay for mycobacterial reactivity. The severity of lesions was determined at post-mortem examination and the bacterial load in tissues were evaluated by culture. The two vaccinated groups had significantly lower lesion and bacterial culture scores than the control group (P<0.05); at the end of the study, the SO 2 vaccinated goats had the lowest lesion and culture scores. These results suggest that the SO 2 vaccine provides some protection against TB infection acquired from natural exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

rBCG30-induced immunity and cross-protection against Mycobacterium leprae challenge are enhanced by boosting with the Mycobacterium tuberculosis 30-kilodalton antigen 85B.

Science.gov (United States)

Gillis, Thomas P; Tullius, Michael V; Horwitz, Marcus A

2014-09-01

Leprosy remains a major global health problem and typically occurs in regions in which tuberculosis is endemic. Vaccines are needed that protect against both infections and do so better than the suboptimal Mycobacterium bovis BCG vaccine. Here, we evaluated rBCG30, a vaccine previously demonstrated to induce protection superior to that of BCG against Mycobacterium tuberculosis and Mycobacterium bovis challenge in animal models, for efficacy against Mycobacterium leprae challenge in a murine model of leprosy. rBCG30 overexpresses the M. tuberculosis 30-kDa major secretory protein antigen 85B, which is 85% homologous with the M. leprae homolog (r30ML). Mice were sham immunized or immunized intradermally with BCG or rBCG30 and challenged 2.5 months later by injection of viable M. leprae into each hind footpad. After 7 months, vaccine efficacy was assessed by enumerating the M. leprae bacteria per footpad. Both BCG and rBCG30 induced significant protection against M. leprae challenge. In the one experiment in which a comparison between BCG and rBCG30 was feasible, rBCG30 induced significantly greater protection than did BCG. Immunization of mice with purified M. tuberculosis or M. leprae antigen 85B also induced protection against M. leprae challenge but less so than BCG or rBCG30. Notably, boosting rBCG30 with M. tuberculosis antigen 85B significantly enhanced r30ML-specific immune responses, substantially more so than boosting BCG, and significantly augmented protection against M. leprae challenge. Thus, rBCG30, a vaccine that induces improved protection against M. tuberculosis, induces cross-protection against M. leprae that is comparable or potentially superior to that induced by BCG, and boosting rBCG30 with antigen 85B further enhances immune responses and protective efficacy. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Resistance to first-line anti-TB drugs is associated with reduced nitric oxide susceptibility in Mycobacterium tuberculosis

DEFF Research Database (Denmark)

Idh, Jonna; Mekonnen, Mekidim; Abate, Ebba

2012-01-01

The relative contribution of nitric oxide (NO) to the killing of Mycobacterium tuberculosis in human tuberculosis (TB) is controversial, although this has been firmly established in rodents. Studies have demonstrated that clinical strains of M. tuberculosis differ in susceptibility to NO, but how...

Immune Responses Involved in Mycobacterium Tuberculosis Infection

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Roghayeh Teimourpour

2016-09-01

Full Text Available Background and Objectives: Mycobacterium tuberculosis is the causative agent of tuberculosis (TB. Approximately one-third of the world's population is infected with M. tuberculosis. Despite the availability of drug and vaccine, it remains one of the leading causes of death in humans especially in developing countries. Epidemiological studies have indicated that only 10-30% of people exposed to tubercle bacillus are infected with M. tuberculosis, and at least 90% of the infected people finally do not acquire TB. The studies have indicated that the host efficient immune system has essential roles in the control of TB infection such that the highest rate of mortality and morbidity is seen in immunocompromised patients such as people infected with HIV. M. tuberculosis is an obligatory intracellular bacterium. It enters the body mainly through the respiratory tract and alveolar macrophages combat this pathogen most commonly. In addition to alveolar macrophages, various T-cell subpopulations need to be activated to overcome this bacterium's resistance to the host defense systems. CD4+ T cells, through production of several cytokines such as IFN-γ and TNF-α, and CD8+ T cells, through cytotoxic activities and induction of apoptosis in infected cells, play critical roles in inducing appropriate immune responses against M. tuberculosis. Although cell-mediated immunity is the cornerstone of host responses against TB and the recent studies have provided evidence for the importance of humoral and innate immune system in the control of TB, a profound understanding of the immune responses would provide a basis for development of new generations of vaccines and drugs. The present study addresses immune responses involved in M. tuberculosis infection.

Detection of mycobacterium tuberculosis in clinical samples by smear and culture

International Nuclear Information System (INIS)

Aftab, R.; Amjad, F.; Khurshid, R.

2009-01-01

A retrospective study was carried out in order to compare the smear stained by ZN and Lowenstein-Jensen (U) medium for the detection of Mycobacterium in clinical samples from different categories. Study Design: Laboratory based, Retrospective. Place and Duration: Sir Ganga Ram Hospital Fatima Jinnah Medical College, Lahore over a 5 year period between Jan 2001 and June 2006. Material and Methods: A total of 798 clinical samples were collected from patients of both sexes and all ages with a provisional diagnosis of tuberculosis. A Ziehl-Neelsen stain (ZN) and culture on U medium was performed for the detection of Mycobacterium. The specimen categories were sputum, pus, lymph node aspirate, urine and endometrial curetting. Results: Out of 5 types of 798 specimens received over a period of five years, only 46.3%) (n=369) were respiratory whereas the remaining 53.7% (n=429) were non respiratory tract category samples including sputum, pus, lymph node aspirate, urine and endometrial curetting. All were examined for the presence of acid-fast-bacilli (AFB) in ZN smear. Among these 3.578% gave a positive ZN stain while 11.65% were positive on culture. Out of a total of 369 respiratory tract category samples, 38 (10.3%) sputum samples were positive for AFB on both ZN and culture. Among the non respiratory tract category, 47 (28.2%) pus, 26 (31%) LN aspirate, 5 (15.6%) urine, 5 (3.42%) endometrial curetting were reported positive. Only 15.16% of clinical samples belonging to 5 different categories of specimens received from patients of both sexes with a provisional diagnosis of tuberculosis, tested positive for Mycobacterium by both ZN stain smear and culture on U medium. Among these, 3.57% were positive for AFB on ZN smear and 11.65% were positive on culture on U medium. Conclusion: These conventional techniques have proved to be reliable testing tools for detection of Mycobacterium tuberculosis in our settings but there is an urgent need to promote the use of Biotic and

Increasing incidence of fluoroquinolone-resistant Mycobacterium tuberculosis in Mumbai, India.

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Agrawal, D; Udwadia, Z F; Rodriguez, C; Mehta, A

2009-01-01

Tertiary referral centre, private hospital, Mumbai, India. To analyse the incidence of fluoroquinolone (FQ) resistant Mycobacterium tuberculosis (TB) in our laboratory from 1995 to 2004. Retrospective review and analysis of the drug susceptibility test records of all M. tuberculosis culture-positive samples from our Microbiology Department from 1995 to 2004. FQ resistance has increased exponentially in our laboratory, from 3% in 1996 to 35% in 2004. The incidence of multidrug-resistant tuberculosis has also increased during the same period, from 33% in 1995 to 56% in 2004. The incidence of FQ-resistant M. tuberculosis is gradually increasing to alarming levels. This may be due to widespread use of this vital group of drugs in the treatment of community-acquired infections. We urge that these broad spectrum antibiotics be used judiciously, and ideally be reserved for treatment of resistant TB in TB-endemic areas.

The Association between Mycobacterium Tuberculosis Genotype and Drug Resistance in Peru.

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Louis Grandjean

Full Text Available The comparison of Mycobacterium tuberculosis bacterial genotypes with phenotypic, demographic, geospatial and clinical data improves our understanding of how strain lineage influences the development of drug-resistance and the spread of tuberculosis.To investigate the association of Mycobacterium tuberculosis bacterial genotype with drug-resistance. Drug susceptibility testing together with genotyping using both 15-loci MIRU-typing and spoligotyping, was performed on 2,139 culture positive isolates, each from a different patient in Lima, Peru. Demographic, geospatial and socio-economic data were collected using questionnaires, global positioning equipment and the latest national census.The Latin American Mediterranean (LAM clade (OR 2.4, p<0.001 was significantly associated with drug-resistance and alone accounted for more than half of all drug resistance in the region. Previously treated patients, prisoners and genetically clustered cases were also significantly associated with drug-resistance (OR's 2.5, 2.4 and 1.8, p<0.001, p<0.05, p<0.001 respectively.Tuberculosis disease caused by the LAM clade was more likely to be drug resistant independent of important clinical, genetic and socio-economic confounding factors. Explanations for this include; the preferential co-evolution of LAM strains in a Latin American population, a LAM strain bacterial genetic background that favors drug-resistance or the "founder effect" from pre-existing LAM strains disproportionately exposed to drugs.

Aspectos relevantes del uso de Mycobacterium´habana´ como candidato vacunal contra la tuberculosis

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Iliana Valdés

2011-12-01

Full Text Available La eficacia protectora de la actual vacuna (BCG contra la tuberculosis, para contrarrestar las formas pulmonares de esta enfermedad y su reactivación, resulta variable o poco eficiente, lo cual impone la búsqueda urgente de nuevas alternativas profilácticas contra esta enfermedad. Basados en las ventajas inmunogénicas que ofrece el uso de vacunas vivas, se han encaminado diferentes estrategias de este tipo empleando mutantes auxotróficos de Mycobacterium tuberculosis , BCG recombinante o micobacterias no tuberculosas. Existen evidencias experimentales acerca de la protección conferida tras la vacunación con cepas vivas, inactivadas o fracciones proteicas de Mycobacterium'habana' TMC-5135 contra la infección por Mycobacterium tuberculosis. Esta respuesta protectora parece ir aparejada de escasos signos de virulencia en los modelos animales ensayados, lo cual coloca a M.´habana´ dentro de los posibles candidatos vacunales contra la tuberculosis al ajustarse a la condición que impone una vacuna clásica de reproducir la infección y los eventos inmunes que le suceden lo más fielmente posible a como ocurren de manera natural, sin causar extensos daños en el receptor.

Consequences of genomic diversity in Mycobacterium tuberculosis

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Coscolla, Mireia; Gagneux, Sebastien

2014-01-01

The causative agent of human tuberculosis, Mycobacterium tuberculosis complex (MTBC), comprises seven phylogenetically distinct lineages associated with different geographical regions. Here we review the latest findings on the nature and amount of genomic diversity within and between MTBC lineages. We then review recent evidence for the effect of this genomic diversity on mycobacterial phenotypes measured experimentally and in clinical settings. We conclude that overall, the most geographically widespread Lineage 2 (includes Beijing) and Lineage 4 (also known as Euro-American) are more virulent than other lineages that are more geographically restricted. This increased virulence is associated with delayed or reduced pro-inflammatory host immune responses, greater severity of disease, and enhanced transmission. Future work should focus on the interaction between MTBC and human genetic diversity, as well as on the environmental factors that modulate these interactions. PMID:25453224

Overexpression, purification and crystallographic analysis of a unique adenosine kinase from Mycobacterium tuberculosis

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Wang, Yimin; Long, Mary C.; Ranganathan, Senthil; Escuyer, Vincent; Parker, William B.; Li, Rongbao, E-mail: li@sri.org [Southern Research Institute, 2000 Ninth Avenue South, Birmingham, Alabama 35205 (United States)

2005-06-01

Adenosine kinase from M. tuberculosis has been overexpressed, purified and crystallized in the presence of adenosine. Structure determination using molecular replacement with diffraction data collected at 2.2 Å reveals a dimeric structure. Adenosine kinase from Mycobacterium tuberculosis is the only prokaryotic adenosine kinase that has been isolated and characterized. The enzyme catalyzes the phosphorylation of adenosine to adenosine monophosphate and is involved in the activation of 2-methyladenosine, a compound that has demonstrated selective activity against M. tuberculosis. The mechanism of action of 2-methyladenosine is likely to be different from those of current tuberculosis treatments and this compound (or other adenosine analogs) may prove to be a novel therapeutic intervention for this disease. The M. tuberculosis adenosine kinase was overexpressed in Escherichia coli and the enzyme was purified with activity comparable to that reported previously. The protein was crystallized in the presence of adenosine using the vapour-diffusion method. The crystals diffracted X-rays to high resolution and a complete data set was collected to 2.2 Å using synchrotron radiation. The crystal belonged to space group P3{sub 1}21, with unit-cell parameters a = 70.2, c = 111.6 Å, and contained a single protein molecule in the asymmetric unit. An initial structural model of the protein was obtained by the molecular-replacement method, which revealed a dimeric structure. The monomers of the dimer were related by twofold crystallographic symmetry. An understanding of how the M. tuberculosis adenosine kinase differs from the human homolog should aid in the design of more potent and selective antimycobacterial agents that are selectively activated by this enzyme.

Overexpression, purification and crystallographic analysis of a unique adenosine kinase from Mycobacterium tuberculosis

International Nuclear Information System (INIS)

Wang, Yimin; Long, Mary C.; Ranganathan, Senthil; Escuyer, Vincent; Parker, William B.; Li, Rongbao

2005-01-01

Adenosine kinase from M. tuberculosis has been overexpressed, purified and crystallized in the presence of adenosine. Structure determination using molecular replacement with diffraction data collected at 2.2 Å reveals a dimeric structure. Adenosine kinase from Mycobacterium tuberculosis is the only prokaryotic adenosine kinase that has been isolated and characterized. The enzyme catalyzes the phosphorylation of adenosine to adenosine monophosphate and is involved in the activation of 2-methyladenosine, a compound that has demonstrated selective activity against M. tuberculosis. The mechanism of action of 2-methyladenosine is likely to be different from those of current tuberculosis treatments and this compound (or other adenosine analogs) may prove to be a novel therapeutic intervention for this disease. The M. tuberculosis adenosine kinase was overexpressed in Escherichia coli and the enzyme was purified with activity comparable to that reported previously. The protein was crystallized in the presence of adenosine using the vapour-diffusion method. The crystals diffracted X-rays to high resolution and a complete data set was collected to 2.2 Å using synchrotron radiation. The crystal belonged to space group P3 1 21, with unit-cell parameters a = 70.2, c = 111.6 Å, and contained a single protein molecule in the asymmetric unit. An initial structural model of the protein was obtained by the molecular-replacement method, which revealed a dimeric structure. The monomers of the dimer were related by twofold crystallographic symmetry. An understanding of how the M. tuberculosis adenosine kinase differs from the human homolog should aid in the design of more potent and selective antimycobacterial agents that are selectively activated by this enzyme

Identification of Secretory Proteins in Mycobacterium tuberculosis Using Pseudo Amino Acid Composition

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Huan Yang

2016-01-01

Full Text Available Tuberculosis is killing millions of lives every year and on the blacklist of the most appalling public health problems. Recent findings suggest that secretory protein of Mycobacterium tuberculosis may serve the purpose of developing specific vaccines and drugs due to their antigenicity. Responding to global infectious disease, we focused on the identification of secretory proteins in Mycobacterium tuberculosis. A novel method called MycoSec was designed by incorporating g-gap dipeptide compositions into pseudo amino acid composition. Analysis of variance-based technique was applied in the process of feature selection and a total of 374 optimal features were obtained and used for constructing the final predicting model. In the jackknife test, MycoSec yielded a good performance with the area under the receiver operating characteristic curve of 0.93, demonstrating that the proposed system is powerful and robust. For user’s convenience, the web server MycoSec was established and an obliging manual on how to use it was provided for getting around any trouble unnecessary.

In-Silico Testing Of Nutraceutical Against The Murd Enzymes From Mycobacterium Tuberculosis

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Mohammad Teimouri

2015-08-01

Full Text Available In spite of availability of moderately protective vaccine and antibiotics new antibacterial agents are urgently needed to decrease the global incidence of Mycobacterium tuberculosis infections. Mur family is an important target for the development of new drugs as they are involved in the biosynthesis of bacterial cell wall. MurC-MurF ligases catalyze a series of irreversible steps in the biosynthesis of peptidoglycan precursor i.e. MurD catalyzes the ligation of D-glutamate to the nucleotide precursor UMA. Here we developed a homology model of MurD from M. Tuberculosis and was validated by using rampage Errat and ProSA online servers. Different nutraceuticals were tested and reported for their activity. Among the 14 nutraceuticals Diosgenin Xanthohumol Capsaicin 1-acetoxychavicol acetate and 6-Gingerol have best docking score. The best of all was Diosgenin with the docking score -14.22988 Xanthohumol with -13.923555 Capsaicin with -12.880404 1-acetoxychavicol acetate with -12.573502 and 6-Gingerol -12.349156 which will play a guiding role in the experimental design and development of mycobacterium tuberculosis MurD

A functional role of Rv1738 in Mycobacterium tuberculosis persistence suggested by racemic protein crystallography.

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Bunker, Richard D; Mandal, Kalyaneswar; Bashiri, Ghader; Chaston, Jessica J; Pentelute, Bradley L; Lott, J Shaun; Kent, Stephen B H; Baker, Edward N

2015-04-07

Protein 3D structure can be a powerful predictor of function, but it often faces a critical roadblock at the crystallization step. Rv1738, a protein from Mycobacterium tuberculosis that is strongly implicated in the onset of nonreplicating persistence, and thereby latent tuberculosis, resisted extensive attempts at crystallization. Chemical synthesis of the L- and D-enantiomeric forms of Rv1738 enabled facile crystallization of the D/L-racemic mixture. The structure was solved by an ab initio approach that took advantage of the quantized phases characteristic of diffraction by centrosymmetric crystals. The structure, containing L- and D-dimers in a centrosymmetric space group, revealed unexpected homology with bacterial hibernation-promoting factors that bind to ribosomes and suppress translation. This suggests that the functional role of Rv1738 is to contribute to the shutdown of ribosomal protein synthesis during the onset of nonreplicating persistence of M. tuberculosis.

Human B cells produce chemokine CXCL10 in the presence of Mycobacterium tuberculosis specific T cells

DEFF Research Database (Denmark)

Hoff, Soren T; Salman, Ahmed M; Ruhwald, Morten

2015-01-01

BACKGROUND: The role of B cells in human host response to Mycobacterium tuberculosis (Mtb) infection is still controversial, but recent evidence suggest that B cell follicle like structures within the lung may influence host responses through regulation of the local cytokine environment. A candid......BACKGROUND: The role of B cells in human host response to Mycobacterium tuberculosis (Mtb) infection is still controversial, but recent evidence suggest that B cell follicle like structures within the lung may influence host responses through regulation of the local cytokine environment...

Recombination in pe/ppe genes contributes to genetic variation in Mycobacterium tuberculosis lineages

KAUST Repository

Phelan, Jody E.

2016-02-29

Background Approximately 10 % of the Mycobacterium tuberculosis genome is made up of two families of genes that are poorly characterized due to their high GC content and highly repetitive nature. The PE and PPE families are typified by their highly conserved N-terminal domains that incorporate proline-glutamate (PE) and proline-proline-glutamate (PPE) signature motifs. They are hypothesised to be important virulence factors involved with host-pathogen interactions, but their high genetic variability and complexity of analysis means they are typically disregarded in genome studies. Results To elucidate the structure of these genes, 518 genomes from a diverse international collection of clinical isolates were de novo assembled. A further 21 reference M. tuberculosis complex genomes and long read sequence data were used to validate the approach. SNP analysis revealed that variation in the majority of the 168 pe/ppe genes studied was consistent with lineage. Several recombination hotspots were identified, notably pe_pgrs3 and pe_pgrs17. Evidence of positive selection was revealed in 65 pe/ppe genes, including epitopes potentially binding to major histocompatibility complex molecules. Conclusions This, the first comprehensive study of the pe and ppe genes, provides important insight into M. tuberculosis diversity and has significant implications for vaccine development.

Expression of Mycobacterium smegmatis pyrazinamidase in Mycobacterium tuberculosis confers hypersensitivity to pyrazinamide and related amides.

Science.gov (United States)

Boshoff, H I; Mizrahi, V

2000-10-01

A pyrazinamidase (PZase)-deficient pncA mutant of Mycobacterium tuberculosis, constructed by allelic exchange, was used to investigate the effects of heterologous amidase gene expression on the susceptibility of this organism to pyrazinamide (PZA) and related amides. The mutant was highly resistant to PZA (MIC, >2,000 microg/ml), in accordance with the well-established role of pncA in the PZA susceptibility of M. tuberculosis (A. Scorpio and Y. Zhang, Nat. Med. 2:662-667, 1996). Integration of the pzaA gene encoding the major PZase/nicotinamidase from Mycobacterium smegmatis (H. I. M. Boshoff and V. Mizrahi, J. Bacteriol. 180:5809-5814, 1998) or the M. tuberculosis pncA gene into the pncA mutant complemented its PZase/nicotinamidase defect. In both pzaA- and pncA-complemented mutant strains, the PZase activity was detected exclusively in the cytoplasm, suggesting an intracellular localization for PzaA and PncA. The pzaA-complemented strain was hypersensitive to PZA (MIC, /=20 microg/ml) and was also sensitive to benzamide (MIC, 20 microg/ml), unlike the wild-type and pncA-complemented mutant strains, which were highly resistant to this amide (MIC, >500 microg/ml). This finding was consistent with the observation that benzamide is hydrolyzed by PzaA but not by PncA. Overexpression of PzaA also conferred sensitivity to PZA, nicotinamide, and benzamide on M. smegmatis (MIC, 150 microg/ml in all cases) and rendered Escherichia coli hypersensitive for growth at low pH.

COIN EFFECT OF TUBERCULOSIS AND DIABETES MELLITUS

OpenAIRE

Deepthy. B. Nair

2017-01-01

Tuberculosis is a common disease caused by various strains of mycobacterium, usually Mycobacterium tuberculosis [1]. The first reference to tuberculosis in non European civilization was found in Vedas. Diabetes mellitus is group of metabolic diseases where the person has high blood sugar level either because the pancreas does not produce insulin or because cells do not respond to insulin that is produced. It may eventually leads to polyuria, polyphagia and polydipsia. This review is to reveal...

Association between Mycobacterium tuberculosis complex phylogenetic lineage and acquired drug resistance.

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Courtney M Yuen

Full Text Available BACKGROUND: Development of resistance to antituberculosis drugs during treatment (i.e., acquired resistance can lead to emergence of resistant strains and consequent poor clinical outcomes. However, it is unknown whether Mycobacterium tuberculosis complex species and lineage affects the likelihood of acquired resistance. METHODS: We analyzed data from the U.S. National Tuberculosis Surveillance System and National Tuberculosis Genotyping Service for tuberculosis cases during 2004-2011 with assigned species and lineage and both initial and final drug susceptibility test results. We determined univariate associations between species and lineage of Mycobacterium tuberculosis complex bacteria and acquired resistance to isoniazid, rifamycins, fluoroquinolones, and second-line injectables. We used Poisson regression with backward elimination to generate multivariable models for acquired resistance to isoniazid and rifamycins. RESULTS: M. bovis was independently associated with acquired resistance to isoniazid (adjusted prevalence ratio = 8.46, 95% CI 2.96-24.14 adjusting for HIV status, and with acquired resistance to rifamycins (adjusted prevalence ratio = 4.53, 95% CI 1.29-15.90 adjusting for homelessness, HIV status, initial resistance to isoniazid, site of disease, and administration of therapy. East Asian lineage was associated with acquired resistance to fluoroquinolones (prevalence ratio = 6.10, 95% CI 1.56-23.83. CONCLUSIONS: We found an association between mycobacterial species and lineage and acquired drug resistance using U.S. surveillance data. Prospective clinical studies are needed to determine the clinical significance of these findings, including whether rapid genotyping of isolates at the outset of treatment may benefit patient management.

1.55 Å resolution X-ray crystal structure of Rv3902c from Mycobacterium tuberculosis

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Reddy, Bharat G.; Moates, Derek B. [University of Alabama at Birmingham, 1025 18th Street South, Birmingham, AL 35233 (United States); Kim, Heung-Bok [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Green, Todd J. [University of Alabama at Birmingham, 1025 18th Street South, Birmingham, AL 35233 (United States); Kim, Chang-Yub; Terwilliger, Thomas C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); DeLucas, Lawrence J., E-mail: duke2@uab.edu [University of Alabama at Birmingham, 1025 18th Street South, Birmingham, AL 35233 (United States)

2014-03-25

The 1.55 Å resolution X-ray crystal structure of Rv3902c from M. tuberculosis reveals a novel fold. The crystallographic structure of the Mycobacterium tuberculosis (TB) protein Rv3902c (176 residues; molecular mass of 19.8 kDa) was determined at 1.55 Å resolution. The function of Rv3902c is unknown, although several TB genes involved in bacterial pathogenesis are expressed from the operon containing the Rv3902c gene. The unique structural fold of Rv3902c contains two domains, each consisting of antiparallel β-sheets and α-helices, creating a hand-like binding motif with a small binding pocket in the palm. Structural homology searches reveal that Rv3902c has an overall structure similar to that of the Salmonella virulence-factor chaperone InvB, with an r.m.s.d. for main-chain atoms of 2.3 Å along an aligned domain.

1.55 Å resolution X-ray crystal structure of Rv3902c from Mycobacterium tuberculosis

International Nuclear Information System (INIS)

Reddy, Bharat G.; Moates, Derek B.; Kim, Heung-Bok; Green, Todd J.; Kim, Chang-Yub; Terwilliger, Thomas C.; DeLucas, Lawrence J.

2014-01-01

The 1.55 Å resolution X-ray crystal structure of Rv3902c from M. tuberculosis reveals a novel fold. The crystallographic structure of the Mycobacterium tuberculosis (TB) protein Rv3902c (176 residues; molecular mass of 19.8 kDa) was determined at 1.55 Å resolution. The function of Rv3902c is unknown, although several TB genes involved in bacterial pathogenesis are expressed from the operon containing the Rv3902c gene. The unique structural fold of Rv3902c contains two domains, each consisting of antiparallel β-sheets and α-helices, creating a hand-like binding motif with a small binding pocket in the palm. Structural homology searches reveal that Rv3902c has an overall structure similar to that of the Salmonella virulence-factor chaperone InvB, with an r.m.s.d. for main-chain atoms of 2.3 Å along an aligned domain

Updates on antibody functions in Mycobacterium tuberculosis infection and their relevance for developing a vaccine against tuberculosis.

Science.gov (United States)

Achkar, Jacqueline M; Prados-Rosales, Rafael

2018-04-12

A more effective vaccine to control tuberculosis (TB), a major global public health problem, is urgently needed. Current vaccine candidates focus predominantly on eliciting cell-mediated immunity but other arms of the immune system also contribute to protection against TB. We review here recent studies that enhance our current knowledge of antibody-mediated functions against Mycobacterium tuberculosis. These findings, which contribute to the increasing evidence that antibodies have a protective role against TB, include demonstrations that firstly distinct human antibody Fc glycosylation patterns, found in latent M. tuberculosis infection but not in active TB, influence the efficacy of the host to control M. tuberculosis infection, secondly antibody isotype influences human antibody functions, and thirdly that antibodies targeting M. tuberculosis surface antigens are protective. We discuss these findings in the context of TB vaccine development and highlight the need for further research on antibody-mediated immunity in M. tuberculosis infection. Copyright © 2018 Elsevier Ltd. All rights reserved.

Line probe assay for differentiation within Mycobacterium tuberculosis complex. Evaluation on clinical specimens and isolates including Mycobacterium pinnipedii

DEFF Research Database (Denmark)

Kjeldsen, Marianne Kirstine; Bek, Dorte; Rasmussen, Erik Michael

2009-01-01

A line probe assay (GenoType MTBC) was evaluated for species differentiation within the Mycobacterium tuberculosis complex (MTBC). We included 387 MTBC isolates, 43 IS6110 low-copy MTBC isolates, 28 clinical specimens with varying microscopy grade, and 30 isolates of non-tuberculous mycobacteria...

Distribution of Insertion- and Deletion-Associated Genetic Polymorphisms among Four Mycobacterium tuberculosis Phospholipase C Genes and Associations with Extrathoracic Tuberculosis: a Population-Based Study

OpenAIRE

Kong, Y.; Cave, M. D.; Yang, D.; Zhang, L.; Marrs, C. F.; Foxman, B.; Bates, J. H.; Wilson, F.; Mukasa, L. N.; Yang, Z. H.

2005-01-01

The Mycobacterium tuberculosis genome contains four phospholipase C (PLC)-encoding genes, designated plcA, plcB, plcC, and plcD, respectively. Each of the four genes contributes to the overall PLC activity of M. tuberculosis. PLC is hypothesized to contribute to M. tuberculosis virulence. Infection of M. tuberculosis strains carrying a truncated plcD gene is associated with the occurrence of extrathoracic tuberculosis. However, whether the other three plc genes are also associated with extrat...

Disinfectant-susceptibility of multi-drug-resistant Mycobacterium tuberculosis isolated in Japan

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Noriko Shinoda

2016-02-01

Full Text Available Abstract Background Multi-drug-resistant Mycobacterium tuberculosis has been an important problem in public health around the world. However, limited information about disinfectant-susceptibility of multi-drug-resistant strain of M. tuberculosis was available. Findings We studied susceptibility of several Japanese isolates of multi-drug-resistant M. tuberculosis against disinfectants, which are commonly used in clinical and research laboratories. We selected a laboratory reference strain (H37Rv and eight Japanese isolates, containing five drug-susceptible strains and three multi-drug-resistant strains, and determined profiles of susceptibility against eight disinfectants. The M. tuberculosis strains were distinguished into two groups by the susceptibility profile. There was no relationship between multi-drug-resistance and disinfectant-susceptibility in the M. tuberculosis strains. Cresol soap and oxydol were effective against all strains we tested, regardless of drug resistance. Conclusions Disinfectant-resistance is independent from multi-drug-resistance in M. tuberculosis. Cresol soap and oxydol were effective against all strains we tested, regardless of drug resistance.

Orchestration of pulmonary T cell immunity during Mycobacterium tuberculosis infection: immunity interruptus

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Behar, Samuel M.; Carpenter, Stephen M.; Booty, Matthew G.; Barber, Daniel L.; Jayaraman, Pushpa

2014-01-01

Despite the introduction almost a century ago of Mycobacterium bovis BCG (BCG), an attenuated form of M. bovis that is used as a vaccine against Mycobacterium tuberculosis, tuberculosis remains a global health threat and kills more than 1.5 million people each year. This is mostly because BCG fails to prevent pulmonary disease – the contagious form of tuberculosis. Although there have been significant advances in understanding how the immune system responds to infection, the qualities that define protective immunity against M. tuberculosis remain poorly characterized. The ability to predict who will maintain control over the infection and who will succumb to clinical disease would revolutionize our approach to surveillance, control, and treatment. Here we review the current understanding of pulmonary T cell responses following M. tuberculosis infection. While infection elicits a strong immune response that contains infection, M. tuberculosis evades eradication. Traditionally, its intracellular lifestyle and alteration of macrophage function are viewed as the dominant mechanisms of evasion. Now we appreciate that chronic inflammation leads to T cell dysfunction. While this may arise as the host balances the goals of bacterial sterilization and avoidance of tissue damage, it is becoming clear that T cell dysfunction impairs host resistance. Defining the mechanisms that lead to T cell dysfunction is crucial as memory T cell responses are likely to be subject to the same subject to the same pressures. Thus, success of T cell based vaccines is predicated on memory T cells avoiding exhaustion while at the same time not promoting overt tissue damage. PMID:25311810

Pulmonary tuberculosis

Science.gov (United States)

TB; Tuberculosis - pulmonary; Mycobacterium - pulmonary ... Pulmonary TB is caused by the bacterium Mycobacterium tuberculosis (M tuberculosis) . TB is contagious. This means the bacteria is easily spread from an infected person ...

bioA mutant of Mycobacterium tuberculosis shows severe growth defect and imparts protection against tuberculosis in guinea pigs

Science.gov (United States)

Kar, Ritika; Nangpal, Prachi; Mathur, Shubhita; Singh, Swati

2017-01-01

Owing to the devastation caused by tuberculosis along with the unsatisfactory performance of the Bacillus Calmette–Guérin (BCG) vaccine, a more efficient vaccine than BCG is required for the global control of tuberculosis. A number of studies have demonstrated an essential role of biotin biosynthesis in the growth and survival of several microorganisms, including mycobacteria, through deletion of the genes involved in de novo biotin biosynthesis. In this study, we demonstrate that a bioA mutant of Mycobacterium tuberculosis (MtbΔbioA) is highly attenuated in the guinea pig model of tuberculosis when administered aerogenically as well as intradermally. Immunization with MtbΔbioA conferred significant protection in guinea pigs against an aerosol challenge with virulent M. tuberculosis, when compared with the unvaccinated animals. Booster immunization with MtbΔbioA offered no advantage over a single immunization. These experiments demonstrate the vaccinogenic potential of the attenuated M. tuberculosis bioA mutant against tuberculosis. PMID:28658275

bioA mutant of Mycobacterium tuberculosis shows severe growth defect and imparts protection against tuberculosis in guinea pigs.

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Ritika Kar

Full Text Available Owing to the devastation caused by tuberculosis along with the unsatisfactory performance of the Bacillus Calmette-Guérin (BCG vaccine, a more efficient vaccine than BCG is required for the global control of tuberculosis. A number of studies have demonstrated an essential role of biotin biosynthesis in the growth and survival of several microorganisms, including mycobacteria, through deletion of the genes involved in de novo biotin biosynthesis. In this study, we demonstrate that a bioA mutant of Mycobacterium tuberculosis (MtbΔbioA is highly attenuated in the guinea pig model of tuberculosis when administered aerogenically as well as intradermally. Immunization with MtbΔbioA conferred significant protection in guinea pigs against an aerosol challenge with virulent M. tuberculosis, when compared with the unvaccinated animals. Booster immunization with MtbΔbioA offered no advantage over a single immunization. These experiments demonstrate the vaccinogenic potential of the attenuated M. tuberculosis bioA mutant against tuberculosis.

Inhibition of Glutamine Synthetase: A Potential Drug Target in Mycobacterium tuberculosis

Directory of Open Access Journals (Sweden)

Sherry L. Mowbray

2014-08-01

Full Text Available Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. Globally, tuberculosis is second only to AIDS in mortality and the disease is responsible for over 1.3 million deaths each year. The impractically long treatment schedules (generally 6–9 months and unpleasant side effects of the current drugs often lead to poor patient compliance, which in turn has resulted in the emergence of multi-, extensively- and totally-drug resistant strains. The development of new classes of anti-tuberculosis drugs and new drug targets is of global importance, since attacking the bacterium using multiple strategies provides the best means to prevent resistance. This review presents an overview of the various strategies and compounds utilized to inhibit glutamine synthetase, a promising target for the development of drugs for TB therapy.

Infections with Mycobacterium tuberculosis and Mycobacterium avium among HIV-infected patients after the introduction of highly active antiretroviral therapy. EuroSIDA Study Group JD

DEFF Research Database (Denmark)

Kirk, O; Gatell, J M; Mocroft, A

2000-01-01

the introduction of HAART, using data from the EuroSIDA study, a European, multicenter observational cohort of more than 7,000 patients. Overall incidences of Mycobacterium tuberculosis (TB) and Mycobacterium avium complex (MAC) were 0.8 and 1.4 cases/100 person-years of follow-up (PYF), decreasing from 1.8 (TB...

Genetic Determinants of Drug Resistance in Mycobacterium tuberculosis and Their Diagnostic Value

NARCIS (Netherlands)

Farhat, M.R.; Sultana, R.; Iartchouk, O.; Bozeman, S.; Galagan, J.; Sisk, P.; Stolte, C.; Nebenzahl-Guimaraes, H.; Jacobson, K.; Sloutsky, A.; Kaur, D.; Posey, J.; Kreiswirth, B.N.; Kurepina, N.; Rigouts, L.; Streicher, E.M.; Victor, T.C.; Warren, R.M.; Soolingen, D. van; Murray, M.

2016-01-01

RATIONALE: The development of molecular diagnostics that detect both the presence of Mycobacterium tuberculosis in clinical samples and drug resistance-conferring mutations promises to revolutionize patient care and interrupt transmission by ensuring early diagnosis. However, these tools require the

Transmission of Mycobacterium tuberculosis from patients who are nucleic acid amplification test- negative.

Science.gov (United States)

Xie, Yingda L; Cronin, Wendy A; Proschan, Michael; Oatis, Richard; Cohn, Silvia; Curry, Scott R; Golub, Jonathan E; Barry Iii, Clifton E; Dorman, Susan E

2018-04-24

Among adults with signs and symptoms of pulmonary tuberculosis (TB), recognition of transmissible TB has implications for airborne infection isolation and public health activities. Sputum smear-negative TB patients account for around one-fifth of tuberculosis transmission. The tuberculosis transmission risk of TB patients with negative results on nucleic acid amplification (NAA) testing of respiratory specimens has not been established. We sought to estimate the tuberculosis transmission risk of NAA test-negative TB patients. We retrospectively reviewed Maryland TB program data from 2004 to 2009 during which NAA testing by the Mycobacterium Tuberculosis Direct Test (MTD) was performed routinely. Patients with sputum Mycobacterium tuberculosis (M.tb) isolates having matching genotypes were assigned to clusters. Transmission sequence was approximated by collection order of individuals' first culture-positive specimens. Minimum transmission risks of NAA (MTD)-negative TB patients and of smear-negative TB patients were estimated based on individuals' positions within clusters. Among 809 patients with culture-confirmed TB, M.tb genotypes were available for 782 (96.7%). For NAA-negative TB patients the minimum transmission risk estimate was 5.1% (95% CI 0-11.4). For smear-negative TB patients the minimum transmission risk estimate was 11.2% (95% CI 7.2-15.3). Minimum transmission risk of NAA-negative TB patients was lower than that of smear-negative TB patients. However, transmission risk of NAA-negative TB patients appears to not be negligible.

Transcriptional and physiological changes during Mycobacterium tuberculosis reactivation from non-replicating persistence

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Peicheng Du

2016-08-01

Full Text Available Mycobacterium tuberculosis can persist for years in the hostile environment of the host in a non-replicating or slowly replicating state. While active disease predominantly results from reactivation of a latent infection, the molecular mechanisms of M. tuberculosis reactivation are still poorly understood. We characterized the physiology and global transcriptomic profiles of M. tuberculosis during reactivation from hypoxia-induced non-replicating persistence. We found that M. tuberculosis reactivation upon reaeration was associated with a lag phase, in which the recovery of cellular physiological and metabolic functions preceded the resumption of cell replication. Enrichment analysis of the transcriptomic dynamics revealed changes to many metabolic pathways and transcription regulons/subnetworks that orchestrated the metabolic and physiological transformation in preparation for cell division. In particular, we found that M. tuberculosis reaeration lag phase is associated with down-regulation of persistence-associated regulons/subnetworks, including DosR, MprA, SigH, SigE and ClgR, as well as metabolic pathways including those involved in the uptake of lipids and their catabolism. More importantly, we identified a number of up-regulated transcription regulons and metabolic pathways, including those involved in metal transport and remobilization, second messenger-mediated responses, DNA repair and recombination, and synthesis of major cell wall components. We also found that inactivation of the major alternative sigma factors SigE or SigH disrupted exit from persistence, underscoring the importance of the global transcriptional reprogramming during M. tuberculosis reactivation. Our observations suggest that M. tuberculosis lag phase is associated with a global gene expression reprogramming that defines the initiation of a reactivation process.

Clinical implications of molecular drug resistance testing for Mycobacterium tuberculosis: a TBNET/RESIST-TB consensus statement

NARCIS (Netherlands)

Domínguez, J.; Boettger, E. C.; Cirillo, D.; Cobelens, F.; Eisenach, K. D.; Gagneux, S.; Hillemann, D.; Horsburgh, R.; Molina-Moya, B.; Niemann, S.; Tortoli, E.; Whitelaw, A.; Lange, C.

2016-01-01

The emergence of drug-resistant strains of Mycobacterium tuberculosis is a challenge to global tuberculosis (TB) control. Although culture-based methods have been regarded as the gold standard for drug susceptibility testing (DST), molecular methods provide rapid information on mutations in the M.

Mycobacterium tuberculosis nuoG is a virulence gene that inhibits apoptosis of infected host cells.

Directory of Open Access Journals (Sweden)

Kamalakannan Velmurugan

2007-07-01

Full Text Available The survival and persistence of Mycobacterium tuberculosis depends on its capacity to manipulate multiple host defense pathways, including the ability to actively inhibit the death by apoptosis of infected host cells. The genetic basis for this anti-apoptotic activity and its implication for mycobacterial virulence have not been demonstrated or elucidated. Using a novel gain-of-function genetic screen, we demonstrated that inhibition of infection-induced apoptosis of macrophages is controlled by multiple genetic loci in M. tuberculosis. Characterization of one of these loci in detail revealed that the anti-apoptosis activity was attributable to the type I NADH-dehydrogenase of M. tuberculosis, and was mainly due to the subunit of this multicomponent complex encoded by the nuoG gene. Expression of M. tuberculosis nuoG in nonpathogenic mycobacteria endowed them with the ability to inhibit apoptosis of infected human or mouse macrophages, and increased their virulence in a SCID mouse model. Conversely, deletion of nuoG in M. tuberculosis ablated its ability to inhibit macrophage apoptosis and significantly reduced its virulence in mice. These results identify a key component of the genetic basis for an important virulence trait of M. tuberculosis and support a direct causal relationship between virulence of pathogenic mycobacteria and their ability to inhibit macrophage apoptosis.

Studium role fosfofruktokinasy A a B v metabolismu Mycobacterium tuberculosis

Czech Academy of Sciences Publication Activity Database

Machová, Iva; Snášel, Jan; Pichová, Iva

2014-01-01

Roč. 108, č. 5 (2014), s. 542 ISSN 0009-2770. [Mezioborové setkání mladých biologů, biochemiků a chemiků /14./. 13.05.2014-16.05.2014, Milovy] Grant - others:European Research Council(XE) FP7-245187 Institutional support: RVO:61388963 Keywords : Mycobacterium tuberculosis * phosphofructokinase Subject RIV: CE - Biochemistry

A case of Manila type Mycobacterium tuberculosis infection in Japan

Science.gov (United States)

Usami, Osamu; Nakajima, Chie; Endo, Shiro; Inomata, Shinya; Kanamori, Hajime; Hirakata, Yoichi; Uchiyama, Bine; Kaku, Mitsuo; Suzuki, Yasuhiko; Hattori, Toshio

2015-01-01

Key Clinical Message A 76-year-old Japanese woman contracted a Mycobacterium tuberculosis (TB, Manila type) infection in Japan, despite never having traveled. However, her son was treated for TB in the Philippines 3 years before he stayed at her house. Spoligotyping allows us to identify the TB genotype and identify the route of infection. PMID:26273455

Differential Expression of Immunogenic Proteins on Virulent Mycobacterium tuberculosis Clinical Isolates

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Pablo Schierloh

2014-01-01

Full Text Available Molecular epidemiology has revealed that Mycobacterium tuberculosis (Mtb, formerly regarded as highly conserved species, displays a considerable degree of genetic variability that can influence the outcome of the disease as well as the innate and adaptive immune response. Recent studies have demonstrated that Mtb families found worldwide today differ in pathology, transmissibility, virulence, and development of immune response. By proteomic approaches seven proteins that were differentially expressed between a local clinical isolate from Latin-American-Mediterranean (LAM and from Haarlem (H lineages were identified. In order to analyze the immunogenic ability, recombinant Rv2241, Rv0009, Rv0407, and Rv2624c proteins were produced for testing specific antibody responses. We found that these proteins induced humoral immune responses in patients with drug-sensitive and drug-resistant tuberculosis with substantial cross-reactivity among the four proteins. Moreover, such reactivity was also correlated with anti-Mtb-cell surface IgM, but not with anti-ManLAM, anti-PPD, or anti-Mtb-surface IgG antibodies. Therefore, the present results describe new Mtb antigens with potential application as biomarkers of TB.

In vitro Inhibition of Mycobacterium smegmatis and Mycobacterium ...

African Journals Online (AJOL)

Some Nigerian plants used in traditional medicine to treat tuberculosis and/or some of its symptoms were screened for in vitro activity against Mycobacterium smegmatis and a clinical isolate of Mycobacterium tuberculosis. Only 3 of the 6 crude methanolic extracts of the 6 plant species exhibited inhibitory activities against ...

Immunogenic Properties of Lactobacillus plantarum Producing Surface-Displayed Mycobacterium tuberculosis Antigens.

Science.gov (United States)

Kuczkowska, Katarzyna; Kleiveland, Charlotte R; Minic, Rajna; Moen, Lars F; Øverland, Lise; Tjåland, Rannei; Carlsen, Harald; Lea, Tor; Mathiesen, Geir; Eijsink, Vincent G H

2017-01-15

Tuberculosis (TB) remains among the most deadly diseases in the world. The only available vaccine against tuberculosis is the bacille Calmette-Guérin (BCG) vaccine, which does not ensure full protection in adults. There is a global urgency for the development of an effective vaccine for preventing disease transmission, and it requires novel approaches. We are exploring the use of lactic acid bacteria (LAB) as a vector for antigen delivery to mucosal sites. Here, we demonstrate the successful expression and surface display of a Mycobacterium tuberculosis fusion antigen (comprising Ag85B and ESAT-6, referred to as AgE6) on Lactobacillus plantarum The AgE6 fusion antigen was targeted to the bacterial surface using two different anchors, a lipoprotein anchor directing the protein to the cell membrane and a covalent cell wall anchor. AgE6-producing L. plantarum strains using each of the two anchors induced antigen-specific proliferative responses in lymphocytes purified from TB-positive donors. Similarly, both strains induced immune responses in mice after nasal or oral immunization. The impact of the anchoring strategies was reflected in dissimilarities in the immune responses generated by the two L. plantarum strains in vivo The present study comprises an initial step toward the development of L. plantarum as a vector for M. tuberculosis antigen delivery. This work presents the development of Lactobacillus plantarum as a candidate mucosal vaccine against tuberculosis. Tuberculosis remains one of the top infectious diseases worldwide, and the only available vaccine, bacille Calmette-Guérin (BCG), fails to protect adults and adolescents. Direct antigen delivery to mucosal sites is a promising strategy in tuberculosis vaccine development, and lactic acid bacteria potentially provide easy, safe, and low-cost delivery vehicles for mucosal immunization. We have engineered L. plantarum strains to produce a Mycobacterium tuberculosis fusion antigen and to anchor this

Mycobacterium tuberculosis Controls Phagosomal Acidification by Targeting CISH-Mediated Signaling

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Christophe J. Queval

2017-09-01

Full Text Available Pathogens have evolved a range of mechanisms to counteract host defenses, notably to survive harsh acidic conditions in phagosomes. In the case of Mycobacterium tuberculosis, it has been shown that regulation of phagosome acidification could be achieved by interfering with the retention of the V-ATPase complexes at the vacuole. Here, we present evidence that M. tuberculosis resorts to yet another strategy to control phagosomal acidification, interfering with host suppressor of cytokine signaling (SOCS protein functions. More precisely, we show that infection of macrophages with M. tuberculosis leads to granulocyte-macrophage colony-stimulating factor (GM-CSF secretion, inducing STAT5-mediated expression of cytokine-inducible SH2-containing protein (CISH, which selectively targets the V-ATPase catalytic subunit A for ubiquitination and degradation by the proteasome. Consistently, we show that inhibition of CISH expression leads to reduced replication of M. tuberculosis in macrophages. Our findings further broaden the molecular understanding of mechanisms deployed by bacteria to survive.

Evaluation of highly conserved hsp65-specific nested PCR primers for diagnosing Mycobacterium tuberculosis.

Science.gov (United States)

Priyadarshini, P; Tiwari, K; Das, A; Kumar, D; Mishra, M N; Desikan, P; Nath, G

2017-02-01

To evaluate the sensitivity and specificity of a new nested set of primers designed for the detection of Mycobacterium tuberculosis complex targeting a highly conserved heat shock protein gene (hsp65). The nested primers were designed using multiple sequence alignment assuming the nucleotide sequence of the M. tuberculosis H37Rv hsp65 genome as base. Multidrug-resistant Mycobacterium species along with other non-mycobacterial and fungal species were included to evaluate the specificity of M. tuberculosis hsp65 gene-specific primers. The sensitivity of the primers was determined using serial 10-fold dilutions, and was 100% as shown by the bands in the case of M. tuberculosis complex. None of the other non M. tuberculosis complex bacterial and fungal species yielded any band on nested polymerase chain reaction (PCR). The first round of amplification could amplify 0.3 ng of the template DNA, while nested PCR could detect 0.3 pg. The present hsp65-specific primers have been observed to be sensitive, specific and cost-effective, without requiring interpretation of biochemical tests, real-time PCR, sequencing or high-performance liquid chromatography. These primer sets do not have the drawbacks associated with those protocols that target insertion sequence 6110, 16S rDNA, rpoB, recA and MPT 64.

Current Methods in the Molecular Typing of Mycobacterium tuberculosis and Other Mycobacteria

Science.gov (United States)

van Ingen, Jakko; Dziadek, Jarosław; Mazur, Paweł K.; Bielecki, Jacek

2014-01-01

In the epidemiology of tuberculosis (TB) and nontuberculous mycobacterial (NTM) diseases, as in all infectious diseases, the key issue is to define the source of infection and to disclose its routes of transmission and dissemination in the environment. For this to be accomplished, the ability of discerning and tracking individual Mycobacterium strains is of critical importance. Molecular typing methods have greatly improved our understanding of the biology of mycobacteria and provide powerful tools to combat the diseases caused by these pathogens. The utility of various typing methods depends on the Mycobacterium species under investigation as well as on the research question. For tuberculosis, different methods have different roles in phylogenetic analyses and person-to-person transmission studies. In NTM diseases, most investigations involve the search for environmental sources or phylogenetic relationships. Here, too, the type of setting determines which methodology is most suitable. Within this review, we summarize currently available molecular methods for strain typing of M. tuberculosis and some NTM species, most commonly associated with human disease. For the various methods, technical practicalities as well as discriminatory power and accomplishments are reviewed. PMID:24527454

Differential T-cell recognition of native and recombinant Mycobacterium tuberculosis GroES

DEFF Research Database (Denmark)

Rosenkrands, I; Weldingh, K; Ravn, P

1999-01-01

Mycobacterium tuberculosis GroES was purified from culture filtrate, and its identity was confirmed by immunoblot analysis and N-terminal sequencing. Comparing the immunological recognition of native and recombinant GroES, we found that whereas native GroES elicited a strong proliferative response...

The curative activity of thioridazine on mice infected with Mycobacterium tuberculosis

DEFF Research Database (Denmark)

Martins, Marta; Viveiros, Miguel; Kristiansen, Jette E

2007-01-01

BACKGROUND: The aim of the study was to evaluate the effectiveness of thioridazine (TZ) at different dose levels on mice that had been infected intraperitoneally (i.p.) with a high dose of the Mycobacterium tuberculosis ATCC H37Rv strain. SUBJECTS AND METHODS: Groups of five female BALB/C mice were...

Total Hip Arthroplasty Loosening Due to Mycobacterium Tuberculosis: A Case Report and Review of the Literature

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Anis Tebourbi

2017-04-01

Full Text Available Context: Prosthetic joint infection due to Mycobacterium tuberculosis with no previous history of pulmonary or extra pulmonary tuberculosis is an extremely rare complication. Aims To report the case of a patient with tuberculous mycobacterial prosthetic hip infection, 14 years after surgery for post traumatic osteoarthritis, with no previous history of tuberculosis. Methods A 46-year-old male presented an acetabular loosening of a cemented total hip arthroplasty with subnormal biologic parameters. A one stage revision surgery was planned. Intraoperative findings suggested mycobacterial tuberculous infection with presence of periacetabular yellowish rice-shaped granules. Results A one-stage prosthesis exchange was performed; Culture on Löwenstein-Jensen medium grew MTB days after inoculation and histological examination confirmed tuberculous infection. Patient was treated by antituberculous agents for 12 months with optimal clinical and biological response and no prosthetic loosening signs at eighteen months follow up. Conclusions Total hip arthroplasty loosening due to mycobacterium tuberculosis is a rare entity, which should be evoked even when no inflammatory signs are shown. Discovery of yellowish rice-shaped granules is an indicator to investigate for tuberculosis. Management of prosthetic joint infection due to M.tuberculosis must involve both medical and surgical approach.

Mycobacterium tuberculosis TlyA Protein Negatively Regulates T Helper (Th) 1 and Th17 Differentiation and Promotes Tuberculosis Pathogenesis*

Science.gov (United States)

Rahman, Md. Aejazur; Sobia, Parveen; Dwivedi, Ved Prakash; Bhawsar, Aakansha; Singh, Dhiraj Kumar; Sharma, Pawan; Moodley, Prashini; Van Kaer, Luc; Bishai, William R; Das, Gobardhan

2015-01-01

Mycobacterium tuberculosis, the causative agent of tuberculosis, is an ancient pathogen and a major cause of death worldwide. Although various virulence factors of M. tuberculosis have been identified, its pathogenesis remains incompletely understood. TlyA is a virulence factor in several bacterial infections and is evolutionarily conserved in many Gram-positive bacteria, but its function in M. tuberculosis pathogenesis has not been elucidated. Here, we report that TlyA significantly contributes to the pathogenesis of M. tuberculosis. We show that a TlyA mutant M. tuberculosis strain induces increased IL-12 and reduced IL-1β and IL-10 cytokine responses, which sharply contrasts with the immune responses induced by wild type M. tuberculosis. Furthermore, compared with wild type M. tuberculosis, TlyA-deficient M. tuberculosis bacteria are more susceptible to autophagy in macrophages. Consequently, animals infected with the TlyA mutant M. tuberculosis organisms exhibited increased host-protective immune responses, reduced bacillary load, and increased survival compared with animals infected with wild type M. tuberculosis. Thus, M. tuberculosis employs TlyA as a host evasion factor, thereby contributing to its virulence. PMID:25847237

DETECTION OF MYCOBACTERIUM TUBERCULOSIS IN BLOOD FOR DIAGNOSIS OF GENERALISED TUBERCULOSIS IN HIV-POSITIVE PATIENTS

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V. N. Zimina

2017-01-01

Full Text Available Objective: To study the informative value of the detection of mycobacteria in blood with the cultural method in patients with suspected tuberculous sepsis and to determine the most significant clinical and laboratory criteria for testing. Materials and methods: The investigation to detect M.tuberculosis was fulfilled in 159 HIV-positive patients with suspected tuberculosis sepsis. Blood culture was completed with culture medium Myco/F Lytic Culture Vials and analyzer BACTEC 9050. Results: Mycobacteria were detected in blood of 19 patients (11,9% of all patients: in 18 patients the growth of М. tuberculosis complex was detected (25,3% of all patients with diagnosed tuberculosis and in 1 patient it was Mycobacterium avium complex (0,6% of all patients. It was shown, that the probability of M.tuberculosis detection was especially associated with the severity of the disease, immunosupression (less than 100 cells/mkl, hemoglobin quantity less than 90 g/l (levels were determined through the seeking for the most significant cutoffs. It was not proofed, that meningoencephalitis develops more often in patients with proven bacteremia. There were no evident differences in detection frequency of mycobacteria in sputum between patients with tuberculous sepsis and without it.

Mycobacterium tuberculosis whole genome sequencing and protein structure modelling provides insights into anti-tuberculosis drug resistance

KAUST Repository

Phelan, Jody

2016-03-23

Background Combating the spread of drug resistant tuberculosis is a global health priority. Whole genome association studies are being applied to identify genetic determinants of resistance to anti-tuberculosis drugs. Protein structure and interaction modelling are used to understand the functional effects of putative mutations and provide insight into the molecular mechanisms leading to resistance. Methods To investigate the potential utility of these approaches, we analysed the genomes of 144 Mycobacterium tuberculosis clinical isolates from The Special Programme for Research and Training in Tropical Diseases (TDR) collection sourced from 20 countries in four continents. A genome-wide approach was applied to 127 isolates to identify polymorphisms associated with minimum inhibitory concentrations for first-line anti-tuberculosis drugs. In addition, the effect of identified candidate mutations on protein stability and interactions was assessed quantitatively with well-established computational methods. Results The analysis revealed that mutations in the genes rpoB (rifampicin), katG (isoniazid), inhA-promoter (isoniazid), rpsL (streptomycin) and embB (ethambutol) were responsible for the majority of resistance observed. A subset of the mutations identified in rpoB and katG were predicted to affect protein stability. Further, a strong direct correlation was observed between the minimum inhibitory concentration values and the distance of the mutated residues in the three-dimensional structures of rpoB and katG to their respective drugs binding sites. Conclusions Using the TDR resource, we demonstrate the usefulness of whole genome association and convergent evolution approaches to detect known and potentially novel mutations associated with drug resistance. Further, protein structural modelling could provide a means of predicting the impact of polymorphisms on drug efficacy in the absence of phenotypic data. These approaches could ultimately lead to novel resistance

Two-Component Systems of Mycobacterium tuberculosis—Structure-Based Approaches

DEFF Research Database (Denmark)

Tucker, Paul; Nowak, Elzbieta; Morth, Jens Preben

2007-01-01

Mycobacterium tuberculosis contains few two‐component systems compared to many other bacteria, possibly because it has more serine/threonine signaling pathways. Even so, these two‐component systems appear to play an important role in early intracellular survival of the pathogen as well as in aspe...

MicroRNA signatures from multidrug-resistant Mycobacterium tuberculosis

Science.gov (United States)

REN, NA; GAO, GUIJU; SUN, YUE; ZHANG, LING; WANG, HUIZHU; HUA, WENHAO; WAN, KANGLIN; LI, XINGWANG

2015-01-01

Tuberculosis (TB) infections, caused by multi-drug-resistant Mycobacterium tuberculosis (MDR MTB), remain a significant public health concern worldwide. The regulatory mechanisms underlying the emergence of MDR MTB strains remain to be fully elucidated, and further investigation is required in order to develop better strategies for TB control. The present study investigated the expression profile of microRNA (miRNA) in MTB strains, and examined the differences between sensitive MTB and MDR MTB using next generation sequencing (NGS) with Illumina Deep Sequencing technology to better understand the mechanisms of resistance in MDR MTB, A total of 5, 785 and 195, and 6, 290 and 595 qualified Illumina reads were obtained from two MDR MTB strains, and 6, 673 and 665, and 7, 210 and 217 qualified Illumina reads were obtained from two sensitive MTB strains. The overall de novo assembly of miRNA sequence data generated 62 and 62, and 95 and 112 miRNAs between the 18 and 30 bp long from sensitive MTB strains and MDR MTB strains, respectively. Comparative miRNA analysis revealed that 142 miRNAs were differentially expressed in the MDR MTB strain, compared with the sensitive MTB strain, of which 48 were upregulated and 94 were downregulated. There were six similarly expressed miRNAs between the MDR and sensitive MTB strains, and 108 miRNAs were expressed only in the MDR MTB strain. The present study acquired miRNA data from sensitive MTB and MDR MTB strains using NGS techniques, and this identification miRNAs may serve as an invaluable resource for revealing the molecular basis of the regulation of expression associated with the mechanism of drug-resistance in MTB. PMID:26324150

MicroRNA signatures from multidrug‑resistant Mycobacterium tuberculosis.

Science.gov (United States)

Ren, Na; Gao, Guiju; Sun, Yue; Zhang, Ling; Wang, Huizhu; Hua, Wenhao; Wan, Kanglin; Li, Xingwang

2015-11-01

Tuberculosis (TB) infections, caused by multidrug‑resistant Mycobacterium tuberculosis (MDR MTB), remain a significant public health concern worldwide. The regulatory mechanisms underlying the emergence of MDR MTB strains remain to be fully elucidated, and further investigation is required in order to develop better strategies for TB control. The present study investigated the expression profile of microRNA (miRNA) in MTB strains, and examined the differences between sensitive MTB and MDR MTB using next generation sequencing (NGS) with Illumina Deep Sequencing technology to better understand the mechanisms of resistance in MDR MTB, A total of 5, 785 and 195, and 6, 290 and 595 qualified Illumina reads were obtained from two MDR MTB strains, and 6, 673 and 665, and 7, 210 and 217 qualified Illumina reads were obtained from two sensitive MTB strains. The overall de novo assembly of miRNA sequence data generated 62 and 62, and 95 and 112 miRNAs between the 18 and 30 bp long from sensitive MTB strains and MDR MTB strains, respectively. Comparative miRNA analysis revealed that 142 miRNAs were differentially expressed in the MDR MTB strain, compared with the sensitive MTB strain, of which 48 were upregulated and 94 were downregulated. There were six similarly expressed miRNAs between the MDR and sensitive MTB strains, and 108 miRNAs were expressed only in the MDR MTB strain. The present study acquired miRNA data from sensitive MTB and MDR MTB strains using NGS techniques, and this identification miRNAs may serve as an invaluable resource for revealing the molecular basis of the regulation of expression associated with the mechanism of drug‑resistance in MTB.

Optimal Combination of VNTR Typing for Discrimination of Isolated Mycobacterium tuberculosis in Korea

OpenAIRE

Lee, Jihye; Kang, Heeyoon; Kim, Sarang; Yoo, Heekyung; Kim, Hee Jin; Park, Young Kil

2014-01-01

Background Variable-number tandem repeat (VNTR) typing is a promising method to discriminate the Mycobacterium tuberculosis isolates in molecular epidemiology. The purpose of this study is to determine the optimal VNTR combinations for discriminating isolated M. tuberculosis strains in Korea. Methods A total of 317 clinical isolates collected throughout Korea were genotyped by using the IS6110 restriction fragment length polymorphism (RFLP), and then analysed for the number of VNTR copies fro...

Cyclic GMP-AMP Synthase Is an Innate Immune DNA Sensor for Mycobacterium tuberculosis.

Science.gov (United States)

Collins, Angela C; Cai, Haocheng; Li, Tuo; Franco, Luis H; Li, Xiao-Dong; Nair, Vidhya R; Scharn, Caitlyn R; Stamm, Chelsea E; Levine, Beth; Chen, Zhijian J; Shiloh, Michael U

2015-06-10

Activation of the DNA-dependent cytosolic surveillance pathway in response to Mycobacterium tuberculosis infection stimulates ubiquitin-dependent autophagy and inflammatory cytokine production, and plays an important role in host defense against M. tuberculosis. However, the identity of the host sensor for M. tuberculosis DNA is unknown. Here we show that M. tuberculosis activated cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) synthase (cGAS) in macrophages to produce cGAMP, a second messenger that activates the adaptor protein stimulator of interferon genes (STING) to induce type I interferons and other cytokines. cGAS localized with M. tuberculosis in mouse and human cells and in human tuberculosis lesions. Knockdown or knockout of cGAS in human or mouse macrophages blocked cytokine production and induction of autophagy. Mice deficient in cGAS were more susceptible to lethality caused by infection with M. tuberculosis. These results demonstrate that cGAS is a vital innate immune sensor of M. tuberculosis infection. Copyright © 2015 Elsevier Inc. All rights reserved.

Origins and properties of Mycobacterium tuberculosis isolates in London.

Science.gov (United States)

Dale, Jeremy W; Bothamley, Graham H; Drobniewski, Francis; Gillespie, Stephen H; McHugh, Timothy D; Pitman, Richard

2005-06-01

Using similarities of IS6110 banding patterns, isolates of Mycobacterium tuberculosis from a population-based study in London were assigned to 12 large groups termed 'superfamilies' (sfams). Analysis of patient data showed a marked geographical association in the distribution of these sfams. In particular, isolates from patients born in Europe were from different sfams than those born elsewhere, indicating that there had been relatively little transmission of tuberculosis in London from immigrant communities into the endogenous population. Multivariate analysis showed that certain sfams were significantly associated with pulmonary rather than extrapulmonary disease, or with sputum smear negativity, independently of country of birth or ethnicity, suggesting that the properties of the infecting organism play a role in the nature of the disease process.

Substituted aminopyrimidine protein kinase B (PknB) inhibitors show activity against Mycobacterium tuberculosis

Science.gov (United States)

Chapman, Timothy M.; Bouloc, Nathalie; Buxton, Roger S.; Chugh, Jasveen; Lougheed, Kathryn E.A.; Osborne, Simon A.; Saxty, Barbara; Smerdon, Stephen J.; Taylor, Debra L.; Whalley, David

2012-01-01

A high-throughput screen against PknB, an essential serine–threonine protein kinase present in Mycobacterium tuberculosis (M. tuberculosis), allowed the identification of an aminoquinazoline inhibitor which was used as a starting point for SAR investigations. Although a significant improvement in enzyme affinity was achieved, the aminoquinazolines showed little or no cellular activity against M. tuberculosis. However, switching to an aminopyrimidine core scaffold and the introduction of a basic amine side chain afforded compounds with nanomolar enzyme binding affinity and micromolar minimum inhibitory concentrations against M. tuberculosis. Replacement of the pyrazole head group with pyridine then allowed equipotent compounds with improved selectivity against a human kinase panel to be obtained. PMID:22469702

Genotyping of rifampin-resistant Mycobacterium tuberculosis isolates from Western Turkey

International Nuclear Information System (INIS)

Cavasoglu, Cengiz; Bilgic, Altinay; Durmaz, Riza; Gunal, Selami

2004-01-01

Although the rate of multiple drug resistance is high there is no published data on the transmission rate of drug-resistant strains of Mycobacterium tuberculosis in the Aegean region of Western Turkey that are based on molecular methods. IS6110 and pTBN12 restriction fragment lengthpolymorphism (RFLP) methods were used for typing Mycobacterium tuberculosis isolated from 26 sputum samples from 26 patients. 19 of rifampin-resistant isolates (73.1%) contained 6 to 11 copies of 156110. Eighteen different IS6110 DNA fingerprint patterns were observed in the 26 rifampin resistant isolates. 23 of the 26 rifampin-resistant isolates were also resistant to isoniazid. When evaluated together, both methods yielded 21 (80.9%) different banding patterns and the level of clustering was 34.6%. The average number per pattern was 1.23 (26/21). IS6110 fingerprinting suggests that the rifampin-resistant isolates obtained from the Aegean region had a relatively high clustering rate and were clonally related. These findings showed that the rifampin-resistant isolates are actively transmitted between patients. Urgent measures should be taken to prevent the spread of these resistant strains. (author)

Urease Activity Represents an Alternative Pathway for Mycobacterium tuberculosis Nitrogen Metabolism

Science.gov (United States)

Lin, Wenwei; Mathys, Vanessa; Ang, Emily Lei Yin; Koh, Vanessa Hui Qi; Martínez Gómez, Julia María; Ang, Michelle Lay Teng; Zainul Rahim, Siti Zarina; Tan, Mai Ping; Pethe, Kevin

2012-01-01

Urease represents a critical virulence factor for some bacterial species through its alkalizing effect, which helps neutralize the acidic microenvironment of the pathogen. In addition, urease serves as a nitrogen source provider for bacterial growth. Pathogenic mycobacteria express a functional urease, but its role during infection has yet to be characterized. In this study, we constructed a urease-deficient Mycobacterium tuberculosis strain and confirmed the alkalizing effect of the urease activity within the mycobacterium-containing vacuole in resting macrophages but not in the more acidic phagolysosomal compartment of activated macrophages. However, the urease-mediated alkalizing effect did not confer any growth advantage on M. tuberculosis in macrophages, as evidenced by comparable growth profiles for the mutant, wild-type (WT), and complemented strains. In contrast, the urease-deficient mutant exhibited impaired in vitro growth compared to the WT and complemented strains when urea was the sole source of nitrogen. Substantial amounts of ammonia were produced by the WT and complemented strains, but not with the urease-deficient mutant, which represents the actual nitrogen source for mycobacterial growth. However, the urease-deficient mutant displayed parental colonization profiles in the lungs, spleen, and liver in mice. Together, our data demonstrate a role for the urease activity in M. tuberculosis nitrogen metabolism that could be crucial for the pathogen's survival in nutrient-limited microenvironments where urea is the sole nitrogen source. Our work supports the notion that M. tuberculosis virulence correlates with its unique metabolic versatility and ability to utilize virtually any carbon and nitrogen sources available in its environment. PMID:22645285

Prevalence of latent Mycobacterium tuberculosis infection in prisoners.

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Navarro, Pedro Daibert de; Almeida, Isabela Neves de; Kritski, Afrânio Lineu; Ceccato, Maria das Graças; Maciel, Mônica Maria Delgado; Carvalho, Wânia da Silva; Miranda, Silvana Spindola de

2016-01-01

To determine the prevalence of and the factors associated with latent Mycobacterium tuberculosis infection (LTBI) in prisoners in the state of Minas Gerais, Brazil. This was a cross-sectional cohort study conducted in two prisons in Minas Gerais. Tuberculin skin tests were performed in the individuals who agreed to participate in the study. A total of 1,120 individuals were selected for inclusion in this study. The prevalence of LTBI was 25.2%. In the multivariate analysis, LTBI was associated with self-reported contact with active tuberculosis patients within prisons (adjusted OR = 1.51; 95% CI: 1.05-2.18) and use of inhaled drugs (adjusted OR = 1.48; 95% CI: 1.03-2.13). Respiratory symptoms were identified in 131 (11.7%) of the participants. Serological testing for HIV was performed in 940 (83.9%) of the participants, and the result was positive in 5 (0.5%). Two cases of active tuberculosis were identified during the study period. Within the prisons under study, the prevalence of LTBI was high. In addition, LTBI was associated with self-reported contact with active tuberculosis patients and with the use of inhaled drugs. Our findings demonstrate that it is necessary to improve the conditions in prisons, as well as to introduce strategies, such as chest X-ray screening, in order to detect tuberculosis cases and, consequently, reduce M. tuberculosis infection within the prison system. Determinar a prevalência e os fatores associados à infecção latente por Mycobacterium tuberculosis (ILTB) em pessoas privadas de liberdade no Estado de Minas Gerais. Estudo de coorte transversal realizado em duas penitenciárias em Minas Gerais. Foi realizada a prova tuberculínica nos indivíduos que aceitaram participar do estudo. Foram selecionados 1.120 indivíduos para a pesquisa. A prevalência da ILTB foi de 25,2%. Na análise multivariada, a ILTB esteve associada com relato de contato com caso de tuberculose ativa dentro da penitenciária (OR ajustada = 1,51; IC95%: 1

Pre-Columbian mycobacterial genomes reveal seals as a source of New World human tuberculosis

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Bos, Kirsten I.; Harkins, Kelly M.; Herbig, Alexander; Coscolla, Mireia; Weber, Nico; Comas, Iñaki; Forrest, Stephen A.; Bryant, Josephine M.; Harris, Simon R.; Schuenemann, Verena J.; Campbell, Tessa J.; Majander, Kerrtu; Wilbur, Alicia K.; Guichon, Ricardo A.; Wolfe Steadman, Dawnie L.; Cook, Della Collins; Niemann, Stefan; Behr, Marcel A.; Zumarraga, Martin; Bastida, Ricardo; Huson, Daniel; Nieselt, Kay; Young, Douglas; Parkhill, Julian; Buikstra, Jane E.; Gagneux, Sebastien; Stone, Anne C.; Krause, Johannes

2015-01-01

Modern strains of Mycobacterium tuberculosis from the Americas are closely related to those from Europe, supporting the assumption that human tuberculosis was introduced post-contact1. This notion, however, is incompatible with archaeological evidence of pre-contact tuberculosis in the New World2. Comparative genomics of modern isolates suggests that M. tuberculosis attained its worldwide distribution following human dispersals out of Africa during the Pleistocene epoch3, although this has yet to be confirmed with ancient calibration points. Here we present three 1,000-year-old mycobacterial genomes from Peruvian human skeletons, revealing that a member of the M. tuberculosis complex caused human disease before contact. The ancient strains are distinct from known human-adapted forms and are most closely related to those adapted to seals and sea lions. Two independent dating approaches suggest a most recent common ancestor for the M. tuberculosis complex less than 6,000 years ago, which supports a Holocene dispersal of the disease. Our results implicate sea mammals as having played a role in transmitting the disease to humans across the ocean. PMID:25141181

Molecular epidemiology of Mycobacterium tuberculosis in aboriginal peoples of Taiwan, 2006-2011.

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Chen, Yih-Yuan; Chang, Jia-Ru; Huang, Wei-Feng; Kuo, Shu-Chen; Yeh, Jun-Jun; Lee, Jen-Jyh; Jang, Chang-Sheng; Sun, Jun-Ren; Chiueh, Tzong-Shi; Su, Ih-Jen; Dou, Horng-Yunn

2014-04-01

Previous research revealed a 6-fold higher incidence of tuberculosis (TB) amongst aborigines compared to Han Chinese in Taiwan. To investigate the reasons for this disparity, we genotyped Mycobacterium tuberculosis (MTB) strains obtained from members of different aboriginal tribes in different geographical regions of Taiwan by using molecular methods. In total, 177 isolates of MTB collected from patients at four hospitals in Taiwan from January 2006 to December 2011 were analysed by spoligotyping, mycobacterial interspersed repetitive unit-variable number tandem-repeat (MIRU-VNTR) typing. The most prevalent strains in the eastern and central regions of Taiwan were Beijing (45.7% in eastern) and Haarlem (39.1% in eastern, 37.1% in central) lineages, whereas in southern regions the most prevalent strains were EAI (47.7%) and Haarlem (20.5%) lineages. The high prevalence of EAI in southern Taiwan aborigines may be closely associated with Austronesian culture. This study provides a first overview of the M. tuberculosis strains circulating in aboriginal populations in Taiwan. The high prevalences of certain MTB lineages within aboriginal sub-populations suggest that transmission of MTB may have been restricted to close contacts. Copyright © 2013 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

CCL2 responses to Mycobacterium tuberculosis are associated with disease severity in tuberculosis.

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Zahra Hasan

Full Text Available BACKGROUND: Leucocyte activating chemokines such as CCL2, CCL3, and CXCL8 together with proinflammatory IFNgamma, TNFalpha and downmodulatory IL10 play a central role in the restriction of M. tuberculosis infections, but is unclear whether these markers are indicative of tuberculosis disease severity. METHODOLOGY: We investigated live M. tuberculosis- and M. bovis BCG-induced peripheral blood mononuclear cell responses in patients with tuberculosis (TB and healthy endemic controls (ECs, n = 36. TB patients comprised pulmonary (PTB, n = 34 and extrapulmonary groups, subdivided into those with less severe localized extrapulmonary TB (L-ETB, n = 16 or severe disseminated ETB (D-ETB, n = 16. Secretion of CCL2, IFNgamma, IL10 and CCL3, and mRNA expression of CCL2, TNFalpha, CCL3 and CXCL8 were determined. RESULTS: M. tuberculosis- and BCG-induced CCL2 secretion was significantly increased in both PTB and D-ETB (p<0.05, p<0.01 as compared with L-ETB patients. CCL2 secretion in response to M. tuberculosis was significantly greater than to BCG in the PTB and D-ETB groups. M. tuberculosis-induced CCL2 mRNA transcription was greater in PTB than L-ETB (p = 0.023, while CCL2 was reduced in L-ETB as compared with D-ETB (p = 0.005 patients. M. tuberculosis-induced IFNgamma was greater in L-ETB than PTB (p = 0.04, while BCG-induced IFNgamma was greater in L-ETB as compared with D-ETB patients (p = 0.036. TNFalpha mRNA expression was raised in PTB as compared with L-ETB group in response to M. tuberculosis (p = 0.02 and BCG (p = 0.03. Mycobacterium-induced CCL3 and CXCL8 was comparable between TB groups. CONCLUSIONS: The increased CCL2 and TNFalpha in PTB patients may support effective leucocyte recruitment and M. tuberculosis localization. CCL2 alone is associated with severity of TB, possibly due to increased systemic inflammation found in severe disseminated TB or due to increased monocyte infiltration to lung parenchyma in pulmonary disease.

Mesa en cuello por Mycobacterium tuberculosis en un paciente infectado por HIV A case of cervical mass due to mycobacterium tuberculosis in an HIV infected patient

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Mónica Soto

1995-02-01

Full Text Available Se presenta el caso de un paciente de sexo masculino con diagnóstico de infección por HIV quien presentó una masa en cuello de 7 x 10 cm, dolorosa, de consistencia dura, adherida, no pulsátil, con edema de la piel adyacente y sin otros signos asociados. La evolución fue de 6 meses. Los estudios de la masa y el esputo dieron como resultado el aislamiento de M. tuberculosis, lo que permitió un adecuado enfoque terapéutico y por consiguiente una respuesta clínica satisfactoria

Bovine tuberculosis

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Tuberculosis (TB) in animals and humans may result from exposure to bacilli within the Mycobacterium tuberculosis complex (i.e., M. tuberculosis, M. bovis, M. africanum, M. pinnipedii, M. microti, M. caprae, or M. canetti) . Mycobacterium bovis is the species most often isolated from tuberculous cat...

Biochemická charakterizace fosfoenolpyruvát karboxykinasy z Mycobacterium tuberculosis

Czech Academy of Sciences Publication Activity Database

Machová, Iva; Snášel, Jan; Pichová, Iva

2013-01-01

Roč. 107, č. 5 (2013), s. 425-425 ISSN 0009-2770. [Mezioborové setkání mladých biologů, biochemiků a chemiků /13./. 14.5.2013-17.5.2013, Žďár nad Sázavou] Grant - others:European Research Council(XE) FP7-245187 Institutional support: RVO:61388963 Keywords : Mycobacterium tuberculosis * Pepck * GDP/GTP Subject RIV: CE - Biochemistry

Structural and Functional Studies of Phosphoenolpyruvate Carboxykinase from Mycobacterium tuberculosis

Czech Academy of Sciences Publication Activity Database

Machová, Iva; Snášel, Jan; Dostál, Jiří; Brynda, Jiří; Fanfrlík, Jindřich; Singh, M.; Tarábek, Ján; Vaněk, O.; Bednárová, Lucie; Pichová, Iva

2015-01-01

Roč. 10, č. 3 (2015), e0120682/1-e0120682/21 E-ISSN 1932-6203 R&D Projects: GA MŠk LO1302 EU Projects: European Commission(XE) 241587 - SYSTEMTB Institutional support: RVO:61388963 Keywords : crystal structure * noncovalent complexes * Mycobacterium tuberculosis * mechanism Subject RIV: CE - Biochemistry Impact factor: 3.057, year: 2015 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0120682

Mycobacterium bovis in a European bison (Bison bonasus) raises concerns about tuberculosis in Brazilian captive wildlife populations: a case report.

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Zimpel, Cristina Kraemer; Brum, Juliana Sperotto; de Souza Filho, Antônio Francisco; Biondo, Alexander Welker; Perotta, João Henrique; Dib, Cristina Corsi; Bonat, Marcelo; Neto, José Soares Ferreira; Brandão, Paulo Eduardo; Heinemann, Marcos Bryan; Guimaraes, Ana Marcia Sa

2017-02-10

Tuberculosis caused by Mycobacterium bovis is an important worldwide zoonosis and has been reported to cause clinical disease in several animal species, including captive wildlife. This report describes a case of M. bovis infection in a European bison from a Brazilian zoo and compiles a number of literature reports that raise concern regarding tuberculosis among captive wildlife in Brazil. A 13 year-old captive-born male bison (Bison bonasus) from a Brazilian zoo began presenting weight loss, diarrhea and respiratory symptoms, which inevitably led to his death. At the animal's necropsy, inspection of the thoracic and abdominal cavities revealed multiple enlarged lymph nodes, ranging from 4 to 10 cm, and pulmonary nodules containing caseous masses with firm white materials consistent with mineralization. Histopathology findings showed a significant amount of acid-alcohol resistant bacilli compatible with Mycobacterium spp. Specimens from lymph nodes and lungs were cultured on Petragnani and Stonebrink media, and specific PCR assays of the bacterial isolate identified it as M. bovis. The European bison reported herein died from a severe form of disseminated tuberculosis caused by M. bovis. A review of the available literature indicates possible widespread occurrence of clinical disease caused by M. bovis or M. tuberculosis affecting multiple animal species in Brazilian wildlife-related institutions. These likely underestimated numbers raise concern regarding the control of the disease in captive animal populations from Brazil.

Tuberculosis associated factors caused by Mycobacterium tuberculosis of the RDRio genotype

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Eloise Brasil Moraes

Full Text Available BACKGROUND Tuberculosis (TB continues to be a disease that affects many countries around the world, including Brazil. Recently, a subtype of Latin American-Mediterranean family strain was identified and characterised by RDRio. The strain has been associated with different characteristics of the disease. OBJECTIVES In the present study we investigated the association of epidemiological, clinical, radiological and bacteriological variables with pulmonary tuberculosis caused by RDRioMycobacterium tuberculosis strain in large regions of São Paulo. METHODS We conducted a cross-sectional study in 530 patients with pulmonary tuberculosis, diagnosed using sputum culture, from two regions of the São Paulo state in Brazil. The samples were brought to São Paulo reference laboratories for epidemiological, clinical, radiological and bacteriological analyses, and the data were obtained from a TB notification system. RDRio genotyping and Spoligotyping of the samples were performed. For the analysis of the categorical variables we used the chi-square test or the Fisher’s exact test, and for the continuous variables, the Mann-Whitney test. In addition, a logistic regression was used for multivariate analysis. Differences with p < 0.05 were considered significant. FINDINGS The RDRio deletion was identified in 152 (28.7% samples. In the univariate analysis, both the age groups above 25 years and alcohol consumption were associated with the RDRio deletion. The multivariate analysis confirmed the association of the RDRio deletion with the age groups: 25-35 years old [OR: 2.28 (1.02-5.07; p = 0.04] and 36-60 years old (OR: 2.36 (1.11-5.05; p = 0.03], and also with alcohol consumption [OR: 1.63 (1.05-2.54; p = 0,03]. MAIN CONCLUSIONS In this study, we identified new factors associated with the M. tuberculosis of the RDRio deletion strains infection.

Predominance of Central Asian and European families among Mycobacterium tuberculosis isolates in Kashmir Valley, India.

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Bashir, Gulnaz; Wani, Tehmeena; Sharma, Pragya; Katoch, V M; Lone, Rubina; Shah, Azra; Katoch, Kiran; Kakru, D K; Chauhan, Devendra Singh

2017-10-01

As there are no data available regarding the strains of Mycobacterium tuberculosis circulating in Kashmir Valley, India, the current study aimed at describing the genetic diversity of M. tuberculosis strains in this region, by spoligotyping and 12-locus-based MIRU-VNTR typing (Mycobacterial Interspersed Repetitive Unit-Variable Number Tandem Repeat). Sputa from 207 smear positive cases with newly diagnosed pulmonary tuberculosis were subjected to culture for M. tuberculosis. Eighty-five isolates confirmed as M. tuberculosis were subjected to drug susceptibility testing and molecular typing by spoligotyping and MIRU-VNTRs. Drug susceptibility results of 72 isolates revealed 76.3% as fully sensitive while 5.5% as multidrug resistant (MDR). Spoligotyping of 85 isolates detected 42 spoligotypes with 50 isolates (58.8%) clustered into seven spoligotypes. SIT26/CAS1_Del was the major spoligotype (23, 27%) followed by SIT127/H4 (12, 14.1%); CAS lineage (37.6%) was predominant, followed by Haarlem (25.8%) and ill-defined T clade (23.5%). MIRU-VNTR analysis displayed 82 MIRU patterns from 85 strains, including 3 small clusters and 79 unique. MIRU 26 was found to be the most discriminatory locus. Kashmir Valley has CAS as the predominant lineage of M. tuberculosis similar to the rest of the Indian sub-continent, while it is peculiar in having Euro American lineages such as Haarlem and ill-defined T clade. Copyright © 2017 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.

Mycobacterium tuberculosis Controls Phagosomal Acidification by Targeting CISH-Mediated Signaling.

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Queval, Christophe J; Song, Ok-Ryul; Carralot, Jean-Philippe; Saliou, Jean-Michel; Bongiovanni, Antonino; Deloison, Gaspard; Deboosère, Nathalie; Jouny, Samuel; Iantomasi, Raffaella; Delorme, Vincent; Debrie, Anne-Sophie; Park, Sei-Jin; Gouveia, Joana Costa; Tomavo, Stanislas; Brosch, Roland; Yoshimura, Akihiko; Yeramian, Edouard; Brodin, Priscille

2017-09-26

Pathogens have evolved a range of mechanisms to counteract host defenses, notably to survive harsh acidic conditions in phagosomes. In the case of Mycobacterium tuberculosis, it has been shown that regulation of phagosome acidification could be achieved by interfering with the retention of the V-ATPase complexes at the vacuole. Here, we present evidence that M. tuberculosis resorts to yet another strategy to control phagosomal acidification, interfering with host suppressor of cytokine signaling (SOCS) protein functions. More precisely, we show that infection of macrophages with M. tuberculosis leads to granulocyte-macrophage colony-stimulating factor (GM-CSF) secretion, inducing STAT5-mediated expression of cytokine-inducible SH2-containing protein (CISH), which selectively targets the V-ATPase catalytic subunit A for ubiquitination and degradation by the proteasome. Consistently, we show that inhibition of CISH expression leads to reduced replication of M. tuberculosis in macrophages. Our findings further broaden the molecular understanding of mechanisms deployed by bacteria to survive. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

In vivo induction of neutrophil extracellular traps by Mycobacterium tuberculosis in a guinea pig model.

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Filio-Rodríguez, Georgina; Estrada-García, Iris; Arce-Paredes, Patricia; Moreno-Altamirano, María M; Islas-Trujillo, Sergio; Ponce-Regalado, M Dolores; Rojas-Espinosa, Oscar

2017-10-01

In 2004, a novel mechanism of cellular death, called 'NETosis', was described in neutrophils. This mechanism, different from necrosis and apoptosis, is characterized by the release of chromatin webs admixed with microbicidal granular proteins and peptides (NETs). NETs trap and kill a variety of microorganisms. Diverse microorganisms, including Mycobacterium tuberculosis, are NET inducers in vitro. The aim of this study was to examine whether M. tuberculosis can also induce NETs in vivo and if the NETs are bactericidal to the microorganism. Guinea pigs were intradermally inoculated with M. tuberculosis H37Rv, and the production of NETs was investigated at several time points thereafter. NETs were detected as early as 30 min post-inoculation and were clearly evident by 4 h post-inoculation. NETs produced in vivo contained DNA, myeloperoxidase, elastase, histones, ROS and acid-fast bacilli. Viable and heat-killed M. tuberculosis, as well as Mycobacterium bovis BCG were efficient NET inducers, as were unilamellar liposomes prepared with lipids from M. tuberculosis. In vitro, guinea pig neutrophils also produced NETs in response to M. tuberculosis. However, neither the in vivo nor the in vitro-produced NETs were able to kill M. tuberculosis. Nevertheless, in vivo, neutrophils might propitiate recruitment and activation of more efficient microbicidal cells.

MicroRNA-365 in macrophages regulates Mycobacterium tuberculosis-induced active pulmonary tuberculosis via interleukin-6.

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Song, Qingzhang; Li, Hui; Shao, Hua; Li, Chunling; Lu, Xiao

2015-01-01

The present study is to investigate the relationship between microRNA (miR)-365 expression and the levels of interleukin (IL)-6 mRNA and protein in patients with active tuberculosis. From June 2011 to June 2014, 48 patients with active pulmonary tuberculosis induced by Mycobacterium tuberculosis were included in the study. In addition, 23 healthy subjects were enrolled as control. Macrophages were collected by pulmonary alveolus lavage. In addition, serum and mononuclear cells were isolated from peripheral blood. The levels of miR-365 and IL-6 in macrophages, mononuclear cells and serum were determined using quantitative real-time polymerase chain reaction. The protein expression of IL-6 in macrophages and mononuclear cells was measured using Western blotting, while that in serum was detected by enzyme-linked immunoabsorbent assay. Expression of IL-6 mRNA and protein was significantly enhanced in patients with active pulmonary tuberculosis. Increase of IL-6 protein concentration in serum was probably due to the release of IL-6 protein from mononuclear cells in the blood. In addition, miR-365 levels were significantly lowered in patients with active pulmonary tuberculosis. Up-regulated IL-6 expression in macrophages, mononuclear cells and serum in patients with active pulmonary tuberculosis is related to the down-regulation of miR-365, suggesting that miR-365 may regulate the occurrence and immune responses of active pulmonary tuberculosis via IL-6.

Spoligotyping of Mycobacterium tuberculosis isolates from patients with pulmonary tuberculosis in Mumbai, India.

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Kulkarni, Savita; Sola, Christophe; Filliol, Ingrid; Rastogi, Nalin; Kadival, Gururaj

2005-05-01

Tuberculosis remains a major health problem in India, with 2 million new cases and 421,000 deaths each year. In this paper, we describe the spoligotyping results of 216 Mycobacterium tuberculosis culture isolates from patients with pulmonary tuberculosis in Mumbai, India. As spoligotyping data from India have rarely been described until now, and as there is limited information on the major circulating clades of M. tuberculosis, the data obtained were also compared to an international spoligotype database (SpolDB4) that contained patterns from 22,546 isolates from more than 100 countries. Eighty-four (39%) of the isolates were definitively marked as orphan strains, indicating the paucity of such data from India. The remaining 132 isolates clustered among 59 shared types; among these, 42 shared types were already present in the database, 17 were newly created, and 5 of them were specifically reported from Mumbai. A total of 9 major types in this study clustered 32% of the isolates. At the phylogenetic level, 30% of the isolates belonged to the Central Asian families CAS1 and CAS2, of the major genetic group (MGG) 1, 29% to MGG 2 and 3 families (spacers 33-36 missing) and 17% to the ancestral East African Indian (EAI) family. Finally, nearly 10% of the isolates belonged to the W-Beijing family in a broad sense, also in the MGG 1 group. In conclusion, historic clones of the MGG 1 group of M. tuberculosis are responsible for roughly 60% of all tuberculosis cases in Mumbai. Together with the fact that organisms presumably of European descent (such as the Haarlem family) were only rarely found, our observations suggest that tuberculosis in Mumbai, India is essentially caused by historical clones of tubercle bacilli undergoing active circulation due to uncontrolled demography, high prevalence of the disease, and a paucity of resources.

Discovery of dormancy associated antigens of Mycobacterium tuberculosis : novel targets for the development of post-exposure or therapeutic tuberculosis vaccines

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Lin, May Young

2009-01-01

The growing number of tuberculosis (TB) casualties urges development of not only more effective drugs and preventive vaccines but also development of post-exposure/therapeutic TB vaccines. Post-exposure/therapeutic TB vaccines are needed since 2 billion people worldwide harbor a latent Mycobacterium

Evaluation of the efficacy of valproic acid and suberoylanilide hydroxamic acid (vorinostat in enhancing the effects of first-line tuberculosis drugs against intracellular Mycobacterium tuberculosis

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Martin Rao

2018-04-01

Full Text Available Background: New tuberculosis (TB drug treatment regimens are urgently needed. This study evaluated the potential of the histone deacetylase inhibitors (HDIs valproic acid (VPA and suberoylanilide hydroxamic acid (SAHA to enhance the effects of first-line anti-TB drugs against intracellular Mycobacterium tuberculosis. Methods: M. tuberculosis H37Rv cultures were exposed to VPA or SAHA over 6 days, in the presence or absence of isoniazid (INH and rifampicin (RIF. The efficacy of VPA and SAHA against intracellular M. tuberculosis with and without INH or RIF was tested by treating infected macrophages. Bactericidal activity was assessed by counting mycobacterial colony-forming units (CFU. Results: VPA treatment exhibited superior bactericidal activity to SAHA (2-log CFU reduction, while both HDIs moderately improved the activity of RIF against extracellular M. tuberculosis. The bactericidal effect of VPA against intracellular M. tuberculosis was greater than that of SAHA (1-log CFU reduction and equalled that of INH (1.5-log CFU reduction. INH/RIF and VPA/SAHA combination treatment inhibited intracellular M. tuberculosis survival in a shorter time span than monotherapy (3 days vs. 6 days. Conclusions: VPA and SAHA have adjunctive potential to World Health Organization-recommended TB treatment regimens. Clinical evaluation of the two drugs with regard to reducing the treatment duration and improving treatment outcomes in TB is warranted. Keywords: Mycobacterium tuberculosis, Adjunct host-directed therapy, Tuberculosis, Histone deacetylase inhibitors, Repurposed drugs

Molecular characterization of Mycobacterium tuberculosis isolates from elephants of Nepal.

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Paudel, Sarad; Mikota, Susan K; Nakajima, Chie; Gairhe, Kamal P; Maharjan, Bhagwan; Thapa, Jeewan; Poudel, Ajay; Shimozuru, Michito; Suzuki, Yasuhiko; Tsubota, Toshio

2014-05-01

Mycobacterium tuberculosis was cultured from the lung tissues of 3 captive elephants in Nepal that died with extensive lung lesions. Spoligotyping, TbD1 detection and multi-locus variable number of tandem repeat analysis (MLVA) results suggested 3 isolates belonged to a specific lineage of Indo-Oceanic clade, EAI5 SIT 138. One of the elephant isolates had a new synonymous single nucleotide polymorphism (SNP) T231C in the gyrA sequence, and the same SNP was also found in human isolates in Nepal. MLVA results and transfer history of the elephants suggested that 2 of them might be infected with M. tuberculosis from the same source. These findings indicated the source of M. tuberculosis infection of those elephants were local residents, presumably their handlers. Further investigation including detailed genotyping of elephant and human isolates is needed to clarify the infection route and eventually prevent the transmission of tuberculosis to susceptible hosts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ancient origin and gene mosaicism of the progenitor of Mycobacterium tuberculosis.

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M Cristina Gutierrez

2005-09-01

Full Text Available The highly successful human pathogen Mycobacterium tuberculosis has an extremely low level of genetic variation, which suggests that the entire population resulted from clonal expansion following an evolutionary bottleneck around 35,000 y ago. Here, we show that this population constitutes just the visible tip of a much broader progenitor species, whose extant representatives are human isolates of tubercle bacilli from East Africa. In these isolates, we detected incongruence among gene phylogenies as well as mosaic gene sequences, whose individual elements are retrieved in classical M. tuberculosis. Therefore, despite its apparent homogeneity, the M. tuberculosis genome appears to be a composite assembly resulting from horizontal gene transfer events predating clonal expansion. The amount of synonymous nucleotide variation in housekeeping genes suggests that tubercle bacilli were contemporaneous with early hominids in East Africa, and have thus been coevolving with their human host much longer than previously thought. These results open novel perspectives for unraveling the molecular bases of M. tuberculosis evolutionary success.

New Approaches and Therapeutic Options for Mycobacterium tuberculosis in a Dormant State.

NARCIS (Netherlands)

Caño-Muñiz, Santiago; Anthony, Richard; Niemann, Stefan; Alffenaar, Jan-Willem C

We are far away from the days when tuberculosis (TB) accounted for 1 in 4 deaths during the 19th century. However,Mycobacterium tuberculosiscomplex (MTBC) strains are still the leading cause of morbidity and mortality by a single infectious disease, with 9.6 million cases and 1.5 million deaths

Transcriptional landscape of Mycobacterium tuberculosis infection in macrophages

KAUST Repository

Roy, Sugata

2018-04-24

Mycobacterium tuberculosis (Mtb) infection reveals complex and dynamic host-pathogen interactions, leading to host protection or pathogenesis. Using a unique transcriptome technology (CAGE), we investigated the promoter-based transcriptional landscape of IFNγ (M1) or IL-4/IL-13 (M2) stimulated macrophages during Mtb infection in a time-kinetic manner. Mtb infection widely and drastically altered macrophage-specific gene expression, which is far larger than that of M1 or M2 activations. Gene Ontology enrichment analysis for Mtb-induced differentially expressed genes revealed various terms, related to host-protection and inflammation, enriched in up-regulated genes. On the other hand, terms related to dis-regulation of cellular functions were enriched in down-regulated genes. Differential expression analysis revealed known as well as novel transcription factor genes in Mtb infection, many of them significantly down-regulated. IFNγ or IL-4/IL-13 pre-stimulation induce additional differentially expressed genes in Mtb-infected macrophages. Cluster analysis uncovered significant numbers, prolonging their expressional changes. Furthermore, Mtb infection augmented cytokine-mediated M1 and M2 pre-activations. In addition, we identified unique transcriptional features of Mtb-mediated differentially expressed lncRNAs. In summary we provide a comprehensive in depth gene expression/regulation profile in Mtb-infected macrophages, an important step forward for a better understanding of host-pathogen interaction dynamics in Mtb infection.

Role of genotype® mycobacterium common mycobacteria/additional species assay for rapid differentiation between Mycobacterium tuberculosis complex and different species of non-tuberculous mycobacteria

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Amresh Kumar Singh

2013-01-01

Full Text Available Background: Mycobacterium tuberculosis complex (MTBC and non-tuberculous mycobacteria (NTM may or may not have same clinical presentations, but the treatment regimens are always different. Laboratory differentiation between MTBC and NTM by routine methods are time consuming and cumbersome to perform. We have evaluated the role of GenoType® Mycobacterium common mycobacteria/additional species (CM/AS assay for differentiation between MTBC and different species of NTM in clinical isolates from tuberculosis (TB cases. Materials and Methods: A total of 1080 clinical specimens were collected from January 2010 to June 2012. Diagnosis was performed by Ziehl-Neelsen staining followed by culture in BacT/ALERT 3D system (bioMerieux, France. A total of 219 culture positive clinical isolates (BacT/ALERT® MP cultures were selected for differentiation by p-nitrobenzoic acid (PNB sensitivity test as and BIO-LINE SD Ag MPT64 TB test considering as the gold standard test. Final identification and differentiation between MTBC and different species of NTM were further confirmed by GenoType® Mycobacterium CM/AS assay (Hain Lifescience, Nehren, Germany. Results: Out of 219 BacT/ALERT® MP culture positive isolates tested by PNB as 153 MTBC (69.9% and by GenoType® Mycobacterium CM/AS assay as 159 (72.6% MTBC and remaining 60 (27.4% were considered as NTM species. The GenoType® Mycobacterium CM/AS assay was proved 99.3% sensitive and 98.3% specific for rapid differentiation of MTBC and NTM. The most common NTM species were; Mycobacterium fortuitum 20 (33.3% among rapid growing mycobacteria and Mycobacterium intracellulare 11 (18.3% among slow growing mycobacteria. Conclusion: The GenoType® Mycobacterium assay makes rapid and accurate identification of NTM species as compared with different phenotypic and molecular diagnostic tool and helps in management of infections caused by different mycobacteria.

Marked microevolution of a unique Mycobacterium tuberculosis strain in 17 years of ongoing transmission in a high risk population.

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Carolina Mehaffy

Full Text Available The transmission and persistence of Mycobacterium tuberculosis within high risk populations is a threat to tuberculosis (TB control. In the current study, we used whole genome sequencing (WGS to decipher the transmission dynamics and microevolution of M. tuberculosis ON-A, an endemic strain responsible for an ongoing outbreak of TB in an urban homeless/under-housed population. Sixty-one M. tuberculosis isolates representing 57 TB cases from 1997 to 2013 were subjected to WGS. Sequencing data was integrated with available epidemiological information and analyzed to determine how the M. tuberculosis ON-A strain has evolved during almost two decades of active transmission. WGS offers higher discriminatory power than traditional genotyping techniques, dividing the M. tuberculosis ON-A strain into 6 sub-clusters, each defined by unique single nucleotide polymorphism profiles. One sub-cluster, designated ON-ANM (Natural Mutant; 26 isolates from 24 cases was also defined by a large, 15 kb genomic deletion. WGS analysis reveals the existence of multiple transmission chains within the same population/setting. Our results help validate the utility of WGS as a powerful tool for identifying genomic changes and adaptation of M. tuberculosis.

Tumor necrosis factor blockers influence macrophage responses to Mycobacterium tuberculosis

OpenAIRE

HARRIS, JAMES; HARRIS, JAMES

2008-01-01

PUBLISHED umor necrosis factor (TNF)?? is a proinflammatory cytokine that mediates inflammation in response to various pathogens, including Mycobacterium tuberculosis, but is also a key factor in the pathogenesis of rheumatoid arthritis and other autoimmune diseases. Three TNF???suppressing drugs have been approved to treat selected autoimmune diseases; 2 are monoclonal antibodies against TNF?? (adalimumab and infliximab), and the other is a soluble TNF receptor/Fc fusion protein (etanerce...

Performance of a Highly Sensitive Mycobacterium tuberculosis Complex Real-Time PCR Assay for Diagnosis of Pulmonary Tuberculosis in a Low-Prevalence Setting: a Prospective Intervention Study.

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Vinuesa, Víctor; Borrás, Rafael; Briones, María Luisa; Clari, María Ángeles; Cresencio, Vicenta; Giménez, Estela; Muñoz, Carmen; Oltra, Rosa; Servera, Emilio; Scheelje, Talia; Tornero, Carlos; Navarro, David

2018-05-01

The potential impact of routine real-time PCR testing of respiratory specimens from patients with presumptive tuberculosis in terms of diagnostic accuracy and time to tuberculosis treatment inception in low-prevalence settings remains largely unexplored. We conducted a prospective intervention cohort study. Respiratory specimens from 1,020 patients were examined by acid-fast bacillus smear microscopy, tested by a real-time Mycobacterium tuberculosis complex PCR assay (Abbott RealTi me MTB PCR), and cultured in mycobacterial media. Seventeen patients tested positive by PCR (5 were acid-fast bacillus smear positive and 12 acid-fast bacillus smear negative), and Mycobacterium tuberculosis was recovered from cultures for 12 of them. Patients testing positive by PCR and negative by culture ( n = 5) were treated and deemed to have responded to antituberculosis therapy. There were no PCR-negative/culture-positive cases, and none of the patients testing positive for nontuberculous mycobacteria ( n = 20) yielded a positive PCR result. The data indicated that routine testing of respiratory specimens from patients with presumptive tuberculosis by the RealTi me MTB PCR assay improves the tuberculosis diagnostic yield and may reduce the time to antituberculosis treatment initiation. On the basis of our data, we propose a novel mycobacterial laboratory algorithm for tuberculosis diagnosis. Copyright © 2018 American Society for Microbiology.

Molecular diversity of Mycobacterium tuberculosis isolates from patients with tuberculosis in Honduras

Directory of Open Access Journals (Sweden)

Ghebremichael Solomon

2010-08-01

Full Text Available Abstract Background Tuberculosis persists as a public health problem in Honduras. A better knowledge of the molecular characteristics of Mycobacterium tuberculosis strains will contribute to understand the transmission dynamics of the disease within the country. The aim of this study was to provide an insight of the genetic biodiversity of M. tuberculosis clinical isolates collected in Honduras between 1994 and 2002. Genotyping was performed using spoligotyping and RFLP. The spoligotypes obtained were compared with the SITVIT2 proprietary database of the Pasteur Institute of Guadeloupe. Results Spoligotyping grouped 84% of the isolates into 27 clusters (2 to 43 strains per cluster. Of the 44 shared international types (SITs identified among the Honduran stains, 8 SITs were newly identified either within the present study or after match with an orphan type previously identified in the SITVIT2 database. In addition, 16 patterns corresponded to orphan, previously unreported isolates. The Latin American Mediterranean (LAM lineage was the most common in this study; 55% of the strains belonged to this family. Other genotypes found were Haarlem (16%, T (16%, X-clade (6%, Unknown signature (5% and S (1%. Only one Beijing strain was identified (0.5%. We observed a high degree of diversity after characterizing the 43 isolates belonging to the main spoligotyping cluster (SIT 33, LAM3 with IS6110-RFLP. A total of 35 different RFLP-fingerprints were detected, of which 6 patterns corresponded to the same number of clusters comprising 14 strains. Conclusions The findings obtained in this study show that tuberculosis transmission in Honduras is due to modern M. tuberculosis lineages with high level of biodiversity.

Molecular diversity of Mycobacterium tuberculosis isolates from patients with tuberculosis in Honduras

Science.gov (United States)

2010-01-01

Background Tuberculosis persists as a public health problem in Honduras. A better knowledge of the molecular characteristics of Mycobacterium tuberculosis strains will contribute to understand the transmission dynamics of the disease within the country. The aim of this study was to provide an insight of the genetic biodiversity of M. tuberculosis clinical isolates collected in Honduras between 1994 and 2002. Genotyping was performed using spoligotyping and RFLP. The spoligotypes obtained were compared with the SITVIT2 proprietary database of the Pasteur Institute of Guadeloupe. Results Spoligotyping grouped 84% of the isolates into 27 clusters (2 to 43 strains per cluster). Of the 44 shared international types (SITs) identified among the Honduran stains, 8 SITs were newly identified either within the present study or after match with an orphan type previously identified in the SITVIT2 database. In addition, 16 patterns corresponded to orphan, previously unreported isolates. The Latin American Mediterranean (LAM) lineage was the most common in this study; 55% of the strains belonged to this family. Other genotypes found were Haarlem (16%), T (16%), X-clade (6%), Unknown signature (5%) and S (1%). Only one Beijing strain was identified (0.5%). We observed a high degree of diversity after characterizing the 43 isolates belonging to the main spoligotyping cluster (SIT 33, LAM3) with IS6110-RFLP. A total of 35 different RFLP-fingerprints were detected, of which 6 patterns corresponded to the same number of clusters comprising 14 strains. Conclusions The findings obtained in this study show that tuberculosis transmission in Honduras is due to modern M. tuberculosis lineages with high level of biodiversity. PMID:20678242

Identification of MHC class II restricted T‐cell‐mediated reactivity against MHC class I binding Mycobacterium tuberculosis peptides

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Wang, Mingjun; Tang, Sheila Tuyet; Stryhn, Anette

2011-01-01

Major histocompatibility complex (MHC) class I restricted cytotoxic T lymphocytes (CTL) are known to play an important role in the control of Mycobacterium tuberculosis infection so identification of CTL epitopes from M. tuberculosis is of importance for the development of effective peptide...

The cell envelope glycoconjugates of Mycobacterium tuberculosis

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Angala, Shiva Kumar; Belardinelli, Juan Manuel; Huc-Claustre, Emilie; Wheat, William H.; Jackson, Mary

2015-01-01

Tuberculosis (TB) remains the second most common cause of death due to a single infectious agent. The cell envelope of Mycobacterium tuberculosis (Mtb), the causative agent of the disease in humans, is a source of unique glycoconjugates and the most distinctive feature of the biology of this organism. It is the basis of much of Mtb pathogenesis and one of the major causes of its intrinsic resistance to chemotherapeutic agents. At the same time, the unique structures of Mtb cell envelope glycoconjugates, their antigenicity and essentiality for mycobacterial growth provide opportunities for drug, vaccine, diagnostic and biomarker development, as clearly illustrated by recent advances in all of these translational aspects. This review focuses on our current understanding of the structure and biogenesis of Mtb glycoconjugates with particular emphasis on one of most intriguing and least understood aspect of the physiology of mycobacteria: the translocation of these complex macromolecules across the different layers of the cell envelope. It further reviews the rather impressive progress made in the last ten years in the discovery and development of novel inhibitors targeting their biogenesis. PMID:24915502

In vitro activities of DA-7157 and DA-7218 against Mycobacterium tuberculosis and Nocardia brasiliensis.

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Vera-Cabrera, Lucio; Gonzalez, Eva; Rendon, Adrian; Ocampo-Candiani, Jorge; Welsh, Oliverio; Velazquez-Moreno, Victor M; Choi, Sung Hak; Molina-Torres, Carmen

2006-09-01

The in vitro activities of DA-7157, a novel oxazolidinone, against clinical isolates of Nocardia brasiliensis and Mycobacterium tuberculosis were determined. Equal MIC(50)s and MIC(90)s (0.25 and 0.5 microg/ml, respectively) were found for susceptible and multidrug-resistant isolates of M. tuberculosis. The N. brasiliensis isolates showed an MIC(90) of 1 microg/ml and an MIC(50) of 1 microg/ml. The DA-7157 prodrug, DA-7218, exhibited similar MICs for M. tuberculosis but fivefold-higher MICs for N. brasiliensis.

Duplex detection of the Mycobacterium tuberculosis complex and medically important non-tuberculosis mycobacteria by real-time PCR based on the rnpB gene.

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Abdeldaim, Guma; Svensson, Erik; Blomberg, Jonas; Herrmann, Björn

2016-11-01

A duplex real-time PCR based on the rnpB gene was developed for Mycobacterium spp. The assay was specific for the Mycobacterium tuberculosis complex (MTB) and also detected all 19 tested species of non-tuberculous mycobacteria (NTM). The assay was evaluated on 404 clinical samples: 290 respiratory samples and 114 from tissue and other non-respiratory body sites. M. tuberculosis was detected by culture in 40 samples and in 30 samples by the assay. The MTB assay showed a sensitivity similar to Roche Cobas Amplicor MTB-PCR (Roche Molecular Systems, Pleasanton, CA, USA). There were only nine samples with non-tuberculous mycobacteria detected by culture. Six of them were detected by the PCR assay. © 2016 APMIS. Published by John Wiley & Sons Ltd.

Laboratory Diagnosis and Susceptibility Testing for Mycobacterium tuberculosis.

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Procop, Gary W

2016-12-01

The laboratory, which utilizes some of the most sophisticated and rapidly changing technologies, plays a critical role in the diagnosis of tuberculosis. Some of these tools are being employed in resource-challenged countries for the rapid detection and characterization of Mycobacterium tuberculosis. Foremost, the laboratory defines appropriate specimen criteria for optimal test performance. The direct detection of mycobacteria in the clinical specimen, predominantly done by acid-fast staining, may eventually be replaced by rapid-cycle PCR. The widespread use of the Xpert MTB/RIF (Cepheid) assay, which detects both M. tuberculosis and key genetic determinants of rifampin resistance, is important for the early detection of multidrug-resistant strains. Culture, using both broth and solid media, remains the standard for establishing the laboratory-based diagnosis of tuberculosis. Cultured isolates are identified far less commonly by traditional biochemical profiling and more commonly by molecular methods, such as DNA probes and broad-range PCR with DNA sequencing. Non-nucleic acid-based methods of identification, such as high-performance liquid chromatography and, more recently, matrix-assisted laser desorption/ionization-time of flight mass spectrometry, may also be used for identification. Cultured isolates of M. tuberculosis should be submitted for susceptibility testing according to standard guidelines. The use of broth-based susceptibility testing is recommended to significantly decrease the time to result. Cultured isolates may also be submitted for strain typing for epidemiologic purposes. The use of massive parallel sequencing, also known as next-generation sequencing, promises to continue to this molecular revolution in mycobacteriology, as whole-genome sequencing provides identification, susceptibility, and typing information simultaneously.

Production of antibodies against glycolipids from the Mycobacterium tuberculosis cell wall in aerosol murine models of tuberculosis.

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Cardona, P J; Julián, E; Vallès, X; Gordillo, S; Muñoz, M; Luquin, M; Ausina, V

2002-06-01

Evolution of antibodies against glycolipids from the Mycobacterium tuberculosis cell wall has been studied for the first time in experimental murine models of tuberculosis induced by aerosol, in which infection, reinfection, reactivation, prophylaxis and treatment with antibiotics have been assayed. Results show a significant humoral response against these antigens, where diacyltrehaloses (DAT) and sulpholipid I (SL-I) elicited higher antibody levels than protein antigens like antigen 85 protein complex (Ag85), culture filtrate proteins (CFP) and purified protein derivative (PPD). Only immunoglobulin M (IgM) antibodies have been detected against DAT and SL-I. Their evolution has a positive correlation with bacillary concentration in tissues.

Immunological response to Mycobacterium tuberculosis infection in blood from type 2 diabetes patients.

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Raposo-García, Sara; Guerra-Laso, José Manuel; García-García, Silvia; Juan-García, Javier; López-Fidalgo, Eduardo; Diez-Tascón, Cristina; Nebreda-Mayoral, Teresa; López-Medrano, Ramiro; Rivero-Lezcano, Octavio Miguel

2017-06-01

The convergence of tuberculosis and diabetes represents a co-epidemic that threatens progress against tuberculosis. We have investigated type 2 diabetes as a risk factor for tuberculosis susceptibility, and have used as experimental model whole blood infected in vitro with Mycobacterium tuberculosis. Blood samples from diabetic patients were found to have a higher absolute neutrophil count that non-diabetic controls, but their immune functionality seemed impaired because they displayed a lower capacity to phagocytose M. tuberculosis, a finding that had been previously reported only for monocytes. In contrast, an increased production of TNFα was detected in infected blood from diabetic patients. Despite the altered phagocytic capacity showed by cells from these patients, the antimicrobial activity measured in both whole blood and monocyte derived macrophages was similar to that of controls. This unexpected result prompts further improvements in the whole blood model to analyze the immune response of diabetes patients to tuberculosis. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

The majority of inducible DNA repair genes in Mycobacterium tuberculosis are induced independently of RecA.

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Rand, Lucinda; Hinds, Jason; Springer, Burkhard; Sander, Peter; Buxton, Roger S; Davis, Elaine O

2003-11-01

In many species of bacteria most inducible DNA repair genes are regulated by LexA homologues and are dependent on RecA for induction. We have shown previously by analysing the induction of recA that two mechanisms for the induction of gene expression following DNA damage exist in Mycobacterium tuberculosis. Whereas one of these depends on RecA and LexA in the classical way, the other mechanism is independent of both of these proteins and induction occurs in the absence of RecA. Here we investigate the generality of each of these mechanisms by analysing the global response to DNA damage in both wild-type M. tuberculosis and a recA deletion strain of M. tuberculosis using microarrays. This revealed that the majority of the genes that were induced remained inducible in the recA mutant stain. Of particular note most of the inducible genes with known or predicted functions in DNA repair did not depend on recA for induction. Amongst these are genes involved in nucleotide excision repair, base excision repair, damage reversal and recombination. Thus, it appears that this novel mechanism of gene regulation is important for DNA repair in M. tuberculosis.

An orphan gyrB in the Mycobacterium smegmatis genome

Indian Academy of Sciences (India)

DNA gyrase is an essential topoisomerase found in all bacteria. It is encoded by gyrB and gyrA genes. These genes are organized differently in different bacteria. Direct comparison of Mycobacterium tuberculosis and Mycobacterium smegmatis genomes reveals presence of an additional gyrB in M. smegmatis flanked by ...

Clinical Concentrations of Thioridazine Kill Intracellular Multidrug-Resistant Mycobacterium tuberculosis

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Ordway, Diane; Viveiros, Miguel; Leandro, Clara; Bettencourt, Rosário; Almeida, Josefina; Martins, Marta; Kristiansen, Jette E.; Molnar, Joseph; Amaral, Leonard

2003-01-01

The phenothiazines chlorpromazine (CPZ) and thioridazine (TZ) have equal in vitro activities against antibiotic-sensitive and -resistant Mycobacterium tuberculosis. These compounds have not been used as anti-M. tuberculosis agents because their in vitro activities take place at concentrations which are beyond those that are clinically achievable. In addition, chronic administration of CPZ produces frequent severe side effects. Because CPZ has been shown to enhance the killing of intracellular M. tuberculosis at concentrations in the medium that are clinically relevant, we have investigated whether TZ, a phenothiazine whose negative side effects are less frequent and serious than those associated with CPZ, kills M. tuberculosis organisms that have been phagocytosed by human macrophages, which have nominal killing activities against these bacteria. Both CPZ and TZ killed intracellular antibiotic-sensitive and -resistant M. tuberculosis organisms when they were used at concentrations in the medium well below those present in the plasma of patients treated with these agents. These concentrations in vitro were not toxic to the macrophage, nor did they affect in vitro cellular immune processes. TZ thus appears to be a serious candidate for the management of a freshly diagnosed infection of pulmonary tuberculosis or as an adjunct to conventional antituberculosis therapy if the patient originates from an area known to have a high prevalence of multidrug-resistant M. tuberculosis isolates. Nevertheless, we must await the outcomes of clinical trials to determine whether TZ itself may be safely and effectively used as an antituberculosis agent. PMID:12604522

Meropenem-Clavulanate is Effective Against Extensive Drug-Resistant Mycobacterium Tuberculosis

Energy Technology Data Exchange (ETDEWEB)

Hugonnet, J.; Tremblay, L; Boshoff, H; Barry, C; Blanchard, J

2009-01-01

e-lactam antibiotics are ineffective against Mycobacterium tuberculosis, being rapidly hydrolyzed by the chromosomally encoded blaC gene product. The carbapenem class of e-lactams are very poor substrates for BlaC, allowing us to determine the three-dimensional structure of the covalent BlaC-meropenem covalent complex at 1.8 angstrom resolution. When meropenem was combined with the e-lactamase inhibitor clavulanate, potent activity against laboratory strains of M. tuberculosis was observed [minimum inhibitory concentration (MICmeropenem) less than 1 microgram per milliliter], and sterilization of aerobically grown cultures was observed within 14 days. In addition, this combination exhibited inhibitory activity against anaerobically grown cultures that mimic the 'persistent' state and inhibited the growth of 13 extensively drug-resistant strains of M. tuberculosis at the same levels seen for drug-susceptible strains. Meropenem and clavulanate are Food and Drug Administration-approved drugs and could potentially be used to treat patients with currently untreatable disease.

Human tuberculosis caused by Mycobacterium bovis: a retrospective comparison with Mycobacterium tuberculosis in a Mexican tertiary care centre, 2000-2015.

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Torres-Gonzalez, Pedro; Cervera-Hernandez, Miguel E; Martinez-Gamboa, Areli; Garcia-Garcia, Lourdes; Cruz-Hervert, Luis P; Bobadilla-Del Valle, Miriam; Ponce-de Leon, Alfredo; Sifuentes-Osornio, Jose

2016-11-08

Human tuberculosis caused by Mycobacterium bovis is believed to be frequent in developing countries. Transmission is usually through ingestion of unpasteurized dairy products, although airborne contagion is possible. Disease caused by M. tuberculosis or M. bovis is clinically indistinguishable from each other. The aim of this study was to determine the factors associated with M. bovis disease. Retrospective analysis of all culture-positive cases of M. bovis and M. tuberculosis from 2000 to 2015, in a Mexican tertiary-care centre. Sociodemographic, clinical, and radiographic data from medical records were compared. Disease site was classified as pulmonary, extrapulmonary, or pulmonary and extrapulmonary, based on cultures. We evaluated 533 cases, 372 (69.7 %) of which were caused by M. tuberculosis and 161 (30.2 %) by M. bovis. Characteristics associated with M. bovis disease were: younger age (aOR 0.97, 95 % CI 0.95-0.98), glucocorticoid use (aOR 2.27, 95 % CI 1.42-3.63), and extrapulmonary disease (aOR 1.80, 95 % CI 1.21-2.69). M. tuberculosis was associated with lower socioeconomic status (aOR 0.52, 95 % CI 0.28-0.97). When we analysed only pulmonary cases, younger age (aOR 0.97, 95 % CI 0.96-0.99), glucocorticoid use (aOR 2.41, 95 % CI 1.30-4.46), and smoking (aOR 1.94, CI 95 % 1.15-3.27) were associated with M. bovis. Both groups showed similar proportions of direct microscopy smear results (respiratory samples) and chest X-ray cavitations. Younger age, glucocorticoid use, and extrapulmonary disease were associated with M. bovis as the causative agent of tuberculosis in a group of patients from a tertiary care centre in a country where bovine tuberculosis is endemic. Further studies must be conducted in the general population to determine pathogen-specific associated factors and outcomes.

Activity of Scottish plant, lichen and fungal endophyte extracts against Mycobacterium aurum and Mycobacterium tuberculosis.

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Gordien, Andréa Y; Gray, Alexander I; Ingleby, Kevin; Franzblau, Scott G; Seidel, Véronique

2010-05-01

With tuberculosis the leading bacterial killer worldwide and other mycobacterial diseases on the increase, the search for new antimycobacterial agents is timely. In this study, extracts from plants, lichens and fungal endophytes of Scottish provenance were screened for activity against Mycobacterium aurum and M. tuberculosis H(37)Rv. The best activity against M. aurum was observed for extracts of Juniperus communis roots and Cladonia arbuscula (MIC = 4 microg/mL), and a fungal endophyte isolated from Vaccinium myrtillus (MIC = 8 microg/mL). The best activity against M. tuberculosis was observed for extracts of C. arbuscula, Empetrum nigrum, J. communis roots, Calluna vulgaris aerial parts, Myrica gale roots and stems (93 to 99% inhibition at 100 microg/mL). Potent antitubercular activity (90 to 96% inhibition at 100 microg/mL) was also observed for the ethanol extracts of Xerocomus badius, Chalciporus piperatus, Suillus luteus and of endophytes isolated from C. vulgaris, E. nigrum, Vaccinium vitis-idaea and V. myrtillus. The results obtained this study provide, in part, some scientific basis for the traditional use of some of the selected plants in the treatment of tuberculosis. They also indicate that fungal endophytes recovered from Scottish plants are a source of antimycobacterial agents worthy of further investigation. Copyright (c) 2009 John Wiley & Sons, Ltd.

Whole genome sequencing reveals complex evolution patterns of multidrug-resistant Mycobacterium tuberculosis Beijing strains in patients.

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Matthias Merker

Full Text Available Multidrug-resistant (MDR Mycobacterium tuberculosis complex (MTBC strains represent a major threat for tuberculosis (TB control. Treatment of MDR-TB patients is long and less effective, resulting in a significant number of treatment failures. The development of further resistances leads to extensively drug-resistant (XDR variants. However, data on the individual reasons for treatment failure, e.g. an induced mutational burst, and on the evolution of bacteria in the patient are only sparsely available. To address this question, we investigated the intra-patient evolution of serial MTBC isolates obtained from three MDR-TB patients undergoing longitudinal treatment, finally leading to XDR-TB. Sequential isolates displayed identical IS6110 fingerprint patterns, suggesting the absence of exogenous re-infection. We utilized whole genome sequencing (WGS to screen for variations in three isolates from Patient A and four isolates from Patient B and C, respectively. Acquired polymorphisms were subsequently validated in up to 15 serial isolates by Sanger sequencing. We determined eight (Patient A and nine (Patient B polymorphisms, which occurred in a stepwise manner during the course of the therapy and were linked to resistance or a potential compensatory mechanism. For both patients, our analysis revealed the long-term co-existence of clonal subpopulations that displayed different drug resistance allele combinations. Out of these, the most resistant clone was fixed in the population. In contrast, baseline and follow-up isolates of Patient C were distinguished each by eleven unique polymorphisms, indicating an exogenous re-infection with an XDR strain not detected by IS6110 RFLP typing. Our study demonstrates that intra-patient microevolution of MDR-MTBC strains under longitudinal treatment is more complex than previously anticipated. However, a mutator phenotype was not detected. The presence of different subpopulations might confound phenotypic and

Microbial sensor for drug susceptibility testing of Mycobacterium tuberculosis.

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Zhang, Z-T; Wang, D-B; Li, C-Y; Deng, J-Y; Zhang, J-B; Bi, L-J; Zhang, X-E

2018-01-01

Drug susceptibility testing (DST) of clinical isolates of Mycobacterium tuberculosis is critical in treating tuberculosis. We demonstrate the possibility of using a microbial sensor to perform DST of M. tuberculosis and shorten the time required for DST. The sensor is made of an oxygen electrode with M. tuberculosis cells attached to its surface. This sensor monitors the residual oxygen consumption of M. tuberculosis cells after treatment with anti-TB drugs with glycerine as a carbon source. In principle, after drug pretreatment for 4-5 days, the response differences between the sensors made of drug-sensitive isolates are distinguishable from the sensors made of drug-resistant isolates. The susceptibility of the M. tuberculosis H37Ra strain, its mutants and 35 clinical isolates to six common anti-TB drugs: rifampicin, isoniazid, streptomycin, ethambutol, levofloxacin and para-aminosalicylic acid were tested using the proposed method. The results agreed well with the gold standard method (LJ) and were determined in significantly less time. The whole procedure takes approximately 11 days and therefore has the potential to inform clinical decisions. To our knowledge, this is the first study that demonstrates the possible application of a dissolved oxygen electrode-based microbial sensor in M. tuberculosis drug resistance testing. This study used the microbial sensor to perform DST of M. tuberculosis and shorten the time required for DST. The overall detection result of the microbial sensor agreed well with that of the conventional LJ proportion method and takes less time than the existing phenotypic methods. In future studies, we will build an O 2 electrode array microbial sensor reactor to enable a high-throughput drug resistance analysis. © 2017 The Authors. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of The Society for Applied Microbiology.

Human ULK1 Variation and Susceptibility to Mycobacterium tuberculosis Infection.

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Horne, David J; Graustein, Andrew D; Shah, Javeed A; Peterson, Glenna; Savlov, Meg; Steele, Sergio; Narita, Masahiro; Hawn, Thomas R

2016-10-15

Unlike tuberculosis, few studies have evaluated a host genetic basis for variability in susceptibility to latent Mycobacterium tuberculosis infection (LTBI). We performed a candidate gene association study of autophagy-related genes and LTBI. We enrolled close contacts of individuals with pulmonary tuberculosis, assessed LTBI status, and determined clinical and sociodemographic risk factors for LTBI. In participants who self-identified as Asian or black, we compared haplotype-tagging single-nucleotide polymorphisms (SNPs) in ULK1 and GABARAP between cases (n = 143) and controls (n = 106). Using CRISPR/Cas9 in U937 monocytes, we investigated the effect of ULK1 deficiency on cytokine expression, autophagy, and M. tuberculosis replication. In Asian participants, we identified 2 ULK1 SNPs (rs12297124 and rs7300908) associated with LTBI. After adjustment for population admixture and clinical risk for LTBI, each rs12297124 minor allele conferred 80% reduction in LTBI risk (odds ratio, 0.18; 95% confidence interval, .07-.46). Compared with controls, ULK1-deficient cells exhibited decreased tumor necrosis factor secretion after stimulation with Toll-like receptor ligands and M. tuberculosis whole-cell lysate, increased M. tuberculosis replication, and decreased selective autophagy. These results demonstrate a strong association of rs12297124, a noncoding ULK1 SNP, with LTBI and a role for ULK1 regulation of TNF secretion, nonspecific and M. tuberculosis-induced autophagy, and M. tuberculosis replication in monocytes. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Crystallization and preliminary X-ray crystallographic studies of Mycobacterium tuberculosis CRP/FNR family transcription regulator

International Nuclear Information System (INIS)

Akif, Mohd; Akhter, Yusuf; Hasnain, Seyed E.; Mande, Shekhar C.

2006-01-01

The CRP/FNR family transcription factor from M. tuberculosis H37Rv has been crystallized in space group P2 1 2 1 2 1 in the absence of cAMP. The crystals show the presence of a dimeric molecule in the asymmetric unit. CRP/FNR family members are transcription factors that regulate the transcription of many genes in Escherichia coli and other organisms. Mycobacterium tuberculosis H37Rv contains a probable CRP/FNR homologue encoded by the open reading frame Rv3676. The deletion of this gene is known to cause growth defects in cell culture, in bone marrow-derived macrophages and in a mouse model of tuberculosis. The mycobacterial gene Rv3676 shares ∼32% sequence identity with prototype E. coli CRP. The structure of the protein might provide insight into transcriptional regulation in the pathogen by this protein. The M. tuberculosis CRP/FNR transcription regulator was crystallized in space group P2 1 2 1 2 1 , with unit-cell parameters a = 54.1, b = 84.6, c = 101.2 Å. The crystal diffracted to a resolution of 2.9 Å. Matthews coefficient and self-rotation function calculations reveal the presence of two monomers in the asymmetric unit

Cytokine responses in relation to age, gender, body mass index, Mycobacterium tuberculosis infection, and otitis media among inuit in greenland

DEFF Research Database (Denmark)

Nielsen, Nina Odgaard; Soborg, Bolette; Børresen, Malene

2013-01-01

To evaluate the cytokine response pattern in Inuit in Greenland in relation to age, gender, body mass index (BMI), Mycobacterium tuberculosis infection (MTI), and otitis media (OM) to assess whether Inuit may have signs of impaired immune responsiveness to infection.......To evaluate the cytokine response pattern in Inuit in Greenland in relation to age, gender, body mass index (BMI), Mycobacterium tuberculosis infection (MTI), and otitis media (OM) to assess whether Inuit may have signs of impaired immune responsiveness to infection....

Tuberculosis transmission of predominant genotypes of Mycobacterium tuberculosis in Northern suburbs of Buenos Aires city region Transmisión de la tuberculosis por genotipos predominantes de Mycobacterium tuberculosis en la región Gran Buenos Aires Norte

Directory of Open Access Journals (Sweden)

N. Morcillo

2007-09-01

Full Text Available In 2003, the incidence of tuberculosis in Argentina showed an increase compared to 2002. The severe national crisis at the end of the 90s has probably strongly contributed to this situation. The goal of this work was to estimate the extent of the spread of the most predominant Mycobacterium tuberculosis strains and to assess the spread of predominant M. tuberculosis clusters as determined by spoligotyping and IS6110 RFLP. The study involved 590 pulmonary, smear-positive TB cases receiving medical attention at health centers and hospitals in Northern Buenos Aires (NBA suburbs, from October 2001 to December 2002. From a total of 208 clinical isolates belonging to 6 major clusters, 63 (30.2% isolates had identical spoligotyping and IS6110 RFLP pattern. Only 22.2% were shown to have epidemiological connections with another member of their respective cluster. In these major clusters, 30.2% of the 208 TB cases studied by both molecular techniques and contact tracing could be convincingly attributable to a recently acquired infection. This knowledge may be useful to assess the clonal distribution of predominant M. tuberculosis clusters in Argentina, which may make an impact on TB control strategies.La incidencia de la tuberculosis en Argentina mostró en 2003 un incremento en comparación con 2002. La grave crisis nacional a fines de los 90 ha probablemente contribuido en gran medida a esta situación. El objetivo del presente trabajo fue determinar la diversidad genética de aislamientos de Mycobacterium tuberculosis y el grado de dispersión de algunas cepas mayoritarias genéticamente relacionadas. El estudio involucró 590 aislamientos clínicos provenientes de muestras respiratorias con examen directo positivo, de pacientes atendidos en los hospitales y centros de salud que conforman la región Gran Buenos Aires Norte (NBA, de octubre de 2001 a diciembre de 2002. De 208 aislamientos que se encontraron en los 6 mayores clusters, 63 (30,2% ten

Difference in TB10.4 T-cell epitope recognition following immunization with recombinant TB10.4, BCG or infection with Mycobacterium tuberculosis

DEFF Research Database (Denmark)

Billeskov, Rolf; Grandal, Michael V; Poulsen, Christian

2010-01-01

vaccine Ag, TB10.4, in a recombinant form, or when expressed by the pathogen Mycobacterium tuberculosis (M.tb), or by the current anti-tuberculosis vaccine, Mycobacterium bovis BCG. We showed that BCG and M.tb induced a similar CD4(+) T-cell specific TB10.4 epitope-pattern, which differed completely from...... that induced by recombinant TB10.4. This difference was not due to post-translational modifications of TB10.4 or because TB10.4 is secreted from BCG and M.tb as a complex with Rv0287. In addition, BCG and TB10.4/CAF01 were both taken up by DC and macrophages in vivo, and in vitro uptake experiments revealed...... that both TB10.4 and BCG were transported to Lamp(+)-compartments. BCG and TB10.4 however, were directed to different types of Lamp(+)-compartments in the same APC, which may lead to different epitope recognition patterns. In conclusion, we show that different vectors can induce completely different...

Description of polymerase chain reaction and sequencing DNA Mycobacterium tuberculosis from specimen sputum of tuberculosis patients in Medan

Science.gov (United States)

Lily; Siregar, Y.; Ilyas, S.

2018-03-01

This study purposed to describe the product Polymerase Chain Reaction (PCR) and sequencing of DNA Mycobacterium (M.) tuberculosis from sputum of tuberculosis (TB) patients in Medan. Sputum was collected from patients that diagnosed with pulmonary TB by a physician. Specimen processed by PCR method of Li et al. and sequencing at Macrogen Laboratory. All of 12 product PCR were showed brightness bands at 126 base pair (bp). These results indicated similarity to the study of Li et al. Sequencing analysis showed the presence of a mutation and non-mutation groups of M. tuberculosis. The reference and outcome berange of the mutation and non-mutation of M. tuberculosis were 56-107, 59-85, 60-120 and 63-94, respectively. The percentage bp difference between the outcome and references for mutation and non-mutation were 3.448-6.569and 3.278-7.428%, respectively. In conclusion, the successful amplification of PCR products in a 1.5% agarose gel electrophoresis where all 12 sputa contained rpoB-positive M. tuberculosis and 0.644% difference was found between the outcome with reference bp of the mutation and non-mutation M. tuberculosis groups.

Crystallization and preliminary X-ray characterization of phosphoglucose isomerase from Mycobacterium tuberculosis H37Rv

International Nuclear Information System (INIS)

Mathur, Divya; Anand, Kanchan; Mathur, Deepika; Jagadish, Nirmala; Suri, Anil; Garg, Lalit C.

2007-01-01

The phosphoglucose isomerase from Mycobacterium tuberculosis H37Rv was crystallized and diffraction data were collected to 2.8 Å resolution. Phosphoglucose isomerase is a ubiquitous enzyme that catalyzes the isomerization of d-glucopyranose-6-phosphate to d-fructofuranose-6-phosphate. The present investigation reports the expression, purification, crystallization and preliminary crystallographic studies of the phosphoglucose isomerase from Mycobacterium tuberculosis H37Rv, which shares 46% sequence identity with that of its human host. The recombinant protein, which was prepared using an Escherichia coli expression system, was crystallized by the hanging-drop vapour-diffusion method. The crystals diffracted to a resolution of 2.8 Å and belonged to the orthorhombic space group I2 1 2 1 2 1 , with unit-cell parameters a = 109.0, b = 119.8, c = 138.9 Å

Guardians of the mycobacterial genome: A review on DNA repair systems in Mycobacterium tuberculosis.

Science.gov (United States)

Singh, Amandeep

2017-12-01

The genomic integrity of Mycobacterium tuberculosis is continuously threatened by the harsh survival conditions inside host macrophages, due to immune and antibiotic stresses. Faithful genome maintenance and repair must be accomplished under stress for the bacillus to survive in the host, necessitating a robust DNA repair system. The importance of DNA repair systems in pathogenesis is well established. Previous examination of the M. tuberculosis genome revealed homologues of almost all the major DNA repair systems, i.e. nucleotide excision repair (NER), base excision repair (BER), homologous recombination (HR) and non-homologous end joining (NHEJ). However, recent developments in the field have pointed to the presence of novel proteins and pathways in mycobacteria. Homologues of archeal mismatch repair proteins were recently reported in mycobacteria, a pathway previously thought to be absent. RecBCD, the major nuclease-helicase enzymes involved in HR in E. coli, were implicated in the single-strand annealing (SSA) pathway. Novel roles of archeo-eukaryotic primase (AEP) polymerases, previously thought to be exclusive to NHEJ, have been reported in BER. Many new proteins with a probable role in DNA repair have also been discovered. It is now realized that the DNA repair systems in M. tuberculosis are highly evolved and have redundant backup mechanisms to mend the damage. This review is an attempt to summarize our current understanding of the DNA repair systems in M. tuberculosis.

Supplementary Material for: Recombination in pe/ppe genes contributes to genetic variation in Mycobacterium tuberculosis lineages

KAUST Repository

Phelan, Jody

2016-01-01

Abstract Background Approximately 10 % of the Mycobacterium tuberculosis genome is made up of two families of genes that are poorly characterized due to their high GC content and highly repetitive nature. The PE and PPE families are typified by their highly conserved N-terminal domains that incorporate proline-glutamate (PE) and proline-proline-glutamate (PPE) signature motifs. They are hypothesised to be important virulence factors involved with host-pathogen interactions, but their high genetic variability and complexity of analysis means they are typically disregarded in genome studies. Results To elucidate the structure of these genes, 518 genomes from a diverse international collection of clinical isolates were de novo assembled. A further 21 reference M. tuberculosis complex genomes and long read sequence data were used to validate the approach. SNP analysis revealed that variation in the majority of the 168 pe/ppe genes studied was consistent with lineage. Several recombination hotspots were identified, notably pe_pgrs3 and pe_pgrs17. Evidence of positive selection was revealed in 65 pe/ppe genes, including epitopes potentially binding to major histocompatibility complex molecules. Conclusions This, the first comprehensive study of the pe and ppe genes, provides important insight into M. tuberculosis diversity and has significant implications for vaccine development.

Novel genetic polymorphisms that further delineate the phylogeny of the Mycobacterium tuberculosis complex.

NARCIS (Netherlands)

Huard, Richard C; Fabre, Michel; Haas, Petra de; Lazzarini, Luiz Claudio Oliveira; Soolingen, Dick van; Cousins, Debby; Ho, John L

2006-01-01

In a previous report, we described a PCR protocol for the differentiation of the various species of the Mycobacterium tuberculosis complex (MTC) on the basis of genomic deletions (R. C. Huard, L. C. de Oliveira Lazzarini, W. R. Butler, D. van Soolingen, and J. L. Ho, J. Clin. Microbiol.

Gamma Interferon Release Assays for Detection of Mycobacterium tuberculosis Infection

Science.gov (United States)

Denkinger, Claudia M.; Kik, Sandra V.; Rangaka, Molebogeng X.; Zwerling, Alice; Oxlade, Olivia; Metcalfe, John Z.; Cattamanchi, Adithya; Dowdy, David W.; Dheda, Keertan; Banaei, Niaz

2014-01-01

SUMMARY Identification and treatment of latent tuberculosis infection (LTBI) can substantially reduce the risk of developing active disease. However, there is no diagnostic gold standard for LTBI. Two tests are available for identification of LTBI: the tuberculin skin test (TST) and the gamma interferon (IFN-γ) release assay (IGRA). Evidence suggests that both TST and IGRA are acceptable but imperfect tests. They represent indirect markers of Mycobacterium tuberculosis exposure and indicate a cellular immune response to M. tuberculosis. Neither test can accurately differentiate between LTBI and active TB, distinguish reactivation from reinfection, or resolve the various stages within the spectrum of M. tuberculosis infection. Both TST and IGRA have reduced sensitivity in immunocompromised patients and have low predictive value for progression to active TB. To maximize the positive predictive value of existing tests, LTBI screening should be reserved for those who are at sufficiently high risk of progressing to disease. Such high-risk individuals may be identifiable by using multivariable risk prediction models that incorporate test results with risk factors and using serial testing to resolve underlying phenotypes. In the longer term, basic research is necessary to identify highly predictive biomarkers. PMID:24396134

The biological and structural characterization of Mycobacterium tuberculosis UvrA provides novel insights into its mechanism of action.

Science.gov (United States)

Rossi, Franca; Khanduja, Jasbeer Singh; Bortoluzzi, Alessio; Houghton, Joanna; Sander, Peter; Güthlein, Carolin; Davis, Elaine O; Springer, Burkhard; Böttger, Erik C; Relini, Annalisa; Penco, Amanda; Muniyappa, K; Rizzi, Menico

2011-09-01

Mycobacterium tuberculosis is an extremely well adapted intracellular human pathogen that is exposed to multiple DNA damaging chemical assaults originating from the host defence mechanisms. As a consequence, this bacterium is thought to possess highly efficient DNA repair machineries, the nucleotide excision repair (NER) system amongst these. Although NER is of central importance to DNA repair in M. tuberculosis, our understanding of the processes in this species is limited. The conserved UvrABC endonuclease represents the multi-enzymatic core in bacterial NER, where the UvrA ATPase provides the DNA lesion-sensing function. The herein reported genetic analysis demonstrates that M. tuberculosis UvrA is important for the repair of nitrosative and oxidative DNA damage. Moreover, our biochemical and structural characterization of recombinant M. tuberculosis UvrA contributes new insights into its mechanism of action. In particular, the structural investigation reveals an unprecedented conformation of the UvrB-binding domain that we propose to be of functional relevance. Taken together, our data suggest UvrA as a potential target for the development of novel anti-tubercular agents and provide a biochemical framework for the identification of small-molecule inhibitors interfering with the NER activity in M. tuberculosis.

Human Tuberculosis Caused by Mycobacterium bovis in the United States, 2006-2013.

Science.gov (United States)

Scott, Colleen; Cavanaugh, Joseph S; Pratt, Robert; Silk, Benjamin J; LoBue, Philip; Moonan, Patrick K

2016-09-01

Using genotyping techniques that have differentiated Mycobacterium bovis from Mycobacterium tuberculosis since 2005, we review the epidemiology of human tuberculosis caused by M. bovis in the United States and validate previous findings nationally. All tuberculosis cases with a genotyped M. tuberculosis complex isolate reported during 2006-2013 in the United States were eligible for analysis. We used binomial regression to identify characteristics independently associated with M. bovis disease using adjusted prevalence ratios (aPRs) and corresponding 95% confidence intervals (CIs). During 2006-2013, the annual percentages of tuberculosis cases attributable to M. bovis remained consistent nationally (range, 1.3%-1.6%) among all tuberculosis cases (N = 59 273). Compared with adults 25-44 years of age, infants aged 0-4 years (aPR, 1.9 [95% CI, 1.4-2.8]) and children aged 5-14 years (aPR, 4.0 [95% CI, 3.1-5.3]) had higher prevalences of M. bovis disease. Patients who were foreign-born (aPR, 1.4 [95% CI, 1.2-1.7]), Hispanic (aPR, 3.9 [95% CI, 3.0-5.0]), female (aPR, 1.4 [95% CI, 1.3-1.6]), and resided in US-Mexico border counties (aPR, 2.0 [95% CI, 1.7-2.4]) also had higher M. bovis prevalences. Exclusively extrapulmonary disease (aPR, 3.7 [95% CI, 3.3-4.2]) or disease that was both pulmonary and extrapulmonary (aPR, 2.4 [95% CI, 2.1-2.9]) were associated with a higher prevalence of M. bovis disease. Children, foreign-born persons, Hispanics, and females are disproportionately affected by M. bovis, which was independently associated with extrapulmonary disease. Targeted prevention efforts aimed at Hispanic mothers and caregivers are warranted. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Phosphorylation of InhA inhibits mycolic acid biosynthesis and growth of Mycobacterium tuberculosis

Energy Technology Data Exchange (ETDEWEB)

Molle, Virginie; Gulten, Gulcin; Vilchèze, Catherine; Veyron-Churlet, Romain; Zanella-Cléon, Isabelle; Sacchettini, James C.; Jacobs, Jr, William R.; Kremer, Laurent (CNRS-UMR); (Einstein); (TAM)

2011-08-24

The remarkable survival ability of Mycobacterium tuberculosis in infected hosts is related to the presence of cell wall-associated mycolic acids. Despite their importance, the mechanisms that modulate expression of these lipids in response to environmental changes are unknown. Here we demonstrate that the enoyl-ACP reductase activity of InhA, an essential enzyme of the mycolic acid biosynthetic pathway and the primary target of the anti-tubercular drug isoniazid, is controlled via phosphorylation. Thr-266 is the unique kinase phosphoacceptor, both in vitro and in vivo. The physiological relevance of Thr-266 phosphorylation was demonstrated using inhA phosphoablative (T266A) or phosphomimetic (T266D/E) mutants. Enoyl reductase activity was severely impaired in the mimetic mutants in vitro, as a consequence of a reduced binding affinity to NADH. Importantly, introduction of inhA{_}T266D/E failed to complement growth and mycolic acid defects of an inhA-thermosensitive Mycobacterium smegmatis strain, in a similar manner to what is observed following isoniazid treatment. This study suggests that phosphorylation of InhA may represent an unusual mechanism that allows M. tuberculosis to regulate its mycolic acid content, thus offering a new approach to future anti-tuberculosis drug development.

Phosphorylation of InhA inhibits mycolic acid biosynthesis and growth of Mycobacterium tuberculosis.

Science.gov (United States)

Molle, Virginie; Gulten, Gulcin; Vilchèze, Catherine; Veyron-Churlet, Romain; Zanella-Cléon, Isabelle; Sacchettini, James C; Jacobs, William R; Kremer, Laurent

2010-12-01

The remarkable survival ability of Mycobacterium tuberculosis in infected hosts is related to the presence of cell wall-associated mycolic acids. Despite their importance, the mechanisms that modulate expression of these lipids in response to environmental changes are unknown. Here we demonstrate that the enoyl-ACP reductase activity of InhA, an essential enzyme of the mycolic acid biosynthetic pathway and the primary target of the anti-tubercular drug isoniazid, is controlled via phosphorylation. Thr-266 is the unique kinase phosphoacceptor, both in vitro and in vivo. The physiological relevance of Thr-266 phosphorylation was demonstrated using inhA phosphoablative (T266A) or phosphomimetic (T266D/E) mutants. Enoyl reductase activity was severely impaired in the mimetic mutants in vitro, as a consequence of a reduced binding affinity to NADH. Importantly, introduction of inhA_T266D/E failed to complement growth and mycolic acid defects of an inhA-thermosensitive Mycobacterium smegmatis strain, in a similar manner to what is observed following isoniazid treatment. This study suggests that phosphorylation of InhA may represent an unusual mechanism that allows M. tuberculosis to regulate its mycolic acid content, thus offering a new approach to future anti-tuberculosis drug development. © 2010 Blackwell Publishing Ltd.

DETECÇÃO DO COMPLEXO Mycobacterium tuberculosis NO LEITE PELA REAÇÃO EM CADEIA DA POLIMERASE SEGUIDA DE ANÁLISE DE RESTRIÇÃO DO FRAGMENTO AMPLIFICADO (PRA DETECTION OF Mycobacterium tuberculosis COMPLEX BY PCR-RESTRICTION FRAGMENT LENGTH POLYMORFISM ANALYSIS OF THE HSP65 GENE

Directory of Open Access Journals (Sweden)

Joab Trajano Silva

2008-12-01

Full Text Available Mycobacterium bovis é membro do complexo Mycobacterium tuberculosis (MTBC, grupo este composto por espécies com grande homologia genética. É o agente etiológico da tuberculose bovina, importante zoonose transmissível ao homem, principalmente através da inalação do bacilo e/ou pelo consumo de leite e derivados não-pasteurizados provenientes de vacas tuberculosas. O objetivo deste estudo foi padronizar a identificação de micobactérias do complexo M. tuberculosis presentes no leite, por metodologia molecular. Fez-se a extração de DNA diretamente do leite contaminado e realizou-se a identificação molecular pela reação em cadeia da polimerase seguida de análise de restrição do fragmento amplificado (PRA. Utilizaram-se inhagens de referência e leite cru artificialmente contaminado com M. bovis IP. Um fragmento de 441pb do gene hsp65 foi amplificado, tratado com BstEII e HaeIII e empregou-se o perfil de restrição enzimática obtido para identificar o complexo M. tuberculosis no leite. Com a PRA foi possível detectar com especificidade e sensibilidade a presença de M. bovis em até 10 UFC/mL de leite. A metodologia padronizada poderá auxiliar os métodos microbiológicos e bioquímicos tradicionalmente usados na identificação do bacilo em alimentos suspeitos de contaminação, como, por exemplo, o leite proveniente de animais suspeitos de infecção por M. bovis.

Palavras-chaves: Análise de perfil de restrição enzimática (PRA, complexo Mycobacterium tuberculosis, leite, Mycobacterium bovis, limite de detecção (PCR. Mycobacterium bovis is a member of the M. tuberculosis complex, a group composed by species with high genetic homology. The pathogen is the etiological agent of bovine tuberculosis, an important zoonosis that is mainly transmitted by inhalation of infectious droplet nuclei or by ingestion of milk and crude milk derivative products from tuberculosis cows. The definitive identification of M. bovis

Bim is a crucial regulator of apoptosis induced by Mycobacterium tuberculosis

Science.gov (United States)

Aguiló, N; Uranga, S; Marinova, D; Martín, C; Pardo, J

2014-01-01

Mycobacterium tuberculosis, the causative agent of tuberculosis, induces apoptosis in infected macrophages in vitro and in vivo. However, the molecular mechanism controlling this process is not known. In order to study the involvement of the mitochondrial apoptotic pathway in M. tuberculosis-induced apoptosis, we analysed cell death in M. tuberculosis-infected embryonic fibroblasts (MEFs) derived from different knockout mice for genes involved in this route. We found that apoptosis induced by M. tuberculosis is abrogated in the absence of Bak and Bax, caspase 9 or the executioner caspases 3 and 7. Notably, we show that MEF deficient in the BH3-only BCL-2-interacting mediator of cell death (Bim) protein were also resistant to this process. The relevance of these results has been confirmed in the mouse macrophage cell line J774, where cell transfection with siRNA targeting Bim impaired apoptosis induced by virulent mycobacteria. Notably, only infection with a virulent strain, but not with attenuated ESX-1-defective strains, such as Bacillus Calmette-Guerin and live-attenuated M. tuberculosis vaccine strain MTBVAC, induced Bim upregulation and apoptosis, probably implicating virulence factor early secreted antigenic target 6-kDa protein in this process. Our results suggest that Bim upregulation and apoptosis is mediated by the p38MAPK-dependent pathway. Our findings show that Bim is a master regulator of apoptosis induced by M. tuberculosis. PMID:25032866

A broad set of different llama antibodies specific for a 16 kDa heat shock protein of Mycobacterium tuberculosis

NARCIS (Netherlands)

Trilling, Anke K.; de Ronde, Hans; Noteboom, Linda; van Houwelingen, Adèle; Roelse, Margriet; Srivastava, Saurabh K.; Haasnoot, Willem; Jongsma, Maarten A.; Kolk, Arend; Zuilhof, Han; Beekwilder, Jules

2011-01-01

Recombinant antibodies are powerful tools in engineering of novel diagnostics. Due to the small size and stable nature of llama antibody domains selected antibodies can serve as a detection reagent in multiplexed and sensitive assays for M. tuberculosis. Antibodies for Mycobacterium tuberculosis (M.

A Rational Approach to Identify Inhibitors of Mycobacterium tuberculosis Enoyl Acyl Carrier Protein Reductase

Czech Academy of Sciences Publication Activity Database

Chhabria, M. T.; Parmar, K. B.; Brahmkshatriya, Pathik

2013-01-01

Roč. 19, č. 21 (2013), s. 3878-3883 ISSN 1381-6128 Institutional support: RVO:61388963 Keywords : mycobacterium tuberculosis * enoyl acyl carrier protein reductase * pharmacophore modeling * molecular docking * binding interactions Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 3.288, year: 2013

Proteomic profiling of Mycobacterium tuberculosis identifies nutrient-starvation-responsive toxin-antitoxin systems

DEFF Research Database (Denmark)

Albrethsen, Jakob; Agner, Jeppe; Piersma, Sander R

2013-01-01

In order to successfully enter the latent stage, Mycobacterium tuberculosis must adapt to conditions such as nutrient limitation and hypoxia. In vitro models that mimic latent infection are valuable tools for describing the changes in metabolism that occur when the bacterium exists in a non......-growing form. We used two complementary proteomic approaches, label-free LC-MS/MS analysis and two-dimensional difference gel electrophoresis, to determine the proteome profile of extracellular proteins from M. tuberculosis cultured under nutrient starvation. Through the label-free LC-MS/MS analysis......, significant differences in the overall metabolism during nutrient starvation were detected. Notably, members of the toxin-antitoxin systems were present in larger quantities in nutrient-starved cultures, supporting a role for these global modules as M. tuberculosis switches its metabolism into dormancy...

Capsular glucan and intracellular glycogen of Mycobacterium tuberculosis: biosynthesis and impact on the persistence in mice

DEFF Research Database (Denmark)

Sambou, Tounkang; Dinadayala, Premkumar; Stadthagen, Gustavo

2008-01-01

Mycobacterium tuberculosis and other pathogenic mycobacterial species produce large amounts of a glycogen-like alpha-glucan that represents the major polysaccharide of their outermost capsular layer. To determine the role of the surface-exposed glucan in the physiology and virulence of these bact......Mycobacterium tuberculosis and other pathogenic mycobacterial species produce large amounts of a glycogen-like alpha-glucan that represents the major polysaccharide of their outermost capsular layer. To determine the role of the surface-exposed glucan in the physiology and virulence...... of these bacteria, orthologues of the glg genes involved in the biosynthesis of glycogen in Escherichia coli were identified in M. tuberculosis H37Rv and inactivated by allelic replacement. Biochemical analyses of the mutants and complemented strains indicated that the synthesis of glucan and glycogen involves...... the alpha-1,4-glucosyltransferases Rv3032 and GlgA (Rv1212c), the ADP-glucose pyrophosphorylase GlgC (Rv1213) and the branching enzyme GlgB (Rv1326c). Disruption of glgC reduced by half the glucan and glycogen contents of M. tuberculosis, whereas the inactivation of glgA and Rv3032 affected the production...

Clustering of Mycobacterium tuberculosis Cases in Acapulco: Spoligotyping and Risk Factors

Directory of Open Access Journals (Sweden)

Elizabeth Nava-Aguilera

2011-01-01

Full Text Available Recurrence and reinfection of tuberculosis have quite different implications for prevention. We identified 267 spoligotypes of Mycobacterium tuberculosis from consecutive tuberculosis patients in Acapulco, Mexico, to assess the level of clustering and risk factors for clustered strains. Point cluster analysis examined spatial clustering. Risk analysis relied on the Mantel Haenszel procedure to examine bivariate associations, then to develop risk profiles of combinations of risk factors. Supplementary analysis of the spoligotyping data used SpolTools. Spoligotyping identified 85 types, 50 of them previously unreported. The five most common spoligotypes accounted for 55% of tuberculosis cases. One cluster of 70 patients (26% of the series produced a single spoligotype from the Manila Family (Clade EAI2. The high proportion (78% of patients infected with cluster strains is compatible with recent transmission of TB in Acapulco. Geomatic analysis showed no spatial clustering; clustering was associated with a risk profile of uneducated cases who lived in single-room dwellings. The Manila emerging strain accounted for one in every four cases, confirming that one strain can predominate in a hyperendemic area.

Autophagy protects type II alveolar epithelial cells from Mycobacterium tuberculosis infection

International Nuclear Information System (INIS)

Guo, Xu-Guang; Ji, Tian-Xing; Xia, Yong; Ma, Yue-Yun

2013-01-01

Highlights: ► We investigated the protective effect of autophagy pathway against MTB infection. ► MTB-infected A549 cells had higher LDH release. ► Inhibition of autophagy signaling significantly enhanced the MTB-induced necrosis. ► Autophagy prevents apoptosis and promotes cell survival in infected cells. -- Abstract: This study was designed to investigate the protective effect of the autophagy signaling pathway against Mycobacterium tuberculosis infection in type II alveolar epithelial cells. An in vitro M. tuberculosis system was established using human A549 cells. Infection-induced changes in the expression of the autophagic marker LC3 were assessed by reverse transcription-PCR and Western blotting. Morphological changes in autophagosomes were detected by transmission electron microscopy (TEM). The function of the autophagy signaling pathway during infection was assessed by measuring the level of cell death and the amount of lactate dehydrogenase (LDH) released in the presence or absence of the inhibitor 3-methyladenine (3-MA). In addition, effects on LDH release were assessed after the siRNA-mediated knockdown of the essential autophagosomal structural membrane protein Atg5. LC3 mRNA expression was significantly reduced in M.tuberculosis-infected A549 cells (16888.76 ± 1576.34 vs. uninfected: 12744.29 ± 1089.37; P < 0.05). TEM revealed M.tuberculosis bacilli-containing compartments that were surrounded by double membranes characteristic of the autophagic process. M.tuberculosis-infected A549 cells released more LDH (1.45 ± 0.12 vs. uninfected: 0.45 ± 0.04; P < 0.05). The inhibition of autophagy signaling significantly enhanced M.tuberculosis-induced necrosis (3-MA: 75 ± 5% vs. untreated: 15 ± 1%; P < 0.05) and LDH release (3-MA: 2.50 ± 0.24 vs. untreated: 0.45 ± 0.04; Atg5 knockdown: 3.19 ± 0.29 vs. untreated: 1.28 ± 0.11; P < 0.05). Our results indicate that autophagy signaling pathway prevents apoptosis in type II alveolar epithelial cells

[Tuberculosis caused by Mycobacterium bovis in workers of bovine tuberculosis sanitation farms in Antioquia, Boyacá and Cundinamarca].

Science.gov (United States)

Leal-Bohórquez, Andrés F; Castro-Osorio, Claudia M; Wintaco-Martínez, Luz M; Villalobos, Rafael; Puerto-Castro, Gloria M

2016-01-01

To perform classic and molecular epidemiological surveillance of human tuberculosis caused by Mycobacterium bovis in bovine supply chains at farms with PPD positive bovines in the departments of Antioquia, Boyacá and Cundinamarca during a one-year period. Livestock farms with PPD positive bovines or buffalos were visited in the study departments according to information obtained in the "Programa Nacional de Tuberculosis bovina" (National program on bovine Tuberculosis) released by ICA (Colombian Agriculture and Livestock Institute). Data on socio-demographic information and tuberculosis risk factors associated to the occupation were collected through a survey applied to all workers at the visited farms. Sputum samples were obtained after informed consent. The sputa underwent microbiological and molecular testing to identify members of the M. tuberculosis complex. Thirty-three livestock farms were visited and information of 164 workers from the bovine supply chain was collected. Staying in a PPD positive farm for more than a year, ignorance about the disease and the presence of possible vectors, like dogs and cats, were identified as possible risk factors for developing tuberculosis. No cases of tuberculosis caused by M. bovis or M. tuberculosis in workers of the visited farms were found. No cases of the disease caused by this zoonotic agent were documented in the departments of Antioquia, Boyacá and Cundinamarca.

Management of latent Mycobacterium tuberculosis infection: WHO guidelines for low tuberculosis burden countries.

Science.gov (United States)

Getahun, Haileyesus; Matteelli, Alberto; Abubakar, Ibrahim; Aziz, Mohamed Abdel; Baddeley, Annabel; Barreira, Draurio; Den Boon, Saskia; Borroto Gutierrez, Susana Marta; Bruchfeld, Judith; Burhan, Erlina; Cavalcante, Solange; Cedillos, Rolando; Chaisson, Richard; Chee, Cynthia Bin-Eng; Chesire, Lucy; Corbett, Elizabeth; Dara, Masoud; Denholm, Justin; de Vries, Gerard; Falzon, Dennis; Ford, Nathan; Gale-Rowe, Margaret; Gilpin, Chris; Girardi, Enrico; Go, Un-Yeong; Govindasamy, Darshini; D Grant, Alison; Grzemska, Malgorzata; Harris, Ross; Horsburgh, C Robert; Ismayilov, Asker; Jaramillo, Ernesto; Kik, Sandra; Kranzer, Katharina; Lienhardt, Christian; LoBue, Philip; Lönnroth, Knut; Marks, Guy; Menzies, Dick; Migliori, Giovanni Battista; Mosca, Davide; Mukadi, Ya Diul; Mwinga, Alwyn; Nelson, Lisa; Nishikiori, Nobuyuki; Oordt-Speets, Anouk; Rangaka, Molebogeng Xheedha; Reis, Andreas; Rotz, Lisa; Sandgren, Andreas; Sañé Schepisi, Monica; Schünemann, Holger J; Sharma, Surender Kumar; Sotgiu, Giovanni; Stagg, Helen R; Sterling, Timothy R; Tayeb, Tamara; Uplekar, Mukund; van der Werf, Marieke J; Vandevelde, Wim; van Kessel, Femke; van't Hoog, Anna; Varma, Jay K; Vezhnina, Natalia; Voniatis, Constantia; Vonk Noordegraaf-Schouten, Marije; Weil, Diana; Weyer, Karin; Wilkinson, Robert John; Yoshiyama, Takashi; Zellweger, Jean Pierre; Raviglione, Mario

2015-12-01

Latent tuberculosis infection (LTBI) is characterised by the presence of immune responses to previously acquired Mycobacterium tuberculosis infection without clinical evidence of active tuberculosis (TB). Here we report evidence-based guidelines from the World Health Organization for a public health approach to the management of LTBI in high risk individuals in countries with high or middle upper income and TB incidence of <100 per 100 000 per year. The guidelines strongly recommend systematic testing and treatment of LTBI in people living with HIV, adult and child contacts of pulmonary TB cases, patients initiating anti-tumour necrosis factor treatment, patients receiving dialysis, patients preparing for organ or haematological transplantation, and patients with silicosis. In prisoners, healthcare workers, immigrants from high TB burden countries, homeless persons and illicit drug users, systematic testing and treatment of LTBI is conditionally recommended, according to TB epidemiology and resource availability. Either commercial interferon-gamma release assays or Mantoux tuberculin skin testing could be used to test for LTBI. Chest radiography should be performed before LTBI treatment to rule out active TB disease. Recommended treatment regimens for LTBI include: 6 or 9 month isoniazid; 12 week rifapentine plus isoniazid; 3-4 month isoniazid plus rifampicin; or 3-4 month rifampicin alone. Copyright ©ERS 2015.

Mycobacterium tuberculosis exploits asparagine to assimilate nitrogen and resist acid stress during infection.

Directory of Open Access Journals (Sweden)

Alexandre Gouzy

2014-02-01

Full Text Available Mycobacterium tuberculosis is an intracellular pathogen. Within macrophages, M. tuberculosis thrives in a specialized membrane-bound vacuole, the phagosome, whose pH is slightly acidic, and where access to nutrients is limited. Understanding how the bacillus extracts and incorporates nutrients from its host may help develop novel strategies to combat tuberculosis. Here we show that M. tuberculosis employs the asparagine transporter AnsP2 and the secreted asparaginase AnsA to assimilate nitrogen and resist acid stress through asparagine hydrolysis and ammonia release. While the role of AnsP2 is partially spared by yet to be identified transporter(s, that of AnsA is crucial in both phagosome acidification arrest and intracellular replication, as an M. tuberculosis mutant lacking this asparaginase is ultimately attenuated in macrophages and in mice. Our study provides yet another example of the intimate link between physiology and virulence in the tubercle bacillus, and identifies a novel pathway to be targeted for therapeutic purposes.

Usefulness of the secondary probe pTBN12 in DNA fingerprinting of Mycobacterium tuberculosis.

OpenAIRE

Chaves, F; Yang, Z; el Hajj, H; Alonso, M; Burman, W J; Eisenach, K D; Dronda, F; Bates, J H; Cave, M D

1996-01-01

A comparison was made between DNA fingerprints of Mycobacterium tuberculosis produced with the insertion sequence IS6110 and those produced with the polymorphic GC-rich repetitive sequence contained in the plasmid pTBN12. A total of 302 M. tuberculosis isolates from the prison system in Madrid, Spain, and the Denver Public Health Department (Denver, Colo.) were analyzed with the two probes. Both probes identified the same isolates in the same clusters when the fingerprints had six or more cop...

Mycobacterium tuberculosis, but not vaccine BCG, specifically upregulates matrix metalloproteinase-1.

Science.gov (United States)

Elkington, Paul T G; Nuttall, Robert K; Boyle, Joseph J; O'Kane, Cecilia M; Horncastle, Donna E; Edwards, Dylan R; Friedland, Jon S

2005-12-15

Pulmonary cavitation is fundamental to the global success of Mycobacterium tuberculosis. However, the mechanisms of this lung destruction are poorly understood. The biochemistry of lung matrix predicts matrix metalloproteinase (MMP) involvement in immunopathology. We investigated gene expression of all MMPs, proteins with a disintegrin and metalloproteinase domain, and tissue inhibitors of metalloproteinases in M. tuberculosis-infected human macrophages by real-time polymerase chain reaction. MMP secretion was measured by zymography and Western analysis, and expression in patients with pulmonary tuberculosis was localized by immunohistochemistry. MMP-1 and MMP-7 gene expression and secretion are potently upregulated by M. tuberculosis, and no increase in tissue inhibitor of metalloproteinase expression occurs to oppose their activity. Dexamethasone completely suppresses MMP-1 but not MMP-7 gene expression and secretion. In patients with active tuberculosis, macrophages express MMP-1 and MMP-7 adjacent to areas of tissue destruction. MMP-1 but not MMP-7 expression and secretion are relatively M. tuberculosis specific, are not upregulated by tuberculosis-associated cytokines, and are prostaglandin dependent. In contrast, the vaccine M. bovis bacillus Calmette-Guérin (BCG) does not stimulate MMP-1 secretion from human macrophages, although M. tuberculosis and BCG do upregulate MMP-7 equally. BCG-infected macrophages secrete reduced prostaglandin E2 concentrations compared with M. tuberculosis-infected macrophages, and prostaglandin pathway supplementation augments MMP-1 secretion from BCG-infected cells. M. tuberculosis specifically upregulates MMP-1 in a cellular model of human infection and in patients with tuberculosis. In contrast, vaccine BCG, which does not cause lung cavitation, does not upregulate prostaglandin E2-dependent MMP-1 secretion.

PREVALÊNCIA DA Mycobacterium tuberculosis NO COMPLEXO PRISIONAL DO MUNICÍPIO DE ITAPERUNA, RJ

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Francislene FERREIRA SILVA

2015-12-01

Full Text Available A presença da tuberculose em sistemas prisionais é descrito como uma ameaça a saúde pública. O presente estudo objetivou a determinar a prevalência da Mycobacterium tuberculosis no sistema prisional Diomedes Vinhosa Muniz em Itaperuna, Rio de Janeiro. O estudo foi submetido e aprovado pelo comitê de ética em pesquisa da Faculdade Redentor em Itaperuna e autorizado pela Secretaria de Estado de Administração Penitenciária (SEAP do estado do Rio de Janeiro. Participaram da pesquisa 10% do total de detentos condenados, estes assinaram um termo de consentimento livre e esclarecido, preencheram um questionário sócio econômico e epidemiológico em seguida foi coletado o material biológico para realização da baciloscopia. Os resultados indicaram que 69% dos detentos analisados não completaram o ensino fundamental, 30% é originário de comunidades faveladas, 55% possuem uma renda mensal de até 2 salários mínimos, 79% consumiam tabaco, 64% relataram que tiveram tosse por mais de 3 semanas, 65% declaram a maconha como a droga ilícita preferencial e 51% usavam cocaína, 3% declararam se portador do HIV, 42% tiveram contato com indivíduos com a tuberculose e 3% dos detentos haviam a presença da Mycobacterium tuberculosis. Logo, conclui-se que no sistema prisional Diomedes Vinhosa Muniz houve uma baixa prevalência da M.ycobacterium tuberculosis.

Tuberculosis transmission of predominant genotypes of Mycobacterium tuberculosis in northern suburbs of Buenos Aires city region.

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Morcillo, N; Zumarraga, M; Imperiale, B; Di Giulio, B; Chirico, C; Kuriger, A; Alito, A; Kremer, K; Cataldi, A

2007-01-01

In 2003, the incidence of tuberculosis in Argentina showed an increase compared to 2002. The severe national crisis at the end of the 90s has probably strongly contributed to this situation. The goal of this work was to estimate the extent of the spread of the most predominant Mycobacterium tuberculosis strains and to assess the spread of predominant M. tuberculosis clusters as determined by spoligotyping and IS6110 RFLP. The study involved 590 pulmonary, smear-positive TB cases receiving medical attention at health centers and hospitals in Northern Buenos Aires (NBA) suburbs, from October 2001 to December 2002. From a total of 208 clinical isolates belonging to 6 major clusters, 63 (30.2%) isolates had identical spoligotyping and IS6110 RFLP pattern. Only 22.2% were shown to have epidemiological connections with another member of their respective cluster. In these major clusters, 30.2% of the 208 TB cases studied by both molecular techniques and contact tracing could be convincingly attributable to a recently acquired infection. This knowledge may be useful to assess the clonal distribution of predominant M. tuberculosis clusters in Argentina, which may make an impact on TB control strategies.

Population Genomics of Mycobacterium tuberculosis in Ethiopia Contradicts the Virgin Soil Hypothesis for Human Tuberculosis in Sub-Saharan Africa.

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Comas, Iñaki; Hailu, Elena; Kiros, Teklu; Bekele, Shiferaw; Mekonnen, Wondale; Gumi, Balako; Tschopp, Rea; Ameni, Gobena; Hewinson, R Glyn; Robertson, Brian D; Goig, Galo A; Stucki, David; Gagneux, Sebastien; Aseffa, Abraham; Young, Douglas; Berg, Stefan

2015-12-21

Colonial medical reports claimed that tuberculosis (TB) was largely unknown in Africa prior to European contact, providing a "virgin soil" for spread of TB in highly susceptible populations previously unexposed to the disease [1, 2]. This is in direct contrast to recent phylogenetic models which support an African origin for TB [3-6]. To address this apparent contradiction, we performed a broad genomic sampling of Mycobacterium tuberculosis in Ethiopia. All members of the M. tuberculosis complex (MTBC) arose from clonal expansion of a single common ancestor [7] with a proposed origin in East Africa [3, 4, 8]. Consistent with this proposal, MTBC lineage 7 is almost exclusively found in that region [9-11]. Although a detailed medical history of Ethiopia supports the view that TB was rare until the 20(th) century [12], over the last century Ethiopia has become a high-burden TB country [13]. Our results provide further support for an African origin for TB, with some genotypes already present on the continent well before European contact. Phylogenetic analyses reveal a pattern of serial introductions of multiple genotypes into Ethiopia in association with human migration and trade. In place of a "virgin soil" fostering the spread of TB in a previously naive population, we propose that increased TB mortality in Africa was driven by the introduction of European strains of M. tuberculosis alongside expansion of selected indigenous strains having biological characteristics that carry a fitness benefit in the urbanized settings of post-colonial Africa. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Use of the VNTR typing technique to determine the origin of Mycobacterium tuberculosis strains isolated from Filipino patients in Korea.

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Lee, Jihye; Tupasi, Thelma E; Park, Young Kil

2014-05-01

With increasing international interchange of personnel, international monitoring is necessary to decrease tuberculosis incidence in the world. This study aims to develop a new tool to determine origin of Mycobacterium tuberculosis strains isolated from Filipino patients living in Korea. Thirty-two variable number tandem repeat (VNTR) loci were used for discrimination of 50 Filipino M. tuberculosis strains isolated in the Philippines, 317 Korean strains isolated in Korea, and 8 Filipino strains isolated in Korea. We found that the VNTR loci 0580, 0960, 2531, 2687, 2996, 0802, 2461, 2163a, 4052, 0424, 1955, 2074, 2347, 2401, 3171, 3690, 2372, 3232, and 4156 had different mode among copy numbers or exclusively distinct copy number in VNTR typing between Filipino and Korean M. tuberculosis strains. When these differences of the VNTR loci were applied to 8 Filipino M. tuberculosis strains isolated in Korea, 6 of them revealed Filipino type while 2 of them had Korean type. Using the differences of mode or repeated number of VNTR loci were very useful in distinguishing the Filipino strain from Korean strain.

Human tuberculosis caused by Mycobacterium bovis: a retrospective comparison with Mycobacterium tuberculosis in a Mexican tertiary care centre, 2000–2015

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Pedro Torres-Gonzalez

2016-11-01

Full Text Available Abstract Background Human tuberculosis caused by Mycobacterium bovis is believed to be frequent in developing countries. Transmission is usually through ingestion of unpasteurized dairy products, although airborne contagion is possible. Disease caused by M. tuberculosis or M. bovis is clinically indistinguishable from each other. The aim of this study was to determine the factors associated with M. bovis disease. Methods Retrospective analysis of all culture-positive cases of M. bovis and M. tuberculosis from 2000 to 2015, in a Mexican tertiary-care centre. Sociodemographic, clinical, and radiographic data from medical records were compared. Disease site was classified as pulmonary, extrapulmonary, or pulmonary and extrapulmonary, based on cultures. Results We evaluated 533 cases, 372 (69.7 % of which were caused by M. tuberculosis and 161 (30.2 % by M. bovis. Characteristics associated with M. bovis disease were: younger age (aOR 0.97, 95 % CI 0.95–0.98, glucocorticoid use (aOR 2.27, 95 % CI 1.42–3.63, and extrapulmonary disease (aOR 1.80, 95 % CI 1.21–2.69. M. tuberculosis was associated with lower socioeconomic status (aOR 0.52, 95 % CI 0.28–0.97. When we analysed only pulmonary cases, younger age (aOR 0.97, 95 % CI 0.96–0.99, glucocorticoid use (aOR 2.41, 95 % CI 1.30–4.46, and smoking (aOR 1.94, CI 95 % 1.15–3.27 were associated with M. bovis. Both groups showed similar proportions of direct microscopy smear results (respiratory samples and chest X-ray cavitations. Conclusions Younger age, glucocorticoid use, and extrapulmonary disease were associated with M. bovis as the causative agent of tuberculosis in a group of patients from a tertiary care centre in a country where bovine tuberculosis is endemic. Further studies must be conducted in the general population to determine pathogen-specific associated factors and outcomes.

Structures of Mycobacterium Tuberculosis Folylpolyglutamate Synthase Complexed With ADP And AMPPCD

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Young, P.G.; Smith, C.A.; Metcalf, P.; Baker, E.N.

2009-05-28

Folate derivatives are essential vitamins for cell growth and replication, primarily because of their central role in reactions of one-carbon metabolism. Folates require polyglutamation to be efficiently retained within the cell and folate-dependent enzymes have a higher affinity for the polyglutamylated forms of this cofactor. Polyglutamylation is dependent on the enzyme folylpolyglutamate synthetase (FPGS), which catalyzes the sequential addition of several glutamates to folate. FPGS is essential for the growth and survival of important bacterial species, including Mycobacterium tuberculosis, and is a potential drug target. Here, the crystal structures of M. tuberculosis FPGS in complex with ADP and AMPPCP are reported at 2.0 and 2.3 angstroms resolution, respectively. The structures reveal a deeply buried nucleotide-binding site, as in the Escherichia coli and Lactobacillus casei FPGS structures, and a long extended groove for the binding of folate substrates. Differences from the E. coli and L. casei FPGS structures are seen in the binding of a key divalent cation, the carbamylation state of an essential lysine side chain and the adoption of an 'open' position by the active-site beta5-alpha6 loop. These changes point to coordinated events that are associated with dihydropteroate/folate binding and the catalysis of the new amide bond with an incoming glutamate residue.

Studies on mycobacterium tuberculosis sensitivity test by using the method of rapid radiometry with appendixes of clinical results

International Nuclear Information System (INIS)

Yang Yongqing; Jiang Yimin; Lu Wendong; Zhu Rongen

1987-01-01

Three standard strains of mycobacterium tuberculosis (H 37 RV-fully sensitive, SM-R1000 μg/ml, RFP-R 100 μg/ml) were tested with 10 concentration of 5 antitubercular agent, INH, SM, PAS, RFP and EB. 114 isolates of mycobacterium tuberculosis taken from patients were tested with INH, PAS, SM and RFP. They were agreed with the results of standard Lowenstein-Jensen method in 81.7%. 82% of the isolate test were completed within 5 days. The method may be used in routine clinical work. The liquid media prepared by authors do not require human serum albumin and it is less expensive and readily available

Genetic diversity and distribution of Mycobacterium tuberculosis genotypes in Limpopo, South Africa.

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Maguga-Phasha, N T C; Munyai, N S; Mashinya, F; Makgatho, M E; Mbajiorgu, E F

2017-12-12

Tuberculosis remains a major health problem and knowledge of the diversity of Mycobacterium tuberculosis strains in specific geographical regions can contribute to the control of the disease. This study describes the genetic profile of M. tuberculosis in five districts of Limpopo Province. A total 487 isolates were collected from the National Health Laboratory Services from all regions/districts of Limpopo Province. Only 215 isolates were confirmed to be M. tuberculosis by Bactec Mycobacterium Growth Indicator Tube 960® and Rhodamine-Auramine staining. Isolates were subcultured on Löwenstein-Jensen medium agar slants to validate purity. They were spoligotyped and data analysed using the international spoligotyping database 4 (SpolDB4). Of the 215 isolates, 134 (62.3%) were genotyped into 21 genotype families while 81 (37.7%) were orphans. The 81 orphans were further subjected to resolution employing SpolDB3/RIM. Overall, the study revealed a high diversity of strains of 32 predominantly the non-Beijing lineages: the LAM- LAM3 (9.8%), LAM9 (4.7%) and LAM11- ZWE (3.3%), the T-T1(15.0%), T2 (0.9%), T2-T3 (1.4%), the CAS-CAS1-Delhi 5 (1.9%) and CAS1-KILI (1.4%) the MANU2 (1.4%), U (0.5%), X-X1(1.4%), X3 (1.9%), S (9.8%), CAS (1.4%), LAM7(0.9%), T3(0.5%), LAM8(4.7%), T4(1.4%), X2(0.4%), AI5(1.9%), LAM1(0.5%), FAMILY33 (1.9%), EAI4(1.4%), M. microti (1.9%). The Beijing and Beijing-like families were (14.9%) and (0.9%), respectively. A total of 28(13%) clusters and 77(36%) unique cases were identified. Beijing strain (SIT 1) formed the biggest cluster constituting 14%, followed by LAM3 (SIT 33), T1 (SIT 53) and LAM4 (SIT 811) with 7%, 5.1% and 2.8%, respectively. The Beijing family was the only genotype found in all the five districts and was predominant in Mopani (18.8%), Sekhukhune (23.7%) and Vhembe (23.3%). Dominant genotypes in Capricorn and Waterberg were LAM3 (11.9%) and T1 (13.3%), respectively. A wide diversity of lineages was demonstrated at district level. A

The endothelin system has a significant role in the pathogenesis and progression of Mycobacterium tuberculosis infection.

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Correa, Andre F; Bailão, Alexandre M; Bastos, Izabela M D; Orme, Ian M; Soares, Célia M A; Kipnis, Andre; Santana, Jaime M; Junqueira-Kipnis, Ana Paula

2014-12-01

Tuberculosis (TB) remains a major global health problem, and although multiple studies have addressed the relationship between Mycobacterium tuberculosis and the host on an immunological level, few studies have addressed the impact of host physiological responses. Proteases produced by bacteria have been associated with important alterations in the host tissues, and a limited number of these enzymes have been characterized in mycobacterial species. M. tuberculosis produces a protease called Zmp1, which appears to be associated with virulence and has a putative action as an endothelin-converting enzyme. Endothelins are a family of vasoactive peptides, of which 3 distinct isoforms exist, and endothelin 1 (ET-1) is the most abundant and the best-characterized isoform. The aim of this work was to characterize the Zmp1 protease and evaluate its role in pathogenicity. Here, we have shown that M. tuberculosis produces and secretes an enzyme with ET-1 cleavage activity. These data demonstrate a possible role of Zmp1 for mycobacterium-host interactions and highlights its potential as a drug target. Moreover, the results suggest that endothelin pathways have a role in the pathogenesis of M. tuberculosis infections, and ETA or ETB receptor signaling can modulate the host response to the infection. We hypothesize that a balance between Zmp1 control of ET-1 levels and ETA/ETB signaling can allow M. tuberculosis adaptation and survival in the lung tissues. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

The 1.25 Å resolution structure of phosphoribosyl-ATP pyrophosphohydrolase from Mycobacterium tuberculosis

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Javid-Majd, Farah; Yang, Dong [Department of Biochemistry and Biophysics, Texas A& M University, College Station, Texas 77843-2128 (United States); Ioerger, Thomas R. [Department of Computer Science, Texas A& M University, College Station, Texas 77843-2128 (United States); Sacchettini, James C., E-mail: sacchett@tamu.edu [Department of Biochemistry and Biophysics, Texas A& M University, College Station, Texas 77843-2128 (United States)

2008-06-01

The crystal structure of M. tuberculosis phosphoribosyl-ATP pyrophosphohydrolase, the second enzyme in the histidine-biosynthetic pathway, is presented. The structural and inferred functional relationships between M. tuberculosis phosphoribosyl-ATP pyrophosphohydrolase and other members of the nucleoside-triphosphate pyrophosphatase-fold family are described. Phosphoribosyl-ATP pyrophosphohydrolase is the second enzyme in the histidine-biosynthetic pathway, irreversibly hydrolyzing phosphoribosyl-ATP to phosphoribosyl-AMP and pyrophosphate. It is encoded by the hisE gene, which is present as a separate gene in many bacteria and archaea but is fused to hisI in other bacteria, fungi and plants. Because of its essentiality for growth in vitro, HisE is a potential drug target for tuberculosis. The crystal structures of two native (uncomplexed) forms of HisE from Mycobacterium tuberculosis have been determined to resolutions of 1.25 and 1.79 Å. The structure of the apoenzyme reveals that the protein is composed of five α-helices with connecting loops and is a member of the α-helical nucleoside-triphosphate pyrophosphatase superfamily. The biological unit of the protein is a homodimer, with an active site on each subunit composed of residues exclusively from that subunit. A comparison with the Campylobacter jejuni dUTPase active site allowed the identification of putative metal- and substrate-binding sites in HisE, including four conserved glutamate and glutamine residues in the sequence that are consistent with a motif for pyrophosphohydrolase activity. However, significant differences between family members are observed in the loop region between α-helices H1 and H3. The crystal structure of M. tuberculosis HisE provides insights into possible mechanisms of substrate binding and the diversity of the nucleoside-triphosphate pyrophosphatase superfamily.

Kinetics and inhibition of nicotinamidase from Mycobacterium tuberculosis.

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Seiner, Derrick R; Hegde, Subray S; Blanchard, John S

2010-11-09

Nicotinamidase/pyrazinamidase (PncA) is involved in the NAD+ salvage pathway of Mycobacterium tuberculosis and other bacteria. In addition to hydrolyzing nicotinamide into nicotinic acid, PncA also hydrolyzes the prodrug pyrazinamide to generate the active form of the drug, pyrazinoic acid, which is an essential component of the multidrug treatment of TB. A coupled enzymatic activity assay has been developed for PncA that allows for the spectroscopic observation of enzyme activity. The enzyme activity was essentially pH-independent under the conditions tested; however, the measurement of the pH dependence of iodoacetamide alkylation revealed a pK value of 6.6 for the active site cysteine. Solvent deuterium kinetic isotope effects revealed an inverse value for kcat of 0.64, reconfirming the involvement of a thiol group in the mechanism. A mechanism is proposed for PncA catalysis that is similar to the mechanisms proposed for members of the nitrilase superfamily, in which nucleophilic attack by the active site cysteine generates a tetrahedral intermediate that collapses with the loss of ammonia and subsequent hydrolysis of the thioester bond by water completes the cycle. An inhibitor screen identified the competitive inhibitor 3-pyridine carboxaldehyde with a Ki of 290 nM. Additionally, pyrazinecarbonitrile was found to be an irreversible inactivator of PncA, with a kinact/KI of 975 M(−1) s(−1).

Crystal structures of the transpeptidase domain of the Mycobacterium tuberculosis penicillin-binding protein PonA1 reveal potential mechanisms of antibiotic resistance.

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Filippova, Ekaterina V; Kieser, Karen J; Luan, Chi-Hao; Wawrzak, Zdzislaw; Kiryukhina, Olga; Rubin, Eric J; Anderson, Wayne F

2016-06-01

Mycobacterium tuberculosis is a human respiratory pathogen that causes the deadly disease tuberculosis. The rapid global spread of antibiotic-resistant M. tuberculosis makes tuberculosis infections difficult to treat. To overcome this problem new effective antimicrobial strategies are urgently needed. One promising target for new therapeutic approaches is PonA1, a class A penicillin-binding protein, which is required for maintaining physiological cell wall synthesis and cell shape during growth in mycobacteria. Here, crystal structures of the transpeptidase domain, the enzymatic domain responsible for penicillin binding, of PonA1 from M. tuberculosis in the inhibitor-free form and in complex with penicillin V are reported. We used site-directed mutagenesis, antibiotic profiling experiments, and fluorescence thermal shift assays to measure PonA1's sensitivity to different classes of β-lactams. Structural comparison of the PonA1 apo-form and the antibiotic-bound form shows that binding of penicillin V induces conformational changes in the position of the loop β4'-α3 surrounding the penicillin-binding site. We have also found that binding of different antibiotics including penicillin V positively impacts protein stability, while other tested β-lactams such as clavulanate or meropenem resulted in destabilization of PonA1. Our antibiotic profiling experiments indicate that the transpeptidase activity of PonA1 in both M. tuberculosis and M. smegmatis mediates tolerance to specific cell wall-targeting antibiotics, particularly to penicillin V and meropenem. Because M. tuberculosis is an important human pathogen, these structural data provide a template to design novel transpeptidase inhibitors to treat tuberculosis infections. Structural data are available in the PDB database under the accession numbers 5CRF and 5CXW. © 2016 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

Diversity of DNA fingerprints of Mycobacterium tuberculosis isolates in the United States.

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Yang, Z; Barnes, P F; Chaves, F; Eisenach, K D; Weis, S E; Bates, J H; Cave, M D

1998-04-01

To investigate the diversity of IS6110 fingerprints of Mycobacterium tuberculosis isolates in the United States and to determine if matching IS6110 fingerprints represent recent interstate tuberculosis transmission, we performed restriction fragment length polymorphism analysis of M. tuberculosis isolates from 1,326 patients in three geographically separated states. Seven hundred ninety-five different IS6110 fingerprint patterns were generated, and pattern diversity was similar in each state. Ninety-six percent of the fingerprint patterns were observed in only one state, demonstrating that most IS6110 fingerprint patterns are confined to a single geographic location. Of the IS6110 fingerprint patterns that were shared by isolates from more than one state, most isolates with 1 to 5 IS6110 copies were separable by pTBN12 fingerprinting whereas those with > 15 copies were not. One high-copy-number M. tuberculosis strain had identical IS6110 and pTBN12 fingerprints and included 57 isolates from three states. Epidemiological data demonstrated significant recent transmission of tuberculosis within each city but not among the states. This suggests that identical fingerprints of isolates from geographically separate locations most likely reflect interstate tuberculosis transmission in the past, with subsequent intrastate spread of disease. Further evaluation of M. tuberculosis strains that cause outbreaks in different geographic locations will provide insight into the epidemiological and bacteriological factors that facilitate the spread of tuberculosis.

Cutaneous squamous cell carcinoma in lupus vulgaris caused by drug resistant Mycobacterium tuberculosis

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Muthu S Kumaran

2017-01-01

Full Text Available Tuberculosis (TB is still a major public health problem in the world, with many factors contributing to this burden, including poor living conditions, overcrowding, poverty, malnutrition, illiteracy, and rapid spread of human immunodeficiency virus infection. Cutaneous tuberculosis is a less common form of extrapulmonary tuberculosis, and in this paucibacillary form the diagnosis depends on histopathology, tuberculin positivity, and response to treatment. The diagnosis is even more difficult in cases with drug resistant Mycobacterium tuberculosis due to lack of awareness and lack of facilities to diagnose drug resistant tuberculosis. In this article, we describe an unusual case of multidrug resistant lupus vulgaris (LV, in a 34-year-old male who responded to anti-tubercular treatment (ATT initially, but developed recurrent disease which failed to respond to standard four-drug ATT; subsequently, tissue culture showed growth of multidrug resistant M. tuberculosis. Subsequently, he also developed cutaneous squamous cell carcinoma. This article aims to exemplify a grave complication that can occur in long-standing case of LV, the limitations faced by clinicians in developing countries where tuberculosis is endemic, and classical methods of proving drug resistance are generally unavailable or fail.

Anti-Mycobacterium tuberculosis activity of fungus Phomopsis stipata

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Karina Andrade de Prince

2012-03-01

Full Text Available Our purpose was to determine the anti-Mycobacterium tuberculosis activity of the metabolites produced by the endophitic fungus Phomopsis stipata (Lib. B. Sutton, (Diaporthaceae, cultivated in different media. The antimycobacterial activity was assessed through the Resazurin Microtiter Assay (REMA and the cytotoxicity test performed on macrophage cell line. The extracts derived from fungi grown on Corn Medium and Potato Dextrose Broth presented the smallest values of Minimum Inhibitory Concentration (MIC and low cytotoxicity, which implies a high selectivity index. This is the first report on the chemical composition and antitubercular activity of metabolites of P. stipata, as well as the influence of culture medium on these properties.

Structural and Functional Aspects of the Sensor Histidine Kinase PrrB from Mycobacterium tuberculosis

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Nowak, E.; Panjikar, S.; Morth, J.P.

2006-01-01

We describe the solution structures of two- and three-domain constructs of the sensor histidine kinase PrrB from Mycobacterium tuberculosis, which allow us to locate the HAMP linker relative to the ATP binding and dimerization domains. We show that the three-domain construct is active both...

Genotyping and drug resistance patterns of Mycobacterium tuberculosis strains observed in a tuberculosis high-burden municipality in Northeast, Brazil

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Roberta dos Santos Silva Luiz

2013-06-01

Full Text Available OBJECTIVES: This study has used a combination of clinical information, spoligotyping, and georeferencing system to elucidate the genetic diversity of the Mycobacterium tuberculosis isolates circulating in a TB-prevalent municipality of Northeast Brazil. METHODS: A total of 115 M. tuberculosis strains were isolated from pulmonary tuberculosis patients from January 2007 to March 2008 in Fortaleza. Drug susceptibility and spoligotyping assays were performed and place of residence of the patients were georeferenced. RESULTS: Of the M. tuberculosis strains studied, 51 (44.3% isolates were resistant to at least one drug (R-TB and 64 (55.7% were sensitive to all the drugs tested (S-TB. A high frequency of resistance was found in previously treated cases (84% and among new cases (16%; p < 0.001. a total of 74 (64% isolates were grouped into 22 spoligotyped lineages, while 41 (36% isolates were identified as new. among the predominant genotypes, 33% were latim american mediterranean (lam, 12% haarlem (h, and 5% u. there was no association of geographic distribution of rt-tb patients as compared to the controls and also the geographic location to the spoligotype patterns. the geospatial analysis revealed that 24 (23% patients (hot spot zones either shared the same residence or lived in a close neighborhood of a case. among these concentration zones, the patients lived in the same residence and shared a common genotype pattern and resistance pattern. DISCUSSION: it was observed that the spoligopatterns family distribution was similar to that reported for south america, prevailing the lam and h lineages. a high rate-case among the resistant TB group occurs as a result of transmitted and acquired resistance. A more effective surveillance program is needed in order to succeed in reducing tuberculosis in Northeast Brazil.

Genotyping and drug resistance patterns of Mycobacterium tuberculosis strains observed in a tuberculosis high-burden municipality in Northeast, Brazil

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Roberta dos Santos Silva Luiz

Full Text Available OBJECTIVES: This study has used a combination of clinical information, spoligotyping, and georeferencing system to elucidate the genetic diversity of the Mycobacterium tuberculosis isolates circulating in a TB-prevalent municipality of Northeast Brazil. METHODS: A total of 115 M. tuberculosis strains were isolated from pulmonary tuberculosis patients from January 2007 to March 2008 in Fortaleza. Drug susceptibility and spoligotyping assays were performed and place of residence of the patients were georeferenced. RESULTS: Of the M. tuberculosis strains studied, 51 (44.3% isolates were resistant to at least one drug (R-TB and 64 (55.7% were sensitive to all the drugs tested (S-TB. A high frequency of resistance was found in previously treated cases (84% and among new cases (16%; p < 0.001. a total of 74 (64% isolates were grouped into 22 spoligotyped lineages, while 41 (36% isolates were identified as new. among the predominant genotypes, 33% were latim american mediterranean (lam, 12% haarlem (h, and 5% u. there was no association of geographic distribution of rt-tb patients as compared to the controls and also the geographic location to the spoligotype patterns. the geospatial analysis revealed that 24 (23% patients (hot spot zones either shared the same residence or lived in a close neighborhood of a case. among these concentration zones, the patients lived in the same residence and shared a common genotype pattern and resistance pattern. DISCUSSION: it was observed that the spoligopatterns family distribution was similar to that reported for south america, prevailing the lam and h lineages. a high rate-case among the resistant TB group occurs as a result of transmitted and acquired resistance. A more effective surveillance program is needed in order to succeed in reducing tuberculosis in Northeast Brazil.

Supplementary Material for: Mycobacterium tuberculosis whole genome sequencing and protein structure modelling provides insights into anti-tuberculosis drug resistance

KAUST Repository

Phelan, Jody

2016-01-01

Abstract Background Combating the spread of drug resistant tuberculosis is a global health priority. Whole genome association studies are being applied to identify genetic determinants of resistance to anti-tuberculosis drugs. Protein structure and interaction modelling are used to understand the functional effects of putative mutations and provide insight into the molecular mechanisms leading to resistance. Methods To investigate the potential utility of these approaches, we analysed the genomes of 144 Mycobacterium tuberculosis clinical isolates from The Special Programme for Research and Training in Tropical Diseases (TDR) collection sourced from 20 countries in four continents. A genome-wide approach was applied to 127 isolates to identify polymorphisms associated with minimum inhibitory concentrations for first-line anti-tuberculosis drugs. In addition, the effect of identified candidate mutations on protein stability and interactions was assessed quantitatively with well-established computational methods. Results The analysis revealed that mutations in the genes rpoB (rifampicin), katG (isoniazid), inhA-promoter (isoniazid), rpsL (streptomycin) and embB (ethambutol) were responsible for the majority of resistance observed. A subset of the mutations identified in rpoB and katG were predicted to affect protein stability. Further, a strong direct correlation was observed between the minimum inhibitory concentration values and the distance of the mutated residues in the three-dimensional structures of rpoB and katG to their respective drugs binding sites. Conclusions Using the TDR resource, we demonstrate the usefulness of whole genome association and convergent evolution approaches to detect known and potentially novel mutations associated with drug resistance. Further, protein structural modelling could provide a means of predicting the impact of polymorphisms on drug efficacy in the absence of phenotypic data. These approaches could ultimately lead to novel

T-cell recognition of Mycobacterium tuberculosis culture filtrate fractions in tuberculosis patients and their household contacts

DEFF Research Database (Denmark)

Demissie, A; Ravn, P; Olobo, J

1999-01-01

We examined the immune responses of patients with active pulmonary tuberculosis (TB) and their healthy household contacts to short-term culture filtrate (ST-CF) of Mycobacterium tuberculosis or molecular mass fractions derived from it. Our goal was to identify fractions strongly recognized...... antigens and immune responses were determined. Household contacts produced significantly higher levels of gamma interferon (IFN-gamma) than the TB patients in response to antigens present in ST-CF and the 10 narrow-molecular-mass fractions. A similar difference in leukocyte proliferative responses...... to the antigens between the two groups was also found. In general, while all fractions stimulated immune responses, the highest activity was seen with the low-molecular-mass fractions, which include well-defined TB antigens such as ESAT-6. Leukocytes from contacts of TB patients with severe disease produced...

T-cell recognition of Mycobacterium tuberculosis culture filtrate fractions in tuberculosis patients and their household contacts

DEFF Research Database (Denmark)

Demissie, A; Ravn, P; Olobo, J

1999-01-01

We examined the immune responses of patients with active pulmonary tuberculosis (TB) and their healthy household contacts to short-term culture filtrate (ST-CF) of Mycobacterium tuberculosis or molecular mass fractions derived from it. Our goal was to identify fractions strongly recognized...... to the antigens between the two groups was also found. In general, while all fractions stimulated immune responses, the highest activity was seen with the low-molecular-mass fractions, which include well-defined TB antigens such as ESAT-6. Leukocytes from contacts of TB patients with severe disease produced...... higher levels of antigen-specific IFN-gamma than those from contacts of patients with minimal disease. Both groups of contacts exhibited higher cell-mediated responses than the patients themselves. The enhanced immune response of healthy contacts, especially those of patients with severe disease...

Improved method for testing susceptibility of Mycobacterium tuberculosis to pyrazinamide.

OpenAIRE

Butler, W R; Kilburn, J O

1982-01-01

The acid medium required to test susceptibility of Mycobacterium tuberculosis to pyrazinamide (PZA) is a major problem in obtaining reliable test results. Satisfactory growth is usually obtained on Middlebrook and Cohn 7H10 medium at pH 5.5 if albumin-dextrose-catalase (ADC) supplement rather than oleic acid-albumin-dextrose-catalase is used; however, some lots of ADC supplement still fail to support growth at this low pH. A rapid turbidimetric test was developed to determine the growth-suppo...

Diminished Adherence and/or Ingestion of Virulent Mycobacterium tuberculosis by Monocyte-Derived Macrophages from Patients with Tuberculosis

Science.gov (United States)

Zabaleta, J.; Arias, M.; Maya, J. R.; García, L. F.

1998-01-01

The interaction between the macrophage and Mycobacterium tuberculosis is mediated by a variety of macrophage membrane-associated proteins. Complement receptors have been implicated in the adherence of M. tuberculosis to macrophages. In the present work, the adherence and/or ingestion of M. tuberculosis H37Rv to human monocyte-derived macrophages (MDM) from patients with tuberculosis (TB) and healthy controls was measured by microscopical examination, [3H]uracil incorporation, and CFU. The adherence and/or ingestion was enhanced by fresh serum and inhibited by heat inactivation, EDTA treatment, and anti-CR1 and anti-CR3 antibodies. Comparison of MDM from TB patients and healthy controls showed that the former exhibited a significantly decreased capacity to adhere and/or ingest M. tuberculosis, as determined by the number of CFU and 3H incorporation. The expression of CR1 (CD35) and CR3 (CD11b/CD18) on MDM from TB patients and healthy controls, as determined by flow cytometry, did not show significant differences. These results suggest that the lower ingestion of M. tuberculosis by MDM from TB patients is not due to defects in complement receptors, and therefore, there might be other molecules involved in the adherence and/or ingestion process that render MDM from TB patients ingest less mycobacteria than those from healthy controls. PMID:9729537

First worldwide proficiency study on variable-number tandem-repeat typing of Mycobacterium tuberculosis complex strains.

NARCIS (Netherlands)

Beer, J.L. de; Kremer, K.; Kodmon, C.; Supply, P.; Soolingen, D. van

2012-01-01

Although variable-number tandem-repeat (VNTR) typing has gained recognition as the new standard for the DNA fingerprinting of Mycobacterium tuberculosis complex (MTBC) isolates, external quality control programs have not yet been developed. Therefore, we organized the first multicenter proficiency

Structure of Rv1848 (UreA), the Mycobacterium tuberculosis urease γ subunit

International Nuclear Information System (INIS)

Habel, Jeff E.; Bursey, Evan H.; Rho, Beom-Seop; Kim, Chang-Yub; Segelke, Brent W.; Rupp, Bernhard; Park, Min S.; Terwilliger, Thomas C.; Hung, Li-Wei

2010-01-01

Crystal and solution structures of Rv1848 protein and their implications in the biological assembly of Mtb urease is presented. The crystal structure of the urease γ subunit (UreA) from Mycobacterium tuberculosis, Rv1848, has been determined at 1.8 Å resolution. The asymmetric unit contains three copies of Rv1848 arranged into a homotrimer that is similar to the UreA trimer in the structure of urease from Klebsiella aerogenes. Small-angle X-ray scattering experiments indicate that the Rv1848 protein also forms trimers in solution. The observed homotrimer and the organization of urease genes within the M. tuberculosis genome suggest that M. tuberculosis urease has the (αβγ) 3 composition observed for other bacterial ureases. The γ subunit may be of primary importance for the formation of the urease quaternary structure

Fluoromycobacteriophages for Rapid, Specific, and Sensitive Antibiotic Susceptibility Testing of Mycobacterium tuberculosis

Science.gov (United States)

Piuri, Mariana; Jacobs, William R.; Hatfull, Graham F.

2009-01-01

Rapid antibiotic susceptibility testing of Mycobacterium tuberculosis is of paramount importance as multiple- and extensively- drug resistant strains of M. tuberculosis emerge and spread. We describe here a virus-based assay in which fluoromycobacteriophages are used to deliver a GFP or ZsYellow fluorescent marker gene to M. tuberculosis, which can then be monitored by fluorescent detection approaches including fluorescent microscopy and flow cytometry. Pre-clinical evaluations show that addition of either Rifampicin or Streptomycin at the time of phage addition obliterates fluorescence in susceptible cells but not in isogenic resistant bacteria enabling drug sensitivity determination in less than 24 hours. Detection requires no substrate addition, fewer than 100 cells can be identified, and resistant bacteria can be detected within mixed populations. Fluorescence withstands fixation by paraformaldehyde providing enhanced biosafety for testing MDR-TB and XDR-TB infections. PMID:19300517

Characterisation of Mycobacterium tuberculosis isolates lacking IS6110 in Viet Nam.

Science.gov (United States)

Huyen, M N T; Tiemersma, E W; Kremer, K; de Haas, P; Lan, N T N; Buu, T N; Sola, C; Cobelens, F G J; van Soolingen, D

2013-11-01

The molecular diagnosis of tuberculosis (TB) in Viet Nam is often based on the detection of insertion sequence (IS) 6110 in Mycobacterium tuberculosis. However, 8-11% of M. tuberculosis strains in South-East Asia do not contain this target and this undermines the validity of these molecular tests. We quantified the frequency of M. tuberculosis strains lacking IS6110 in rural Viet Nam and studied their epidemiological and clinical characteristics. Consecutively diagnosed adult TB patients in rural Southern Viet Nam submitted two sputum samples for culture, IS6110 restriction fragment length polymorphism (RFLP) spoligotyping and 15-loci variable number tandem repeat typing. Polymerase chain reaction (PCR) was performed to confirm the absence of IS6110 elements in strains lacking IS6110 hybridisation in RFLP. Among 2664 TB patient isolates examined, 109 (4.1%) had no IS6110 element. Compared to other strains, these no-copy strains were less often resistant to anti-tuberculosis drugs, particularly to streptomycin (adjusted OR 0.2, 95%CI 0.1-0.5), and showed significant geographic variation. No associations with TB history or demographic factors were found. Strains without the IS6110 target pose a problem in Viet Nam as regards false-negative molecular TB diagnosis in PCR. Compared to other strains circulating in Viet Nam, no-copy strains are more susceptible to anti-tuberculosis drugs.

Total synthesis, stereochemical elucidation and biological evaluation of Ac(2)SGL; a 1,3-methyl branched sulfoglycolipid from Mycobacterium tuberculosis

NARCIS (Netherlands)

Geerdink, Danny; ter Horst, Bjorn; Lepore, Marco; Mori, Lucia; Puzo, Germain; Hirsch, Anna K. H.; Gilleron, Martine; de Libero, Gennaro; Minnaard, Adriaan J.

2012-01-01

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), continues to represent a challenging pathogen causing many deaths. A reason for the persistence of this pathogen is the cell-envelope composition, which consists of long-tailed (glyco) lipids, involved in the modulation of the

Overview of errors in the reference sequence and annotation of Mycobacterium tuberculosis H37Rv, and variation amongst its isolates

KAUST Repository

Kö ser, Claudio U.; Niemann, Stefan; Summers, David K.; Archer, John A.C.

2012-01-01

Since its publication in 1998, the genome sequence of the Mycobacterium tuberculosis H37Rv laboratory strain has acted as the cornerstone for the study of tuberculosis. In this review we address some of the practical aspects that have come to light

LIGAND-BINDING SITES ON THE MYCOBACTERIUM TUBERCULOSIS UREASE

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Lisnyak Yu. V.

2017-10-01

Full Text Available Introduction. Mycobacterium tuberculosis is the causative agent of tuberculosis that remains a serious medical and social health problem. Despite intensive efforts have been made in the past decade, there are no new efficient anti-tuberculosis drugs today, and that need is growing due to the spread of drug-resistant strains of M.tuberculosis. M. tuberculosis urease (MTU, being an important factor of the bacterium viability and virulence, is an attractive target for anti-tuberculosis drugs acting by inhibition of urease activity. However, the commercially available urease inhibitors are toxic and unstable, that prevent their clinical use. Therefore, new more potent anti-tuberculosis drugs inhibiting new targets are urgently needed. A useful tool for the search of novel inhibitors is a computational drug design. The inhibitor design is significantly easier if binding sites on the enzyme are identified in advance. This paper aimed to determine the probable ligand binding sites on the surface of M. tuberculosis urease. Methods. To identify ligand binding sites on MTU surface, сomputational solvent mapping method FTSite was applied by the use of MTU homology model we have built earlier. The method places molecular probes (small organic molecules containing various functional groups on a dense grid defined around the enzyme, and for each probe finds favorable positions. The selected poses are refined by free energy minimization, the low energy conformations are clustered, and the clusters are ranked on the basis of the average free energy. FTSite server outputs the protein residues delineating a binding sites and the probe molecules representing each cluster. To predict allosteric pockets on MTU, AlloPred and AlloSite servers were applied. AlloPred uses the normal mode analysis (NMA and models how the dynamics of a protein would be altered in the presence of a modulator at a specific pocket. Pockets on the enzyme are predicted using the Fpocket

Roles of Mucosal Immunity against Mycobacterium tuberculosis Infection

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Wu Li

2012-01-01

Full Text Available Mycobacterium tuberculosis (Mtb, the causative agent of tuberculosis (TB, is one of the world's leading infectious causes of morbidity and mortality. As a mucosal-transmitted pathogen, Mtb infects humans and animals mainly through the mucosal tissue of the respiratory tract. Apart from providing a physical barrier against the invasion of pathogen, the major function of the respiratory mucosa may be to serve as the inductive sites to initiate mucosal immune responses and sequentially provide the first line of defense for the host to defend against this pathogen. A large body of studies in the animals and humans have demonstrated that the mucosal immune system, rather than the systemic immune system, plays fundamental roles in the host’s defense against Mtb infection. Therefore, the development of new vaccines and novel delivery routes capable of directly inducing respiratory mucosal immunity is emphasized for achieving enhanced protection from Mtb infection. In this paper, we outline the current state of knowledge regarding the mucosal immunity against Mtb infection, including the development of TB vaccines, and respiratory delivery routes to enhance mucosal immunity are discussed.

Identification of Mycobacterium tuberculosis BioA inhibitors by using structure-based virtual screening

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Singh S

2018-05-01

Full Text Available Swati Singh,1 Garima Khare,1 Ritika Kar Bahal,1 Prahlad C Ghosh,1 Anil K Tyagi1,2 1Department of Biochemistry, University of Delhi South Campus, New Delhi, India; 2Guru Gobind Singh Indraprastha University, New Delhi, India Background: 7,8-Diaminopelargonic acid synthase (BioA, an enzyme of biotin biosynthesis pathway, is a well-known promising target for anti-tubercular drug development. Methods: In this study, structure-based virtual screening was employed against the active site of BioA to identify new chemical entities for BioA inhibition and top ranking compounds were evaluated for their ability to inhibit BioA enzymatic activity. Results: Seven compounds inhibited BioA enzymatic activity by greater than 60% at 100 µg/mL with most potent compounds being A36, A35 and A65, displaying IC50 values of 10.48 µg/mL (28.94 µM, 33.36 µg/mL (88.16 µM and 39.17 µg/mL (114.42 µM, respectively. Compounds A65 and A35 inhibited Mycobacterium tuberculosis (M. tuberculosis growth with MIC90 of 20 µg/mL and 80 µg/mL, respectively, whereas compound A36 exhibited relatively weak inhibition of M. tuberculosis growth (83% inhibition at 200 µg/mL. Compound A65 emerged as the most potent compound identified in our study that inhibited BioA enzymatic activity and growth of the pathogen and possessed drug-like properties. Conclusion: Our study has identified a few hit molecules against M. tuberculosis BioA that can act as potential candidates for further development of potent anti-tubercular therapeutic agents. Keywords: Mycobacterium tuberculosis, BioA, virtual screening, drug discovery

Conserved hypothetical protein Rv1977 in Mycobacterium tuberculosis strains contains sequence polymorphisms and might be involved in ongoing immune evasion.

Science.gov (United States)

Jiang, Yi; Liu, Haican; Wang, Xuezhi; Li, Guilian; Qiu, Yan; Dou, Xiangfeng; Wan, Kanglin

2015-01-01

Host immune pressure and associated parasite immune evasion are key features of host-pathogen co-evolution. A previous study showed that human T cell epitopes of Mycobacterium tuberculosis are evolutionarily hyperconserved and thus it was deduced that M. tuberculosis lacks antigenic variation and immune evasion. Here, we selected 151 clinical Mycobacterium tuberculosis isolates from China, amplified gene encoding Rv1977 and compared the sequences. The results showed that Rv1977, a conserved hypothetical protein, is not conserved in M. tuberculosis strains and there are polymorphisms existed in the protein. Some mutations, especially one frameshift mutation, occurred in the antigen Rv1977, which is uncommon in M.tb strains and may lead to the protein function altering. Mutations and deletion in the gene all affect one of three T cell epitopes and the changed T cell epitope contained more than one variable position, which may suggest ongoing immune evasion.

First insights into the genetic diversity of Mycobacterium tuberculosis strains in Salvador, Bahia State, Brazil Primeiro ensaio sobre diversidade genética das cepas de Mycobacterium tuberculosis em Salvador, Bahia, Brasil

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Aída Cristina do Nascimento Silva

2011-09-01

Full Text Available This study constitutes a first attempt to describe the genetic population structure of Mycobacterium tuberculosis circulating in Salvador, Bahia State, Brazil. A total of 56 confirmed cases of pulmonary tuberculosis, identified between March and June 2008, were analyzed using restriction fragment length polymorphism (IS6110-RFLP. The study population was characterized by a predominance of males (71.43% over 30 years of age (68.75%. Forty-one isolates were found to belong to a single pattern (73.2%, while 15 (26.7% were found in group patterns, forming six clusters. The higher level of diversity observed is much more suggestive of endogenous reactivation than recent transmission.Este é o primeiro estudo realizado na Bahia, Brasil, visando à descrição da estrutura da população genética circulante do Mycobacterium tuberculosis na cidade de Salvador. Um total de 56 casos confirmados de tuberculose pulmonar, identificados entre março e junho de 2008, foi analisado pelo método Restriction Fragment Lenght Polymorphism (IS6110-RFLP. A população de estudo foi caracterizada como a maioria do sexo masculino (71,43 %, idade acima de 30 anos (68,75%. Quarenta e um isolados (73,21% com padrão único, enquanto 15 (26,75% apresentaram padrões agrupáveis, formando seis clusters. A alta taxa de diversidade das cepas de M. tuberculosis observada é mais sugestiva de reativação endógena do que transmissão recente.

[Study on VNTR diversity of clinical Mycobacterium tuberculosis isolates from Qinghai].

Science.gov (United States)

Li, Bin; Liu, Haican; Wang, Zhaofen; Ma, Yongcheng; Su, Xiaodong; Jiang, Mingxia; Wan, Kanglin; Liu, Shou; Zhao, Xiuqin; Qu, Shugen

2015-10-01

To investigate the variable number tandem repeats (VNTR) genetic polymorphisms, genotyping and distribution pattern of clinical Mycobacterium (M.) tuberculosis isolates from Qinghai province. The clinical M. tuberculosis strains isolated from the patients with tuberculosis and related background data were collected from Qinghai Provincial Center for Disease Control and Prevention from 2009 to 2012. Genotyping was conducted by using multiple locus VNTR analysis (MLVA). Genomic DNA was extracted and 15 VNTR loci were amplified with PCR and the PCR products were detected with gel electrophoresis. The VNTR diversity and clusters of genotyping were analyzed with BioNumerics (Version 5.0). A total of 251 clinical M. tuberculosis isolates were analyzed with 15 VNTR loci showing that there were great genetic diversity in these isolates. Six of the 15 VNTR loci, showed that the Hunter-Gaston index (HGI) were higher than 0.6, in which the highest resolution was MIRU26. The clusters of genotyping showed that these isolates could be categorized into four gene clusters and 238 genotypes. The four gene clusters accounted for 4.9%, 91.9%, 1.6% and 1.6% of the clinical isolates, respectively. The results showed that there is great variety of VNTR genetic polymorphisms in clinical M. tuberculosis isolates in Qinghai province.

Genetic Mimetics of Mycobacterium tuberculosis and Methicillin-Resistant Staphylococcus aureus as Verification Standards for Molecular Diagnostics.

Science.gov (United States)

Machowski, Edith Erika; Kana, Bavesh Davandra

2017-12-01

Molecular diagnostics have revolutionized the management of health care through enhanced detection of disease or infection and effective enrollment into treatment. In recognition of this, the World Health Organization approved the rollout of nucleic acid amplification technologies for identification of Mycobacterium tuberculosis using platforms such as GeneXpert MTB/RIF, the GenoType MTBDR plus line probe assay, and, more recently, GeneXpert MTB/RIF Ultra. These assays can simultaneously detect tuberculosis infection and assess rifampin resistance. However, their widespread use in health systems requires verification and quality assurance programs. To enable development of these, we report the construction of genetically modified strains of Mycobacterium smegmatis that mimic the profile of Mycobacterium tuberculosis on both the GeneXpert MTB/RIF and the MTBDR plus line probe diagnostic tests. Using site-specific gene editing, we also created derivatives that faithfully mimic the diagnostic result of rifampin-resistant M. tuberculosis , with mutations at positions 513, 516, 526, 531, and 533 in the rifampin resistance-determining region of the rpoB gene. Next, we extended this approach to other diseases and demonstrated that a Staphylococcus aureus gene sequence can be introduced into M. smegmatis to generate a positive response for the SCC mec probe in the GeneXpert SA Nasal Complete molecular diagnostic cartridge, designed for identification of methicillin-resistant S. aureus These biomimetic strains are cost-effective, have low biohazard content, accurately mimic drug resistance, and can be produced with relative ease, thus illustrating their potential for widespread use as verification standards for diagnosis of a variety of diseases. Copyright © 2017 American Society for Microbiology.

Immunogenicity of 60 novel latency-related antigens of Mycobacterium tuberculosis.

Science.gov (United States)

Serra-Vidal, Mᵃdel Mar; Latorre, Irene; Franken, Kees L C M; Díaz, Jéssica; de Souza-Galvão, Maria Luiza; Casas, Irma; Maldonado, José; Milà, Cèlia; Solsona, Jordi; Jimenez-Fuentes, M Ángeles; Altet, Neus; Lacoma, Alícia; Ruiz-Manzano, Juan; Ausina, Vicente; Prat, Cristina; Ottenhoff, Tom H M; Domínguez, José

2014-01-01

The aim of our work here was to evaluate the immunogenicity of 60 mycobacterial antigens, some of which have not been previously assessed, notably a novel series of in vivo-expressed Mycobacterium tuberculosis (IVE-TB) antigens. We enrolled 505 subjects and separated them in individuals with and without latent tuberculosis infection (LTBI) vs. patients with active tuberculosis (TB). Following an overnight and 7 days stimulation of whole blood with purified recombinant M. tuberculosis antigens, interferon-γ (IFN-γ) levels were determined by ELISA. Several antigens could statistically significantly differentiate the groups of individuals. We obtained promising antigens from all studied antigen groups [dormancy survival regulon (DosR regulon) encoded antigens; resuscitation-promoting factors (Rpf) antigens; IVE-TB antigens; reactivation associated antigens]. Rv1733, which is a probable conserved transmembrane protein encoded in DosR regulon, turned out to be very immunogenic and able to discriminate between the three defined TB status, thus considered a candidate biomarker. Rv2389 and Rv2435n, belonging to Rpf family and IVE-TB group of antigens, respectively, also stood out as LTBI biomarkers. Although more studies are needed to support our findings, the combined use of these antigens would be an interesting approach to TB immunodiagnosis candidates.

Mycobacterium tuberculosis Lineage 4 comprises globally distributed and geographically restricted sublineages

Science.gov (United States)

Coscolla, Mireia; Liu, Qingyun; Trauner, Andrej; Fenner, Lukas; Rutaihwa, Liliana; Borrell, Sonia; Luo, Tao; Gao, Qian; Kato-Maeda, Midori; Ballif, Marie; Egger, Matthias; Macedo, Rita; Mardassi, Helmi; Moreno, Milagros; Tudo Vilanova, Griselda; Fyfe, Janet; Globan, Maria; Thomas, Jackson; Jamieson, Frances; Guthrie, Jennifer L.; Asante-Poku, Adwoa; Yeboah-Manu, Dorothy; Wampande, Eddie; Ssengooba, Willy; Joloba, Moses; Henry Boom, W.; Basu, Indira; Bower, James; Saraiva, Margarida; Vaconcellos, Sidra E. G.; Suffys, Philip; Koch, Anastasia; Wilkinson, Robert; Gail-Bekker, Linda; Malla, Bijaya; Ley, Serej D.; Beck, Hans-Peter; de Jong, Bouke C.; Toit, Kadri; Sanchez-Padilla, Elisabeth; Bonnet, Maryline; Gil-Brusola, Ana; Frank, Matthias; Penlap Beng, Veronique N.; Eisenach, Kathleen; Alani, Issam; Wangui Ndung’u, Perpetual; Revathi, Gunturu; Gehre, Florian; Akter, Suriya; Ntoumi, Francine; Stewart-Isherwood, Lynsey; Ntinginya, Nyanda E.; Rachow, Andrea; Hoelscher, Michael; Cirillo, Daniela Maria; Skenders, Girts; Hoffner, Sven; Bakonyte, Daiva; Stakenas, Petras; Diel, Roland; Crudu, Valeriu; Moldovan, Olga; Al-Hajoj, Sahal; Otero, Larissa; Barletta, Francesca; Jane Carter, E.; Diero, Lameck; Supply, Philip; Comas, Iñaki; Niemann, Stefan; Gagneux, Sebastien

2016-01-01

Generalist and specialist species differ in the breadth of their ecological niche. Little is known about the niche width of obligate human pathogens. Here we analyzed a global collection of Mycobacterium tuberculosis Lineage 4 clinical isolates, the most geographically widespread cause of human tuberculosis. We show that Lineage 4 comprises globally distributed and geographically restricted sublineages, suggesting a distinction between generalists and specialists. Population genomic analyses showed that while the majority of human T cell epitopes were conserved in all sublineages, the proportion of variable epitopes was higher in generalists. Our data further support a European origin for the most common generalist sublineage. Hence, the global success of Lineage 4 reflects distinct strategies adopted by different sublineages and the influence of human migration. PMID:27798628

Targeting Mycobacterium tuberculosis nucleoid-associated protein HU with structure-based inhibitors

Science.gov (United States)

Bhowmick, Tuhin; Ghosh, Soumitra; Dixit, Karuna; Ganesan, Varsha; Ramagopal, Udupi A.; Dey, Debayan; Sarma, Siddhartha P.; Ramakumar, Suryanarayanarao; Nagaraja, Valakunja

2014-06-01

The nucleoid-associated protein HU plays an important role in maintenance of chromosomal architecture and in global regulation of DNA transactions in bacteria. Although HU is essential for growth in Mycobacterium tuberculosis (Mtb), there have been no reported attempts to perturb HU function with small molecules. Here we report the crystal structure of the N-terminal domain of HU from Mtb. We identify a core region within the HU-DNA interface that can be targeted using stilbene derivatives. These small molecules specifically inhibit HU-DNA binding, disrupt nucleoid architecture and reduce Mtb growth. The stilbene inhibitors induce gene expression changes in Mtb that resemble those induced by HU deficiency. Our results indicate that HU is a potential target for the development of therapies against tuberculosis.

Comprehensive functional analysis of Mycobacterium tuberculosis toxin-antitoxin systems: implications for pathogenesis, stress responses, and evolution.

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Holly R Ramage

2009-12-01

Full Text Available Toxin-antitoxin (TA systems, stress-responsive genetic elements ubiquitous in microbial genomes, are unusually abundant in the major human pathogen Mycobacterium tuberculosis. Why M. tuberculosis has so many TA systems and what role they play in the unique biology of the pathogen is unknown. To address these questions, we have taken a comprehensive approach to identify and functionally characterize all the TA systems encoded in the M. tuberculosis genome. Here we show that 88 putative TA system candidates are present in M. tuberculosis, considerably more than previously thought. Comparative genomic analysis revealed that the vast majority of these systems are conserved in the M. tuberculosis complex (MTBC, but largely absent from other mycobacteria, including close relatives of M. tuberculosis. We found that many of the M. tuberculosis TA systems are located within discernable genomic islands and were thus likely acquired recently via horizontal gene transfer. We discovered a novel TA system located in the core genome that is conserved across the genus, suggesting that it may fulfill a role common to all mycobacteria. By expressing each of the putative TA systems in M. smegmatis, we demonstrate that 30 encode a functional toxin and its cognate antitoxin. We show that the toxins of the largest family of TA systems, VapBC, act by inhibiting translation via mRNA cleavage. Expression profiling demonstrated that four systems are specifically activated during stresses likely encountered in vivo, including hypoxia and phagocytosis by macrophages. The expansion and maintenance of TA genes in the MTBC, coupled with the finding that a subset is transcriptionally activated by stress, suggests that TA systems are important for M. tuberculosis pathogenesis.

Mycobacterium tuberculosis complex lipid virulence factors preserved in the 17,000-year-old skeleton of an extinct bison, Bison antiquus.

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Oona Y-C Lee

Full Text Available Tracing the evolution of ancient diseases depends on the availability and accessibility of suitable biomarkers in archaeological specimens. DNA is potentially information-rich but it depends on a favourable environment for preservation. In the case of the major mycobacterial pathogens, Mycobacterium tuberculosis and Mycobacterium leprae, robust lipid biomarkers are established as alternatives or complements to DNA analyses. A DNA report, a decade ago, suggested that a 17,000-year-old skeleton of extinct Bison antiquus, from Natural Trap Cave, Wyoming, was the oldest known case of tuberculosis. In the current study, key mycobacterial lipid virulence factor biomarkers were detected in the same two samples from this bison. Fluorescence high-performance liquid chromatography (HPLC indicated the presence of mycolic acids of the mycobacterial type, but they were degraded and could not be precisely correlated with tuberculosis. However, pristine profiles of C(29, C(30 and C(32 mycocerosates and C(27 mycolipenates, typical of the Mycobacterium tuberculosis complex, were recorded by negative ion chemical ionization gas chromatography mass spectrometry of pentafluorobenzyl ester derivatives. These findings were supported by the detection of C(34 and C(36 phthiocerols, which are usually esterified to the mycocerosates. The existence of Pleistocene tuberculosis in the Americas is confirmed and there are many even older animal bones with well-characterised tuberculous lesions similar to those on the analysed sample. In the absence of any evidence of tuberculosis in human skeletons older than 9,000 years BP, the hypothesis that this disease evolved as a zoonosis, before transfer to humans, is given detailed consideration and discussion.

Identification of potential leads against 4-hydroxytetrahydrodipicolinate synthase from Mycobacterium tuberculosis

OpenAIRE

Rehman, Ajijur; Akhtar, Salman; Siddiqui, Mohd Haris; Sayeed, Usman; Ahmad, Syed Sayeed; Arif, Jamal M.; Khan, M. Kalim A.

2016-01-01

4-hydroxy-tetrahydrodipicolinate synthase (DHDPS) is an important enzyme needed for the biosynthesis of lysine and many more key metabolites in Mycobacterium tuberculosis (Mtb). Inhibition of DHDPS is supposed to a promising therapeutic target due to its specific role in sporulation, cross-linking of the peptidiglycan polymers and biosynthesis of amino acids. In this work, a known inhibitor-based similarity search was carried out against a natural products database (Super Natural II) towards ...

Methyltransferase Erm(37) Slips on rRNA to Confer Atypical Resistance in Mycobacterium tuberculosis

Czech Academy of Sciences Publication Activity Database

Madsen, Ch. T.; Jakobsen, L.; Buriánková, Karolína; Doucet-Populaire, F.; Perdonet, J. L.; Douthwaite, S.

2005-01-01

Roč. 280, č. 47 (2005), s. 38942-38947 ISSN 0021-9258 R&D Projects: GA ČR GA310/03/0292 Institutional research plan: CEZ:AV0Z50200510 Keywords : methyltransferase erm * mycobacterium tuberculosis * rRNA Subject RIV: EE - Microbiology, Virology Impact factor: 5.854, year: 2005

Whole blood assay to access T cell-immune responses to Mycobacterium tuberculosis antigens in healthy Brazilian individuals

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Paulo RZ Antas

2004-02-01

Full Text Available The production of interferon gamma (IFNgamma guarantees effective T cell-mediated immunity against Mycobacterium tuberculosis infection. In the present study, we simply compare the in vitro immune responses to Mycobacterium antigens in terms of IFNg production in a total of 10 healthy Brazilian volunteers. Whole blood and mononuclear cells were cultivated in parallel with PPD, Ag85B, and M. bovis hsp65, and five-days supernatants were harvested for cytokine detection by ELISA. The inter-assay result was that the overall profile of agreement in response to antigens was highly correlated (r² = 0.9266; p = 0.0102. Potential analysis is in current progress to dictate the usefulness of this method to access the immune responses also in tuberculosis patients and its contacts.

A multiplex PCR method for detection of Aspergillus spp. and Mycobacterium tuberculosis in BAL specimens.

Science.gov (United States)

Amini, F; Kachuei, R; Noorbakhsh, F; Imani Fooladi, A A

2015-06-01

The aim of this study was the detection of Aspergillus species and Mycobacterium tuberculosis together in bronchoalveolar lavage (BAL) using of multiplex PCR. In this study, from September 2012 until June 2013, 100 bronchoalveolar lavage (BAL) specimens were collected from patients suspected of tuberculosis (TB). After the direct and culture test, multiplex PCR were utilized in order to diagnose Aspergillus species and M. tuberculosis. Phenol-chloroform manual method was used in order to extract DNA from these microorganisms. Aspergillus specific primers, M. tuberculosis designed primers and beta actin primers were used for multiplex PCR. In this study, by multiplex PCR method, Aspergillus species were identified in 12 samples (12%), positive samples in direct and culture test were respectively 11% and 10%. Sensitivity and specificity of this method in comparison to direct test were respectively 100% and 98.8%, also sensitivity and specificity of this method in comparison to culture test were respectively 100% and 97.7%. In this assay, M. tuberculosis was identified in 8 samples (8%). Mycobacterium-positive samples in molecular method, direct and culture test were respectively 6%, 5% and 7%. Sensitivity and specificity of PCR method in comparison to direct test were 80% and 97.8% also sensitivity and specificity of this method in comparison to culture test was 71.4% and 98.9%. In the present study, multiplex PCR method had higher sensitivity than direct and culture test in order to identify and detect Aspergillus, also this method had lower sensitivity for identification of M. tuberculosis, suggesting that the method of DNA extraction was not suitable. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Preparation and biological evaluation of ethionamide-mesoporous silicon nanoparticles against Mycobacterium tuberculosis

OpenAIRE

Vale, Nuno; Correia, Alexandra; Silva, Sara; Figueiredo, Patrícia; Mäkilä, , Ermei; Salonen, Jarno; Hirvonen, Jouni; Pedrosa, Jorge; Santos Hélder A.; Fraga, Alexandra

2017-01-01

Ethionamide (ETH) is an important second-line antituberculosis drug used for the treatment of patients infected with multidrug-resistant Mycobacterium tuberculosis. Recently, we reported that the loading of ETH into thermally carbonized-porous silicon (TCPSi) nanoparticles enhanced the solubility and permeability of ETH at different pH-values and also increased its metabolization process. Based on these results, we synthesized carboxylic acid functionalized thermally hydrocarbonized porous si...

Mycobacterium tuberculosis Phosphoenolpyruvate Carboxykinase Is Regulated by Redox Mechanisms and Interaction with Thioredoxin

Czech Academy of Sciences Publication Activity Database

Machová, Iva; Snášel, Jan; Zimmermann, M.; Laubitz, D.; Plocinski, P.; Oehlmann, W.; Singh, M.; Dostál, Jiří; Sauer, U.; Pichová, Iva

2014-01-01

Roč. 289, č. 19 (2014), s. 13066-13078 ISSN 0021-9258 EU Projects: European Commission(XE) 241587 - SYSTEMTB Grant - others:OPPK(CZ) CZ.2.16/3.1.00/24016 Institutional support: RVO:61388963 Keywords : enzyme kinetics * hypoxia * metabolism * Mycobacterium tuberculosis * oxidation-reduction * thioredoxin * Phosphoenolpyruvate carboxykinase Subject RIV: CE - Biochemistry Impact factor: 4.573, year: 2014

Crystal structure of DNA polymerase III β sliding clamp from Mycobacterium tuberculosis.

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Gui, Wen-Jun; Lin, Shi-Qiang; Chen, Yuan-Yuan; Zhang, Xian-En; Bi, Li-Jun; Jiang, Tao

2011-02-11

The sliding clamp is a key component of DNA polymerase III (Pol III) required for genome replication. It is known to function with diverse DNA repair proteins and cell cycle-control proteins, making it a potential drug target. To extend our understanding of the structure/function relationship of the sliding clamp, we solved the crystal structure of the sliding clamp from Mycobacterium tuberculosis (M. tuberculosis), a human pathogen that causes most cases of tuberculosis (TB). The sliding clamp from M. tuberculosis forms a ring-shaped head-to-tail dimer with three domains per subunit. Each domain contains two α helices in the inner ring that lie against two β sheets in the outer ring. Previous studies have indicated that many Escherichia coli clamp-binding proteins have a conserved LF sequence, which is critical for binding to the hydrophobic region of the sliding clamp. Here, we analyzed the binding affinities of the M. tuberculosis sliding clamp and peptides derived from the α and δ subunits of Pol III, which indicated that the LF motif also plays an important role in the binding of the α and δ subunits to the sliding clamp of M. tuberculosis. Copyright © 2011 Elsevier Inc. All rights reserved.

Estudo do papel do gene Rv1358 no estabelecimento e maturação dos biofilmes formados por bactérias do complexo Mycobacterium Tuberculosis

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Vaz, Marta Helena Melo de Campos e Cunha

2016-01-01

Tese de mestrado, Biologia Molecular e Genética, Universidade de Lisboa, Faculdade de Ciências, 2016 A tuberculose é uma doença infeciosa de etiologia bacteriana, com uma incidência anual média superior a 9 milhões de casos e tendo sido associada à morte de 1.5 milhões de indivíduos só em 2014. Dentro do género Mycobacterium, o complexo Mycobacterium tuberculosis (MTC) engloba várias espécies patogénicas, fenotipica e genotipicamente relacionadas, nomeadamente Mycobacterium tuberculosis, o...

Activity of Medicinal Plant Extracts on Multiplication of Mycobacterium tuberculosis under Reduced Oxygen Conditions Using Intracellular and Axenic Assays

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Purva D. Bhatter

2016-01-01

Full Text Available Aim. Test the activity of selected medicinal plant extracts on multiplication of Mycobacterium tuberculosis under reduced oxygen concentration which represents nonreplicating conditions. Material and Methods. Acetone, ethanol and aqueous extracts of the plants Acorus calamus L. (rhizome, Ocimum sanctum L. (leaf, Piper nigrum L. (seed, and Pueraria tuberosa DC. (tuber were tested on Mycobacterium tuberculosis H37Rv intracellularly using an epithelial cell (A549 infection model. The extracts found to be active intracellularly were further studied axenically under reducing oxygen concentrations. Results and Conclusions. Intracellular multiplication was inhibited ≥60% by five of the twelve extracts. Amongst these 5 extracts, in axenic culture, P. nigrum (acetone was active under aerobic, microaerophilic, and anaerobic conditions indicating presence of multiple components acting at different levels and P. tuberosa (aqueous showed bactericidal activity under microaerophilic and anaerobic conditions implying the influence of anaerobiosis on its efficacy. P. nigrum (aqueous and A. calamus (aqueous and ethanol extracts were not active under axenic conditions but only inhibited intracellular growth of Mycobacterium tuberculosis, suggesting activation of host defense mechanisms to mediate bacterial killing rather than direct bactericidal activity.

Structural measurements and cell line studies of the copper-PEG-Rifampicin complex against Mycobacterium tuberculosis.

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Manning, Thomas; Mikula, Rachel; Wylie, Greg; Phillips, Dennis; Jarvis, Jackie; Zhang, Fengli

2015-02-01

The bacterium responsible for tuberculosis is increasing its resistance to antibiotics resulting in new multidrug-resistant Mycobacterium tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB). In this study, several analytical techniques including NMR, FT-ICR, MALDI-MS, LC-MS and UV/Vis are used to study the copper-Rifampicin-Polyethylene glycol (PEG-3350) complex. The copper (II) cation is a carrier for the antibiotic Rifampicin as well as nutrients for the bacterium. The NIH-NIAID cell line containing several Tb strains (including antibiotic resistant strains) is tested against seven copper-PEG-RIF complex variations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prevalence of tuberculosis-like lesions in goats slaughtered at ...

African Journals Online (AJOL)

ADEYEYE

2016-02-12

Feb 12, 2016 ... Tuberculosis in goat and sheep is caused by members of Mycobacterium tuberculosis complex predominantly. Mycobacterium bovis and. Mycobacterium caprae (Crawshaw et al., 2008) and in some cases by Mycobacterium tuberculosis. (Cadmus et al., 2009). In goats, the disease normally spread through ...

Mycobacterium tuberculosis PPD-induced immune biomarkers measurable in vitro following BCG vaccination of UK adolescents by multiplex bead array and intracellular cytokine staining

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Worth Andrew

2010-07-01

Full Text Available Abstract Background The vaccine efficacy reported following Mycobacterium bovis Bacillus Calmette Guerin (BCG administration to UK adolescents is 77% and defining the cellular immune response in this group can inform us as to the nature of effective immunity against tuberculosis. The aim of this study was to identify which cytokines and lymphocyte populations characterise the peripheral blood cellular immune response following BCG vaccination. Results Diluted blood from before and after vaccination was stimulated with Mycobacterium tuberculosis purified protein derivative for 6 days, after which soluble biomarkers in supernatants were assayed by multiplex bead array. Ten out of twenty biomarkers measured were significantly increased (p Mycobacterium tuberculosis purified protein derivative stimulation of PBMC samples from the 12 month group revealed that IFNγ expression was detectable in CD4 and CD8 T-cells and natural killer cells. Polyfunctional flow cytometry analysis demonstrated that cells expressing IFNγ alone formed the majority in each subpopulation of cells. Only in CD4 T-cells and NK cells were there a notable proportion of responding cells of a different phenotype and these were single positive, TNFα producers. No significant expression of the cytokines IL-2, IL-17 or IL-10 was seen in any population of cells. Conclusions The broad array of biomarker responses detected by multiplex bead array suggests that BCG vaccination is capable, in this setting, of inducing a complex immune phenotype. Although polyfunctional T-cells have been proposed to play a role in protective immunity, they were not present in vaccinated adolescents who, based on earlier epidemiological studies, should have developed protection against pulmonary tuberculosis. This may be due to the later sampling time point available for testing or on the kinetics of the assays used.

Bacterial immunostat: Mycobacterium tuberculosis lipids and their role in the host immune response

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Adriano Queiroz

Full Text Available Abstract: The lipid-rich cell wall of Mycobacterium tuberculosis is a dynamic structure that is involved in the regulation of the transport of nutrients, toxic host-cell effector molecules, and anti-tuberculosis drugs. It is therefore postulated to contribute to the long-term bacterial survival in an infected human host. Accumulating evidence suggests that M. tuberculosis remodels the lipid composition of the cell wall as an adaptive mechanism against host-imposed stress. Some of these lipid species (trehalose dimycolate, diacylated sulphoglycolipid, and mannan-based lipoglycans trigger an immunopathologic response, whereas others (phthiocerol dimycocerosate, mycolic acids, sulpholipid-1, and di-and polyacyltrehalose appear to dampen the immune responses. These lipids appear to be coordinately expressed in the cell wall of M. tuberculosis during different phases of infection, ultimately determining the clinical fate of the infection. This review summarizes the current state of knowledge on the metabolism, transport, and homeostatic or immunostatic regulation of the cell wall lipids, and their orchestrated interaction with host immune responses that results in bacterial clearance, persistence, or tuberculosis.

Segmentation of touching mycobacterium tuberculosis from Ziehl-Neelsen stained sputum smear images

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Xu, Chao; Zhou, Dongxiang; Liu, Yunhui

2015-12-01

Touching Mycobacterium tuberculosis objects in the Ziehl-Neelsen stained sputum smear images present different shapes and invisible boundaries in the adhesion areas, which increases the difficulty in objects recognition and counting. In this paper, we present a segmentation method of combining the hierarchy tree analysis with gradient vector flow snake to address this problem. The skeletons of the objects are used for structure analysis based on the hierarchy tree. The gradient vector flow snake is used to estimate the object edge. Experimental results show that the single objects composing the touching objects are successfully segmented by the proposed method. This work will improve the accuracy and practicability of the computer-aided diagnosis of tuberculosis.

Molecular characterization of tlyA gene product, Rv1694 of Mycobacterium tuberculosis: A non-conventional hemolysin and a ribosomal RNA methyl transferase

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Ahmed Neesar

2010-09-01

Full Text Available Abstract Background Mycobacterium tuberculosis is a virulent bacillus causing tuberculosis, a disease responsible for million deaths each year worldwide. In order to understand its mechanism of pathogenesis in humans and to help control tuberculosis, functions of numerous Mycobacterium tuberculosis genes are being characterized. In this study we report the dual functionality of tlyA gene product of Mycobacterium tuberculosis annotated as Rv1694, a 268 amino acid long basic protein. Results The recombinant purified Rv1694 protein was found to exhibit hemolytic activity in vitro. It showed concentration and time-dependent hemolysis of rabbit and human erythrocytes. Multiple oligomeric forms (dimers to heptamers of this protein were seen on the membranes of the lysed erythrocytes. Like the oligomers of conventional, well-known, pore-forming toxins, the oligomers of Rv1694 were found to be resistant to heat and SDS, but were susceptible to reducing agents like β-mercaptoethanol as it had abolished the hemolytic activity of Rv1694 indicating the role of disulfide bond(s. The Rv1694 generated de novo by in vitro transcription and translation also exhibited unambiguous hemolysis confirming the self assembly and oligomerization properties of this protein. Limited proteolytic digestion of this protein has revealed that the amino terminus is susceptible while in solution but is protected in presence of membrane. Striking feature of Rv1694 is its presence on the cell wall of E. coli as visualized by confocal microscopy. The surface expression is consistent with the contact dependent haemolytic ability of E. coli expressing this protein. Also, immune serum specific to this protein inhibits the contact dependent hemolysis. Moreover, Rv1694 protein binds to and forms stable oligomers on the macrophage phagosomal membranes. In addition to all these properties, E. coli expressing Rv1694 was found to be susceptible to the antibiotic capreomycin as its growth

High-contrast imaging of mycobacterium tuberculosis using third-harmonic generation microscopy

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Kim, Bo Ram; Lee, Eungjang; Park, Seung-Han

2015-07-01

Nonlinear optical microcopy has become an important tool in investigating biomaterials due to its various advantages such as label-free imaging capabilities. In particular, it has been shown that third-harmonic generation (THG) signals can be produced at interfaces between an aqueous medium (e.g. cytoplasm, interstitial fluid) and a mineralized lipidic surface. In this work, we have demonstrated that label-free high-contrast THG images of the mycobacterium tuberculosis can be obtained using THG microscopy.

Biochemical and structural studies of the Mycobacterium tuberculosis O6-methylguanine methyltransferase and mutated variants.

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Miggiano, Riccardo; Casazza, Valentina; Garavaglia, Silvia; Ciaramella, Maria; Perugino, Giuseppe; Rizzi, Menico; Rossi, Franca

2013-06-01

Mycobacterium tuberculosis displays remarkable genetic stability despite continuous exposure to the hostile environment represented by the host's infected macrophages. Similarly to other organisms, M. tuberculosis possesses multiple systems to counteract the harmful potential of DNA alkylation. In particular, the suicidal enzyme O(6)-methylguanine-DNA methyltransferase (OGT) is responsible for the direct repair of O(6)-alkylguanine in double-stranded DNA and is therefore supposed to play a central role in protecting the mycobacterial genome from the risk of G · C-to-A · T transition mutations. Notably, a number of geographically widely distributed M. tuberculosis strains shows nonsynonymous single-nucleotide polymorphisms in their OGT-encoding gene, leading to amino acid substitutions at position 15 (T15S) or position 37 (R37L) of the N-terminal domain of the corresponding protein. However, the role of these mutations in M. tuberculosis pathogenesis is unknown. We describe here the in vitro characterization of M. tuberculosis OGT (MtOGT) and of two point-mutated versions of the protein mimicking the naturally occurring ones, revealing that both mutated proteins are impaired in their activity as a consequence of their lower affinity for alkylated DNA than the wild-type protein. The analysis of the crystal structures of MtOGT and MtOGT-R37L confirms the high level of structural conservation of members of this protein family and provides clues to an understanding of the molecular bases for the reduced affinity for the natural substrate displayed by mutated MtOGT. Our in vitro results could contribute to validate the inferred participation of mutated OGTs in M. tuberculosis phylogeny and biology.

Phosphorylation of KasB Regulates Virulence and Acid-Fastness in Mycobacterium tuberculosis

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Vilchèze, Catherine; Molle, Virginie; Carrère-Kremer, Séverine; Leiba, Jade; Mourey, Lionel; Shenai, Shubhada; Baronian, Grégory; Tufariello, Joann; Hartman, Travis; Veyron-Churlet, Romain; Trivelli, Xavier; Tiwari, Sangeeta; Weinrick, Brian; Alland, David; Guérardel, Yann; Jacobs, William R.; Kremer, Laurent

2014-01-01

Mycobacterium tuberculosis bacilli display two signature features: acid-fast staining and the capacity to induce long-term latent infections in humans. However, the mechanisms governing these two important processes remain largely unknown. Ser/Thr phosphorylation has recently emerged as an important regulatory mechanism allowing mycobacteria to adapt their cell wall structure/composition in response to their environment. Herein, we evaluated whether phosphorylation of KasB, a crucial mycolic acid biosynthetic enzyme, could modulate acid-fast staining and virulence. Tandem mass spectrometry and site-directed mutagenesis revealed that phosphorylation of KasB occurred at Thr334 and Thr336 both in vitro and in mycobacteria. Isogenic strains of M. tuberculosis with either a deletion of the kasB gene or a kasB_T334D/T336D allele, mimicking constitutive phosphorylation of KasB, were constructed by specialized linkage transduction. Biochemical and structural analyses comparing these mutants to the parental strain revealed that both mutant strains had mycolic acids that were shortened by 4–6 carbon atoms and lacked trans-cyclopropanation. Together, these results suggested that in M. tuberculosis, phosphorylation profoundly decreases the condensing activity of KasB. Structural/modeling analyses reveal that Thr334 and Thr336 are located in the vicinity of the catalytic triad, which indicates that phosphorylation of these amino acids would result in loss of enzyme activity. Importantly, the kasB_T334D/T336D phosphomimetic and deletion alleles, in contrast to the kasB_T334A/T336A phosphoablative allele, completely lost acid-fast staining. Moreover, assessing the virulence of these strains indicated that the KasB phosphomimetic mutant was attenuated in both immunodeficient and immunocompetent mice following aerosol infection. This attenuation was characterized by the absence of lung pathology. Overall, these results highlight for the first time the role of Ser/Thr kinase

Phosphorylation of KasB regulates virulence and acid-fastness in Mycobacterium tuberculosis.

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Catherine Vilchèze

2014-05-01

Full Text Available Mycobacterium tuberculosis bacilli display two signature features: acid-fast staining and the capacity to induce long-term latent infections in humans. However, the mechanisms governing these two important processes remain largely unknown. Ser/Thr phosphorylation has recently emerged as an important regulatory mechanism allowing mycobacteria to adapt their cell wall structure/composition in response to their environment. Herein, we evaluated whether phosphorylation of KasB, a crucial mycolic acid biosynthetic enzyme, could modulate acid-fast staining and virulence. Tandem mass spectrometry and site-directed mutagenesis revealed that phosphorylation of KasB occurred at Thr334 and Thr336 both in vitro and in mycobacteria. Isogenic strains of M. tuberculosis with either a deletion of the kasB gene or a kasB_T334D/T336D allele, mimicking constitutive phosphorylation of KasB, were constructed by specialized linkage transduction. Biochemical and structural analyses comparing these mutants to the parental strain revealed that both mutant strains had mycolic acids that were shortened by 4-6 carbon atoms and lacked trans-cyclopropanation. Together, these results suggested that in M. tuberculosis, phosphorylation profoundly decreases the condensing activity of KasB. Structural/modeling analyses reveal that Thr334 and Thr336 are located in the vicinity of the catalytic triad, which indicates that phosphorylation of these amino acids would result in loss of enzyme activity. Importantly, the kasB_T334D/T336D phosphomimetic and deletion alleles, in contrast to the kasB_T334A/T336A phosphoablative allele, completely lost acid-fast staining. Moreover, assessing the virulence of these strains indicated that the KasB phosphomimetic mutant was attenuated in both immunodeficient and immunocompetent mice following aerosol infection. This attenuation was characterized by the absence of lung pathology. Overall, these results highlight for the first time the role of

Direct detection of rpoB and katG gene mutations of Mycobacterium tuberculosis in clinical samples

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Sunil Pandey

2017-08-01

Conclusions: We can conclude that genetic mutation in Mycobacterium tuberculosis can be identified directly from the clinical samples. However, we have carried this study in less sample size and to validate research on large number of sample is recommended.

Mycobacterium tuberculosis: approach to development of improved strategies for disease control through vaccination and immunodiagnosis.

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Mirlekar, B; Pathak, S; Pathade, G

2013-01-01

Tuberculosis is a major health problem throughout the world causing large number of deaths, more than that from any other single infectious disease. Estimates till date ascertain the fact that Tuberculosis (TB) is continuing to be the leading cause of death worldwide. The infection from single infectious agent Mycobacterium tuberculosis is killing about 3 million individuals every year and accounts for around 18.5% of all deaths in adults between the age group of 15 and 65. An average of 1.79 billion people, which constitutes roughly one-third of the world's population, is infected with the causative agent M. tuberculosis and is at risk of developing the disease. This situation highlights the relative shortcomings of the current treatment and diagnosis strategies for TB and the limited effectiveness of public health systems, particularly in resource-poor countries where the main TB burden lies. The timely identification of persons infected with Mycobacterium tuberculosis and rapid laboratory confirmation of tuberculosis are two key factors for the treatment and prevention of the disease. Novel molecular assays for diagnosis and drug susceptibility testing offer several potential advantages over the above methods including faster turnaround times, very sensitive and specific detection of nucleic acids, and minimal, or possibly no, prior culture. The need for new technologies for rapid diagnosis of tuberculosis is clear. Most studies of mycobacterial immunity attributes focus on proliferation of T cells, production of cytokines and cytolytic activity. A proper vaccine for tuberculosis can be developed by using a combination of antigens and adjuvants capable of inducing appropriate and long-lasting T cell immunity. Development of new vaccines against TB should include some important aspects learned from BCG use such as mucosal routes of immunization; revaccination of BCG immunized subjects, booster immunization and prime-boost strategy with wild-type BCG, and other

Limonia acidissima L. leaf mediated synthesis of zinc oxide nanoparticles: A potent tool against Mycobacterium tuberculosis.

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Taranath, Tarikere C; Patil, Bheemanagouda N

2016-06-01

The present investigation was undertaken to synthesize zinc oxide nanoparticles using Limonia acidissima L. and to test their efficacy against the growth of Mycobacterium tuberculosis. The formation of zinc oxide nanoparticles was confirmed with UV-visible spectrophotometry. Fourier transform infrared spectroscopy shows the presence of bio-molecules involved in the stabilization of zinc oxide nanoparticles. The shape and size was confirmed with atomic force microscope, X-ray diffraction, and high resolution transmission electron microscope. These nanoparticles were tested for their effect on the growth of M. tuberculosis through the microplate alamar blue assay technique. The UV-visible data reveal that an absorbance peak at 374nm confirms formation of zinc oxide nanoparticles and they are spherical in shape with sizes between 12nm and 53nm. These nanoparticles control the growth of M. tuberculosis at 12.5μg/mL. Phytosynthesis of zinc oxide nanoparticles is a green, eco-friendly technology because it is inexpensive and pollution free. In the present investigation, based on our results we conclude that the aqueous extract of leaves of L. acidissima can be used for the synthesis of zinc oxide nanoparticles. These nanoparticles control the growth of M. tuberculosis and this was confirmed with the microplate alamar blue method. The potential of biogenic zinc oxide nanoparticles may be harnessed as a novel medicine ingredient to combat tuberculosis disease. Copyright © 2016 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

Infection caused by Mycobacterium tuberculosis.

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Peloquin, C A; Berning, S E

1994-01-01

To update readers on the clinical management of infections caused by Mycobacterium tuberculosis, to provide a general description of the organism, culture and susceptibility testing, and clinical manifestations of the disease, and to provide several aspects of the treatment of the disease, including historical perspective, current approaches, and research opportunities for the future. The current medical literature, including abstracts presented at recent international meetings, is reviewed. References were identified through MEDLINE, MEDLARS II, Current Contents, and published meeting abstracts. Data regarding the epidemiology, clinical manifestations, culture and susceptibility testing, and treatment of tuberculosis are cited. Specific attention has been focused on the clinical management of patients with noncontagious infection and potentially contagious active disease (TB) caused by M. tuberculosis. Information contributing to the discussion of the topics selected by the authors is reviewed. Data supporting and disputing specific conclusions are presented. The incidence of TB is increasing in the US, despite the fact that available technologies are capable of controlling the vast majority of existing cases. Fueling the fire is the problem of coinfection with HIV and M. tuberculosis. Very few drugs are available for the treatment of TB, and few of these approach the potency of isoniazid and rifampin. Preventive therapy of patients exposed to multiple-drug-resistant M. tuberculosis (MDR-TB) is controversial and of unknown efficacy. Treatment of active disease caused by MDR-TB requires up to four times longer, is associated with increased toxicity, and is far less successful than the treatment of drug-susceptible TB. Strategies for the management of such cases are presented. The rising incidence of TB in the US reflects a breakdown in the healthcare systems responsible for controlling the disease, which reflects the past budgetary reductions. Although TB control

Common Bile Duct Perforation Due to Tuberculosis: A Case Report

OpenAIRE

Razman Jarmin; Shaharin Shaharuddin

2004-01-01

A young man with HIV presented with biliary peritonitis secondary to spontaneous common bile duct perforation. Investigation revealed that the perforation was due to Mycobacterium tuberculosis. Tuberculosis of the bile duct is uncommon and usually presents with obstructive jaundice due to stricture. Bile duct perforation due to tuberculosis is extremely rare. Its management is discussed.

Characterisation of iunH gene knockout strain from Mycobacterium tuberculosis

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Anne Drumond Villela

Full Text Available BACKGROUND Tuberculosis (TB is an infectious disease caused mainly by the bacillus Mycobacterium tuberculosis. The better understanding of important metabolic pathways from M. tuberculosis can contribute to the development of novel therapeutic and prophylactic strategies to combat TB. Nucleoside hydrolase (MtIAGU-NH, encoded by iunH gene (Rv3393, is an enzyme from purine salvage pathway in M. tuberculosis. MtIAGU-NH accepts inosine, adenosine, guanosine, and uridine as substrates, which may point to a pivotal metabolic role. OBJECTIVES Our aim was to construct a M. tuberculosis knockout strain for iunH gene, to evaluate in vitro growth and the effect of iunH deletion in M. tuberculosis in non-activated and activated macrophages models of infection. METHODS A M. tuberculosis knockout strain for iunH gene was obtained by allelic replacement, using pPR27xylE plasmid. The complemented strain was constructed by the transformation of the knockout strain with pNIP40::iunH. MtIAGU-NH expression was analysed by Western blot and LC-MS/MS. In vitro growth was evaluated in Sauton’s medium. Bacterial load of non-activated and interferon-γ activated RAW 264.7 cells infected with knockout strain was compared with wild-type and complemented strains. FINDINGS Western blot and LC-MS/MS validated iunH deletion at protein level. The iunH knockout led to a delay in M. tuberculosis growth kinetics in Sauton’s medium during log phase, but did not affect bases and nucleosides pool in vitro. No significant difference in bacterial load of knockout strain was observed when compared with both wild-type and complemented strains after infection of non-activated and interferon-γ activated RAW 264.7 cells. MAIN CONCLUSION The disruption of iunH gene does not influence M. tuberculosis growth in both non-activated and activated RAW 264.7 cells, which show that iunH gene is not important for macrophage invasion and virulence. Our results indicated that MtIAGU-NH is not a

Evolution and role of corded cell aggregation in Mycobacterium tuberculosis cultures.

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Caceres, Neus; Vilaplana, Cristina; Prats, Clara; Marzo, Elena; Llopis, Isaac; Valls, Joaquim; Lopez, Daniel; Cardona, Pere-Joan

2013-11-01

The aim of this study was to evaluate the evolution and role of corded cell aggregation in Mycobacterium tuberculosis cultures according to growth time and conditions. Thus, in standard culture using aerated 7H9 Middlebrook broth supplemented with 0.05% Tween 80, a dramatic CFU decrease was observed at the end of the exponential phase. This phase was followed by a stable stationary phase that led to dissociation between the optical density (O.D.) and CFU values, together with the formation of opaque colonies in solid culture. Further analysis revealed that this was due to cording. Scanning electron microscopy showed that cording led to the formation of very stable coiled structures and corded cell aggregations which proved impossible to disrupt by any of the physical means tested. Modulation of cording with a high but non-toxic concentration of Tween 80 led to a slower growth rate, avoidance of a sudden drop-off to the stationary phase, the formation of weaker cording structures and the absence of opaque colonies, together with a lower survival at later time-points. An innovative automated image analysis technique has been devised to characterize the cording process. This analysis has led to important practical consequences for the elaboration of M. tuberculosis inocula and suggests the importance of biofilm formation in survival of the bacilli in the extracellular milieu. Copyright © 2013. Published by Elsevier Ltd.

Role of P27 -P55 operon from Mycobacterium tuberculosis in the resistance to toxic compounds

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Cataldi Angel A

2011-07-01

Full Text Available Abstract Background The P27-P55 (lprG-Rv1410c operon is crucial for the survival of Mycobacterium tuberculosis, the causative agent of human tuberculosis, during infection in mice. P55 encodes an efflux pump that has been shown to provide Mycobacterium smegmatis and Mycobacterium bovis BCG with resistance to several drugs, while P27 encodes a mannosylated glycoprotein previously described as an antigen that modulates the immune response against mycobacteria. The objective of this study was to determine the individual contribution of the proteins encoded in the P27-P55 operon to the resistance to toxic compounds and to the cell wall integrity of M. tuberculosis. Method In order to test the susceptibility of a mutant of M. tuberculosis H37Rv in the P27-P55 operon to malachite green, sodium dodecyl sulfate, ethidium bromide, and first-line antituberculosis drugs, this strain together with the wild type strain and a set of complemented strains were cultivated in the presence and in the absence of these drugs. In addition, the malachite green decolorization rate of each strain was obtained from decolorization curves of malachite green in PBS containing bacterial suspensions. Results The mutant strain decolorized malachite green faster than the wild type strain and was hypersensitive to both malachite green and ethidium bromide, and more susceptible to the first-line antituberculosis drugs: isoniazid and ethambutol. The pump inhibitor reserpine reversed M. tuberculosis resistance to ethidium bromide. These results suggest that P27-P55 functions through an efflux-pump like mechanism. In addition, deletion of the P27-P55 operon made M. tuberculosis susceptible to sodium dodecyl sulfate, suggesting that the lack of both proteins causes alterations in the cell wall permeability of the bacterium. Importantly, both P27 and P55 are required to restore the wild type phenotypes in the mutant. Conclusions The results clearly indicate that P27 and P55 are

The Genotypic Population Structure of Mycobacterium tuberculosis Complex from Moroccan Patients Reveals a Predominance of Euro-American Lineages

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Lahlou, Ouafae; Millet, Julie; Chaoui, Imane; Sabouni, Radia; Filali-Maltouf, Abdelkarim; Akrim, Mohammed; El Mzibri, Mohammed; Rastogi, Nalin; El Aouad, Rajae

2012-01-01

Background Tuberculosis (TB) remains a major health problem in Morocco. Characterization of circulating Mycobacterium tuberculosis genotypic lineages, important to understand the dynamic of the disease, was hereby addressed for the first time at a national level. Methodology/Principal Findings Spoligotyping was performed on a panel of 592 M. tuberculosis complex strains covering a 2-year period (2004–2006). It identified 129 patterns: 105 (n = 568 strains) corresponded to a SIT number in the SITVIT2 database, while 24 patterns were labeled as orphan. A total of 523 (88.3%) strains were clustered vs. 69 or 11.7% unclustered. Classification of strains within 3 large phylogenetical groups was as follows: group 1– ancestral/TbD1+/PGG1 (EAI, Bovis, Africanum), group 2– modern/TbD1−/PGG1 group (Beijing, CAS), group 3– evolutionary recent/TbD1−/PGG2/3 (Haarlem, X, S, T, LAM; alternatively designated as the Euro-American lineage). As opposed to group 3 strains (namely LAM, Haarlem, and T) that predominated (86.5% of all isolates), 6 strains belonged to group 2 (Beijing n = 5, CAS n = 1), and 3 strains (BOV_1 n = 2, BOV_4-CAPRAE) belonged to ancestral group 1 (EAI and AFRI lineage strains were absent). 12-loci MIRU-VNTR typing of the Casablanca subgroup (n = 114 strains) identified 71 patterns: 48 MITs and 23 orphan patterns; it allowed to reduce the clustering rate from 72.8% to 29.8% and the recent transmission rate from 64% to 20.2%. Conclusion The M. tuberculosis population structure in Morocco is highly homogeneous, and is characterized by the predominance of the Euro-American lineages, namely LAM, Haarlem, and T, which belong to the “evolutionary recent” TbD1−/PGG2/3 phylogenetic group. The combination of spoligotyping and MIRUs decreased the clustering rate significantly, and should now be systematically applied in larger studies. The methods used in this study appear well suited to monitor the M. tuberculosis population

Pathology of the emerging Mycobacterium tuberculosis complex pathogen, M. mungi in the banded mongoose (Mungos mungo)

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Wild banded mongooses (Mungos mungo) in northeastern Botswana and Northwest Zimbabwe are infected with a novel Mycobacterium tuberculosis complex pathogen (MTC), M. mungi. This pathogen is transmitted environmentally between mongoose hosts through exposure to infected scent marks used in olfactory c...

Supplementary Material for: Recombination in pe/ppe genes contributes to genetic variation in Mycobacterium tuberculosis lineages

KAUST Repository

Phelan, Jody; Coll, Francesc; Bergval, Indra; Anthony, Richard; Warren, Rob; Sampson, Samantha; Pittius, Nicolaas Gey van; Glynn, Judith; Crampin, Amelia; Alves, Adriana; Bessa, Theolis; Campino, Susana; Dheda, Keertan; Grandjean, Louis; Hasan, Rumina; Hasan, Zahra; Miranda, Anabela; Moore, David; Panaiotov, Stefan; Perdigao, Joao; Portugal, Isabel; Sheen, Patricia; Sousa, Erivelton de Oliveira; Streicher, Elizabeth; Helden, Paul van; Viveiros, Miguel; Hibberd, Martin; Pain, Arnab; McNerney, Ruth; Clark, Taane

2016-01-01

Abstract Background Approximately 10 % of the Mycobacterium tuberculosis genome is made up of two families of genes that are poorly characterized due to their high GC content and highly repetitive nature. The PE and PPE families are typified

INHIBITION OF MYCOLIC ACID TRANSPORT ACROSS THE MYCOBACTERIUM TUBERCULOSIS PLASMA MEMBRANE

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Grzegorzewicz, Anna E.; Pham, Ha; Gundi, Vijay A. K. B.; Scherman, Michael S.; North, Elton J.; Hess, Tamara; Jones, Victoria; Gruppo, Veronica; Born, Sarah E. M.; Korduláková, Jana; Chavadi, Sivagami Sundaram; Morisseau, Christophe; Lenaerts, Anne J.; Lee, Richard E.; McNeil, Michael R.; Jackson, Mary

2011-01-01

New chemotherapeutics active against multidrug-resistant Mycobacterium tuberculosis (M. tb) are urgently needed. We report on the identification of an adamantyl urea compound displaying potent bactericidal activity against M. tb and a unique mode of action, namely the abolition of the translocation of mycolic acids from the cytoplasm where they are synthesized to the periplasmic side of the plasma membrane where they are transferred onto cell wall arabinogalactan or used in the formation of virulence-associated outer membrane trehalose-containing glycolipids. Whole genome sequencing of spontaneous resistant mutants of M. tb selected in vitro followed by genetic validation experiments revealed that our prototype inhibitor targets the inner membrane transporter, MmpL3. Conditional gene expression of mmpL3 in mycobacteria and analysis of inhibitor-treated cells validate MmpL3 as essential for mycobacterial growth and support the involvement of this transporter in the translocation of trehalose monomycolate across the plasma membrane. PMID:22344175

Drug Resistance and Population Structure of Mycobacterium tuberculosis Beijing Strains Isolated in Poland.

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Kozińska, Monika; Augustynowicz-Kopeć, Ewa

2015-01-01

In total, 1095 Mycobacterium tuberculosis clinical isolates from 282 patients with drug-resistant and 813 with drug-sensitive tuberculosis (TB) in Poland during 2007-2011 were analysed. Seventy-one (6.5%) patients were found to have strains of Beijing genotype as defined by spoligotyping. The majority of patients were Polish-born; among foreign-born a large proportion came from Chechnya and Vietnam. Analysis showed strong associations between Beijing genotype infection and MDR, pre-XDR and XDR resistance, with a considerable relative risk among new patients, suggesting that this is due to increased spread of drug-resistant strains rather than acquisition of resistance during treatment.

Mycobacterium tuberculosis Complex Members Adapted to Wild and Domestic Animals.

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Malone, Kerri M; Gordon, Stephen V

2017-01-01

The Mycobacterium tuberculosis complex (MTBC) is composed of several highly genetically related species that can be broadly classified into those that are human-host adapted and those that possess the ability to propagate and transmit in a variety of wild and domesticated animals. Since the initial description of the bovine tubercle bacillus, now known as Mycobacterium bovis, by Theobald Smith in the late 1800's, isolates originating from a wide range of animal hosts have been identified and characterized as M. microti, M. pinnipedii, the Dassie bacillus, M. mungi, M. caprae, M. orygis and M. suricattae. This chapter outlines the events resulting in the identification of each of these animal-adapted species, their close genetic relationships, and how genome-based phylogenetic analyses of species-specific variation amongst MTBC members is beginning to unravel the events that resulted in the evolution of the MTBC and the observed host tropism between the human- and animal-adapted member species.

Design and Construction of a Cloning Vector Containing the hspX Gene of Mycobacterium tuberculosis.

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Yaghoubi, Atieh; Aryan, Ehsan; Zare, Hosna; Alami, Shadi; Teimourpour, Roghayeh; Meshkat, Zahra

2016-10-01

Tuberculosis (TB) is a major cause of death worldwide. Finding an effective vaccine against TB is the best way to control it. Several vaccines against this disease have been developed but none are completely protective. The aim of this study was to design and construct a cloning vector containing the Mycobacterium tuberculosis (M. tuberculosis) heat shock protein X (hspX) . First, an hspX fragment was amplified by PCR and cloned into plasmid pcDNA3.1(+) and recombinant vector was confirmed. A 435 bp hspX fragment was isolated. The fragment was 100% homologous with hspX of M. tuberculosis strain H37Rv in GenBank. In this study, the cloning vector pcDNA3.1(+), containing a 435-bp hspX fragment of M. tuberculosis , was constructed. This could be used as a DNA vaccine to induce immune responses in animal models in future studies.

Mycobacterium tuberculosis Transcription Machinery: Ready To Respond to Host Attacks

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Flentie, Kelly; Garner, Ashley L.

2016-01-01

Regulating responses to stress is critical for all bacteria, whether they are environmental, commensal, or pathogenic species. For pathogenic bacteria, successful colonization and survival in the host are dependent on adaptation to diverse conditions imposed by the host tissue architecture and the immune response. Once the bacterium senses a hostile environment, it must enact a change in physiology that contributes to the organism's survival strategy. Inappropriate responses have consequences; hence, the execution of the appropriate response is essential for survival of the bacterium in its niche. Stress responses are most often regulated at the level of gene expression and, more specifically, transcription. This minireview focuses on mechanisms of regulating transcription initiation that are required by Mycobacterium tuberculosis to respond to the arsenal of defenses imposed by the host during infection. In particular, we highlight how certain features of M. tuberculosis physiology allow this pathogen to respond swiftly and effectively to host defenses. By enacting highly integrated and coordinated gene expression changes in response to stress, M. tuberculosis is prepared for battle against the host defense and able to persist within the human population. PMID:26883824

IFNG-mediated immune responses enhance autophagy against Mycobacterium tuberculosis antigens in patients with active tuberculosis

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Rovetta, Ana I; Peña, Delfina; Hernández Del Pino, Rodrigo E; Recalde, Gabriela M; Pellegrini, Joaquín; Bigi, Fabiana; Musella, Rosa M; Palmero, Domingo J; Gutierrez, Marisa; Colombo, María I; García, Verónica E

2015-01-01

Protective immunity against Mycobacterium tuberculosis (Mtb) requires IFNG. Besides, IFNG-mediated induction of autophagy suppresses survival of virulent Mtb in macrophage cell lines. We investigated the contribution of autophagy to the defense against Mtb antigen (Mtb-Ag) in cells from tuberculosis patients and healthy donors (HD). Patients were classified as high responders (HR) if their T cells produced significant IFNG against Mtb-Ag; and low responders (LR) when patients showed weak or no T cell responses to Mtb-Ag. The highest autophagy levels were detected in HD cells whereas the lowest quantities were observed in LR patients. Interestingly, upon Mtb-Ag stimulation, we detected a positive correlation between IFNG and MAP1LC3B-II/LC3-II levels. Actually, blockage of Mtb-Ag-induced IFNG markedly reduced autophagy in HR patients whereas addition of limited amounts of IFNG significantly increased autophagy in LR patients. Therefore, autophagy collaborates with human immune responses against Mtb in close association with specific IFNG secreted against the pathogen. PMID:25426782

Colorimetric microwell plate reverse-hybridization assay for Mycobacterium tuberculosis detection

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Candice Tosi Michelon

2011-03-01

Full Text Available 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.

Protection against Mycobacterium tuberculosis infection by adoptive immunotherapy. Requirement for T cell-deficient recipients

International Nuclear Information System (INIS)

Orme, I.M.; Collins, F.M.

1983-01-01

The results of this study demonstrate that spleen cells taken from mice at the height of the primary immune response to intravenous infection with Mycobacterium tuberculosis possess the capacity to transfer adoptive protection to M. tuberculosis-infected recipients, but only if these recipients are first rendered T cell-deficient, either by thymectomy and gamma irradiation, or by sublethal irradiation. A similar requirement was necessary to demonstrate the adoptive protection of the lungs after exposure to an acute aerosol-delivered M. tuberculosis infection. In both infectious models successful adoptive immunotherapy was shown to be mediated by T lymphocytes, which were acquired in the donor animals in response to the immunizing infection. It is proposed that the results of this study may serve as a basic model for the subsequent analysis of the nature of the T cell-mediated immune response to both systemic and aerogenic infections with M. tuberculosis

Mutations in ppe38 block PE_PGRS secretion and increase virulence of Mycobacterium tuberculosis.

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Ates, Louis S; Dippenaar, Anzaan; Ummels, Roy; Piersma, Sander R; van der Woude, Aniek D; van der Kuij, Kim; Le Chevalier, Fabien; Mata-Espinosa, Dulce; Barrios-Payán, Jorge; Marquina-Castillo, Brenda; Guapillo, Carolina; Jiménez, Connie R; Pain, Arnab; Houben, Edith N G; Warren, Robin M; Brosch, Roland; Hernández-Pando, Rogelio; Bitter, Wilbert

2018-02-01

Mycobacterium tuberculosis requires a large number of secreted and exported proteins for its virulence, immune modulation and nutrient uptake. Most of these proteins are transported by the different type VII secretion systems 1,2 . The most recently evolved type VII secretion system, ESX-5, secretes dozens of substrates belonging to the PE and PPE families, which are named for conserved proline and glutamic acid residues close to the amino terminus 3,4 . However, the role of these proteins remains largely elusive 1 . Here, we show that mutations of ppe38 completely block the secretion of two large subsets of ESX-5 substrates, that is, PPE-MPTR and PE_PGRS, together comprising >80 proteins. Importantly, hypervirulent clinical M. tuberculosis strains of the Beijing lineage have such a mutation and a concomitant loss of secretion 5 . Restoration of PPE38-dependent secretion partially reverted the hypervirulence phenotype of a Beijing strain, and deletion of ppe38 in moderately virulent M. tuberculosis increased virulence. This indicates that these ESX-5 substrates have an important role in virulence attenuation. Phylogenetic analysis revealed that deletion of ppe38 occurred at the branching point of the 'modern' Beijing sublineage and is shared by Beijing outbreak strains worldwide, suggesting that this deletion may have contributed to their success and global distribution 6,7 .

Mutations in ppe38 block PE_PGRS secretion and increase virulence of Mycobacterium tuberculosis

KAUST Repository

Ates, Louis S.

2018-01-12

Mycobacterium tuberculosis requires a large number of secreted and exported proteins for its virulence, immune modulation and nutrient uptake. Most of these proteins are transported by the different type VII secretion systems1,2. The most recently evolved type VII secretion system, ESX-5, secretes dozens of substrates belonging to the PE and PPE families, which are named for conserved proline and glutamic acid residues close to the amino terminus3,4. However, the role of these proteins remains largely elusive1. Here, we show that mutations of ppe38 completely block the secretion of two large subsets of ESX-5 substrates, that is, PPE-MPTR and PE_PGRS, together comprising >80 proteins. Importantly, hypervirulent clinical M. tuberculosis strains of the Beijing lineage have such a mutation and a concomitant loss of secretion5. Restoration of PPE38-dependent secretion partially reverted the hypervirulence phenotype of a Beijing strain, and deletion of ppe38 in moderately virulent M. tuberculosis increased virulence. This indicates that these ESX-5 substrates have an important role in virulence attenuation. Phylogenetic analysis revealed that deletion of ppe38 occurred at the branching point of the ‘modern’ Beijing sublineage and is shared by Beijing outbreak strains worldwide, suggesting that this deletion may have contributed to their success and global distribution6,7.

Mutations in ppe38 block PE_PGRS secretion and increase virulence of Mycobacterium tuberculosis

KAUST Repository

Ates, Louis S.; Dippenaar, Anzaan; Ummels, Roy; Piersma, Sander R.; van der Woude, Aniek D.; van der Kuij, Kim; Le Chevalier, Fabien; Mata-Espinosa, Dulce; Barrios-Payá n, Jorge; Marquina-Castillo, Brenda; Guapillo, Carolina; Jimé nez, Connie R.; Pain, Arnab; Houben, Edith N. G.; Warren, Robin M.; Brosch, Roland; Herná ndez-Pando, Rogelio; Bitter, Wilbert

2018-01-01

Mycobacterium tuberculosis requires a large number of secreted and exported proteins for its virulence, immune modulation and nutrient uptake. Most of these proteins are transported by the different type VII secretion systems1,2. The most recently evolved type VII secretion system, ESX-5, secretes dozens of substrates belonging to the PE and PPE families, which are named for conserved proline and glutamic acid residues close to the amino terminus3,4. However, the role of these proteins remains largely elusive1. Here, we show that mutations of ppe38 completely block the secretion of two large subsets of ESX-5 substrates, that is, PPE-MPTR and PE_PGRS, together comprising >80 proteins. Importantly, hypervirulent clinical M. tuberculosis strains of the Beijing lineage have such a mutation and a concomitant loss of secretion5. Restoration of PPE38-dependent secretion partially reverted the hypervirulence phenotype of a Beijing strain, and deletion of ppe38 in moderately virulent M. tuberculosis increased virulence. This indicates that these ESX-5 substrates have an important role in virulence attenuation. Phylogenetic analysis revealed that deletion of ppe38 occurred at the branching point of the ‘modern’ Beijing sublineage and is shared by Beijing outbreak strains worldwide, suggesting that this deletion may have contributed to their success and global distribution6,7.

LytB1 and LytB2 of Mycobacterium tuberculosis Are Not Genetically Redundant.

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Amanda Claire Brown

Full Text Available Mycobacterium tuberculosis synthesises isoprenoid precursors via the MEP/DOXP pathway and at least five enzymes in the pathway (Dxs1, Dxr/IspC, IspD, IspF, and GcpE/IspG are required for growth in vitro. We investigated the role of LytB (IspH in M. tuberculosis; M. tuberculosis is unusual in that it has two homologs-LytB1 and LytB2. We were unable to delete the lytB2 gene unless we provided an additional copy elsewhere, demonstrating that this is the essential homolog. We expressed lytB1 from the lytB2 promoter and confirmed that this could not complement for loss of function of lytB2, despite LytB1 possessing all the previously described conserved critical residues. Interestingly the sole LytB homolog of Mycobacterium smegmatis was able to compensate for loss of LytB2 in M. tuberculosis. We tested translational fusions of LytB1 and LytB2 for functionality in M. tuberculosis, but only a fusion with 90% N-terminal LytB2 and 10% C-terminal LytB1 was functional. In order to identify the key difference between the two proteins, site directed mutagenesis was used to change LytB2 residues into their counterparts in LytB1. None of these amino acid substitutions was essential for function and all lytB2 mutant alleles were functional. In contrast, mutation of the key residues for [Fe4S4] cluster formation, as well as a catalytic residue in LytB1 did not result in functional complementation. Thus, although LytB1 and LytB2 are not genetically redundant, this is not dependent on small amino acid changes, but is likely to be a result of major overall structural differences.

Common Bile Duct Perforation Due to Tuberculosis: A Case Report

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Razman Jarmin

2004-10-01

Full Text Available A young man with HIV presented with biliary peritonitis secondary to spontaneous common bile duct perforation. Investigation revealed that the perforation was due to Mycobacterium tuberculosis. Tuberculosis of the bile duct is uncommon and usually presents with obstructive jaundice due to stricture. Bile duct perforation due to tuberculosis is extremely rare. Its management is discussed.

Expression, purification and preliminary crystallographic analysis of Mycobacterium tuberculosis CysQ, a phosphatase involved in sulfur metabolism

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Erickson, Anna I.; Sarsam, Reta D.; Fisher, Andrew J., E-mail: ajfisher@ucdavis.edu

2014-05-10

The cysQ gene from Mycobacterium tuberculosis was cloned and the expressed protein, a 3′-phosphoadenosine-5′’-phosphatase, was purified and crystallized. X-ray diffraction data were collected to 1.7 Å resolution.

MicroRNA-27b Modulates Inflammatory Response and Apoptosis during Mycobacterium tuberculosis Infection.

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Liang, Shuxin; Song, Zhigang; Wu, Yongyan; Gao, Yuanpeng; Gao, Mingqing; Liu, Fayang; Wang, Fengyu; Zhang, Yong

2018-04-16

Mycobacterium tuberculosis poses a significant global health threat. MicroRNAs play an important role in regulating host anti-mycobacterial defense; however, their role in apoptosis-mediated mycobacterial elimination and inflammatory response remains unclear. In this study, we explored the role of microRNA-27b (miR-27b) in murine macrophage responses to M. tuberculosis infection. We uncovered that the TLR-2/MyD88/NF-κB signaling pathway induced the expression of miR-27b and miR-27b suppressed the production of proinflammatory factors and the activity of NF-κB, thereby avoiding an excessive inflammation during M. tuberculosis infection. Luciferase reporter assay and Western blotting showed that miR-27b directly targeted Bcl-2-associated athanogene 2 (Bag2) in macrophages. Overexpression of Bag2 reversed miR-27b-mediated inhibition of the production of proinflammatory factors. In addition, miR-27b increased p53-dependent cell apoptosis and the production of reactive oxygen species and decreased the bacterial burden. We also showed that Bag2 interacts with p53 and negatively regulates its activity, thereby controlling cell apoptosis and facilitating bacterial survival. In summary, we revealed a novel role of the miR-27b/Bag2 axis in the regulation of inflammatory response and apoptosis and provide a potential molecular host defense mechanism against mycobacteria. Copyright © 2018 by The American Association of Immunologists, Inc.

Crystal structure of the apurinic/apyrimidinic endonuclease IV from Mycobacterium tuberculosis.

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Zhang, Wei; Xu, Yueyang; Yan, Mengrong; Li, Shanshan; Wang, Huiying; Yang, Haitao; Zhou, Weihong; Rao, Zihe

2018-03-25

Endonuclease IV is a typical endonuclease of the apurinic-apyrimidinic (AP) or abasic endonuclease superfamily. It repairs damaged DNA through base excision repair by cleaving the DNA backbone immediately 5' of an AP site. In Mycobacterium tuberculosis, endonuclease IV is the major AP endonuclease. This enzyme is absent from mammalian cells, making it an attractive target for anti-tuberculosis drug development. In this study, the structure of the recombinant endonuclease IV from M. tuberculosis (MtbEndo IV) was determined at a high resolution of 1.18 Å. MtbEndo IV was found to have a classical α8β8-fold TIM barrel with loops on its surface connecting the α-helices and β-strands that constitute a groove for DNA binding. Three zinc ions were identified at the active site. A comparison between the structures of MtbEndo IV and Escherichia coli End IV suggested that Gln32 of MtbEndo IV may plays a role in regulating substrate binding. Copyright © 2018. Published by Elsevier Inc.

Unanticipated Mycobacterium tuberculosis complex culture inhibition by immune modulators, immune suppressants, a growth enhancer, and vitamins A and D: clinical implications.

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Greenstein, Robert J; Su, Liya; Shahidi, Azra; Brown, William D; Clifford, Anya; Brown, Sheldon T

2014-09-01

The development of novel antibiotics to treat multidrug-resistant (MDR) tuberculosis is time-consuming and expensive. Multiple immune modulators, immune suppressants, anti-inflammatories, and growth enhancers, and vitamins A and D, inhibit Mycobacterium avium subspecies paratuberculosis (MAP) in culture. We studied the culture inhibition of Mycobacterium tuberculosis complex by these agents. Biosafety level two M. tuberculosis complex (ATCC 19015 and ATCC 25177) was studied in radiometric Bactec or MGIT culture. Agents evaluated included clofazimine, methotrexate, 6-mercaptopurine, cyclosporine A, rapamycin, tacrolimus, monensin, and vitamins A and D. All the agents mentioned above caused dose-dependent inhibition of the M. tuberculosis complex. There was no inhibition by the anti-inflammatory 5-aminosalicylic acid, which causes bacteriostatic inhibition of MAP. We conclude that, at a minimum, studies with virulent M. tuberculosis are indicated with the agents mentioned above, as well as with the thioamide 5-propothiouricil, which has previously been shown to inhibit the M. tuberculosis complex in culture. Our data additionally emphasize the importance of vitamins A and D in treating mycobacterial diseases. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Amperometric immunosensor for rapid detection of Mycobacterium tuberculosis

International Nuclear Information System (INIS)

Hiraiwa, Morgan; Lee, Hyun-Boo; Inoue, Shinnosuke; Chung, Jae-Hyun; Kim, Jong-Hoon; Becker, Annie L; Weigel, Kris M; Cangelosi, Gerard A; Lee, Kyong-Hoon

2015-01-01

Tuberculosis (TB) has been a major public health problem, which can be better controlled by using accurate and rapid diagnosis in low-resource settings. A simple, portable, and sensitive detection method is required for point-of-care (POC) settings. This paper studies an amperometric biosensor using a microtip immunoassay for a rapid and low-cost detection of Mycobacterium tuberculosis (MTB) in sputum. MTB in sputum is specifically captured on the functionalized microtip surface and detected by electric current. According to the numerical study, the current signal on the microtip surface is linearly changed with increasing immersion depth. Using a reference microtip, the immersion depth is compensated for a sensing microtip. On the microtip surface, target bacteria are concentrated and organized by a coffee-ring effect, which amplifies the electric current. To enhance the signal-to-noise ratio, both the sample processing and rinsing steps are presented with the use of deionized water as a medium for the amperometric measurement. When applied to cultured MTB cells spiked into human sputum, the detection limit was 100 CFU mL −1 , comparable to a more labor-intensive fluorescence detection method reported previously. (paper)

Amperometric immunosensor for rapid detection of Mycobacterium tuberculosis

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Hiraiwa, Morgan; Kim, Jong-Hoon; Lee, Hyun-Boo; Inoue, Shinnosuke; Becker, Annie L.; Weigel, Kris M.; Cangelosi, Gerard A.; Lee, Kyong-Hoon; Chung, Jae-Hyun

2015-05-01

Tuberculosis (TB) has been a major public health problem, which can be better controlled by using accurate and rapid diagnosis in low-resource settings. A simple, portable, and sensitive detection method is required for point-of-care (POC) settings. This paper studies an amperometric biosensor using a microtip immunoassay for a rapid and low-cost detection of Mycobacterium tuberculosis (MTB) in sputum. MTB in sputum is specifically captured on the functionalized microtip surface and detected by electric current. According to the numerical study, the current signal on the microtip surface is linearly changed with increasing immersion depth. Using a reference microtip, the immersion depth is compensated for a sensing microtip. On the microtip surface, target bacteria are concentrated and organized by a coffee-ring effect, which amplifies the electric current. To enhance the signal-to-noise ratio, both the sample processing and rinsing steps are presented with the use of deionized water as a medium for the amperometric measurement. When applied to cultured MTB cells spiked into human sputum, the detection limit was 100 CFU mL-1, comparable to a more labor-intensive fluorescence detection method reported previously.

Structure of Ribosomal Silencing Factor Bound to Mycobacterium tuberculosis Ribosome.

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Li, Xiaojun; Sun, Qingan; Jiang, Cai; Yang, Kailu; Hung, Li-Wei; Zhang, Junjie; Sacchettini, James C

2015-10-06

The ribosomal silencing factor RsfS slows cell growth by inhibiting protein synthesis during periods of diminished nutrient availability. The crystal structure of Mycobacterium tuberculosis (Mtb) RsfS, together with the cryo-electron microscopy (EM) structure of the large subunit 50S of Mtb ribosome, reveals how inhibition of protein synthesis by RsfS occurs. RsfS binds to the 50S at L14, which, when occupied, blocks the association of the small subunit 30S. Although Mtb RsfS is a dimer in solution, only a single subunit binds to 50S. The overlap between the dimer interface and the L14 binding interface confirms that the RsfS dimer must first dissociate to a monomer in order to bind to L14. RsfS interacts primarily through electrostatic and hydrogen bonding to L14. The EM structure shows extended rRNA density that it is not found in the Escherichia coli ribosome, the most striking of these being the extended RNA helix of H54a. Copyright © 2015 Elsevier Ltd. All rights reserved.

Learn About Tuberculosis

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... Diseases > Lung Disease Lookup > Tuberculosis (TB) Learn About Tuberculosis Tuberculosis (TB) is an airborne bacterial infection caused by the organism Mycobacterium tuberculosis that primarily affects the lungs, although other organs ...

Tuberculosis

Science.gov (United States)

Friend, Milton

1999-01-01

Avian tuberculosis is usually caused by the bacterium Mycobacterium avium. At least 20 different types of M. avium have been identified, only three of which are known to cause disease in birds. Other types of Mycobacterium rarely cause tuberculosis in most avian species; however, parrots, macaws, and other large perching birds are susceptible to human and bovine types of tuberculosis bacilli. Avian tuberculosis generally is transmitted by direct contact with infected birds, ingestion of contaminated feed and water, or contact with a contaminated environment. Inhalation of the bacterium can cause respiratory tract infections. Wild bird studies in the Netherlands disclosed tuberculosis-infected puncture-type injuries in birds of prey that fight at the nest site (kestrels) or on the ground (buteo-type buzzards), but tuberculosisinfected injuries were not found in accipiters (falco

Purification, crystallization and preliminary X-ray crystallographic studies of Rv3705c from Mycobacterium tuberculosis

International Nuclear Information System (INIS)

Lu, Feifei; Gao, Feng; Li, Honglin; Gong, Weimin; Zhou, Lin; Bi, Lijun

2014-01-01

The cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of Rv3705c from M. tuberculosis are described. The conserved protein Rv3705c from Mycobacterium tuberculosis has been cloned, expressed, purified and crystallized by the sitting-drop vapour-diffusion method using PEG 3350 as a precipitant. The Rv3705c crystals exhibited space group P6 1 22 or P6 5 22, with unit-cell parameters a = b = 198.0, c = 364.1 Å, α = β = 90, γ = 120°, and diffracted to a resolution of 3.3 Å

Purification, crystallization and preliminary X-ray crystallographic studies of Rv3705c from Mycobacterium tuberculosis

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Lu, Feifei [East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People’s Republic of (China); Gao, Feng [Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People’s Republic of (China); Li, Honglin [East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People’s Republic of (China); Gong, Weimin [Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People’s Republic of (China); Zhou, Lin, E-mail: gdtb-bg@vip.163.com [Center for Tuberculosis Control of Guangdong Province, Guangzhou, People’s Republic of (China); Bi, Lijun, E-mail: gdtb-bg@vip.163.com [East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People’s Republic of (China)

2014-07-23

The cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of Rv3705c from M. tuberculosis are described. The conserved protein Rv3705c from Mycobacterium tuberculosis has been cloned, expressed, purified and crystallized by the sitting-drop vapour-diffusion method using PEG 3350 as a precipitant. The Rv3705c crystals exhibited space group P6{sub 1}22 or P6{sub 5}22, with unit-cell parameters a = b = 198.0, c = 364.1 Å, α = β = 90, γ = 120°, and diffracted to a resolution of 3.3 Å.