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Sample records for intracellular mycobacterium tuberculosis

  1. 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

    that siderocalin expression is upregulated following M.tb infection of mouse macrophage cell lines and primary murine alveolar macrophages. Furthermore, siderocalin added exogenously as a recombinant protein or overexpressed in the RAW264.7 macrophage cell line inhibited the intracellular growth of the pathogen......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....... A variant form of siderocalin, which is expressed only in the macrophage cytosol, inhibited intracellular M.tb growth as effectively as the normal, secreted form, an observation that provides mechanistic insight into how siderocalin might influence iron acquisition by the bacteria in the phagosome. Our...

  2. 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...

  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....

  4. Analysis of intracellular expressed proteins of Mycobacterium tuberculosis clinical isolates

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    Singhal Neelja

    2012-03-01

    Full Text Available Abstract Background Tuberculosis (TB is the most threatening infectious disease globally. Although progress has been made to reduce global incidence of TB, emergence of multidrug resistant (MDR TB threatens to undermine these advances. To combat the disease, novel intervention strategies effective against drug resistant and sensitive subpopulations of M. tuberculosis are urgently required as adducts in the present treatment regimen. Using THP-1 cells we have analyzed and compared the global protein expression profile of broth-cultured and intraphagosomally grown drug resistant and sensitive M.tuberculosis clinical isolates. Results On comparing the two dimensional (2-DE gels, many proteins were found to be upregulated/expressed during intracellular state which were identified by matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS. Four proteins (adenosylhomocysteinase, aspartate carbomyltransferase, putatitive thiosulfate sulfurtransferase and universal stress protein were present in both intracellular MDR and sensitive isolates and three of these belonged to intermediary metabolism and respiration category. Two proteins (alanine dehydrogenase and adenosine kinase of intracellular MDR isolate and two (glucose-6-phosphate isomerase and ATP synthase epsilon chain of intracellular sensitive isolate belonged to intermediary metabolism and respiration category. One protein (Peroxidase/Catalase of intracellular MDR and three (HSPX, 14 kDa antigen and 10 kDa chaperonin of sensitive isolate belonged to virulence, detoxification and adaptation category. ESAT-6 of intracellular MDR belonged to cell wall and cell processes category. Two proteins (Antigen 85-C and Antigen 85-A of intracellular sensitive isolate were involved in lipid metabolism while probable peptidyl-prolyl cis-trans isomerase A was involved in information pathways. Four (Rv0635, Rv1827, Rv0036c and Rv2032 of intracellular MDR and two proteins (Rv2896c and Rv2558c of

  5. Mycobacterium tuberculosis.

    Science.gov (United States)

    Koch, Anastasia; Mizrahi, Valerie

    2018-03-23

    In this infographic, the genetics, phylogeny, physiology, and pathogenesis mechanisms of Mycobacterium tuberculosis are shown. Mycobacterium tuberculosis is the etiological agent of tuberculosis (TB), the leading cause of death due to a single infectious agent, claiming 1.7 million lives in 2016. Of the deaths attributable to TB in 2016, 22% occurred in people coinfected with HIV, and close to 5% of the 10.4 million incident cases of this disease were resistant to at least two of the first-line TB drugs. In this infographic, we describe the fundamental features of the genetics, phylogeny, and physiology of this member of the phylum Actinobacteria, which is associated increasingly with drug resistance mediated by mutations and rearrangements in its single, circular chromosome. We also highlight the key pathogenesis mechanisms employed by this slow-growing, facultative intracellular bacterium, which include avoidance of host cell clearance by arrest of the normal macrophage maturation process. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Intracellular activity of tedizolid phosphate and ACH-702 versus Mycobacterium tuberculosis infected macrophages.

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    Molina-Torres, Carmen A; Barba-Marines, Alejandra; Valles-Guerra, Orestes; Ocampo-Candiani, Jorge; Cavazos-Rocha, Norma; Pucci, Michael J; Castro-Garza, Jorge; Vera-Cabrera, Lucio

    2014-04-04

    Due to the emergency of multidrug-resistant strains of Mycobacterium tuberculosis, is necessary the evaluation of new compounds. Tedizolid, a novel oxazolidinone, and ACH-702, a new isothiazoloquinolone, were tested against M. tuberculosis infected THP-1 macrophages. These two compounds significantly decreased the number of intracellular mycobacteria at 0.25X, 1X, 4X and 16X the MIC value. The drugs were tested either in nanoparticules or in free solution. Tedizolid and ACH-702 have a good intracellular killing activity comparable to that of rifampin or moxifloxacin.

  7. Linking the transcriptional profiles and the physiological states of Mycobacterium tuberculosis during an extended intracellular infection.

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    Kyle H Rohde

    Full Text Available Intracellular pathogens such as Mycobacterium tuberculosis have evolved strategies for coping with the pressures encountered inside host cells. The ability to coordinate global gene expression in response to environmental and internal cues is one key to their success. Prolonged survival and replication within macrophages, a key virulence trait of M. tuberculosis, requires dynamic adaptation to diverse and changing conditions within its phagosomal niche. However, the physiological adaptations during the different phases of this infection process remain poorly understood. To address this knowledge gap, we have developed a multi-tiered approach to define the temporal patterns of gene expression in M. tuberculosis in a macrophage infection model that extends from infection, through intracellular adaptation, to the establishment of a productive infection. Using a clock plasmid to measure intracellular replication and death rates over a 14-day infection and electron microscopy to define bacterial integrity, we observed an initial period of rapid replication coupled with a high death rate. This was followed by period of slowed growth and enhanced intracellular survival, leading finally to an extended period of net growth. The transcriptional profiles of M. tuberculosis reflect these physiological transitions as the bacterium adapts to conditions within its host cell. Finally, analysis with a Transcriptional Regulatory Network model revealed linked genetic networks whereby M. tuberculosis coordinates global gene expression during intracellular survival. The integration of molecular and cellular biology together with transcriptional profiling and systems analysis offers unique insights into the host-driven responses of intracellular pathogens such as M. tuberculosis.

  8. Clinical Concentrations of Thioridazine Kill Intracellular Multidrug-Resistant Mycobacterium tuberculosis

    Science.gov (United States)

    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

  9. Killing of intracellular Mycobacterium tuberculosis by receptor-mediated drug delivery

    International Nuclear Information System (INIS)

    Majumdar, S.; Basu, S.K.

    1991-01-01

    p-Aminosalicylic acid (PAS) conjugated to maleylated bovine serum albumin (MBSA) was taken up efficiently through high-affinity MBSA-binding sites on macrophages. Binding of the radiolabeled conjugate to cultured mouse peritoneal macrophages at 4 degrees C was competed for by MBSA but not by PAS. At 37 degrees C, the radiolabeled conjugate was rapidly degraded by the macrophages, leading to release of acid-soluble degradation products in the medium. The drug conjugate was nearly 100 times as effective as free PAS in killing the intracellular mycobacteria in mouse peritoneal macrophages infected in culture with Mycobacterium tuberculosis. The killing of intracellular mycobacteria mediated by the drug conjugate was effectively prevented by simultaneous addition of excess MBSA (100 micrograms/ml) or chloroquine (3 microM) to the medium, whereas these agents did not affect the microbicidal action of free PAS. These results suggest that (i) uptake of the PAS-MBSA conjugate was mediated by cell surface receptors on macrophages which recognize MBSA and (ii) lysosomal hydrolysis of the internalized conjugate resulted in intracellular release of a pharmacologically active form of the drug, which led to selective killing of the M. tuberculosis harbored by mouse macrophages infected in culture. This receptor-mediated modality of delivering drugs to macrophages could contribute to greater therapeutic efficacy and minimization of toxic side effects in the management of tuberculosis and other intracellular mycobacterial infections

  10. 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

    Directory of Open Access Journals (Sweden)

    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

  11. Mycobacterium tuberculosis

    Science.gov (United States)

    Zhang, Susan; Burns-Huang, Kristin E; Janssen, Guido V; Li, Huilin; Ovaa, Huib; Hedstrom, Lizbeth; Darwin, K Heran

    2017-02-21

    The protein degradation machinery of Mycobacterium tuberculosis includes a proteasome and a ubiquitin-like protein (Pup). Proteasome accessory factor A (PafA) attaches Pup to proteins to target them for degradation by the proteasome. Free Pup is unstable and never observed in extracts of M. tuberculosis , an observation that led us to hypothesize that PafA may need alternative sources of Pup. Here, we show that PafA can move Pup from one proteasome substrate, inositol 1-phosphate synthetase (Ino1), to two different proteins, malonyl coenzyme A (CoA)-acyl carrier protein transacylase (FabD) and lonely guy (Log). This apparent "transpupylation" reaction required a previously unrecognized depupylase activity in PafA, and, surprisingly, this depupylase activity was much more efficient than the activity of the dedicated depupylase Dop (deamidase of Pup). Thus, PafA can potentially use both newly synthesized Pup and recycled Pup to doom proteins for degradation. IMPORTANCE Unlike eukaryotes, which contain hundreds of ubiquitin ligases, Pup-containing bacteria appear to have a single ligase to pupylate dozens if not hundreds of different proteins. The observation that PafA can depupylate and transpupylate in vitro offers new insight into how protein stability is regulated in proteasome-bearing bacteria. Importantly, PafA and the dedicated depupylase Dop are each required for the full virulence of Mycobacterium tuberculosis Thus, inhibition of both enzymes may be extremely attractive for the development of therapeutics against tuberculosis. Copyright © 2017 Zhang et al.

  12. Activity of Medicinal Plant Extracts on Multiplication of Mycobacterium tuberculosis under Reduced Oxygen Conditions Using Intracellular and Axenic Assays.

    Science.gov (United States)

    Bhatter, Purva D; Gupta, Pooja D; Birdi, Tannaz J

    2016-01-01

    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.

  13. Intracellular bacillary burden reflects a burst size for Mycobacterium tuberculosis in vivo.

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    Teresa Repasy

    2013-02-01

    Full Text Available We previously reported that Mycobacterium tuberculosis triggers macrophage necrosis in vitro at a threshold intracellular load of ~25 bacilli. This suggests a model for tuberculosis where bacilli invading lung macrophages at low multiplicity of infection proliferate to burst size and spread to naïve phagocytes for repeated cycles of replication and cytolysis. The current study evaluated that model in vivo, an environment significantly more complex than in vitro culture. In the lungs of mice infected with M. tuberculosis by aerosol we observed three distinct mononuclear leukocyte populations (CD11b(- CD11c(+/hi, CD11b(+/lo CD11c(lo/-, CD11b(+/hi CD11c(+/hi and neutrophils hosting bacilli. Four weeks after aerosol challenge, CD11b(+/hi CD11c(+/hi mononuclear cells and neutrophils were the predominant hosts for M. tuberculosis while CD11b(+/lo CD11c(lo/- cells assumed that role by ten weeks. Alveolar macrophages (CD11b(- CD11c(+/hi were a minority infected cell type at both time points. The burst size model predicts that individual lung phagocytes would harbor a range of bacillary loads with most containing few bacilli, a smaller proportion containing many bacilli, and few or none exceeding a burst size load. Bacterial load per cell was enumerated in lung monocytic cells and neutrophils at time points after aerosol challenge of wild type and interferon-γ null mice. The resulting data fulfilled those predictions, suggesting a median in vivo burst size in the range of 20 to 40 bacilli for monocytic cells. Most heavily burdened monocytic cells were nonviable, with morphological features similar to those observed after high multiplicity challenge in vitro: nuclear condensation without fragmentation and disintegration of cell membranes without apoptotic vesicle formation. Neutrophils had a narrow range and lower peak bacillary burden than monocytic cells and some exhibited cell death with release of extracellular neutrophil traps. Our studies suggest

  14. Mycobacterium tuberculosis

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    Namugenyi, Sarah B; Aagesen, Alisha M; Elliott, Sarah R; Tischler, Anna D

    2017-07-11

    The Mycobacterium tuberculosis phosphate-specific transport (Pst) system controls gene expression in response to phosphate availability by inhibiting the activation of the SenX3-RegX3 two-component system under phosphate-rich conditions, but the mechanism of communication between these systems is unknown. In Escherichia coli , inhibition of the two-component system PhoR-PhoB under phosphate-rich conditions requires both the Pst system and PhoU, a putative adaptor protein. E. coli PhoU is also involved in the formation of persisters, a subpopulation of phenotypically antibiotic-tolerant bacteria. M. tuberculosis encodes two PhoU orthologs, PhoY1 and PhoY2. We generated phoY single- and double-deletion mutants and examined the expression of RegX3-regulated genes by quantitative reverse transcription-PCR (qRT-PCR). Gene expression was increased only in the Δ phoY1 Δ phoY2 double mutant and could be restored to the wild-type level by complementation with either phoY1 or phoY2 or by deletion of regX3 These data suggest that the PhoY proteins function redundantly to inhibit SenX3-RegX3 activation. We analyzed the frequencies of antibiotic-tolerant persister variants in the phoY mutants using several antibiotic combinations. Persister frequency was decreased at least 40-fold in the Δ phoY1 Δ phoY2 mutant compared to the frequency in the wild type, and this phenotype was RegX3 dependent. A Δ pstA1 mutant lacking a Pst system transmembrane component exhibited a similar RegX3-dependent decrease in persister frequency. In aerosol-infected mice, the Δ phoY1 Δ phoY2 and Δ pstA1 mutants were more susceptible to treatment with rifampin but not isoniazid. Our data demonstrate that disrupting phosphate sensing mediated by the PhoY proteins and the Pst system enhances the susceptibility of M. tuberculosis to antibiotics both in vitro and during infection. IMPORTANCE Persister variants, subpopulations of bacteria that are phenotypically antibiotic tolerant, contribute to

  15. Identification of host-dependent survival factors for intracellular Mycobacterium tuberculosis through an siRNA screen.

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    Shilpi Jayaswal

    2010-04-01

    Full Text Available The stable infection of host macrophages by Mycobacterium tuberculosis (Mtb involves, and depends on, the attenuation of the diverse microbicidal responses mounted by the host cell. This is primarily achieved through targeted perturbations of the host cellular signaling machinery. Therefore, in view of the dependency of the pathogen on host molecules for its intracellular survival, we wanted to test whether targeting such factors could provide an alternate route for the therapeutic management of tuberculosis. To first identify components of the host signaling machinery that regulate intracellular survival of Mtb, we performed an siRNA screen against all known kinases and phosphatases in murine macrophages infected with the virulent strain, H37Rv. Several validated targets could be identified by this method where silencing led either to a significant decrease, or enhancement in the intracellular mycobacterial load. To further resolve the functional relevance of these targets, we also screened against these identified targets in cells infected with different strains of multiple drug-resistant mycobacteria which differed in terms of their intracellular growth properties. The results obtained subsequently allowed us to filter the core set of host regulatory molecules that functioned independently of the phenotypic variations exhibited by the pathogen. Then, using a combination of both in vitro and in vivo experimentation, we could demonstrate that at least some of these host factors provide attractive targets for anti-TB drug development. These results provide a "proof-of-concept" demonstration that targeting host factors subverted by intracellular Mtb provides an attractive and feasible strategy for the development of anti-tuberculosis drugs. Importantly, our findings also emphasize the advantage of such an approach by establishing its equal applicability to infections with Mtb strains exhibiting a range of phenotypic diversifications, including

  16. of Mycobacterium tuberculosis

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-18

    Aug 18, 2009 ... Recombinant and synthetic peptides to identify. Mycobacterium tuberculosis antigens and epitopes of diagnostic and vaccine relevance. Tuberculosis. 85: 367–376. Okkels LM, Andersen P (2004). Protein-protein interactions of proteins from the ESAT-6 family of Mycobacterium tuberculosis. J. Bacteriol.

  17. Mycobacterium bovis (Bovine Tuberculosis) in Humans

    Science.gov (United States)

    Mycobacterium bovis (Bovine Tuberculosis) in Humans What is Mycobacterium bovis ? In the United States, the majority of tuberculosis (TB) cases in people are caused by Mycobacterium tuberculosis (M. tuberculosis). Mycobacterium bovis (M. bovis) is ...

  18. A docking study of enhanced intracellular survival protein from Mycobacterium tuberculosis with human DUSP16/MKP-7

    International Nuclear Information System (INIS)

    Yoon, Hye-Jin; Kim, Kyoung Hoon; Yang, Jin Kuk; Suh, Se Won; Kim, Hyunsik; Jang, Soonmin

    2013-01-01

    A docking study of Mtb Eis with its substrate DUSP16/MKP-7 was performed. The docking model suggests dissociation of hexameric Mtb Eis into dimers or monomers. The intracellular pathogen Mycobacterium tuberculosis (Mtb) causes tuberculosis, and one of its secreted effector proteins, called enhanced intracellular survival (Eis) protein, enhances its survival in macrophages. Mtb Eis activates JNK-specific dual-specificity protein phosphatase 16 (DUSP16)/mitogen-activated protein kinase phosphatase-7 (MKP-7) through the acetylation on Lys55, thus inactivating JNK by dephosphorylation. Based on the recently reported crystal structure of Mtb Eis, a docking model for the binding of Mtb Eis to DUSP16/MKP-7 was generated. In the docking model, the substrate helix containing Lys55 of DUSP16/MKP-7 fits nicely into the active-site cleft of Mtb Eis; the twisted β-sheet of Eis domain II embraces the substrate helix from one side. Most importantly, the side-chain of Lys55 is inserted toward acetyl-CoA and the resulting distance is 4.6 Å between the NZ atom of Lys55 and the carbonyl carbon of the acetyl group in acetyl-CoA. The binding of Mtb Eis and DUSP16/MKP-7 is maintained by strong electrostatic interactions. The active-site cleft of Mtb Eis has a negatively charged surface formed by Asp25, Glu138, Asp286, Glu395 and the terminal carboxylic group of Phe396. In contrast, DUSP16/MKP-7 contains five basic residues, Lys52, Lys55, Arg56, Arg57 and Lys62, which point toward the negatively charged surface of the active-site pocket of Mtb Eis. Thus, the current docking model suggests that the binding of DUSP16/MKP-7 to Mtb Eis should be established by charge complementarity in addition to a very favorable geometric arrangement. The suggested mode of binding requires the dissociation of the hexameric Mtb Eis into dimers or monomers. This study may be useful for future studies aiming to develop inhibitors of Mtb Eis as a new anti-tuberculosis drug candidate

  19. The Mycobacterium tuberculosis homologue of the Mycobacterium ...

    African Journals Online (AJOL)

    With the completion of genome sequencing of Mycobacterium tuberculosis and upsurge in the incidence of M. tuberculosis infection worldwide partly as a result of HIV pandemic, there is need for rationale approach to vaccine and chemotherapy discoveries for M. tuberculosis. The homologue of mig gene of. Mycobacterium ...

  20. Extracellular Vesicles Released from Mycobacterium tuberculosis-Infected Neutrophils Promote Macrophage Autophagy and Decrease Intracellular Mycobacterial Survival

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    Alvarez-Jiménez, Violeta D.; Leyva-Paredes, Kahiry; García-Martínez, Mariano; Vázquez-Flores, Luis; García-Paredes, Víctor Gabriel; Campillo-Navarro, Marcia; Romo-Cruz, Israel; Rosales-García, Víctor Hugo; Castañeda-Casimiro, Jessica; González-Pozos, Sirenia; Hernández, José Manuel; Wong-Baeza, Carlos; García-Pérez, Blanca Estela; Ortiz-Navarrete, Vianney; Estrada-Parra, Sergio; Serafín-López, Jeanet; Wong-Baeza, Isabel; Chacón-Salinas, Rommel; Estrada-García, Iris

    2018-01-01

    Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis (Mtb). In the lungs, macrophages and neutrophils are the first immune cells that have contact with the infecting mycobacteria. Neutrophils are phagocytic cells that kill microorganisms through several mechanisms, which include the lytic enzymes and antimicrobial peptides that are found in their lysosomes, and the production of reactive oxygen species. Neutrophils also release extracellular vesicles (EVs) (100–1,000 nm in diameter) to the extracellular milieu; these EVs consist of a lipid bilayer surrounding a hydrophilic core and participate in intercellular communication. We previously demonstrated that human neutrophils infected in vitro with Mtb H37Rv release EVs (EV-TB), but the effect of these EVs on other cells relevant for the control of Mtb infection, such as macrophages, has not been completely analyzed. In this study, we characterized the EVs produced by non-stimulated human neutrophils (EV-NS), and the EVs produced by neutrophils stimulated with an activator (PMA), a peptide derived from bacterial proteins (fMLF) or Mtb, and observed that the four EVs differed in their size. Ligands for toll-like receptor (TLR) 2/6 were detected in EV-TB, and these EVs favored a modest increase in the expression of the co-stimulatory molecules CD80, a higher expression of CD86, and the production of higher amounts of TNF-α and IL-6, and of lower amounts of TGF-β, in autologous human macrophages, compared with the other EVs. EV-TB reduced the amount of intracellular Mtb in macrophages, and increased superoxide anion production in these cells. TLR2/6 ligation and superoxide anion production are known inducers of autophagy; accordingly, we found that EV-TB induced higher expression of the autophagy-related marker LC3-II in macrophages, and the co-localization of LC3-II with Mtb inside infected macrophages. The intracellular mycobacterial load increased when autophagy was inhibited with

  1. Extracellular Vesicles Released from Mycobacterium tuberculosis-Infected Neutrophils Promote Macrophage Autophagy and Decrease Intracellular Mycobacterial Survival

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    Violeta D. Alvarez-Jiménez

    2018-02-01

    Full Text Available Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis (Mtb. In the lungs, macrophages and neutrophils are the first immune cells that have contact with the infecting mycobacteria. Neutrophils are phagocytic cells that kill microorganisms through several mechanisms, which include the lytic enzymes and antimicrobial peptides that are found in their lysosomes, and the production of reactive oxygen species. Neutrophils also release extracellular vesicles (EVs (100–1,000 nm in diameter to the extracellular milieu; these EVs consist of a lipid bilayer surrounding a hydrophilic core and participate in intercellular communication. We previously demonstrated that human neutrophils infected in vitro with Mtb H37Rv release EVs (EV-TB, but the effect of these EVs on other cells relevant for the control of Mtb infection, such as macrophages, has not been completely analyzed. In this study, we characterized the EVs produced by non-stimulated human neutrophils (EV-NS, and the EVs produced by neutrophils stimulated with an activator (PMA, a peptide derived from bacterial proteins (fMLF or Mtb, and observed that the four EVs differed in their size. Ligands for toll-like receptor (TLR 2/6 were detected in EV-TB, and these EVs favored a modest increase in the expression of the co-stimulatory molecules CD80, a higher expression of CD86, and the production of higher amounts of TNF-α and IL-6, and of lower amounts of TGF-β, in autologous human macrophages, compared with the other EVs. EV-TB reduced the amount of intracellular Mtb in macrophages, and increased superoxide anion production in these cells. TLR2/6 ligation and superoxide anion production are known inducers of autophagy; accordingly, we found that EV-TB induced higher expression of the autophagy-related marker LC3-II in macrophages, and the co-localization of LC3-II with Mtb inside infected macrophages. The intracellular mycobacterial load increased when autophagy was inhibited

  2. 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

    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...

  3. High throughput phenotypic selection of Mycobacterium tuberculosis mutants with impaired resistance to reactive oxygen species identifies genes important for intracellular growth.

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    Olga Mestre

    Full Text Available Mycobacterium tuberculosis has the remarkable capacity to survive within the hostile environment of the macrophage, and to resist potent antibacterial molecules such as reactive oxygen species (ROS. Thus, understanding mycobacterial resistance mechanisms against ROS may contribute to the development of new anti-tuberculosis therapies. Here we identified genes involved in such mechanisms by screening a high-density transposon mutant library, and we show that several of them are involved in the intracellular lifestyle of the pathogen. Many of these genes were found to play a part in cell envelope functions, further strengthening the important role of the mycobacterial cell envelope in protection against aggressions such as the ones caused by ROS inside host cells.

  4. Mycobacterium tuberculosis Metabolism

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    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

  5. Safety assessment in primary Mycobacterium tuberculosis smear ...

    African Journals Online (AJOL)

    . Safety assessment in primary Mycobacterium tuberculosis smear microscopy centres in Blantyre. Malawi: a facility based cross sectional survey. ABSTRACT. Introduction. Tuberculosis (TB) is caused by Mycobacterium tuberculosis and is.

  6. Innate invariant NKT cells recognize Mycobacterium tuberculosis-infected macrophages, produce interferon-gamma, and kill intracellular bacteria.

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    Isabel Sada-Ovalle

    2008-12-01

    Full Text Available Cellular immunity to Mycobacterium tuberculosis (Mtb requires a coordinated response between the innate and adaptive arms of the immune system, resulting in a type 1 cytokine response, which is associated with control of infection. The contribution of innate lymphocytes to immunity against Mtb remains controversial. We established an in vitro system to study this question. Interferon-gamma is produced when splenocytes from uninfected mice are cultured with Mtb-infected macrophages, and, under these conditions, bacterial replication is suppressed. This innate control of bacterial replication is dependent on CD1d-restricted invariant NKT (iNKT cells, and their activation requires CD1d expression by infected macrophages as well as IL-12 and IL-18. We show that iNKT cells, even in limiting quantities, are sufficient to restrict Mtb replication. To determine whether iNKT cells contribute to host defense against tuberculosis in vivo, we adoptively transferred iNKT cells into mice. Primary splenic iNKT cells obtained from uninfected mice significantly reduce the bacterial burden in the lungs of mice infected with virulent Mtb by the aerosol route. Thus, iNKT cells have a direct bactericidal effect, even in the absence of synthetic ligands such as alpha-galactosylceramide. Our finding that iNKT cells protect mice against aerosol Mtb infection is the first evidence that CD1d-restricted NKT cells mediate protection against Mtb in vivo.

  7. EFFECT OF SOME MEDICINAL PLANTS ON GROWTH OF MYCOBACTERIUM TUBERCULOSIS, MULTI DRUG RESISTANT MYCOBACTERIUM TUBERCULOSIS AND MYCOBACTERIUM OTHER THAN TUBERCULOSIS

    Directory of Open Access Journals (Sweden)

    Prashant Shukla

    2013-12-01

    Full Text Available Six plants of medicinal uses were tried for their inhibitory effect on Mycobacterium tuberculosis (MTB, multi drug resistant Mycobacterium tuberculosis (MDR MTB and Mycobacterium other than tuberculosis (MOTT. MTB, MDR MTB and MOTT were cultured in 12B medium vials for Bacterc 460 TB system and incubated at 37˚C. The vials were read in Bacterc 460 TB system. Garlic, Ocimum sanctum, onion and neem showed effectiveness towards Mycobacterium tuberculosis and multi drug resistant Mycobacterium tuberculosis to some extent but ginger showed no effect at all. None of the plants studied had any inhibitory effect on Mycobacterium other than tuberculosis. Aloe vera had opposite effect on the growth and it was found to be assisting the growth of Mycobacterium tuberculosis and multi drug resistant Mycobacterium tuberculosis. The tests performed were in-vitro and the authors conlude that in-vivo the results may vary.

  8. Innate immunity to Mycobacterium tuberculosis.

    NARCIS (Netherlands)

    Crevel, R. van; Ottenhoff, T.H.; Meer, J.W.M. van der

    2002-01-01

    The different manifestations of infection with Mycobacterium tuberculosis reflect the balance between the bacillus and host defense mechanisms. Traditionally, protective immunity to tuberculosis has been ascribed to T-cell-mediated immunity, with CD4(+) T cells playing a crucial role. Recent

  9. 21 CFR 866.3370 - Mycobacterium tuberculosis immunofluorescent reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mycobacterium tuberculosis immunofluorescent... § 866.3370 Mycobacterium tuberculosis immunofluorescent reagents. (a) Identification. Mycobacterium... used to identify Mycobacterium tuberculosis directly from clinical specimens. The identification aids...

  10. Mycobacterium tuberculosis CYP125A1, a steroid C27 monooxygenase that detoxifies intracellularly generated cholest-4-en-3-one.

    Science.gov (United States)

    Ouellet, Hugues; Guan, Shenheng; Johnston, Jonathan B; Chow, Eric D; Kells, Petrea M; Burlingame, Alma L; Cox, Jeffery S; Podust, Larissa M; de Montellano, Paul R Ortiz

    2010-08-01

    The infectivity and persistence of Mycobacterium tuberculosis requires the utilization of host cell cholesterol. We have examined the specific role of cytochrome P450 CYP125A1 in the cholesterol degradation pathway using genetic, biochemical and high-resolution mass spectrometric approaches. The analysis of lipid profiles from cells grown on cholesterol revealed that CYP125A1 is required to incorporate the cholesterol side-chain carbon atoms into cellular lipids, as evidenced by an increase in the mass of the methyl-branched phthiocerol dimycocerosates. We observed that cholesterol-exposed cells lacking CYP125A1 accumulate cholest-4-en-3-one, suggesting that this is a physiological substrate for this enzyme. Reconstitution of enzymatic activity with spinach ferredoxin and ferredoxin reductase revealed that recombinant CYP125A1 indeed binds both cholest-4-en-3-one and cholesterol, efficiently hydroxylates both of them at C-27, and then further oxidizes 27-hydroxycholest-4-en-3-one to cholest-4-en-3-one-27-oic acid. We determined the X-ray structure of cholest-4-en-3-one-bound CYP125A1 at a resolution of 1.58 A. CYP125A1 is essential for growth of CDC1551 in media containing cholesterol or cholest-4-en-3-one. In its absence, the latter compound is toxic for both CDC1551 and H37Rv when added with glycerol as a second carbon source. CYP125A1 is a key enzyme in cholesterol metabolism and plays a crucial role in circumventing the deleterious effect of cholest-4-en-3-one.

  11. 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 ...

  12. Drug Resistance of Mycobacterium tuberculosis Complex among ...

    African Journals Online (AJOL)

    BACKGROUND: In Burkina Faso, there is no recent data about the level of drug resistance in Mycobacterium tuberculosis strains among newly diagnosed tuberculosis cases. OBJECTIVE: To provide an update of the primary drug resistance of mycobacterium tuberculosis among patients in Burkina faso. METHODS: ...

  13. 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

  14. Mycobacterium tuberculosis PPD-induced immune biomarkers measurable in vitro following BCG vaccination of UK adolescents by multiplex bead array and intracellular cytokine staining

    Directory of Open Access Journals (Sweden)

    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.

  15. Ecotypes of the Mycobacterium tuberculosis complex.

    NARCIS (Netherlands)

    Smith, Noel H; Kremer, Kristin; Inwald, Jacqueline; Dale, James; Driscoll, Jeffrey R; Gordon, Stephen V; Soolingen, Dick van; Hewinson, R Glyn; Smith, John Maynard

    2006-01-01

    A phylogeny of the Mycobacterium tuberculosis complex has recently shown that the animal-adapted strains are found in a single lineage marked by the deletion of chromosomal region 9 (RD9) [Brosch et al., 2002. A new evolutionary scenario for the Mycobacterium tuberculosis complex. Proc. Natl Acad.

  16. Molecular flexibility of Mycobacterium tuberculosis ribosome ...

    Indian Academy of Sciences (India)

    2013-11-06

    Nov 6, 2013 ... Mycobacterium tuberculosis RRF does not complement E. coli for its deficiency of RRF (in the ... [Selvaraj M, Govindan A, Seshadri A, Dubey B, Varshney U and Vijayan M 2013 Molecular flexibility of Mycobacterium tuberculosis ribosome ...... Janosi L, Mottagui-Tabar S, Isaksson LA, Sekine Y, Ohtsubo E,.

  17. Immune Responses Involved in Mycobacterium Tuberculosis Infection

    Directory of Open Access Journals (Sweden)

    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.

  18. In vitro susceptibility of Mycobacterium tuberculosis, Mycobacterium africanum, Mycobacterium bovis, Mycobacterium avium, Mycobacterium fortuitum, and Mycobacterium chelonae to ticarcillin in combination with clavulanic acid.

    OpenAIRE

    Casal, M J; Rodriguez, F C; Luna, M D; Benavente, M C

    1987-01-01

    The in vitro susceptibility of Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium africanum, Mycobacterium avium, Mycobacterium fortuitum, and Mycobacterium chelonae (M. chelonei) to ticarcillin in combination with calvulanic acid (CA) was studied by the agar dilution method. All the M. tuberculosis, M. bovis, and M. africanum strains were inhibited at a ticarcillin concentration of 32 micrograms/ml or lower in combination with 5 micrograms of CA. M. chelonae and M. avium strains ...

  19. Copper homeostasis in Mycobacterium tuberculosis.

    Science.gov (United States)

    Shi, Xiaoshan; Darwin, K Heran

    2015-06-01

    Copper (Cu) is a trace element essential for the growth and development of almost all organisms, including bacteria. However, Cu overload in most systems is toxic. Studies show Cu accumulates in macrophage phagosomes infected with bacteria, suggesting Cu provides an innate immune mechanism to combat invading pathogens. To counteract the host-supplied Cu, increasing evidence suggests that bacteria have evolved Cu resistance mechanisms to facilitate their pathogenesis. In particular, Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, has evolved multiple pathways to respond to Cu. Here, we summarize what is currently known about Cu homeostasis in Mtb and discuss potential sources of Cu encountered by this and other pathogens in a mammalian host.

  20. mycobacterium tuberculosis genetic diversity and drug resistance ...

    African Journals Online (AJOL)

    East African Medical Journal Vol. 88 No. 12 December 2011. MYCOBACTERIUM TUBERCULOSIS GENETIC DIVERSITY AND DRUG RESISTANCE CONFERRING MUTATIONS. IN THE DEMOCRATIC REPUBLIC OF THE CONGO. L. Fenner, Institute of Social and Preventive Medicine, University of Bern, Switzerland, S.

  1. Radiographic differentiation of atypical tuberculosis from mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Tarver, R.D.; Pearcy, E.A.; Conces, D.J. Jr.; Mathur, P.N.

    1987-01-01

    The chest radiographs of 95 patients with the new diagnosis of atypical turberculosis were reviewed to determine if any significant differences between atypical tuberculosis and that caused by Mycobacterium tuberculosis could be discerned. Findings included upper lobe involvement in B4 of the 95 patients and cavities in 76, with nearly equal groups having no, moderate, or extensive surrounding alveolar disease. Nodules were common; in six patients a nodule was the sole manifestation of disease. Adenopathy was seen in 12 of the 95 patients, atlectasis in 45, pleural thickening in 90, and effusions in three. These radiographic findings did not allow the radiographic differentiation of atypical tuberculosis from Mycobacterium tuberculosis infection

  2. Polymorphisms of twenty regulatory proteins between Mycobacterium tuberculosis and Mycobacterium bovis

    Science.gov (United States)

    Mycobacterium tuberculosis and Mycobacterium bovis are responsible for tuberculosis in humans or animals, respectively. Both species are closely related and belong to the Mycobacterium tuberculosis complex (MTC). M. tuberculosis is the most ancient species from which M. bovis and the other members o...

  3. Molecular epidemiology of Mycobacterium tuberculosis in Lisbon

    Directory of Open Access Journals (Sweden)

    Isabel Portugal

    2008-03-01

    Full Text Available We conducted a molecular epidemiology study of Mycobacterium tuberculosis strains isolated from patients in Lisbon hospitals. We used restriction fragment length polymorphism (RFLP to detect Lisbon family strains and to determine the genetic diversity of Mycobacterium tuberculosis strains isolated in Lisbon, through identification of the most important risk factors of tuberculosis transmission analysis, with the insertion sequence IS6110 as a probe to fingerprint isolates of Mycobacterium tuberculosis. 64.8% of the 290 Mycobacterium tuberculosis isolates were grouped in clusters. This figure was 60.7% if we excluded strains with five or fewer IS6110 copies. Multidrug-resistance was observed in 4.1% of the strains and they were all in clusters. Forty-five (18.2% strains were included in the Lisbon family. Considering the relatively high percentage of strains in cluster detected in this study, we believe that active transmission is still taking place in Lisbon. Moreover, clusters of Lisbon strains represent the predominant strains circulating in Lisbon and are still related to drug resistance although presenting a lower percentage than that observed in previous studies. Resumo: Foi realizado um estudo de epidemiologia molecular a estirpes de Mycobacterium tuberculosis isoladas em hospitais de Lisboa. Analisaram-se geneticamente os isolados de Mycobacterium tuberculosis com o método restriction fragment length polymorphism (RFLP utilizando a sequência de inserção IS6110 como sonda, com o objectivo de detectar as estirpes da família Lisboa e determinar a diversidade genética das estirpes de Mycobacterium tuberculosis isoladas em Lisboa, identificando os mais importantes factores de risco de transmissão da tuberculose.Foram analisados 290 isolados de Mycobacterium tuberculosis, dos quais 64,8% se encontraram agrupados em clusters; mesmo excluindo as estirpes que apresentaram mais de 5 cópias de IS6110, a percentagem de agrupamento foi de 60

  4. 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 ...

  5. 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 ...

  6. Host immunity to Mycobacterium tuberculosis and risk of tuberculosis

    DEFF Research Database (Denmark)

    Michelsen, Sascha Wilk; Soborg, Bolette; Agger, Else-Marie

    2016-01-01

    BACKGROUND: Human immune responses to latent Mycobacterium tuberculosis (Mtb) infection (LTBI) may enable individuals to control Mtb infection and halt progression to tuberculosis (TB), a hypothesis applied in several novel TB vaccines. We aimed to evaluate whether immune responses to selected LTBI...

  7. Epidemiologia molecular de Mycobacterium tuberculosis em Lisboa

    Directory of Open Access Journals (Sweden)

    Isabel Portugal

    2008-03-01

    Full Text Available Resumo: Foi realizado um estudo de epidemiologia molecular a estirpes de Mycobacterium tuberculosis isoladas em hospitais de Lisboa. Analisaram-se geneticamente os isolados de Mycobacterium tuberculosis com o método restriction fragment length polymorphism (RFLP utilizando a sequência de inserção IS6110 como sonda, com o objectivo de detectar as estirpes da família Lisboa e determinar a diversidade genética das estirpes de Mycobacterium tuberculosis isoladas em Lisboa, identificando os mais importantes factores de risco de transmissão da tuberculose.Foram analisados 290 isolados de Mycobacterium tuberculosis, dos quais 64,8% se encontraram agrupados em clusters; mesmo excluindo as estirpes que apresentaram mais de 5 cópias de IS6110, a percentagem de agrupamento foi de 60,7%. A multirresistência foi observada em 4,1% das estirpes e encontraram-se todas em clusters. Quarenta e cinco isolados (18,2% pertenciam à família Lisboa. Considerando a percentagem relativamente alta de estirpes em cluster detectada neste estudo, cremos que a transmissão activa continua a ser uma realidade em Lisboa. Para além disso, as estirpes dos clusters Lisboa representam as estirpes predominantes que circulam em Lisboa. continuando muito relacionadas com a resistência aos antibacilares, embora correspondam a uma percentagem inferior à verificada em estudos anteriores.Rev Port Pneumol 2007; XIV (2: 239-259 Abstract: We conducted a molecular epidemiology study of Mycobacterium tuberculosis strains isolated from patients in Lisbon hospitals. We used restriction fragment length polymorphism (RFLP to detect Lisbon family strains and to determine the genetic diversity of Mycobacterium tuberculosis strains isolated in Lisbon, through identification of the most important risk factors of tuberculosis transmission analysis, with the insertion sequence IS6110 as a probe to fingerprint isolates of Mycobacterium tuberculosis. 64.8% of the 290 Mycobacterium

  8. Mycobacterium tuberculosis H37Ra genome sequencing

    Indian Academy of Sciences (India)

    2007-02-09

    Feb 9, 2007 ... Home; Journals; Journal of Biosciences; Volume 32; Issue 2. Commentary: The value of comparative genomics in understanding mycobacterial virulence: Mycobacterium tuberculosis H37Ra genome sequencing – a worthwhile endeavour. Deepak Sharma Jaya Sivaswami Tyagi. Volume 32 Issue 2 March ...

  9. Mycobacterium tuberculosis complex identification by polymerase ...

    African Journals Online (AJOL)

    Mycobacterium tuberculosis complex identification by polymerase chain reaction from positive culture in patients from Jamot and Mbalmayo district hospitals. ... On the same way, MTBC were differentiated from other mycobacreia using the PNP inhibition test. DNA extracted from positive cultures was subjected to PCR ...

  10. Transcriptional Profiling Mycobacterium tuberculosis from Patient Sputa.

    Science.gov (United States)

    Wildner, Leticia Muraro; Gould, Katherine A; Waddell, Simon J

    2018-01-01

    The emergence of drug resistance threatens to destroy tuberculosis control programs worldwide, with resistance to all first-line drugs and most second-line drugs detected. Drug tolerance (or phenotypic drug resistance) is also likely to be clinically relevant over the 6-month long standard treatment for drug-sensitive tuberculosis. Transcriptional profiling the response of Mycobacterium tuberculosis to antimicrobial drugs offers a novel interpretation of drug efficacy and mycobacterial drug-susceptibility that likely varies in dynamic microenvironments, such as the lung. This chapter describes the noninvasive sampling of tuberculous sputa and techniques for mRNA profiling M. tb bacilli during patient therapy to characterize real-world drug actions.

  11. Mechanisms of fluoroquinolone resistance in Mycobacterium tuberculosis.

    Science.gov (United States)

    Zhang, Yu-jiao; Li, Xiao-jing; Mi, Kai-xia

    2016-10-20

    Tuberculosis, caused by the pathogen Mycobacterium tuberculosis, is one of the world's deadliest bacterial infectious disease. It is still a global-health threat, particularly because of the drug-resistant forms. Fluoroquinolones, with target of gyrase, are among the drugs used to treat tuberculosis. However, their widespread use has led to bacterial resistance. The molecular mechanisms of fluoroquinolone resistance in mycobacterium tuberculosis have been reported, such as DNA gyrase mutations, drug efflux pumps system, bacterial cell wall thickness and pentapeptide proteins (MfpA) mediated regulation of gyrase. Mutations in gyrase conferring quinolone resistance play important roles and have been extensively studied. Recent studies have shown that the regulation of DNA gyrase affects mycobacterial drug resistance, but the mechanisms, especially by post-translational modification and regulatory proteins, are poorly understood. In this review, we summarize the fluoroquinolone drug development, and the molecular genetics of fluoroquinolone resistance in mycobacteria. Comprehensive understanding of the mechanisms of fluoroquinolone resistance in Mycobacterium tuberculosis will open a new view on understanding drug resistance in mycobacteria and lead to novel strategies to develop new accurate diagnosis methods.

  12. Infection of human THP-1 cells with dormant Mycobacterium tuberculosis.

    Science.gov (United States)

    Iona, Elisabetta; Pardini, Manuela; Gagliardi, Maria Cristina; Colone, Marisa; Stringaro, Anna Rita; Teloni, Raffaela; Brunori, Lara; Nisini, Roberto; Fattorini, Lanfranco; Giannoni, Federico

    2012-09-01

    Dormant, non-replicating Mycobacterium tuberculosis H37Rv strain cultured in hypoxic conditions was used to infect THP-1 cells. CFUs counting, Kinyoun staining and electron microscopy showed that dormant bacilli infected THP-1 cells at a rate similar to replicating M. tuberculosis, but failed to grow during the first 6 days of infection. The absence of growth was specific to the intracellular compartment, as demonstrated by efficient growth in liquid medium. Quantification of β-actin mRNA recovered from infected cells showed that, in contrast with log-phase bacteria, infection with dormant bacilli determined a reduced THP-1 cell death. Gene expression of intracellular non-replicating bacteria showed a pattern typical of a dormant state. Intracellular dormant bacteria induced the activation of genes associated to a proinflammatory response in THP-1 cells. Though, higher levels of TNFα, IL-1β and IL-8 mRNAs compared to aerobic H37Rv infected cells were not paralleled by increased cytokine accumulation in the supernatants. Moreover, dormant bacilli induced a higher expression of inducible cox-2 gene, accompanied by increased PGE2 secretion. Overall, our data describe a new model of in vitro infection using dormant M. tuberculosis that could provide the basis for understanding how non-replicating bacilli survive intracellularly and influence the maintenance of the hypoxic granuloma. Copyright © 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  13. Intracellular accumulation of norfloxacin in Mycobacterium smegmatis.

    Science.gov (United States)

    Corti, S; Chevalier, J; Cremieux, A

    1995-01-01

    To evaluate the intracellular accumulation of norfloxacin in mycobacteria, two methods were used with Mycobacterium smegmatis. A radiometric method (K. V. Cundy, C. E. Fasching, K. E. Willard, and L. R. Peterson, J. Antimicrob. Chemother. 28:491-497, 1991) was used without great modification, but the fluorometric method (P. G. S. Mortimer and L. J. V. Piddock, J. Antimicrob. Chemother. 28:639-653, 1991) was changed considerably. Indeed, adsorption of the quinolone to the bacterial surface was characterized by measuring the level of accumulation of 0 degree C. Taking into account the adsorption, the pH of the washing buffer was increased from 7.0 to 9.0 to improve the desorption of norfloxacin from the cell surface. Both the fluorometric method, with the technical improvement, and the radiometric method could be used to estimate the intracellular accumulation of norfloxacin, which resulted from the difference between the whole uptake measured at 37 degrees C and the adsorption measured at 0 degrees C. A total of 35 ng of norfloxacin per mg of cells (dry weight) penetrated into the M. smegmatis cell, and the steady state was achieved in 5 min. Use of inhibitors of the proton motive force revealed that transport of norfloxacin was energy independent. Thus, the same mechanisms of quinolone accumulation that occur in eubacteria seem to occur in mycobacteria, at least in M. smegmatis. PMID:8585727

  14. Progression to active tuberculosis, but not transmission, varies by Mycobacterium tuberculosis lineage in The Gambia

    NARCIS (Netherlands)

    de Jong, Bouke C.; Hill, Philip C.; Aiken, Alex; Awine, Timothy; Antonio, Martin; Adetifa, Ifedayo M.; Jackson-Sillah, Dolly J.; Fox, Annette; Deriemer, Kathryn; Gagneux, Sebastien; Borgdorff, Martien W.; McAdam, Keith P. W. J.; Corrah, Tumani; Small, Peter M.; Adegbola, Richard A.

    2008-01-01

    BACKGROUND: There is considerable variability in the outcome of Mycobacterium tuberculosis infection. We hypothesized that Mycobacterium africanum was less likely than M. tuberculosis to transmit and progress to tuberculosis disease. METHODS: In a cohort study of patients with tuberculosis and their

  15. Gamma/delta T lymphocytes in Mycobacterium tuberculosis infection

    OpenAIRE

    Baliko, Z.; Szereday, L.; Szekeres-Bartho, J.

    1997-01-01

    BACKGROUND: Data on the percentage of gamma/delta T lymphocytes in the peripheral blood of patients infected with Mycobacterium tuberculosis are few and contradictory. The percentage of gamma/delta T lymphocytes in the peripheral blood of tuberculin positive and tuberculin negative patients with Mycobacterium tuberculosis infection and healthy controls was compared. METHODS: Thirty six patients infected with Mycobacterium tuberculosis and 11 healthy controls were studied. Lymphocytes we...

  16. 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

  17. EVIDENCE FOR THE MACROPHAGE INDUCING GENE IN MYCOBACTERIUM INTRACELLULARE

    Science.gov (United States)

    Background: The Mycobacterium avium Complex (MAC) includes the species M. avium (MA), M. intracellulare (MI), and possibly others. Organisms belonging to the MAC are phylogenetically closely related, opportunistic pathogens. The macrophage inducing gene (mig) is the only well-des...

  18. Nicotine Impairs Macrophage Control of Mycobacterium tuberculosis.

    Science.gov (United States)

    Bai, Xiyuan; Stitzel, Jerry A; Bai, An; Zambrano, Cristian A; Phillips, Matthew; Marrack, Philippa; Chan, Edward D

    2017-09-01

    Pure nicotine impairs macrophage killing of Mycobacterium tuberculosis (MTB), but it is not known whether the nicotine component in cigarette smoke (CS) plays a role. Moreover, the mechanisms by which nicotine impairs macrophage immunity against MTB have not been explored. To neutralize the effects of nicotine in CS extract, we used a competitive inhibitor to the nicotinic acetylcholine receptor (nAChR)-mecamylamine-as well as macrophages derived from mice with genetic disruption of specific subunits of nAChR. We also determined whether nicotine impaired macrophage autophagy and whether nicotine-exposed T regulatory cells (Tregs) could subvert macrophage anti-MTB immunity. Mecamylamine reduced the CS extract increase in MTB burden by 43%. CS extract increase in MTB was also significantly attenuated in macrophages from mice with genetic disruption of either the α7, β2, or β4 subunit of nAChR. Nicotine inhibited autophagosome formation in MTB-infected THP-1 cells and primary murine alveolar macrophages, as well as increased the intracellular MTB burden. Nicotine increased migration of THP-1 cells, consistent with the increased number of macrophages found in the lungs of smokers. Nicotine induced Tregs to produce transforming growth factor-β. Naive mouse macrophages co-cultured with nicotine-exposed Tregs had significantly greater numbers of viable MTB recovered with increased IL-10 production and urea production, but no difference in secreted nitric oxide as compared with macrophages cocultured with unexposed Tregs. We conclude that nicotine in CS plays an important role in subverting macrophage control of MTB infection.

  19. 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

  20. 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.

  1. An Elucidation of Neutrophil Functions against Mycobacterium tuberculosis Infection

    Directory of Open Access Journals (Sweden)

    Devin Morris

    2013-01-01

    Full Text Available We characterized the functions of neutrophils in response to Mycobacterium tuberculosis (M. tb infection, with particular reference to glutathione (GSH. We examined the effects of GSH in improving the ability of neutrophils to control intracellular M. tb infection. Our findings indicate that increasing the intracellular levels of GSH with a liposomal formulation of GSH (L-GSH resulted in reduction in the levels of free radicals and increased acidification of M. tb containing phagosomes leading to the inhibition in the growth of M. tb. This inhibitory mechanism is dependent on the presence of TNF-α and IL-6. Our studies demonstrate a novel regulatory mechanism adapted by the neutrophils to control M. tb infection.

  2. 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

  3. High Persister Mutants in Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Heather L Torrey

    Full Text Available Mycobacterium tuberculosis forms drug-tolerant persister cells that are the probable cause of its recalcitrance to antibiotic therapy. While genetically identical to the rest of the population, persisters are dormant, which protects them from killing by bactericidal antibiotics. The mechanism of persister formation in M. tuberculosis is not well understood. In this study, we selected for high persister (hip mutants and characterized them by whole genome sequencing and transcriptome analysis. In parallel, we identified and characterized clinical isolates that naturally produce high levels of persisters. We compared the hip mutants obtained in vitro with clinical isolates to identify candidate persister genes. Genes involved in lipid biosynthesis, carbon metabolism, toxin-antitoxin systems, and transcriptional regulators were among those identified. We also found that clinical hip isolates exhibited greater ex vivo survival than the low persister isolates. Our data suggest that M. tuberculosis persister formation involves multiple pathways, and hip mutants may contribute to the recalcitrance of the infection.

  4. 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.

  5. 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....

  6. 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.

  7. Genome-wide requirements for Mycobacterium tuberculosis adaptation and survival in macrophages

    OpenAIRE

    Rengarajan, Jyothi; Bloom, Barry R.; Rubin, Eric J.

    2005-01-01

    Macrophages are central to host defense against microbes, but intracellular pathogens have evolved to evade their antimicrobial functions. Mycobacterium tuberculosis (MTB) has successfully exploited macrophages as its primary niche in vivo, but the bacterial genome-wide requirements that promote its intracellular survival remain undefined. Here we comprehensively identify the MTB genes required for survival by screening for transposon mutants that fail to grow within primary macrophages. We i...

  8. 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

  9. Radiometric diagnosis of Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Laszlo, A.

    1986-01-01

    The results of this study confirm that rapid radiometric diagnostic tests such as the NAP selective inhibition test for the M. tuberculosis complex followed by the radiometric drug susceptibility tests are extremely reliable and compare favourably with conventional methodologies. This study also shows that referred cultures growing on solid medium can be processed by radiometric procedures without prior subculture. This circumstance by itself shortens the time needed for reporting. (Auth.)

  10. Microaerobic growth and anaerobic survival of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum

    Directory of Open Access Journals (Sweden)

    Amy Herndon Lewis

    2015-01-01

    Full Text Available Representative strains of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum (MAIS grew at equal rates in laboratory medium at 21% (air and 12% oxygen. Growth in 6% oxygen proceeded at a 1.4–1.8-fold lower rate. Colony formation was the same at 21% (air and 6% oxygen. The MAIS strains survived rapid shifts from aerobic to anaerobic conditions as measured by two experimental approaches (Falkinham (1996 [1]. MAIS cells grown aerobically to log phase in broth were diluted, spread on agar medium, and incubated anaerobically for up to 20 days at 37 °C. Although no colonies formed anaerobically, upon transfer to aerobic conditions, greater than 25% of the colony forming units (CFU survived after 20 days of anaerobic incubation (Prince et al. (1989 [2]. MAIS cells grown in broth aerobically to log phase were sealed and vigorous agitation led to oxygen depletion (Wayne model. After 12 days anaerobic incubation, M. avium and M. scrofulaceum survival were high (>50%, while M. intracellulare survival was lower (22%. M. avium cells shifted to anaerobiosis in broth had increased levels of glycine dehydrogenase and isocitrate lyase. Growth of MAIS strains at low oxygen levels and their survival following a rapid shift to anaerobiosis is consistent with their presence in environments with fluctuating oxygen levels.

  11. Microaerobic growth and anaerobic survival of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum.

    Science.gov (United States)

    Lewis, Amy Herndon; Falkinham, Joseph O

    2015-03-01

    Representative strains of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum (MAIS) grew at equal rates in laboratory medium at 21% (air) and 12% oxygen. Growth in 6% oxygen proceeded at a 1.4-1.8-fold lower rate. Colony formation was the same at 21% (air) and 6% oxygen. The MAIS strains survived rapid shifts from aerobic to anaerobic conditions as measured by two experimental approaches (Falkinham (1996) [1]). MAIS cells grown aerobically to log phase in broth were diluted, spread on agar medium, and incubated anaerobically for up to 20 days at 37°C. Although no colonies formed anaerobically, upon transfer to aerobic conditions, greater than 25% of the colony forming units (CFU) survived after 20 days of anaerobic incubation (Prince et al. (1989) [2]). MAIS cells grown in broth aerobically to log phase were sealed and vigorous agitation led to oxygen depletion (Wayne model). After 12 days anaerobic incubation, M. avium and M. scrofulaceum survival were high (>50%), while M. intracellulare survival was lower (22%). M. avium cells shifted to anaerobiosis in broth had increased levels of glycine dehydrogenase and isocitrate lyase. Growth of MAIS strains at low oxygen levels and their survival following a rapid shift to anaerobiosis is consistent with their presence in environments with fluctuating oxygen levels. Copyright © 2015 Asian African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

  12. Mycobacterium avium Subsp. avium Infection in Four Veal Calves: Differentiation from Intestinal Tuberculosis

    Directory of Open Access Journals (Sweden)

    Christine Goepfert

    2014-01-01

    Full Text Available Mycobacterium avium subsp. avium (Maa is an intracellular pathogen belonging to the Mycobacterium avium-intracellulare complex (MAC. Reservoirs of MAC are the natural environment, wildlife and domestic animals. In adult bovine, MAC infections are typically caused by Mycobacterium avium subsp. paratuberculosis (Map. Maa infections in bovine are rarely reported but may cause clinical disease and pathological lesions similar to those observed in paratuberculosis or those induced by members of the Mycobacterium tuberculosis complex (MTBC. Therefore, differentiation of MAC from MTBC infection should be attempted, especially if unusual mycobacterial lesions are encountered. Four veal calves from a fattening farm dying with clinical signs of otitis media, fever, and weight loss were submitted for necropsy. Samples from affected organs were taken for histologic investigation, bacteriologic culture, and bacterial specification using PCR. Macroscopic thickening of the intestinal mucosa was induced by granulomatous enteritis and colitis. Intracytoplasmic acid-fast bacteria were detected by Ziehl-Neelsen stains and PCR revealed positive results for Mycobacterium avium subsp. avium. Clinical and pathological changes of Maa infection in veal calves had features of Mycobacterium avium subsp. paratuberculosis and the MTBC. Therefore, Mycobacterium tuberculosis complex infection should be considered in cases of granulomatous enteritis in calves.

  13. Radiometric studies of mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Edwaldo E. Camargo

    1987-02-01

    Full Text Available An in vitro assay system that included automated radiometric quantification of 14CO2 released as a result of oxidation of 14C- substrates was applied for studying the metabolic activity of M. tuberculosis under various experimental conditions. These experiments included the study of a mtabolic pathways, b detection times for various inoculum sizes, c effect of filtration on reproducibility of results, d influence of stress environment e minimal inhibitory concentrations for isoniazid, streptomycin, ethambutol and rifampin, and f generation times of M. tuberculosis and M. bovis. These organisms were found to metabolize 14C-for-mate, (U-14C acetate, (U-14C glycerol, (1-14C palmitic acid, 1-14C lauric acid, (U-14C L-malic acid, (U-14C D-glucose, and (U-14C D-glucose, but not (1-14C L-glucose, (U-14C glycine, or (U-14C pyruvate to 14CO2. By using either 14C-for-mate, (1-14C palmitic acid, or (1-14C lauric acid, 10(7 organisms/vial could be detected within 24 48 hours and as few as 10 organisms/vial within 16-20 days. Reproducible results could be obtained without filtering the bacterial suspension, provided that the organisms were grown in liquid 7H9 medium with 0.05% polysorbate 80 and homogenized prior to the study. Drugs that block protein synthesis were found to have lower minimal inhibitory concentrations with the radiometric method when compared to the conventional agar dilution method. The mean generation time obtained for M. bovis and different strains of M. tuberculosis with various substrates was 9 ± 1 hours.

  14. Mycobacterium tuberculosis Infection among Asian Elephants in Captivity.

    Science.gov (United States)

    Simpson, Gary; Zimmerman, Ralph; Shashkina, Elena; Chen, Liang; Richard, Michael; Bradford, Carol M; Dragoo, Gwen A; Saiers, Rhonda L; Peloquin, Charles A; Daley, Charles L; Planet, Paul; Narachenia, Apurva; Mathema, Barun; Kreiswirth, Barry N

    2017-03-01

    Although awareness of tuberculosis among captive elephants is increasing, antituberculosis therapy for these animals is not standardized. We describe Mycobacterium tuberculosis transmission between captive elephants based on whole genome analysis and report a successful combination treatment. Infection control protocols and careful monitoring of treatment of captive elephants with tuberculosis are warranted.

  15. HIV infection and mycobacterium tuberculosis drug-resistance ...

    African Journals Online (AJOL)

    The aim of this study was to compare the drug-resistance patterns of Mycobacterium tuberculosis strains among pulmonary tuberculosis patients, according to their HIV serostatus, in Burkina Faso. Tuberculosis (TB) patients were classified in new and previously treated cases by using a structured questionnaire.

  16. Consequences of genomic diversity in Mycobacterium tuberculosis

    Science.gov (United States)

    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

  17. 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.

  18. Cell biology of mycobacterium tuberculosis phagosome.

    Science.gov (United States)

    Vergne, Isabelle; Chua, Jennifer; Singh, Sudha B; Deretic, Vojo

    2004-01-01

    Phagocytosis and phagolysosome biogenesis represent fundamental biological processes essential for proper tissue homeostasis, development, elimination of invading microorganisms, and antigen processing and presentation. Phagosome formation triggers a preprogrammed pathway of maturation into the phagolysosome, a process controlled by Ca2+ and the regulators of organellar trafficking centered around the small GTP-binding proteins Rabs and their downstream effectors, including lipid kinases, organellar tethering molecules, and membrane fusion apparatus. Mycobacterium tuberculosis is a potent human pathogen parasitizing macrophages. It interferes with the Rab-controlled membrane trafficking and arrests the maturing phagosome at a stage where no harm can be done to the pathogen while the delivery of nutrients and membrane to the vacuole harboring the microorganism continues. This process, referred to as the M. tuberculosis phagosome maturation arrest or inhibition of phagosome-lysosome fusion, is critical for M. tuberculosis persistence in human populations. It also provides a general model system for dissecting the phagolysosome biogenesis pathways. Here we review the fundamental trafficking processes targeted by M. tuberculosis and the mycobacterial products that interfere with phagosomal maturation.

  19. Tuberculosis (Mycobacterium tuberculosis) in a pregnant baboon (Papio cynocephalus).

    Science.gov (United States)

    Martino, M; Hubbard, G B; Schlabritz-Loutsevitch, N

    2007-04-01

    Old World monkeys are considered more susceptible to tuberculosis (TB) than New World monkeys. Several cases of TB in baboons are described in the literature. The data regarding baboon reaction to the tuberculin skin test (TST) are controversial. Some authors described anergy in this species, while the others documented a positive reaction. An 8-year-old clinically healthy pregnant female baboon (Papio cynocephalus anubis) developed positive TST after 3 years of negative tests in captivity while not pregnant. Thoracic radiographs demonstrated three nodular densities in the lung. Histological examination of tracheobronchial lymph nodes revealed multiple coalescing pyogranulomas filled with caseonecrotic debris and mineralized foci with numerous large foreign body-type and Langhans-type multinucleated giant cells. The bacterial culture contained a slow growing Mycobacterium tuberculosis complex. We describe, to the best of our knowledge, the first case of a positive TST in a wild caught, pregnant baboon with latent infection after 3 years in captivity.

  20. 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

  1. Deciphering the metabolic response of Mycobacterium tuberculosis to nitrogen stress.

    Science.gov (United States)

    Williams, Kerstin J; Jenkins, Victoria A; Barton, Geraint R; Bryant, William A; Krishnan, Nitya; Robertson, Brian D

    2015-09-01

    A key component to the success of Mycobacterium tuberculosis as a pathogen is the ability to sense and adapt metabolically to the diverse range of conditions encountered in vivo, such as oxygen tension, environmental pH and nutrient availability. Although nitrogen is an essential nutrient for every organism, little is known about the genes and pathways responsible for nitrogen assimilation in M. tuberculosis. In this study we have used transcriptomics and chromatin immunoprecipitation and high-throughput sequencing to address this. In response to nitrogen starvation, a total of 185 genes were significantly differentially expressed (96 up-regulated and 89 down regulated; 5% genome) highlighting several significant areas of metabolic change during nitrogen limitation such as nitrate/nitrite metabolism, aspartate metabolism and changes in cell wall biosynthesis. We identify GlnR as a regulator involved in the nitrogen response, controlling the expression of at least 33 genes in response to nitrogen limitation. We identify a consensus GlnR binding site and relate its location to known transcriptional start sites. We also show that the GlnR response regulator plays a very different role in M. tuberculosis to that in non-pathogenic mycobacteria, controlling genes involved in nitric oxide detoxification and intracellular survival instead of genes involved in nitrogen scavenging. © 2015 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

  2. Complex multifractal nature in Mycobacterium tuberculosis genome

    Science.gov (United States)

    Mandal, Saurav; Roychowdhury, Tanmoy; Chirom, Keilash; Bhattacharya, Alok; Brojen Singh, R. K.

    2017-04-01

    The mutifractal and long range correlation (C(r)) properties of strings, such as nucleotide sequence can be a useful parameter for identification of underlying patterns and variations. In this study C(r) and multifractal singularity function f(α) have been used to study variations in the genomes of a pathogenic bacteria Mycobacterium tuberculosis. Genomic sequences of M. tuberculosis isolates displayed significant variations in C(r) and f(α) reflecting inherent differences in sequences among isolates. M. tuberculosis isolates can be categorised into different subgroups based on sensitivity to drugs, these are DS (drug sensitive isolates), MDR (multi-drug resistant isolates) and XDR (extremely drug resistant isolates). C(r) follows significantly different scaling rules in different subgroups of isolates, but all the isolates follow one parameter scaling law. The richness in complexity of each subgroup can be quantified by the measures of multifractal parameters displaying a pattern in which XDR isolates have highest value and lowest for drug sensitive isolates. Therefore C(r) and multifractal functions can be useful parameters for analysis of genomic sequences.

  3. Isolation of Mycobacterium tuberculosis complex (MTBC) from dairy ...

    African Journals Online (AJOL)

    Isolation of Mycobacterium tuberculosis complex (MTBC) from dairy cows in China. Yingyu Chen, Siguo Liu, Yujiong Wang, Yanfen Du, Min Li, Shi Cheng, Huanan Wang, Qin Xie, Huanchun Chen, Aizhen Guo ...

  4. 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...

  5. Mycobacterium tuberculosis phagosome maturation arrest: selective targeting of PI3P-dependent membrane trafficking.

    Science.gov (United States)

    Vergne, Isabelle; Chua, Jennifer; Deretic, Vojo

    2003-09-01

    The ability of Mycobacterium tuberculosis to enter host macrophages, and reside in a phagosome, which does not mature into a phagolysosome, is central to the spread of tuberculosis and the associated pandemic involving billions of people worldwide. Tuberculosis can be viewed as a disease with a significant intracellular trafficking and organellar biogenesis component. Current understanding of the block in M. tuberculosis phagosome maturation also sheds light on fundamental aspects of phagolysosome biogenesis. The maturation block involves interference with the recruitment and function of rabs, rab effectors (phosphatidylinositol 3-kinases and tethering molecules such as EEA1), SNAREs (Syntaxin 6 and cellubrevin) and Ca2+/calmodulin signaling. M. tuberculosis analogs of mammalian phosphatidylinositols interfere with these systems and associated processes.

  6. 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.

  7. Mycobacterium bovis and Other Uncommon Members of the Mycobacterium tuberculosis Complex.

    Science.gov (United States)

    Esteban, Jaime; Muñoz-Egea, Maria-Carmen

    2016-12-01

    Since its discovery by Theobald Smith, Mycobacterium bovis has been a human pathogen closely related to animal disease. At present, M. bovis tuberculosis is still a problem of importance in many countries and is considered the main cause of zoonotic tuberculosis throughout the world. Recent development of molecular epidemiological tools has helped us to improve our knowledge about transmission patterns of this organism, which causes a disease indistinguishable from that caused by Mycobacterium tuberculosis. Diagnosis and treatment of this mycobacterium are similar to those for conventional tuberculosis, with the important exceptions of constitutive resistance to pyrazinamide and the fact that multidrug-resistant and extremely drug-resistant M. bovis strains have been described. Among other members of this complex, Mycobacterium africanum is the cause of many cases of tuberculosis in West Africa and can be found in other areas mainly in association with immigration. M. bovis BCG is the currently available vaccine for tuberculosis, but it can cause disease in some patients. Other members of the M. tuberculosis complex are mainly animal pathogens with only exceptional cases of human disease, and there are even some strains, like "Mycobacterium canettii," which is a rare human pathogen that could have an important role in the knowledge of the evolution of tuberculosis in the history.

  8. Innate immune response to Mycobacterium tuberculosis Beijing and other genotypes.

    NARCIS (Netherlands)

    Wang, C.; Peyron, P.; Mestre, O.; Kaplan, G.; Soolingen, D. van; Gao, Q.; Gicquel, B.; Neyrolles, O.

    2010-01-01

    BACKGROUND: As a species, Mycobacterium tuberculosis is more diverse than previously thought. In particular, the Beijing family of M. tuberculosis strains is spreading and evaluating throughout the world and this is giving rise to public health concerns. Genetic diversity within this family has

  9. 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...

  10. 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 ...

  11. 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

  12. Structural studies on Mycobacterium tuberculosis RecA: Molecular ...

    Indian Academy of Sciences (India)

    2015-01-11

    Jan 11, 2015 ... with the protein, characterized in the structures reported here, could be useful for design of inhibitors against. M. tuberculosis RecA. .... rotating anode generator, both using a MAR345 image plate. The crystal to detector ...... structures of Mycobacterium tuberculosis peptidyl-tRNA hydro- lase. J. Mol. Biol.

  13. In-Vitro Susceptibility of Mycobacterium Tuberculosis to Extracts of ...

    African Journals Online (AJOL)

    Tuberculosis is a global burden with one –third of the world's population infected with the pathogen Mycobacterium tuberculosis and an annual 2 million deaths from the disease. This high incidence of infection and the increased rate of resistant strains of the organism (MDR- and XDR- TB) have called for an urgent need to ...

  14. 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

  15. A Case of False-Positive Mycobacterium tuberculosis Caused by Mycobacterium celatum

    OpenAIRE

    Gildeh, Edward; Abdel-Rahman, Zaid; Sengupta, Ruchira; Johnson, Laura

    2016-01-01

    Mycobacterium celatum is a nontuberculous mycobacterium shown to cause symptoms similar to pulmonary M. tuberculosis. Certain strains have been shown to cross-react with the probes used to detect M. tuberculosis, making this a diagnostic challenge. We present a 56-year-old gentleman who developed signs and symptoms of lung infection with computed tomography scan of the chest showing right lung apex cavitation. Serial sputum samples were positive for acid-fast bacilli and nucleic acid amplific...

  16. Identification of Nudix Hydrolase Family Members with an Antimutator Role in Mycobacterium tuberculosis and Mycobacterium smegmatis†

    OpenAIRE

    Dos Vultos, T.; Blázquez, J.; Rauzier, J.; Matic, I.; Gicquel, B.

    2006-01-01

    Mycobacterium tuberculosis and Mycobacterium smegmatis MutT1, MutT2, MutT3, and Rv3908 (MutT4) enzymes were screened for an antimutator role. Results indicate that both MutT1, in M. tuberculosis and M. smegmatis, and MutT4, in M. smegmatis, have that role. Furthermore, an 8-oxo-guanosine triphosphatase function for MutT1 and MutT2 is suggested.

  17. The cell envelope glycoconjugates of Mycobacterium tuberculosis

    Science.gov (United States)

    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

  18. Autophagy in Mycobacterium tuberculosis and HIV infections

    Directory of Open Access Journals (Sweden)

    Lucile eEspert

    2015-06-01

    Full Text Available Human Immunodeficiency Virus (HIV and Mycobacterium tuberculosis (M.tb are among the most lethal human pathogens worldwide, each being responsible for around 1.5 million deaths annually. Moreover, synergy between acquired immune deficiency syndrome (AIDS and tuberculosis (TB has turned HIV/M.tb co-infection into a major public health threat in developing countries. In the past decade, autophagy, a lysosomal catabolic process, has emerged as a major host immune defense mechanism against infectious agents like M.tb and HIV. Nevertheless, in some instances, autophagy machinery appears to be instrumental for HIV infection. Finally, there is mounting evidence that both pathogens deploy various countermeasures to thwart autophagy. This mini-review proposes an overview of the roles and regulations of autophagy in HIV and M.tb infections with an emphasis on microbial factors. We also discuss the role of autophagy manipulation in the context of HIV/M.tb co-infection. In future, a comprehensive understanding of autophagy interaction with these pathogens will be critical for development of autophagy-based prophylactic and therapeutic interventions for AIDS and TB.

  19. 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 detection...

  20. Profiling the Proteome of Mycobacterium tuberculosis during Dormancy and Reactivation*

    OpenAIRE

    Gopinath, Vipin; Raghunandanan, Sajith; Gomez, Roshna Lawrence; Jose, Leny; Surendran, Arun; Ramachandran, Ranjit; Pushparajan, Akhil Raj; Mundayoor, Sathish; Jaleel, Abdul; Kumar, Ramakrishnan Ajay

    2015-01-01

    Tuberculosis, caused by Mycobacterium tuberculosis, still remains a major global health problem. The main obstacle in eradicating this disease is the ability of this pathogen to remain dormant in macrophages, and then reactivate later under immuno-compromised conditions. The physiology of hypoxic nonreplicating M. tuberculosis is well-studied using many in vitro dormancy models. However, the physiological changes that take place during the shift from dormancy to aerobic growth (reactivation) ...

  1. Lymphadenitis in children is caused by Mycobacterium avium hominissuis and not related to 'bird tuberculosis'

    NARCIS (Netherlands)

    Bruijnesteijn van Coppenraet, L.E.S.; de Haas, P.E.W.; Lindeboom, J.A.; Kuijper, E.J.; van Soolingen, D.

    2008-01-01

    Mycobacterium avium is the most commonly encountered mycobacterium species among non-Mycobacterium tuberculosis complex (nontuberculous mycobacteria) isolates worldwide and frequently causes lymphadenitis in children. During a multi-centre study in The Netherlands that was performed to determine the

  2. Curcumin enhances human macrophage control of Mycobacterium tuberculosis infection.

    Science.gov (United States)

    Bai, Xiyuan; Oberley-Deegan, Rebecca E; Bai, An; Ovrutsky, Alida R; Kinney, William H; Weaver, Michael; Zhang, Gong; Honda, Jennifer R; Chan, Edward D

    2016-07-01

    With the worldwide emergence of highly drug-resistant tuberculosis (TB), novel agents that have direct antimycobacterial effects or that enhance host immunity are urgently needed. Curcumin is a polyphenol responsible for the bright yellow-orange colour of turmeric, a spice derived from the root of the perennial herb Curcuma longa. Curcumin is a potent inducer of apoptosis-an effector mechanism used by macrophages to kill intracellular Mycobacterium tuberculosis (MTB). An in vitro human macrophage infection model was used to determine the effects of curcumin on MTB survival. We found that curcumin enhanced the clearance of MTB in differentiated THP-1 human monocytes and in primary human alveolar macrophages. We also found that curcumin was an inducer of caspase-3-dependent apoptosis and autophagy. Curcumin mediated these anti-MTB cellular functions, in part, via inhibition of nuclear factor-kappa B (NFκB) activation. Curcumin protects against MTB infection in human macrophages. The host-protective role of curcumin against MTB in macrophages needs confirmation in an animal model; if validated, the immunomodulatory anti-TB effects of curcumin would be less prone to drug resistance development. © 2016 Asian Pacific Society of Respirology.

  3. Mycobacterium marinum: a potential immunotherapy for Mycobacterium tuberculosis infection

    Directory of Open Access Journals (Sweden)

    Tian WW

    2013-07-01

    Full Text Available Wei-wei Tian,1 Qian-qiu Wang,1 Wei-da Liu,2 Jian-ping Shen,1 Hong-sheng Wang11Laboratory of Mycobacterial Disease, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, Jiangsu, People’s Republic of China; 2Department of Mycology, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, Jiangsu, People’s Republic of ChinaPurpose: The aim of the present study was to investigate the immune response induced by Mycobacterium marinum infection in vitro and the potential of M. marinum as an immunotherapy for M. tuberculosis infection.Methods: The potential human immune response to certain bacillus infections was investigated in an immune cell–bacillus coculture system in vitro. As a potential novel immunotherapy, M. marinum was studied and compared with two other bacilli, Bacillus Calmette-Guérin (BCG and live attenuated M. tuberculosis. We examined the changes in both the bacilli and immune cells, especially the time course of the viability of mycobacteria in the coculture system and host immune responses including multinuclear giant cell formation by Wright–Giemsa modified staining, macrophage polarization by cell surface antigen expression, and cytokines/chemokine production by both mRNA expression and protein secretion.Results: The M. marinum stimulated coculture group showed more expression of CD209, CD68, CD80, and CD86 than the BCG and M. tuberculosis (an attenuated strain, H37Ra groups, although the differences were not statistically significant. Moreover, the M. marinum group expressed more interleukin (IL-1B and IL-12p40 on day 3 (IL-1B: P = 0.003 and 0.004, respectively; IL-12p40: P = 0.001 and 0.011, respectively, a higher level of CXCL10 on day 1 (P = 0.006 and 0.026, respectively, and

  4. Mycobacterium avium-intracellulare: a rare cause of subacromial bursitis.

    Science.gov (United States)

    Sinha, Raj; Tuckett, John; Hide, Geoff; Dildey, Petra; Karsandas, Alvin

    2015-01-01

    Septic subacromial bursitis is an uncommon disorder with only a few reported cases in the literature. The most common causative organism is Staphylococcus aureus. We report the case of a 61-year-old female with a septic subacromial bursitis where the causative organism was found to be Mycobacterium avium-intracellulare (MAI). The diagnosis was only made following a biopsy, and we use this case to highlight the importance of recognising the need to consider a biopsy and aspiration in atypical situations.

  5. Mycobacterium tuberculosis induces an atypical cell death mode to escape from infected macrophages.

    Directory of Open Access Journals (Sweden)

    Jinhee Lee

    Full Text Available BACKGROUND: Macrophage cell death following infection with Mycobacterium tuberculosis plays a central role in tuberculosis disease pathogenesis. Certain attenuated strains induce extrinsic apoptosis of infected macrophages but virulent strains of M. tuberculosis suppress this host response. We previously reported that virulent M. tuberculosis induces cell death when bacillary load exceeds ∼20 per macrophage but the precise nature of this demise has not been defined. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the characteristics of cell death in primary murine macrophages challenged with virulent or attenuated M. tuberculosis complex strains. We report that high intracellular bacillary burden causes rapid and primarily necrotic death via lysosomal permeabilization, releasing hydrolases that promote Bax/Bak-independent mitochondrial damage and necrosis. Cell death was independent of cathepsins B or L and notable for ultrastructural evidence of damage to lipid bilayers throughout host cells with depletion of several host phospholipid species. These events require viable bacteria that can respond to intracellular cues via the PhoPR sensor kinase system but are independent of the ESX1 system. CONCLUSIONS/SIGNIFICANCE: Cell death caused by virulent M. tuberculosis is distinct from classical apoptosis, pyroptosis or pyronecrosis. Mycobacterial genes essential for cytotoxicity are regulated by the PhoPR two-component system. This atypical death mode provides a mechanism for viable bacilli to exit host macrophages for spreading infection and the eventual transition to extracellular persistence that characterizes advanced pulmonary tuberculosis.

  6. Detection of Mycobacterium tuberculosis in cerebrospinal fluid following immunomagnetic enrichment.

    Science.gov (United States)

    Mazurek, G H; Reddy, V; Murphy, D; Ansari, T

    1996-01-01

    The detection of Mycobacterium tuberculosis by culture of cerebrospinal fluid (CSF) is unacceptably slow. Low numbers of organisms and the presence of reaction inhibitors may prevent detection of M. tuberculosis by PCR. We used immunomagnetic enrichment to accelerate and enhance the detection of mycobacteria in CSF after demonstrating the utility of the method with pure suspensions. Growth was detected earlier in Bactec cultures of magnetically recovered mycobacteria than in untreated CSF (7 versus 15 days). We detected M. tuberculosis DNA by PCR in the immunomagnetically enriched sample but not in untreated CSF. PCR fingerprintings of the immunomagnetically recovered M. tuberculosis and of the isolate subsequently recovered by culture were identical. PMID:8789037

  7. Pulmonary disease due to Mycobacterium tuberculosis in a horse: zoonotic concerns and limitations of antemortem testing

    Science.gov (United States)

    A case of pulmonary tuberculosis caused by Mycobacterium tuberculosis was diagnosed in a horse. Clinical evaluation performed prior to euthanasia did not suggest tuberculosis, but postmortem examination provided pathological and bacteriological evidence of disease. In the lungs, multiple tuberculoid...

  8. A Case of False-Positive Mycobacterium tuberculosis Caused by Mycobacterium celatum

    Directory of Open Access Journals (Sweden)

    Edward Gildeh

    2016-01-01

    Full Text Available Mycobacterium celatum is a nontuberculous mycobacterium shown to cause symptoms similar to pulmonary M. tuberculosis. Certain strains have been shown to cross-react with the probes used to detect M. tuberculosis, making this a diagnostic challenge. We present a 56-year-old gentleman who developed signs and symptoms of lung infection with computed tomography scan of the chest showing right lung apex cavitation. Serial sputum samples were positive for acid-fast bacilli and nucleic acid amplification testing identified M. tuberculosis ribosomal RNA, resulting in treatment initiation. Further testing with high performance liquid chromatography showed a pattern consistent with M. celatum. This case illustrates the potential for M. celatum to mimic M. tuberculosis in both its clinical history and laboratory testing due to the identical oligonucleotide sequence contained in both. An increasing number of case reports suggest that early reliable differentiation could reduce unnecessary treatment and public health intervention associated with misdiagnosed tuberculosis.

  9. DETECTION OF TISSUE MYCOBACTERIUM TUBERCULOSIS BY DIFFERENTIATING IMMUNOPEROXIDASE STAINING

    Directory of Open Access Journals (Sweden)

    A. P. Lysenko

    2014-01-01

    Full Text Available Staining impression smears from organ and tissues with peroxidase conjugated antibodies to Mycobacterium tuberculosis complex antigens, followed by visualization with diaminobenzidine and Kinyoun stains, ensured the painting of acid-resistant Mycobacterium tuberculosis forms to rubin red, acid-susceptible ones to brown, and tissue cells and microorganisms of other species to blue. Typical bacilli were absent in the lymph nodes of patients and animals with latent infection, but acid-resistant (rubin-red granular forms were encountered in the granulomatous masses. Brown fat cells containing mycobacterial antigens, as well as acid-susceptible granular, reticular, fungoid, and rod-like forms were also found in considerable quantities.

  10. 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

  11. 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

  12. Lung Mucosa Lining Fluid Modification of Mycobacterium tuberculosis to Reprogram Human Neutrophil Killing Mechanisms.

    Science.gov (United States)

    Arcos, Jesús; Diangelo, Lauren E; Scordo, Julia M; Sasindran, Smitha J; Moliva, Juan I; Turner, Joanne; Torrelles, Jordi B

    2015-09-15

    We have shown that human alveolar lining fluid (ALF) contains homeostatic hydrolases capable of altering the Mycobacterium tuberculosis cell wall and subsequently its interaction with human macrophages. Neutrophils are also an integral part of the host immune response to M. tuberculosis infection. Here we show that the human lung mucosa influences M. tuberculosis interaction with neutrophils, enhancing the intracellular killing of ALF-exposed M. tuberculosis and up-regulating the expression of tumor necrosis factor and interleukin 8. In contrast, ALF-exposed M. tuberculosis does not induce neutrophil apoptosis or necrosis, degranulation, or release of extracellular traps, and it decreases the oxidative response. These results suggest an important role for the human alveolar mucosa: increasing the innate capacity of the neutrophil to recognize and kill M. tuberculosis by favoring the use of intracellular mechanisms, while at the same time limiting neutrophil extracellular inflammatory responses to minimize their associated tissue damage. © The Author 2015. 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.

  13. 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

  14. 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

  15. 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

  16. Mycobacterium tuberculosis drug-resistance in previously treated ...

    African Journals Online (AJOL)

    Keywords: Burkina faso, drug resistance, Ouagadougou, tuberculosis. Résumé. Arrière-plan: Tuberculose pharmacorésistance devient commun en Afrique; Toutefois, très peu de données est disponibles au Burkina Faso. L'objectif de cette étude est pour évaluer la résistance acquise de Mycobacterium tuberculosis ...

  17. [Resistance of Mycobacterium tuberculosis strains to antimycobacterial preparations].

    Science.gov (United States)

    Iavors'ka, H V; Puhachevs'ka, L P

    2006-01-01

    Investigations of dynamics of Mycobacterium tuberculosis strains, isolated from patients with pulmonary tuberculosis were carried out in the Lviv region during 1994-2003. As a result of conducted investigations the tendency was revealed to increasing the amount of cultures resistant to streptomycine, isoniazide, canamycine, ethambutol, ryfampycine and their multiresistance during the investigation years. High quantity of resistant strains was revealed in common in 1997, 1999 and 2002.

  18. Dramatic reduction of culture time of Mycobacterium tuberculosis

    Science.gov (United States)

    Ghodbane, Ramzi; Raoult, Didier; Drancourt, Michel

    2014-02-01

    Mycobacterium tuberculosis culture, a critical technique for routine diagnosis of tuberculosis, takes more than two weeks. Here, step-by-step improvements in the protocol including a new medium, microaerophlic atmosphere or ascorbic-acid supplement and autofluorescence detection dramatically shortened this delay. In the best case, primary culture and rifampicin susceptibility testing were achieved in 72 hours when specimens were inoculated directly on the medium supplemented by antibiotic at the beginning of the culture.

  19. Game of 'Somes: Protein Destruction for Mycobacterium tuberculosis Pathogenesis.

    Science.gov (United States)

    Samanovic, Marie I; Darwin, K Heran

    2016-01-01

    The proteasome system of Mycobacterium tuberculosis is required for causing disease. Proteasomes are multisubunit chambered proteases and, until recently, were only known to participate in adenosine triphosphate (ATP)-dependent proteolysis in bacteria. In this review, we discuss the latest advances in understanding how both ATP-dependent and ATP-independent proteasome-regulated pathways contribute to M. tuberculosis virulence. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Mycobacterium tuberculosis Mutations Associated with Reduced Susceptibility to Linezolid

    Science.gov (United States)

    Zhang, Shuo; Chen, Jiazhen; Cui, Peng; Shi, Wanliang; Shi, Xiaohong; Niu, Hongxia; Chan, Denise; Yew, Wing Wai; Zhang, Wenhong

    2016-01-01

    Linezolid (LZD) has become increasingly important for the treatment of multidrug-resistant tuberculosis (MDR-TB), but its mechanisms of resistance are not well characterized. We isolated 32 mutants of Mycobacterium tuberculosis with reduced susceptibility to LZD, which was accounted for by rrl and rplC mutations in almost equal proportions, causing lower and higher MICs, respectively. Our findings provide useful information for the rapid detection of LZD resistance for improved treatment of MDR-TB. PMID:26810645

  1. The Delta fbpA mutant derived from Mycobacterium tuberculosis H37Rv has an enhanced susceptibility to intracellular antimicrobial oxidative mechanisms, undergoes limited phagosome maturation and activates macrophages and dendritic cells.

    Science.gov (United States)

    Katti, Muralidhar K; Dai, Guixiang; Armitige, Lisa Y; Rivera Marrero, Carlos; Daniel, Sundarsingh; Singh, Christopher R; Lindsey, Devin R; Dhandayuthapani, Subramanian; Hunter, Robert L; Jagannath, Chinnaswamy

    2008-06-01

    Mycobacterium tuberculosis H37Rv (Mtb) excludes phagocyte oxidase (phox) and inducible nitric oxide synthase (iNOS) while preventing lysosomal fusion in macrophages (MPhis). The antigen 85A deficient (Delta fbpA) mutant of Mtb was vaccinogenic in mice and the mechanisms of attenuation were compared with MPhis infected with H37Rv and BCG. Delta fbpA contained reduced amounts of trehalose 6, 6, dimycolate and induced minimal levels of SOCS-1 in MPhis. Blockade of oxidants enhanced the growth of Delta fbpA in MPhis that correlated with increased colocalization with phox and iNOS. Green fluorescent protein-expressing strains within MPhis or purified phagosomes were analysed for endosomal traffick with immunofluorescence and Western blot. Delta fbpA phagosomes were enriched for rab5, rab11, LAMP-1 and Hck suggesting enhanced fusion with early, recycling and late endosomes in MPhis compared with BCG or H37Rv. Delta fbpA phagosomes were thus more mature than H37Rv or BCG although, they failed to acquire rab7 and CD63 preventing lysosomal fusion. Finally, Delta fbpA infected MPhis and dendritic cells (DCs) showed an enhanced MHC-II and CD1d expression and primed immune T cells to release more IFN-gamma compared with those infected with BCG and H37Rv. Delta fbpA was thus more immunogenic in MPhis and DCs because of an enhanced susceptibility to oxidants and increased maturation.

  2. Mycobacterium Lysine ε-aminotransferase is a novel alarmone metabolism related persister gene via dysregulating the intracellular amino acid level.

    Science.gov (United States)

    Duan, Xiangke; Li, Yunsong; Du, Qinglin; Huang, Qinqin; Guo, Siyao; Xu, Mengmeng; Lin, Yanping; Liu, Zhidong; Xie, Jianping

    2016-01-25

    Bacterial persisters, usually slow-growing, non-replicating cells highly tolerant to antibiotics, play a crucial role contributing to the recalcitrance of chronic infections and treatment failure. Understanding the molecular mechanism of persister cells formation and maintenance would obviously inspire the discovery of new antibiotics. The significant upregulation of Mycobacterium tuberculosis Rv3290c, a highly conserved mycobacterial lysine ε-aminotransferase (LAT) during hypoxia persistent model, suggested a role of LAT in persistence. To test this, a lat deleted Mycobacterium smegmatis was constructed. The expression of transcriptional regulator leucine-responsive regulatory protein (LrpA) and the amino acids abundance in M. smegmatis lat deletion mutants were lowered. Thus, the persistence capacity of the deletion mutant was impaired upon norfloxacin exposure under nutrient starvation. In summary, our study firstly reported the involvement of mycobacterium LAT in persister formation, and possibly through altering the intracellular amino acid metabolism balance.

  3. The regulation of sulfur metabolism in Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Stavroula K Hatzios

    2011-07-01

    Full Text Available Mycobacterium tuberculosis (Mtb has evolved into a highly successful human pathogen. It deftly subverts the bactericidal mechanisms of alveolar macrophages, ultimately inducing granuloma formation and establishing long-term residence in the host. These hallmarks of Mtb infection are facilitated by the metabolic adaptation of the pathogen to its surrounding environment and the biosynthesis of molecules that mediate its interactions with host immune cells. The sulfate assimilation pathway of Mtb produces a number of sulfur-containing metabolites with important contributions to pathogenesis and survival. This pathway is regulated by diverse environmental cues and regulatory proteins that mediate sulfur transactions in the cell. Here, we discuss the transcriptional and biochemical mechanisms of sulfur metabolism regulation in Mtb and potential small molecule regulators of the sulfate assimilation pathway that are collectively poised to aid this intracellular pathogen in its expert manipulation of the host. From this global analysis, we have identified a subset of sulfur-metabolizing enzymes that are sensitive to multiple regulatory cues and may be strong candidates for therapeutic intervention.

  4. Differential Recognition of Mycobacterium tuberculosis-Specific Epitopes as a Function of Tuberculosis Disease History.

    Science.gov (United States)

    Scriba, Thomas J; Carpenter, Chelsea; Pro, Sebastian Carrasco; Sidney, John; Musvosvi, Munyaradzi; Rozot, Virginie; Seumois, Grégory; Rosales, Sandy L; Vijayanand, Pandurangan; Goletti, Delia; Makgotlho, Edward; Hanekom, Willem; Hatherill, Mark; Peters, Bjoern; Sette, Alessandro; Arlehamn, Cecilia S Lindestam

    2017-09-15

    Individuals with a history of tuberculosis (TB) disease are at elevated risk of disease recurrence. The underlying cause is not known, but one explanation is that previous disease results in less-effective immunity against Mycobacterium tuberculosis (Mtb). We hypothesized that the repertoire of Mtb-derived epitopes recognized by T cells from individuals with latent Mtb infection differs as a function of previous diagnosis of active TB disease. T-cell responses to peptide pools in samples collected from an adult screening and an adolescent validation cohort were measured by IFN-γ enzyme-linked immunospot assay or intracellular cytokine staining. We identified a set of "type 2" T-cell epitopes that were recognized at 10-fold-lower levels in Mtb-infected individuals with a history of TB disease less than 6 years ago than in those without previous TB. By contrast, "type 1" epitopes were recognized equally well in individuals with or without previous TB. The differential epitope recognition was not due to differences in HLA class II binding, memory phenotypes, or gene expression in the responding T cells. Instead, "TB disease history-sensitive" type 2 epitopes were significantly (P < 0.0001) more homologous to sequences from bacteria found in the human microbiome than type 1 epitopes. Preferential loss of T-cell reactivity to Mtb epitopes that are homologous to bacteria in the microbiome in persons with previous TB disease may reflect long-term effects of antibiotic TB treatment on the microbiome.

  5. [Comparison study on polymerase chain reaction (PCR) and standard culture technique in detecting mycobacterium tuberculosis to diagnose of joint tuberculosis].

    Science.gov (United States)

    Sun, Yong-sheng; Wen, Jian-min; Lü, Wei-xin; Lou, Si-quan; Jiao, Chang-geng; Yang, Su-min; Xu, Hai-bin; Duan, Yong-zhuang

    2009-07-01

    To study the role of PCR technique in detection of mycobacterium tuberculosis in the samples from joint tuberculosis, and to evaluate the clinical value of PCR in diagnosis of joint tuberculosis. From June 1993 to August 2001, PCR was used to detect DNA of mycobacterium tuberculosis, and the standard culture was applied to detect mycobacterium tuberculosis. Mycobacterium tuberculosis were respectively blindly by the two techniques in the samples obtained from 95 patients with joint tuberculosis (55 males and 40 females, the age ranging from 2 to 75 years, with an average of 34 years). The positive rate of mycobacterium tuberculosis detection was calculated. In the detection of mycobacterium tuberculosis, positive rate was 82% (78/95) in PCR technique, and 16% (15/95) in standard culture technique. There were statistical differences between the two groups (chi2=67, Ptechnique is a rapid, simple, sensitive and specific method for detection of mycobacterium tuberculosis in the samples of joint tuberculosis, showing more marked advantages than the standard culture technique. It is valuable in the early rapid diagnosis and differential diagnosis of joint tuberculosis.

  6. 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.

  7. 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.

  8. 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.

  9. 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 ...

  10. 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.

  11. 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

  12. 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

  13. Structural studies on Mycobacterium tuberculosis RecA: Molecular ...

    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 ...

  14. Isolation of Mycobacterium tuberculosis complex (MTBC) from dairy ...

    African Journals Online (AJOL)

    ajl4

    2012-11-08

    Nov 8, 2012 ... Eleven thousand five hundred and eighty non-blood samples from dairy cows were subjected to mycobacterium culture and ... tuberculosis infection in cattle is a new risk to public health and should be paid more attention. Key words: ..... S, Zhao YL (2012). Spoligotyping and drug resistance analysis of.

  15. 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....

  16. cor, a novel carbon monoxide resistance gene, is essential for Mycobacterium tuberculosis pathogenesis.

    Science.gov (United States)

    Zacharia, Vineetha M; Manzanillo, Paolo S; Nair, Vidhya R; Marciano, Denise K; Kinch, Lisa N; Grishin, Nick V; Cox, Jeffery S; Shiloh, Michael U

    2013-11-19

    Tuberculosis, caused by Mycobacterium tuberculosis, remains a devastating human infectious disease, causing two million deaths annually. We previously demonstrated that M. tuberculosis induces an enzyme, heme oxygenase (HO1), that produces carbon monoxide (CO) gas and that M. tuberculosis adapts its transcriptome during CO exposure. We now demonstrate that M. tuberculosis carries a novel resistance gene to combat CO toxicity. We screened an M. tuberculosis transposon library for CO-susceptible mutants and found that disruption of Rv1829 (carbon monoxide resistance, Cor) leads to marked CO sensitivity. Heterologous expression of Cor in Escherichia coli rescued it from CO toxicity. Importantly, the virulence of the cor mutant is attenuated in a mouse model of tuberculosis. Thus, Cor is necessary and sufficient to protect bacteria from host-derived CO. Taken together, this represents the first report of a role for HO1-derived CO in controlling infection of an intracellular pathogen and the first identification of a CO resistance gene in a pathogenic organism. Macrophages produce a variety of antimicrobial molecules, including nitric oxide (NO), hydrogen peroxide (H2O2), and acid (H+), that serve to kill engulfed bacteria. In addition to these molecules, human and mouse macrophages also produce carbon monoxide (CO) gas by the heme oxygenase (HO1) enzyme. We observed that, in contrast to other bacteria, mycobacteria are resistant to CO, suggesting that this might be an evolutionary adaptation of mycobacteria for survival within macrophages. We screened a panel of ~2,500 M. tuberculosis mutants to determine which genes are required for survival of M. tuberculosis in the presence of CO. Within this panel, we identified one such gene, cor, that specifically confers CO resistance. Importantly, we found that the ability of M. tuberculosis cells carrying a mutated copy of this gene to cause tuberculosis in a mouse disease model is significantly attenuated. This indicates that

  17. Comparative Analyses of Nonpathogenic, Opportunistic, and Totally Pathogenic Mycobacteria Reveal Genomic and Biochemical Variabilities and Highlight the Survival Attributes of Mycobacterium tuberculosis

    Science.gov (United States)

    Singh, Yadvir; Kohli, Sakshi; Ahmad, Javeed; Ehtesham, Nasreen Z.; Tyagi, Anil K.

    2014-01-01

    ABSTRACT Mycobacterial evolution involves various processes, such as genome reduction, gene cooption, and critical gene acquisition. Our comparative genome size analysis of 44 mycobacterial genomes revealed that the nonpathogenic (NP) genomes were bigger than those of opportunistic (OP) or totally pathogenic (TP) mycobacteria, with the TP genomes being smaller yet variable in size—their genomic plasticity reflected their ability to evolve and survive under various environmental conditions. From the 44 mycobacterial species, 13 species, representing TP, OP, and NP, were selected for genomic-relatedness analyses. Analysis of homologous protein-coding genes shared between Mycobacterium indicus pranii (NP), Mycobacterium intracellulare ATCC 13950 (OP), and Mycobacterium tuberculosis H37Rv (TP) revealed that 4,995 (i.e., ~95%) M. indicaus pranii proteins have homology with M. intracellulare, whereas the homologies among M. indicus pranii, M. intracellulare ATCC 13950, and M. tuberculosis H37Rv were significantly lower. A total of 4,153 (~79%) M. indicus pranii proteins and 4,093 (~79%) M. intracellulare ATCC 13950 proteins exhibited homology with the M. tuberculosis H37Rv proteome, while 3,301 (~82%) and 3,295 (~82%) M. tuberculosis H37Rv proteins showed homology with M. indicus pranii and M. intracellulare ATCC 13950 proteomes, respectively. Comparative metabolic pathway analyses of TP/OP/NP mycobacteria showed enzymatic plasticity between M. indicus pranii (NP) and M. intracellulare ATCC 13950 (OP), Mycobacterium avium 104 (OP), and M. tuberculosis H37Rv (TP). Mycobacterium tuberculosis seems to have acquired novel alternate pathways with possible roles in metabolism, host-pathogen interactions, virulence, and intracellular survival, and by implication some of these could be potential drug targets. PMID:25370496

  18. 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.

  19. Mycobacterium tuberculosis Bacteremia Among Acutely Febrile Children in Western Kenya.

    Science.gov (United States)

    Pavlinac, Patricia B; Naulikha, Jaqueline M; John-Stewart, Grace C; Onchiri, Frankline M; Okumu, Albert O; Sitati, Ruth R; Cranmer, Lisa M; Lokken, Erica M; Singa, Benson O; Walson, Judd L

    2015-11-01

    In children, Mycobacterium tuberculosis (M. tuberculosis) frequently disseminates systemically, presenting with nonspecific signs including fever. We determined prevalence of M. tuberculosis bacteremia among febrile children presenting to hospitals in Nyanza, Kenya (a region with high human immunodeficiency virus (HIV) and M. tuberculosis prevalence). Between March 2013 and February 2014, we enrolled children aged 6 months to 5 years presenting with fever (axillary temperature ≥ 37.5°C) and no recent antibiotic use. Blood samples were collected for bacterial and mycobacterial culture using standard methods. Among 148 children enrolled, median age was 3.1 years (interquartile range: 1.8-4.1 years); 10.3% of children were living with a household member diagnosed with M. tuberculosis in the last year. Seventeen percent of children were stunted (height-for-age z-score children (11.5%) had one or more signs of tuberculosis (TB). All children had a Bacille Calmette-Guerin vaccination scar. Among 134 viable blood cultures, none (95% confidence interval: 0-2.7%) had Mycobacterium isolated. Despite exposure to household TB contacts, HIV exposure, and malnutrition, M. tuberculosis bacteremia was not detected in this pediatric febrile cohort, a finding consistent with other pediatric studies. © The American Society of Tropical Medicine and Hygiene.

  20. Cytokinins beyond plants: synthesis byMycobacterium tuberculosis.

    Science.gov (United States)

    Samanovic, Marie I; Darwin, K H

    2015-05-04

    Mycobacterium tuberculosis ( M. tuberculosis ) resides mainly inside macrophages, which produce nitric oxide (NO) to combat microbial infections. Earlier studies revealed that proteasome-associated genes are required for M. tuberculosis to resist NO via a previously uncharacterized mechanism. Twelve years later, we elucidated the link between proteasome function and NO resistance in M. tuberculosis in Molecular Cell , 57 (2015), pp. 984-994. In a proteasome degradation-defective mutant, Rv1205, a homologue of the plant enzyme LONELY GUY (LOG) that is involved in the synthesis of phytohormones called cytokinins, accumulates and as a consequence results in the overproduction of cytokinins. Cytokinins break down into aldehydes that kill mycobacteria in the presence of NO. Importantly, this new discovery reveals for the first time that a mammalian bacterial pathogen produces cytokinins and leaves us with the question: why is M. tuberculosis , an exclusively human pathogen, producing cytokinins?

  1. 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...

  2. Mycobacterium avium-intracellulare cellulitis occurring with septic arthritis after joint injection: a case report

    Directory of Open Access Journals (Sweden)

    Murdoch David M

    2007-02-01

    Full Text Available Abstract Background Cellulitis caused by Mycobacterium avium-intracellulare has rarely been described. Mycobacterium avium-intracellulare is a rare cause of septic arthritis after intra-articular injection, though the causative role of injection is difficult to ascertain in such cases. Case presentation A 57-year-old with rheumatoid arthritis treated with prednisone and azathioprine developed bilateral painful degenerative shoulder arthritis. After corticosteroid injections into both acromioclavicular joints, he developed bilateral cellulitis centered over the injection sites. Skin biopsy showed non-caseating granulomas, and culture grew Mycobacterium avium-intracellulare. Joint aspiration also revealed Mycobacterium avium-intracellulare infection. Conclusion Although rare, skin and joint infections caused by Mycobacterium avium-intracellulare should be considered in any immunocompromised host, particularly after intra-articular injection. Stains for acid-fast bacilli may be negative in pathologic samples even in the presence of infection; cultures of tissue specimens should always be obtained.

  3. An insight into the regulation of mce4 operon of Mycobacterium tuberculosis.

    Science.gov (United States)

    Rathor, Nisha; Chandolia, Amita; Saini, Neeraj Kumar; Sinha, Rajesh; Pathak, Rakesh; Garima, Kushal; Singh, Satendra; Varma-Basil, Mandira; Bose, Mridula

    2013-07-01

    The mce4 operon is reported to be involved in cholesterol utilization and intracellular survival of Mycobacterium tuberculosis (M. tuberculosis). The regulatory mechanism of this important operon was unknown so far. Here we report detection of the promoter region and regulatory factors of the mce4 operon. The in silico analyzed putative promoter region was cloned in promoter selection vector and promoter strength was measured by O-Nitrophenyl-β-D-galactopyranosidase (ONPG) assay. The transcription start site was determined by 5' Rapid amplification of C terminal end (5'RACE). Surface stress, hypoxia and presence of cholesterol, were found to be stimulatory for mce4 operon promoter induction. Pull down assay coupled with 2D gel electrophoresis resolved many proteins; few prominent spots were processed for identification. MALDI TOF-TOF identified proteins of M. tuberculosis which supported the regulatory function of the identified promoter region and cholesterol utilization of mce4 operon. Since mce4 operon is involved in cholesterol utilization and intracellular survival of M. tuberculosis in the later phase of infection, identification of the promoter sequence as reported in the present communication may facilitate development of effective inhibitors to regulate expression of mce4 operon which may prove to be a good drug target to prevent latency in tuberculosis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Phylogenetic analysis of vitamin B12-related metabolism in Mycobacterium tuberculosis

    OpenAIRE

    Young, Douglas B.; Comas, I?aki; de Carvalho, Luiz P. S.

    2015-01-01

    Comparison of genome sequences from clinical isolates of Mycobacterium tuberculosis with phylogenetically-related pathogens Mycobacterium marinum, Mycobacterium kansasii, and Mycobacterium leprae reveals diversity amongst genes associated with vitamin B12-related metabolism. Diversity is generated by gene deletion events, differential acquisition of genes by horizontal transfer, and single nucleotide polymorphisms (SNPs) with predicted impact on protein function and transcriptional regulation...

  5. 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...

  6. Analysis of CD4+ Th1 cells in immunity to intracellular Mycobacterium avium infection

    OpenAIRE

    Bakke, Marit Øien

    2013-01-01

    Mycobacterial infections are considered a major health problem internationally. Mycobacterium tuberculosis (Mtb), the infectious agent causing tuberculosis, kills 1.4 million people each year. Other non-tuberculous species such as Mycobacterium avium (M. avium) are less pathogenic but cause opportunistic infections mainly in immune-compromised people. The current treatment for different mycobacterial infections is elaborate, expensive and ineffective and new targets for treatment are needed. ...

  7. Gamma/delta T lymphocytes in Mycobacterium tuberculosis infection.

    Science.gov (United States)

    Balikó, Z; Szereday, L; Szekeres-Bartho, J

    1997-04-01

    Data on the percentage of gamma/delta T lymphocytes in the peripheral blood of patients infected with Mycobacterium tuberculosis are few and contradictory. The percentage of gamma/delta T lymphocytes in the peripheral blood of tuberculin positive and tuberculin negative patients with Mycobacterium tuberculosis infection and healthy controls was compared. Thirty six patients infected with Mycobacterium tuberculosis and 11 healthy controls were studied. Lymphocytes were separated, cytocentrifuged onto glass microscope slides, and reacted with anti-gamma/delta monoclonal antibody. The percentage of gamma/delta positive cells was determined by microscopic counting of 300 lymphocytes. No difference was found in the percentage of gamma/delta T lymphocytes between patients and controls. However, when the patients were divided into two groups according to reactivity or non-reactivity in the Mantoux skin reaction a higher percentage of gamma/delta T lymphocytes was found in the peripheral blood of patients with tuberculin anergy than in tuberculin positive patients or controls. Higher gamma/delta T cell counts are found in tuberculin negative patients with tuberculosis than in tuberculin positive patients or tuberculin positive controls. The high gamma/delta T cell counts in tuberculin anergic patients may reflect a shift in the immune response in a Th2 direction characterised by increased antibody production and decreased cell mediated responses.

  8. 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.

  9. Selective Killing of Dormant Mycobacterium tuberculosis by Marine Natural Products.

    Science.gov (United States)

    Rodrigues Felix, Carolina; Gupta, Rashmi; Geden, Sandra; Roberts, Jill; Winder, Priscilla; Pomponi, Shirley A; Diaz, Maria Cristina; Reed, John K; Wright, Amy E; Rohde, Kyle H

    2017-08-01

    The dormant phenotype acquired by Mycobacterium tuberculosis during infection poses a major challenge in disease treatment, since these bacilli show tolerance to front-line drugs. Therefore, it is imperative to find novel compounds that effectively kill dormant bacteria. By screening 4,400 marine natural product samples against dual-fluorescent M. tuberculosis under both replicating and nonreplicating conditions, we have identified compounds that are selectively active against dormant M. tuberculosis This validates our strategy of screening all compounds in both assays as opposed to using the dormancy model as a secondary screen. Bioassay-guided deconvolution enabled the identification of unique pharmacophores active in each screening model. To confirm the activity of samples against dormant M. tuberculosis , we used a luciferase reporter assay and enumerated CFU. The structures of five purified active compounds were defined by nuclear magnetic resonance (NMR) and mass spectrometry. We identified two lipid compounds with potent activity toward dormant and actively growing M. tuberculosis strains. One of these was commercially obtained and showed similar activity against M. tuberculosis in both screening models. Furthermore, puupehenone-like molecules were purified with potent and selective activity against dormant M. tuberculosis In conclusion, we have identified and characterized antimycobacterial compounds from marine organisms with novel activity profiles which appear to target M. tuberculosis pathways that are conditionally essential for dormancy survival. Copyright © 2017 American Society for Microbiology.

  10. 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.

  11. Determination of Urinary Neopterin/Creatinine Ratio to Distinguish Active Tuberculosis from Latent Mycobacterium tuberculosis Infection

    Directory of Open Access Journals (Sweden)

    Michael Eisenhut

    2016-01-01

    Full Text Available Background. Biomarkers to distinguish latent from active Mycobacterium (M. tuberculosis infection in clinical practice are lacking. The urinary neopterin/creatinine ratio can quantify the systemic interferon-gamma effect in patients with M. tuberculosis infection. Methods. In a prospective observational study, urinary neopterin levels were measured by enzyme linked immunosorbent assay in patients with active tuberculosis, in people with latent M. tuberculosis infection, and in healthy controls and the urinary neopterin/creatinine ratio was calculated. Results. We included a total of 44 patients with M. tuberculosis infection and nine controls. 12 patients had active tuberculosis (8 of them culture-confirmed. The median age was 15 years (range 4.5 to 49. Median urinary neopterin/creatinine ratio in patients with active tuberculosis was 374.1 micromol/mol (129.0 to 1072.3, in patients with latent M. tuberculosis infection it was 142.1 (28.0 to 384.1, and in controls it was 146.0 (40.3 to 200.0, with significantly higher levels in patients with active tuberculosis (p<0.01. The receiver operating characteristics curve had an area under the curve of 0.84 (95% CI 0.70 to 0.97 (p<0.01. Conclusions. Urinary neopterin/creatinine ratios are significantly higher in patients with active tuberculosis compared to patients with latent infection and may be a significant predictor of active tuberculosis in patients with M. tuberculosis infection.

  12. Proteomic analysis of extracellular vesicles derived from Mycobacterium tuberculosis.

    Science.gov (United States)

    Lee, Jaewook; Kim, Si-Hyun; Choi, Dong-Sic; Lee, Jong Seok; Kim, Dae-Kyum; Go, Gyeongyun; Park, Seon-Min; Kim, Si Hyun; Shin, Jeong Hwan; Chang, Chulhun L; Gho, Yong Song

    2015-10-01

    The release of extracellular vesicles, also known as outer membrane vesicles, membrane vesicles, exosomes, and microvesicles, is an evolutionarily conserved phenomenon from bacteria to eukaryotes. It has been reported that Mycobacterium tuberculosis releases extracellular vesicles harboring immunologically active molecules, and these extracellular vesicles have been suggested to be applicable in vaccine development and biomarker discovery. However, the comprehensive proteomic analysis has not been performed for M. tuberculosis extracellular vesicles. In this study, we identified a total of 287 vesicular proteins by four LC-MS/MS analyses with high confidence. In addition, we identified several vesicular proteins associated with the virulence of M. tuberculosis. This comprehensive proteome profile will help elucidate the pathogenic mechanism of M. tuberculosis. The data have been deposited to the ProteomeXchange with identifier PXD001160 (http://proteomecentral.proteomexchange.org/dataset/PXD001160). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Evasion and subversion of antigen presentation by Mycobacterium tuberculosis.

    Science.gov (United States)

    Baena, A; Porcelli, S A

    2009-09-01

    Mycobacterium tuberculosis is one of the most successful of human pathogens and has acquired the ability to establish latent or progressive infection and persist even in the presence of a fully functioning immune system. The ability of M. tuberculosis to avoid immune-mediated clearance is likely to reflect a highly evolved and coordinated program of immune evasion strategies, including some that interfere with antigen presentation to prevent or alter the quality of T-cell responses. Here, we review an extensive array of published studies supporting the view that antigen presentation pathways are targeted at many points by pathogenic mycobacteria. These studies show the multiple potential mechanisms by which M. tuberculosis may actively inhibit, subvert or otherwise modulate antigen presentation by major histocompatibility complex class I, class II and CD1 molecules. Unraveling the mechanisms by which M. tuberculosis evades or modulates antigen presentation is of critical importance for the development of more effective new vaccines based on live attenuated mycobacterial strains.

  14. 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.

  15. Genetic profile of Mycobacterium tuberculosis and treatment ...

    African Journals Online (AJOL)

    In conclusion, M. tuberculosis isolates from pulmonary tuberculosis cases in Tanzania were classified mostly within the CAS, LAM, and EAI and T families. Consistently good treatment outcomes were recorded across the spoligotype families. The proportion of drug resistance strains was low. The findings also suggest ...

  16. 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.

  17. 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...

  18. Different transcriptional profiles of human monocyte-derived dendritic cells infected with distinct strains of Mycobacterium tuberculosis and Mycobacterium bovis bacillus Calmette-Guérin.

    Science.gov (United States)

    Sanarico, Nunzia; Colone, Alessia; Grassi, Manuela; Speranza, Viviana; Giovannini, Daniela; Ciaramella, Antonio; Colizzi, Vittorio; Mariani, Francesca

    2011-01-01

    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.

  19. Mycobacterium tuberculosis complex mycobacteria as amoeba-resistant organisms.

    Directory of Open Access Journals (Sweden)

    Felix Mba Medie

    Full Text Available BACKGROUND: Most environmental non-tuberculous mycobacteria have been demonstrated to invade amoebal trophozoites and cysts, but such relationships are largely unknown for members of the Mycobacterium tuberculosis complex. An environmental source has been proposed for the animal Mycobacterium bovis and the human Mycobacterium canettii. METHODOLOGY/PRINCIPAL FINDINGS: Using optic and electron microscopy and co-culture methods, we observed that 89±0.6% of M. canettii, 12.4±0.3% of M. tuberculosis, 11.7±2% of M. bovis and 11.2±0.5% of Mycobacterium avium control organisms were phagocytized by Acanthamoeba polyphaga, a ratio significantly higher for M. canettii (P = 0.03, correlating with the significantly larger size of M. canetti organisms (P = 0.035. The percentage of intraamoebal mycobacteria surviving into cytoplasmic vacuoles was 32±2% for M. canettii, 26±1% for M. tuberculosis, 28±2% for M. bovis and 36±2% for M. avium (P = 0.57. M. tuberculosis, M. bovis and M. avium mycobacteria were further entrapped within the double wall of <1% amoebal cysts, but no M. canettii organisms were observed in amoebal cysts. The number of intracystic mycobacteria was significantly (P = 10(-6 higher for M. avium than for the M. tuberculosis complex, and sub-culturing intracystic mycobacteria yielded significantly more (P = 0.02 M. avium organisms (34×10(4 CFU/mL than M. tuberculosis (42×10(1 CFU/mL and M. bovis (35×10(1 CFU/mL in the presence of a washing fluid free of mycobacteria. Mycobacteria survived in the cysts for up to 18 days and cysts protected M. tuberculosis organisms against mycobactericidal 5 mg/mL streptomycin and 2.5% glutaraldehyde. CONCLUSIONS/SIGNIFICANCE: These data indicate that M. tuberculosis complex organisms are amoeba-resistant organisms, as previously demonstrated for non-tuberculous, environmental mycobacteria. Intercystic survival of tuberculous mycobacteria, except for M. canettii, protect them

  20. Replication rates of Mycobacterium tuberculosis in human macrophages do not correlate with mycobacterial antibiotic susceptibility.

    Directory of Open Access Journals (Sweden)

    Johanna Raffetseder

    Full Text Available The standard treatment of tuberculosis (TB takes six to nine months to complete and this lengthy therapy contributes to the emergence of drug-resistant TB. TB is caused by Mycobacterium tuberculosis (Mtb and the ability of this bacterium to switch to a dormant phenotype has been suggested to be responsible for the slow clearance during treatment. A recent study showed that the replication rate of a non-virulent mycobacterium, Mycobacterium smegmatis, did not correlate with antibiotic susceptibility. However, the question whether this observation also holds true for Mtb remains unanswered. Here, in order to mimic physiological conditions of TB infection, we established a protocol based on long-term infection of primary human macrophages, featuring Mtb replicating at different rates inside the cells. During conditions that restricted Mtb replication, the bacterial phenotype was associated with reduced acid-fastness. However, these phenotypically altered bacteria were as sensitive to isoniazid, pyrazinamide and ethambutol as intracellularly replicating Mtb. In support of the recent findings with M. smegmatis, we conclude that replication rates of Mtb do not correlate with antibiotic tolerance.

  1. Replication rates of Mycobacterium tuberculosis in human macrophages do not correlate with mycobacterial antibiotic susceptibility.

    Science.gov (United States)

    Raffetseder, Johanna; Pienaar, Elsje; Blomgran, Robert; Eklund, Daniel; Patcha Brodin, Veronika; Andersson, Henrik; Welin, Amanda; Lerm, Maria

    2014-01-01

    The standard treatment of tuberculosis (TB) takes six to nine months to complete and this lengthy therapy contributes to the emergence of drug-resistant TB. TB is caused by Mycobacterium tuberculosis (Mtb) and the ability of this bacterium to switch to a dormant phenotype has been suggested to be responsible for the slow clearance during treatment. A recent study showed that the replication rate of a non-virulent mycobacterium, Mycobacterium smegmatis, did not correlate with antibiotic susceptibility. However, the question whether this observation also holds true for Mtb remains unanswered. Here, in order to mimic physiological conditions of TB infection, we established a protocol based on long-term infection of primary human macrophages, featuring Mtb replicating at different rates inside the cells. During conditions that restricted Mtb replication, the bacterial phenotype was associated with reduced acid-fastness. However, these phenotypically altered bacteria were as sensitive to isoniazid, pyrazinamide and ethambutol as intracellularly replicating Mtb. In support of the recent findings with M. smegmatis, we conclude that replication rates of Mtb do not correlate with antibiotic tolerance.

  2. 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.

  3. 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

  4. 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

  5. Specificity and Diversity of Antibodies to Mycobacterium tuberculosis Arabinomannan

    OpenAIRE

    Navoa, Josephine Anne D.; Laal, Suman; Pirofski, Liise-Anne; McLean, Gary R.; Dai, Zhongdong; Robbins, John B.; Schneerson, Rachel; Casadevall, Arturo; Glatman-Freedman, Aharona

    2003-01-01

    Arabinomannan (AM) is a polysaccharide antigen of the mycobacterial capsule. However, it is uncertain whether AM constitutes an immunologically distinct fraction of Mycobacterium tuberculosis. In this study, we analyzed the repertoire and specificity of antibodies to AM by using AM-binding murine monoclonal antibodies (MAbs) and human serum samples. Murine MAbs were found to be diverse in their specificity to AM and cross-reactivity with other arabinose-containing mycobacterial polysaccharide...

  6. Diagnostic moléculaire du complexe Mycobacterium tuberculosis ...

    African Journals Online (AJOL)

    Méthodes: le diagnostic du Complexe Mycobacterium Tuberculosis (CMTB) a été effectué par microscopie après coloration au Ziehl Nielsen et par PCR en temps réel en utilisant le kit d'identification du complexe MTB (Sacace Biotechnologie, Italie). Les résistances à la Rifampicine et à l'Isoniazide ont été étudiées par la ...

  7. Protein synthesis in the human virulent Strain of Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Shaila, M.S.; Gopinathan, K.P.; Ramakrishnan, T.

    1975-01-01

    An efficient in vitro amino acid incorporating system from the human virulent strain of Mycobacterium tuberculosis has been standardized. The effects of various antitubercular drugs and 'known inhibitors' of protein synthesis on amino acid incorporation were studied. Antibiotics like chloramphenicol, tetracycline and streptomycine were studied for their inhibitory action. 14 C-amino acids, 14 C-chlorella protein hydrolasate and 3 H-dihydrostreptomycine sesqui-sulphate were used in the studies. (M.G.B.)

  8. 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

  9. nourishing molecule in endurance of Mycobacterium tuberculosis

    Indian Academy of Sciences (India)

    Pratap C Mali

    2018-01-24

    rich molecules as an energy source obtained from host cell debris remains interesting. Additionally, the potential of M. tuberculosis to survive under different stress conditions leading to its dormant state in pathogenesis remains ...

  10. Characterization of a 10- to 14-kilodalton protease-sensitive Mycobacterium tuberculosis H37Ra antigen that stimulates human gamma delta T cells.

    OpenAIRE

    Boom, W H; Balaji, K N; Nayak, R; Tsukaguchi, K; Chervenak, K A

    1994-01-01

    gamma delta T-cell receptor-bearing T cells (gamma delta T cells) are readily activated by intracellular bacterial pathogens such as Mycobacterium tuberculosis. The bacterial antigens responsible for gamma delta T-cell activation remain poorly characterized. We have found that heat treatment of live M. tuberculosis bacilli released into the supernatant an antigen which stimulated human gamma delta T cells. gamma delta T-cell activation was measured by determining the increase in percentage of...

  11. Chlorhexidine decontamination of sputum for culturing Mycobacterium tuberculosis.

    Science.gov (United States)

    Asmar, Shady; Drancourt, Michel

    2015-08-05

    Culture of Mycobacterium tuberculosis is the gold standard method for the laboratory diagnosis of pulmonary tuberculosis, after effective decontamination. We evaluated squalamine and chlorhexidine to decontaminate sputum specimens for the culture of mycobacteria. Eight sputum specimens were artificially infected with 10(5) colony-forming units (cfu)/mL Mycobacterium tuberculosis and Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans as contaminants. In the second step, we tested chlorhexidine-based decontamination on 191 clinical specimens, (Chlorhexidine, 0.1, 0.5 and 0.7 %). In a last step, growth of contaminants and mycobacteria was measured in 75 consecutive sputum specimens using the routine NALC-NaOH decontamination protocol or with 0.7 % chlorhexidine decontamination and an inoculation on Coletsos medium. In the artificially model, contaminants grew in 100 % of the artificially infected sputum specimens decontaminated using 100 mg/mL squalamine, in 62.5 % of specimens decontaminated using N-Acetyl-L-Cysteine-Sodium Hydroxide (NALC-NaOH), and in 0 % of specimens decontaminated using 0.1 %, 0.35 %, or 1 % chlorhexidine (P  1.4.10(2) cfu M. tuberculosis when any concentration of chlorhexidine was used (P decontamination method, 8/75 (10.7 %) specimens yielded M. tuberculosis colonies with a time to detection of 17.5 ± 3 days and an 8 % contamination rate. Additionally, 14 specimens yielded mycobacteria colonies (12 M. tuberculosis, and 2 Mycobacterium bolletii) (18.7 %) (P = 0.25), which has yielded a 100 % sensitivity for the chlorhexidine protocol. Time to detection was of 15.86 ± 4.7 days (P = 0.39) and a 0 % contamination rate (P decontamination is superior to the standard NALC-NaOH method in the isolation of M. tuberculosis from sputum specimens. We currently use 0.7 %-chlorhexidine for the routine decontamination of sputum specimens for the isolation of M. tuberculosis and non-tuberculosis

  12. High genetic diversity among Mycobacterium tuberculosis strains in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    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

  13. Genetic incorporation of unnatural amino acids into proteins in Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Feng Wang

    2010-02-01

    Full Text Available New tools are needed to study the intracellular pathogen Mycobacterium tuberculosis (Mtb, the causative agent of tuberculosis (TB, to facilitate new drug discovery and vaccine development. We have developed methodology to genetically incorporate unnatural amino acids into proteins in Mycobacterium smegmatis, BCG and Mtb, grown both extracellularly in culture and inside host cells. Orthogonal mutant tRNATyr/tyrosyl-tRNA synthetase pairs derived from Methanococcus jannaschii and evolved in Escherichia coli incorporate a variety of unnatural amino acids (including photocrosslinking, chemically reactive, heavy atom containing, and immunogenic amino acids into proteins in response to the amber nonsense codon. By taking advantage of the fidelity and suppression efficiency of the MjtRNA/pIpaRS pair in mycobacteria, we are also able to use p-iodophenylalanine to induce the expression of proteins in mycobacteria both extracellularly in culture and inside of mammalian host cells. This provides a new approach to regulate the expression of reporter genes or mycobacteria endogenous genes of interest. The establishment of the unnatural amino acid expression system in Mtb, an intracellular pathogen, should facilitate studies of TB biology and vaccine development.

  14. Cutting edge: Vitamin D regulates lipid metabolism in Mycobacterium tuberculosis infection.

    Science.gov (United States)

    Salamon, Hugh; Bruiners, Natalie; Lakehal, Karim; Shi, Lanbo; Ravi, Janani; Yamaguchi, Ken D; Pine, Richard; Gennaro, Maria Laura

    2014-07-01

    Vitamin D has long been linked to resistance to tuberculosis, an infectious respiratory disease that is increasingly hard to treat because of multidrug resistance. Previous work established that vitamin D induces macrophage antimicrobial functions against Mycobacterium tuberculosis. In this article, we report a novel, metabolic role for vitamin D in tuberculosis identified through integrated transcriptome and mechanistic studies. Transcriptome analysis revealed an association between vitamin D receptor (VDR) and lipid metabolism in human tuberculosis and infected macrophages. Vitamin D treatment of infected macrophages abrogated infection-induced accumulation of lipid droplets, which are required for intracellular M. tuberculosis growth. Additional transcriptomics results showed that vitamin D downregulates the proadipogenic peroxisome proliferator-activated receptor γ (PPARγ) in infected macrophages. PPARγ agonists reversed the antiadipogenic and the antimicrobial effects of VDR, indicating a link between VDR and PPARγ signaling in regulating both vitamin D functions. These findings suggest the potential for host-based, adjunct antituberculosis therapy targeting lipid metabolism. Copyright © 2014 by The American Association of Immunologists, Inc.

  15. 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.

  16. 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.

  17. A new approach for pyrazinamide susceptibility testing in Mycobacterium tuberculosis.

    Science.gov (United States)

    Zimic, Mirko; Loli, Sebastian; Gilman, Robert H; Gutierrez, Andrés; Fuentes, Patricia; Cotrina, Milagros; Kirwan, Daniela; Sheen, Patricia

    2012-08-01

    Pyrazinamide (PZA) is an important drug in the treatment of tuberculosis. Microbiological methods of PZA susceptibility testing are controversial and have low reproducibility. After conversion of PZA into pyrazinoic acid (POA) by the bacterial pyrazinamidase enzyme, the drug is expelled from the bacteria by an efflux pump. To evaluate the rate of POA extrusion from Mycobacterium tuberculosis as a parameter to detect PZA resistance. The rate of POA extrusion and PZA susceptibility determined by BACTEC 460 were measured for 34 strains in a previous study. PZA resistance was modeled in a logistic regression with the pyrazinoic efflux rate. POA efflux rate predicted PZA resistance with 70.83%-92.85% sensitivity and 100% specificity compared with BACTEC 460. POA efflux rate could be a useful tool for predicting PZA resistance in M. tuberculosis. Further exploration of this approach may lead to the development of new tools for diagnosing PZA resistance, which may be of public health importance.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. Microbial sensor for drug susceptibility testing of Mycobacterium tuberculosis.

    Science.gov (United States)

    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.

  3. Potential of Mycobacterium vanbaalenii as a model organism to study drug transporters of Mycobacterium tuberculosis, Mycobacterium marinum and Mycobacterium ulcerans: homology analysis of M. tuberculosis drug transporters among mycobacterial species.

    Science.gov (United States)

    Gupta, Anuj Kumar; Katoch, V M; Chauhan, D S; Lavania, Mallika

    2012-06-01

    Drug efflux pumps have been one of the important mechanisms of drug resistance in Mycobacterium tuberculosis. There is a prerequisite to study the behavior and mechanisms of these drug efflux pumps in detail for being considered in future anti-TB drug designing. The need of a rapid grower non-pathogenic mycobacterium with significant genomic homology for such type of studies is often being felt. During microarray and Real-Time PCR analysis of drug efflux pump genes of M. tuberculosis, we found 10 genes to be over-expressed during stress induced by common anti-TB drugs. In the present study homology analysis of these genes was done in order to know its phylogenetic relationship among other bacteria/mycobacteria. It was found that amino acid sequences of 7 out of 10 genes were significantly (>40%) identical to a non-pathogenic rapid grower environmental mycobacterium, Mycobacterium vanbaalenii. The protein sequences of M. vanbaalenii share important sequence motifs with M. tuberculosis useful for drug efflux mechanism based study across species. Like Mycobacterium smegmatis, it can be used as a model organism to study drug efflux pumps of M. tuberculosis and also other pathogenic mycobacteria such as Mycobacterium ulcerans and Mycobacterium marinum. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Diversity of Mycobacterium tuberculosis lineages in French Polynesia.

    Science.gov (United States)

    Osman, Djaltou Aboubaker; Phelippeau, Michael; Drancourt, Michel; Musso, Didier

    2017-04-01

    French Polynesia is an overseas territory located in the South Pacific. The incidence of tuberculosis in French Polynesia has been stable since 2000 with an average of 20 cases/y/100,000 inhabitants. Molecular epidemiology of Mycobacterium tuberculosis in French Polynesia is unknown because M. tuberculosis isolates have not been routinely genotyped. From 2009 to 2012, 34 isolates collected from 32 French Polynesian patients were identified as M. tuberculosis by probe hybridization. These isolates were genotyped using spoligotyping and 24-loci mycobacterial interspersed repetitive units (MIRUs)-variable number of tandem repeat (VNTR). Spoligotype patterns obtained using commercial kits were compared with the online international database SITVIT. MIRU-VNTR genotyping was performed using an in-house protocol based on capillary electrophoresis sizing for 24-loci MIRU-VNTR genotyping. The results of the spoligotyping method revealed that 25 isolates grouped into six previously described spoligotypes [H1, H3, U likely (S), T1, Manu, and Beijing] and nine isolates grouped into six new spoligotypes. Comparison with the international database MIRU-VNTRplus distributed 30 isolates into five lineages (Haarlem, Latin American Mediterranean, S, X, and Beijing) and four as unassigned isolates. Genotyping identified four phylogenetic lineages belonging to the modern Euro-American subgroup, one Beijing genotype responsible for worldwide pandemics, including remote islands in the South Pacific, and one Manu genotype of the ancestral lineage of M. tuberculosis. Copyright © 2015. Published by Elsevier B.V.

  5. Dormant non-culturable Mycobacterium tuberculosis retains stable low-abundant mRNA

    OpenAIRE

    Ignatov, Dmitriy V.; Salina, Elena G.; Fursov, Mikhail V.; Skvortsov, Timofey A.; Azhikina, Tatyana L.; Kaprelyants, Arseny S.

    2015-01-01

    Background Dormant Mycobacterium tuberculosis bacilli are believed to play an important role in latent tuberculosis infection. Previously, we have demonstrated that cultivation of M. tuberculosis in K+-deficient medium resulted in generation of dormant cells. These bacilli were non-culturable on solid media (a key feature of dormant M. tuberculosis in vivo) and characterized by low metabolism and tolerance to anti-tuberculosis drugs. The dormant bacteria demonstrated a high potential to react...

  6. Small Molecule-directed Immunotherapy against Recurrent Infection by Mycobacterium tuberculosis *

    OpenAIRE

    Bhattacharya, Debapriya; Dwivedi, Ved Prakash; Maiga, Mamoudou; Maiga, Mariama; Van Kaer, Luc; Bishai, William R.; Das, Gobardhan

    2014-01-01

    Tuberculosis remains the biggest infectious threat to humanity with one-third of the population infected and 1.4 million deaths and 8.7 million new cases annually. Current tuberculosis therapy is lengthy and consists of multiple antimicrobials, which causes poor compliance and high treatment dropout, resulting in the development of drug-resistant variants of tuberculosis. Therefore, alternate methods to treat tuberculosis are urgently needed. Mycobacterium tuberculosis evades host immune resp...

  7. Targeting Mycobacterium tuberculosis topoisomerase I by small-molecule inhibitors.

    Science.gov (United States)

    Godbole, Adwait Anand; Ahmed, Wareed; Bhat, Rajeshwari Subray; Bradley, Erin K; Ekins, Sean; Nagaraja, Valakunja

    2015-03-01

    We describe inhibition of Mycobacterium tuberculosis topoisomerase I (MttopoI), an essential mycobacterial enzyme, by two related compounds, imipramine and norclomipramine, of which imipramine is clinically used as an antidepressant. These molecules showed growth inhibition of both Mycobacterium smegmatis and M. tuberculosis cells. The mechanism of action of these two molecules was investigated by analyzing the individual steps of the topoisomerase I (topoI) reaction cycle. The compounds stimulated cleavage, thereby perturbing the cleavage-religation equilibrium. Consequently, these molecules inhibited the growth of the cells overexpressing topoI at a low MIC. Docking of the molecules on the MttopoI model suggested that they bind near the metal binding site of the enzyme. The DNA relaxation activity of the metal binding mutants harboring mutations in the DxDxE motif was differentially affected by the molecules, suggesting that the metal coordinating residues contribute to the interaction of the enzyme with the drug. Taken together, the results highlight the potential of these small molecules, which poison the M. tuberculosis and M. smegmatis topoisomerase I, as leads for the development of improved molecules to combat mycobacterial infections. Moreover, targeting metal coordination in topoisomerases might be a general strategy to develop new lead molecules. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Clinical and morphological variants of cutaneous tuberculosis and its relation to mycobacterium species

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    Gopinathan R

    2001-01-01

    Full Text Available Cutaneous tuberculosis forms a small proportion of extrapulmonary tuberculosis. The incidence of cutaneous tuberculosis has fallen from 2% to 0.15% in India whereas it is rare in developed countries. The present study is an attempt at finding out the Mycobacterium species associated with cutaneous tuberculosis. A total of 51 cases of clinically suspected cutaneous tuberculosis were studied over a period of 18 months from July 1997 to December 1998. Of these, 32 (62.75% were Scrofuloderma cases, 12 (23.52% cases of Lupus vulgaris and 7 (13.73% were Tuberculosis verrucosa cutis (TBVC cases. Twenty nine mycobacterial isolates from 51 specimens gave an isolation rate of 56.86%. These were subjected to a battery of biochemical tests for identification to species level. Twenty six out of 29 isolates were identified as Mycobacterium tuberculosis, two were identified as Mycobacterium Scrofulaceum and one Mycobacterium avium complex was isolated. Sixteen Mycobacterial isolates were recovered from Scrofuloderma cases, 9 were isolated from Lupus vulgaris and 4 from TBVC cases. The three atypical mycobacterial isolates were recovered from Scrofuloderma cases. Though Mycobacterium tuberculosis was the most common isolate, Mycobacterium scrofulaceum and Mycobacterium avium complex were also isolated in the present study.

  9. Iron Homeostasis in Mycobacterium tuberculosis: Mechanistic Insights into Siderophore-Mediated Iron Uptake

    Science.gov (United States)

    2016-01-01

    Mycobacterium tuberculosis requires iron for normal growth but faces a limitation of the metal ion due to its low solubility at biological pH and the withholding of iron by the mammalian host. The pathogen expresses the Fe3+-specific siderophores mycobactin and carboxymycobactin to chelate the metal ion from insoluble iron and the host proteins transferrin, lactoferrin, and ferritin. Siderophore-mediated iron uptake is essential for the survival of M. tuberculosis, as knockout mutants, which were defective in siderophore synthesis or uptake, failed to survive in low-iron medium and inside macrophages. But as excess iron is toxic due to its catalytic role in the generation of free radicals, regulation of iron uptake is necessary to maintain optimal levels of intracellular iron. The focus of this review is to present a comprehensive overview of iron homeostasis in M. tuberculosis that is discussed in the context of mycobactin biosynthesis, transport of iron across the mycobacterial cell envelope, and storage of excess iron. The clinical significance of the serum iron status and the expression of the iron-regulated protein HupB in tuberculosis (TB) patients is presented here, highlighting the potential of HupB as a marker, notably in extrapulmonary TB cases. PMID:27402628

  10. Insights on the Emergence of Mycobacterium tuberculosis from the Analysis of Mycobacterium kansasii

    Science.gov (United States)

    Wang, Joyce; McIntosh, Fiona; Radomski, Nicolas; Dewar, Ken; Simeone, Roxane; Enninga, Jost; Brosch, Roland; Rocha, Eduardo P.; Veyrier, Frédéric J.; Behr, Marcel A.

    2015-01-01

    By phylogenetic analysis, Mycobacterium kansasii is closely related to Mycobacterium tuberculosis. Yet, although both organisms cause pulmonary disease, M. tuberculosis is a global health menace, whereas M. kansasii is an opportunistic pathogen. To illuminate the differences between these organisms, we have sequenced the genome of M. kansasii ATCC 12478 and its plasmid (pMK12478) and conducted side-by-side in vitro and in vivo investigations of these two organisms. The M. kansasii genome is 6,432,277 bp, more than 2 Mb longer than that of M. tuberculosis H37Rv, and the plasmid contains 144,951 bp. Pairwise comparisons reveal conserved and discordant genes and genomic regions. A notable example of genomic conservation is the virulence locus ESX-1, which is intact and functional in the low-virulence M. kansasii, potentially mediating phagosomal disruption. Differences between these organisms include a decreased predicted metabolic capacity, an increased proportion of toxin–antitoxin genes, and the acquisition of M. tuberculosis-specific genes in the pathogen since their common ancestor. Consistent with their distinct epidemiologic profiles, following infection of C57BL/6 mice, M. kansasii counts increased by less than 10-fold over 6 weeks, whereas M. tuberculosis counts increased by over 10,000-fold in just 3 weeks. Together, these data suggest that M. kansasii can serve as an image of the environmental ancestor of M. tuberculosis before its emergence as a professional pathogen, and can be used as a model organism to study the switch from an environmental opportunistic pathogen to a professional host-restricted pathogen. PMID:25716827

  11. Mycobacterium tuberculosis Complex Members Adapted to Wild and Domestic Animals.

    Science.gov (United States)

    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.

  12. Bacterial subversion of cAMP signalling inhibits cathelicidin expression, which is required for innate resistance to Mycobacterium tuberculosis

    Science.gov (United States)

    Gupta, Shashank; Winglee, Kathryn; Gallo, Richard; Bishai, William R

    2017-01-01

    Antimicrobial peptides such as cathelicidins are an important component of innate immune defence against inhaled microorganisms and have demonstrated antimicrobial activity against Mycobacterium tuberculosis with in vitro models. Despite this, little is known about the regulation and expression of cathelicidin during tuberculosis in vivo. We sought to determine whether the cathelicidin-related antimicrobial peptide (Cramp) gene, the murine functional homologue of the human cathelicidin gene (CAMP or LL-37), is required for regulating protective immunity during M. tuberculosis infection in vivo. We used Cramp−/− mice in a validated model of pulmonary tuberculosis and conducted cell-based assays with macrophages from these mice. We evaluated the in vivo susceptibility of Cramp−/− mice to infection and further dissected various pro-inflammatory immune responses against M. tuberculosis. We observed increased susceptibility of Cramp−/− mice to M. tuberculosis compared to wild type mice. Macrophages from Cramp−/− mice were unable to control M. tuberculosis growth in an in vitro infection model, were deficient in intracellular calcium influx and were defective in stimulating T-cells. Additionally, CD4 and CD8 T-cells from Cramp−/− mice produced less IFNβ upon stimulation. Furthermore, bacterial-derived cyclic-AMP modulated cathelicidin expression in macrophages. Our results demonstrate that cathelicidin is required for innate resistance to M. tuberculosis in a relevant animal model and is a key mediator in regulating the levels of pro-inflammatory cytokines by calcium and cyclic nucleotides. PMID:28097645

  13. 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

  14. Spoligotype patterns of Mycobacterium tuberculosis isolated from extra pulmonary tuberculosis patients in Puducherry, India

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    G Kandhakumari

    2015-01-01

    Full Text Available Purpose: Genotyping studies like spoligotyping are valuable tools in understanding the genetic diversity and epidemiology of Mycobacterium tuberculosis. Though there are reports of spoligotyping of M. tuberculosis isolates from pulmonary specimens from different parts of India, spoligotyping of extra pulmonary tuberculosis isolates are very few. Puducherry has not yet recorded spoligopatterns of M. tuberculosis from either pulmonary or extra pulmonary (EPTB specimens. The aim of this study is to analyze the spoligotype patterns of EPTB strains circulating in Puducherry and neighboring districts of Tamil Nadu. Materials and Methods: During June 2011 to December 2013, 570 EPTB specimens were processed by culturing on to Lowenstein Jensen (LJ medium and automated Mycobacterium Growth Indicator Tube system (MGIT960. Identification of M. tuberculosis was carried out as per standard procedures, and MPT 64 antigen positivity in a commercial immunochromatography kit. Spoligotyping was carried out at National Institute of Research in Tuberculosis (ICMR, Chennai. Results: M. tuberculosis was isolated from 67 single EPTB specimens (11.8% like pus/cold abscess (34, TB spine (10, pleural fluid (10, urine (5, tissue bit (2, lymph nodes (2, ascitic fluid (2, synovial fluid (1 and endometrial curetting (1. Among 67 isolates with 41 spoligopatterns, EAI lineage with 28 isolates (41.8% predominated followed by 18 orphans (26.9%, 10 Beijing (14.9% and 8 U (11.9%. BOVIS1_BCG (ST482, T1-T2 (ST78 and H3 (ST50 were represented by one strain each (1.5%. C onclusions: Spoligotyping plays a significant role in the epidemiology of tuberculosis. Three spoligotypes, T1-T2 (ST78, EAI6 (ST292 and U (ST1429 are reported for the first time in India.

  15. Mycobacterium tuberculosis decreases human macrophage IFN-γ responsiveness through miR-132 and miR-26a.

    Science.gov (United States)

    Ni, Bin; Rajaram, Murugesan V S; Lafuse, William P; Landes, Michelle B; Schlesinger, Larry S

    2014-11-01

    IFN-γ-activated macrophages play an essential role in controlling intracellular pathogens; however, macrophages also serve as the cellular home for the intracellular pathogen Mycobacterium tuberculosis. Based on previous evidence that M. tuberculosis can modulate host microRNA (miRNA) expression, we examined the miRNA expression profile of M. tuberculosis-infected primary human macrophages. We identified 31 differentially expressed miRNAs in primary human macrophages during M. tuberculosis infection by NanoString and confirmed our findings by quantitative real-time RT-PCR. In addition, we determined a role for two miRNAs upregulated upon M. tuberculosis infection, miR-132 and miR-26a, as negative regulators of transcriptional coactivator p300, a component of the IFN-γ signaling cascade. Knockdown expression of miR-132 and miR-26a increased p300 protein levels and improved transcriptional, translational, and functional responses to IFN-γ in human macrophages. Collectively, these data validate p300 as a target of miR-132 and miR-26a, and demonstrate a mechanism by which M. tuberculosis can limit macrophage responses to IFN-γ by altering host miRNA expression. Copyright © 2014 by The American Association of Immunologists, Inc.

  16. 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...

  17. Activity of drug combinations against dormant Mycobacterium tuberculosis.

    Science.gov (United States)

    Filippini, Perla; Iona, Elisabetta; Piccaro, Giovanni; Peyron, Pascale; Neyrolles, Olivier; Fattorini, Lanfranco

    2010-06-01

    Aerobic (5-day-old cultures) and nonreplicating (dormant) Mycobacterium tuberculosis (5-, 12-, and 19-day-old cultures) bacteria were treated with rifampin (R), moxifloxacin (MX), metronidazole (MZ), amikacin (AK), or capreomycin (CP) for 7, 14, and 21 days. R-MX-MZ-AK and R-MX-MZ-CP killed both aerobic and dormant bacilli in 21 days, as shown by lack of regrowth in solid and liquid media. R-MX-MZ-AK and R-MX-MZ-CP also caused a strong decrease of nonreplicating bacilli in 7 days in a cell-based dormancy model.

  18. The pup-proteasome system of Mycobacterium tuberculosis.

    Science.gov (United States)

    Samanovic, Marie I; Li, Huilin; Darwin, K Heran

    2013-01-01

    Proteasomes are ATP-dependent protein degradation machines present in all archaea and eukaryotes, and found in several bacterial species of the order Actinomycetales. Mycobacterium tuberculosis (Mtb), an Actinomycete pathogenic to humans, requires proteasome function to cause disease. In this chapter, we describe what is currently understood about the biochemistry of the Mtb proteasome and its role in virulence. The characterization of the Mtb proteasome has led to the discovery that proteins can be targeted for degradation by a small protein modifier in bacteria as they are in eukaryotes. Furthermore, the understanding of proteasome function in Mtb has helped reveal new insight into how the host battles infections.

  19. Anti-Mycobacterium tuberculosis activity of fungus Phomopsis stipata

    Directory of Open Access Journals (Sweden)

    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.

  20. Characterisation of Mycobacterium tuberculosis isolates lacking IS6110 in Viet Nam

    NARCIS (Netherlands)

    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.

    2013-01-01

    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.

  1. Characterisation of Mycobacterium tuberculosis isolates lacking IS6110 in Viet Nam.

    NARCIS (Netherlands)

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

    2013-01-01

    SETTING: 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

  2. Mice lacking SIGNR1 have stronger T helper 1 responses to Mycobacterium tuberculosis

    NARCIS (Netherlands)

    Wieland, Catharina W.; Koppel, Estella A.; den Dunnen, Jeroen; Florquin, Sandrine; McKenzie, Andrew N. J.; van Kooyk, Yvette; van der Poll, Tom; Geijtenbeek, Teunis B. H.

    2007-01-01

    Mycobacterium tuberculosis and the associated disease tuberculosis are health risks causing many deaths worldwide each year in humans. M. tuberculosis targets dendritic cell (DC)-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN) to induce immunosuppression, since interaction

  3. Association between passive smoking and infection with Mycobacterium tuberculosis in children

    NARCIS (Netherlands)

    den Boon, Saskia; Verver, Suzanne; Marais, Ben J.; Enarson, Donald A.; Lombard, Carl J.; Bateman, Eric D.; Irusen, Elvis; Jithoo, Anamika; Gie, Robert P.; Borgdorff, Martien W.; Beyers, Nulda

    2007-01-01

    OBJECTIVE: Tuberculosis and smoking are both significant public health problems. The association between passive smoking and Mycobacterium tuberculosis infection is not well documented. The objective of this study was to examine the influence of passive smoking on M. tuberculosis infection in

  4. Mycobacterium tuberculosis Infection following Kidney Transplantation

    Directory of Open Access Journals (Sweden)

    Karima Boubaker

    2013-01-01

    Full Text Available Introduction and Aims. Post-transplant tuberculosis (TB is a problem in successful long-term outcome of renal transplantation recipients. Our objective was to describe the pattern and risk factors of TB infection and the prognosis in our transplant recipients. Patients and Methods. This study was a retrospective review of the records of 491 renal transplant recipients in our hospital during the period from January 1986 to December 2009. The demographic data, transplant characteristics, clinical manifestations, diagnostic criteria, treatment protocol, and long-term outcome of this cohort of patients were analyzed. Results. 16 patients (3,2% developed post-transplant TB with a mean age of 32,5 ± 12,7 (range: 13–60 years and a mean post-transplant period of 36,6months (range: 12,3 months–15,9 years. The forms of the diseases were pulmonary in 10/16 (62,6%, disseminated in 3/16 (18,7%, and extrapulmonary in 3/16 (18,7%. Graft dysfunction was observed in 7 cases (43,7% with tissue-proof acute rejection in 3 cases and loss of the graft in 4 cases. Hepatotoxicity developed in 3 patients (18,7% during treatment. Recurrences were observed in 4 cases after early stop of treatment. Two patients (12.5% died. Conclusion. Extra pulmonary and disseminated tuberculosis were observed in third of our patients. More than 9months of treatment may be necessary to prevent recurrence.

  5. 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)

  6. Programmatic implementation of rapid DST for Mycobacterium tuberculosis in Peru.

    Science.gov (United States)

    Asencios, L; Yale, G; Yagui, M; Quispe, N; Taylor, A; Blaya, J; Contreras, C; Cegielski, P; Bayona, J; Bonilla, C; Shin, S

    2008-07-01

    Performance characteristics of novel rapid drug susceptibility tests (DST) for Mycobacterium tuberculosis may change when moving from research to implementation in actual public health practice. We describe the performance characteristics of a direct, rapid DST when implemented in Lima, Peru. A district laboratory validated conventional proportions and nitrate reductase methods. We collected data on samples submitted for DST from January 2005 to June 2007 and calculated frequency of testing and results, and median time to test results. A total of 4102 DSTs were performed by conventional DST and 895 by nitrate reductase. Results were obtained from 72.8% of samples by conventional DST and from 70.2% of those processed by Griess; respectively 26.4% and 31.5% were multidrug-resistant tuberculosis. The median time from sample collection to test result was 31 days for Griess vs. 99 days for conventional DST. Preliminary experience with the Griess method demonstrates favorable performance under program conditions.

  7. 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.

  8. A novel peptide interferes with Mycobacterium tuberculosis virulence and survival

    Directory of Open Access Journals (Sweden)

    Sachin Kumar Samuchiwal

    2014-01-01

    Full Text Available Tuberculosis (TB is a huge global burden, with new and resistant strains emerging at an alarming rate, necessitating an urgent need for a new class of drug candidates. Here, we report that SL3, a novel 33-amino acid peptide, causes debilitating effects on mycobacterial morphology. Treatment with SL3 drastically inhibits the growth of Mycobacterium tuberculosis in vitro as well as in a pre-clinical mouse model for M.tb infection. Microarray analysis of SL3-expressing strain demonstrates wide-scale transcriptional disruption in M.tb. We therefore believe that SL3 and similar peptides may herald a new approach towards discovering new molecules for TB therapy.

  9. Animal-adapted members of the Mycobacterium tuberculosis complex endemic to the southern African subregion

    Directory of Open Access Journals (Sweden)

    Charlene Clarke

    2016-02-01

    Full Text Available Members of the Mycobacterium tuberculosis complex (MTC cause tuberculosis (TB in both animals and humans. In this article, three animal-adapted MTC strains that are endemic to the southern African subregion – that is, Mycobacterium suricattae, Mycobacterium mungi, and the dassie bacillus – are reviewed with a focus on clinical and pathological presentations, geographic distribution, genotyping methods, diagnostic tools and evolution. Moreover, factors influencing the transmission and establishment of TB pathogens in novel host populations, including ecological, immunological and genetic factors of both the host and pathogen, are discussed. The risks associated with these infections are currently unknown and further studies will be required for greater understanding of this disease in the context of the southern African ecosystem.Keywords: dassie bacillus; ecology; evolution; host jump; Mycobacterium mungi; Mycobacterium suricattae; Mycobacterium tuberculosis complex; phylogeny

  10. Small Molecule Efflux Pump Inhibitors in Mycobacterium tuberculosis: A Rational Drug Design Perspective.

    Science.gov (United States)

    Kapp, Erika; Malan, Sarel F; Joubert, Jacques; Sampson, Samantha L

    2018-01-01

    Drug resistance in Mycobacterium tuberculosis (M. tuberculosis) complicates management of tuberculosis. Efflux pumps contribute to low level resistance and acquisition of additional high level resistance mutations through sub-therapeutic concentrations of intracellular antimycobacterials. Various efflux pump inhibitors (EPIs) have been described for M. tuberculosis but little is known regarding the mechanism of efflux inhibition. As knowledge relating to the mechanism of action and drug target is central to the rational drug design of safe and sufficiently selective EPIs, this review aims to examine recent developments in the study of EPIs in M. tuberculosis from a rational drug development perspective and to provide an overview to facilitate systematic development of therapeutically effective EPIs. Review of literature points to a reduction in cellular energy or direct binding to the efflux pump as likely mechanisms for most EPIs described for M. tuberculosis. This review demonstrates that, where a direct interaction with efflux pumps is expected, both molecular structure and general physicochemical properties should be considered to accurately predict efflux pump substrates and inhibitors. Non-competitive EPIs do not necessarily demonstrate the same requirements as competitive inhibitors and it is therefore essential to differentiate between competitive and non-competitive inhibition to accurately determine structure activity relationships for efflux pump inhibition. It is also evident that there are various similarities between inhibitors of prokaryotic and eukaryotic efflux pumps but, depending on the specific chemical scaffolds under investigation, it may be possible to design EPIs that are less prone to inhibition of human P-glycoprotein, thereby reducing side effects and drug-drug interactions. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. High throughput phenotypic analysis of Mycobacterium tuberculosis and Mycobacterium bovis strains' metabolism using biolog phenotype microarrays.

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    Bhagwati Khatri

    Full Text Available Tuberculosis is a major human and animal disease of major importance worldwide. Genetically, the closely related strains within the Mycobacterium tuberculosis complex which cause disease are well-characterized but there is an urgent need better to understand their phenotypes. To search rapidly for metabolic differences, a working method using Biolog Phenotype MicroArray analysis was developed. Of 380 substrates surveyed, 71 permitted tetrazolium dye reduction, the readout over 7 days in the method. By looking for ≥5-fold differences in dye reduction, 12 substrates differentiated M. tuberculosis H37Rv and Mycobacterium bovis AF2122/97. H37Rv and a Beijing strain of M. tuberculosis could also be distinguished in this way, as could field strains of M. bovis; even pairs of strains within one spoligotype could be distinguished by 2 to 3 substrates. Cluster analysis gave three clear groups: H37Rv, Beijing, and all the M. bovis strains. The substrates used agreed well with prior knowledge, though an unexpected finding that AF2122/97 gave greater dye reduction than H37Rv with hexoses was investigated further, in culture flasks, revealing that hexoses and Tween 80 were synergistic for growth and used simultaneously rather than in a diauxic fashion. Potential new substrates for growth media were revealed, too, most promisingly N-acetyl glucosamine. Osmotic and pH arrays divided the mycobacteria into two groups with different salt tolerance, though in contrast to the substrate arrays the groups did not entirely correlate with taxonomic differences. More interestingly, these arrays suggested differences between the amines used by the M. tuberculosis complex and enteric bacteria in acid tolerance, with some hydrophobic amino acids being highly effective. In contrast, γ-aminobutyrate, used in the enteric bacteria, had no effect in the mycobacteria. This study proved principle that Phenotype MicroArrays can be used with slow-growing pathogenic mycobacteria

  12. Cloning and Characterization of Secretory Tyrosine Phosphatases of Mycobacterium tuberculosis

    Science.gov (United States)

    Koul, Anil; Choidas, Axel; Treder, Martin; Tyagi, Anil K.; Drlica, Karl; Singh, Yogendra; Ullrich, Axel

    2000-01-01

    Two genes with sequence homology to those encoding protein tyrosine phosphatases were cloned from genomic DNA of Mycobacterium tuberculosis H37Rv. The calculated molecular masses of these two putative tyrosine phosphatases, designated MPtpA and MPtpB, were 17.5 and 30 kDa, respectively. MPtpA and MPtpB were expressed as glutathione S-transferase fusion proteins in Escherichia coli. The affinity-purified proteins dephosphorylated the phosphotyrosine residue of myelin basic protein (MBP), but they failed to dephosphorylate serine/threonine residues of MBP. The activity of these phosphatases was inhibited by sodium orthovanadate, a specific inhibitor of tyrosine phosphatases, but not by okadaic acid, an inhibitor of serine/threonine phosphatases. Mutations at the catalytic site motif, cysteine 11 of MPtpA and cysteine 160 of MPtpB, abolished enzyme activity. Southern blot analysis revealed that, while mptpA is present in slow-growing mycobacterial species as well as fast-growing saprophytes, mptpB was restricted to members of the M. tuberculosis complex. These phosphatases were present in both whole-cell lysates and culture filtrates of M. tuberculosis, suggesting that these proteins are secreted into the extracellular medium. Since tyrosine phosphatases are essential for the virulence of several pathogenic bacteria, the restricted distribution of mptpB makes it a good candidate for a virulence gene of M. tuberculosis. PMID:10986245

  13. Cloning and characterization of secretory tyrosine phosphatases of Mycobacterium tuberculosis.

    Science.gov (United States)

    Koul, A; Choidas, A; Treder, M; Tyagi, A K; Drlica, K; Singh, Y; Ullrich, A

    2000-10-01

    Two genes with sequence homology to those encoding protein tyrosine phosphatases were cloned from genomic DNA of Mycobacterium tuberculosis H(37)Rv. The calculated molecular masses of these two putative tyrosine phosphatases, designated MPtpA and MPtpB, were 17. 5 and 30 kDa, respectively. MPtpA and MPtpB were expressed as glutathione S-transferase fusion proteins in Escherichia coli. The affinity-purified proteins dephosphorylated the phosphotyrosine residue of myelin basic protein (MBP), but they failed to dephosphorylate serine/threonine residues of MBP. The activity of these phosphatases was inhibited by sodium orthovanadate, a specific inhibitor of tyrosine phosphatases, but not by okadaic acid, an inhibitor of serine/threonine phosphatases. Mutations at the catalytic site motif, cysteine 11 of MPtpA and cysteine 160 of MPtpB, abolished enzyme activity. Southern blot analysis revealed that, while mptpA is present in slow-growing mycobacterial species as well as fast-growing saprophytes, mptpB was restricted to members of the M. tuberculosis complex. These phosphatases were present in both whole-cell lysates and culture filtrates of M. tuberculosis, suggesting that these proteins are secreted into the extracellular medium. Since tyrosine phosphatases are essential for the virulence of several pathogenic bacteria, the restricted distribution of mptpB makes it a good candidate for a virulence gene of M. tuberculosis.

  14. Genotyping of Mycobacterium tuberculosis using whole genome sequencing.

    Science.gov (United States)

    Amlerova, Jana; Bitar, Ibrahim; Hrabak, Jaroslav

    2018-03-17

    Tuberculosis (TB) is considered one of the most serious infectious diseases worldwide. Effective control of tuberculosis infection involves multiple steps, such as reliable detection, treatment, an epidemiological control as a part of case management, and further surveillance and monitoring of TB spread in the human population. Due to the accelerating advances in molecular biology, especially in DNA sequencing, in the past decade, the application of these methods has become crucial for TB evolution studies, differentiation of Mycobacterium tuberculosis genotypes, and their distribution. Currently, several molecular genetic methods are available. The oldest typing methods (e.g., IS6110-RFLP, spoligotyping, and MIRU-VNTR) can discover the chain of transmission to the patient. Currently, whole genome sequencing facilitates is furthermore able to identify the source of infection, the transmission trays among individuals sharing the same isolate, as well as determination of the TB evolution and its resistance to antituberculotic agents. It is obvious that this technique will become a new gold standard in genotyping methods in tuberculosis molecular epidemiological studies. In this article, molecular genetic typing methods with a special focus on whole genome sequencing and data management are reviewed.

  15. Innate immune response to Mycobacterium tuberculosis Beijing and other genotypes.

    Directory of Open Access Journals (Sweden)

    Chongzhen Wang

    Full Text Available BACKGROUND: As a species, Mycobacterium tuberculosis is more diverse than previously thought. In particular, the Beijing family of M. tuberculosis strains is spreading and evaluating throughout the world and this is giving rise to public health concerns. Genetic diversity within this family has recently been delineated further and a specific genotype, called Bmyc10, has been shown to represent over 60% of all Beijing clinical isolates in several parts of the world. How the host immune system senses and responds to various M. tuberculosis strains may profoundly influence clinical outcome and the relative epidemiological success of the different mycobacterial lineages. We hypothesised that the success of the Bmyc10 group may, at least in part, rely upon its ability to alter innate immune responses and the secretion of cytokines and chemokines by host phagocytes. METHODOLOGY/PRINCIPAL FINDINGS: We infected human macrophages and dendritic cells with a collection of genetically well-defined M. tuberculosis clinical isolates belonging to various mycobacterial families, including Beijing. We analyzed cytokine and chemokine secretion on a semi-global level using antibody arrays allowing the detection of sixty-five immunity-related soluble molecules. Our data indicate that Beijing strains induce significantly less interleukin (IL-6, tumor necrosis factor (TNF, IL-10 and GRO-α than the H37Rv reference strain, a feature that is variously shared by other modern and ancient M. tuberculosis families and which constitutes a signature of the Beijing family as a whole. However, Beijing strains did not differ relative to each other in their ability to modulate cytokine secretion. CONCLUSIONS/SIGNIFICANCE: Our results confirm and expand upon previous reports showing that M. tuberculosis Beijing strains in general are poor in vitro cytokine inducers in human phagocytes. The results suggest that the epidemiological success of the Beijing Bmyc10 is unlikely to rely

  16. Stratification of Latent Mycobacterium tuberculosis Infection by Cellular Immune Profiling

    Science.gov (United States)

    Halliday, Alice; Whitworth, Hilary; Kottoor, Sherine Hermagild; Niazi, Umar; Menzies, Sarah; Kunst, Heinke; Bremang, Samuel; Badhan, Amarjit; Beverley, Peter; Kon, Onn Min

    2017-01-01

    Abstract Background. Recently acquired and remotely acquired latent Mycobacterium tuberculosis infection (LTBI) are clinically indistinguishable, yet recent acquisition of infection is the greatest risk factor for progression to tuberculosis in immunocompetent individuals. We aimed to evaluate the ability of cellular immune signatures that differ between active tuberculosis and LTBI to distinguish recently from remotely acquired LTBI. Methods. Fifty-nine individuals were recruited: 20 had active tuberculosis, 19 had recently acquired LTBI, and 20 had remotely acquired LTBI. The proportion of mycobacteria-specific CD4+ T cells secreting tumor necrosis factor α (TNF-α) but not interferon γ or interleukin 2 which had a differentiated effector phenotype (TNF-α–only TEFF), and the level of CD27 expression on IFN-γ–producing CD4+ T cells, were detected by flow cytometry. Results. The TNF-α–only TEFF signature was significantly higher in the group with recently acquired LTBI, compared with the group with remotely acquired LTBI (P < .0001), and it discriminated between these groups with high sensitivity and specificity, with an area under the curve of 0.87. Two signatures incorporating CD27 expression did not distinguish between recently and remotely acquired LTBI. Interestingly, the TNF-α–only TEFF signature in participants with recently acquired LTBI was more similar to that in participants with tuberculosis than that in participants with remotely acquired LTBI, suggesting that recently acquired LTBI is immunologically more similar to tuberculosis than remotely acquired LTBI. Conclusions. These findings reveal marked biological heterogeneity underlying the clinically homogeneous phenotype of LTBI, providing a rationale for immunological risk stratification to improve targeting of LTBI treatment. PMID:28329119

  17. Profiling the Proteome of Mycobacterium tuberculosis during Dormancy and Reactivation*

    Science.gov (United States)

    Gopinath, Vipin; Raghunandanan, Sajith; Gomez, Roshna Lawrence; Jose, Leny; Surendran, Arun; Ramachandran, Ranjit; Pushparajan, Akhil Raj; Mundayoor, Sathish; Jaleel, Abdul; Kumar, Ramakrishnan Ajay

    2015-01-01

    Tuberculosis, caused by Mycobacterium tuberculosis, still remains a major global health problem. The main obstacle in eradicating this disease is the ability of this pathogen to remain dormant in macrophages, and then reactivate later under immuno-compromised conditions. The physiology of hypoxic nonreplicating M. tuberculosis is well-studied using many in vitro dormancy models. However, the physiological changes that take place during the shift from dormancy to aerobic growth (reactivation) have rarely been subjected to a detailed investigation. In this study, we developed an in vitro reactivation system by re-aerating the virulent laboratory strain of M. tuberculosis that was made dormant employing Wayne's dormancy model, and compared the proteome profiles of dormant and reactivated bacteria using label-free one-dimensional LC/MS/MS analysis. The proteome of dormant bacteria was analyzed at nonreplicating persistent stage 1 (NRP1) and stage 2 (NRP2), whereas that of reactivated bacteria was analyzed at 6 and 24 h post re-aeration. Proteome of normoxially grown bacteria served as the reference. In total, 1871 proteins comprising 47% of the M. tuberculosis proteome were identified, and many of them were observed to be expressed differentially or uniquely during dormancy and reactivation. The number of proteins detected at different stages of dormancy (764 at NRP1, 691 at NRP2) and reactivation (768 at R6 and 983 at R24) was very low compared with that of the control (1663). The number of unique proteins identified during normoxia, NRP1, NRP2, R6, and R24 were 597, 66, 56, 73, and 94, respectively. We analyzed various biological functions during these conditions. Fluctuation in the relative quantities of proteins involved in energy metabolism during dormancy and reactivation was the most significant observation we made in this study. Proteins that are up-regulated or uniquely expressed during reactivation from dormancy offer to be attractive targets for therapeutic

  18. Genetic Diversity and Dynamic Distribution of Mycobacterium tuberculosis Isolates Causing Pulmonary and Extrapulmonary Tuberculosis in Thailand

    Science.gov (United States)

    Srilohasin, Prapaporn; Tokunaga, Katsushi; Nishida, Nao; Prammananan, Therdsak; Smittipat, Nat; Mahasirimongkol, Surakameth; Chaiyasirinroje, Boonchai; Yanai, Hideki; Palittapongarnpim, Prasit

    2014-01-01

    This study examined the genetic diversity and dynamicity of circulating Mycobacterium tuberculosis strains in Thailand using nearly neutral molecular markers. The single nucleotide polymorphism (SNP)-based genotypes of 1,414 culture-positive M. tuberculosis isolates from 1,282 pulmonary tuberculosis (PTB) and 132 extrapulmonary TB (EPTB) patients collected from 1995 to 2011 were characterized. Among the eight SNP cluster groups (SCG), SCG2 (44.1%), which included the Beijing (BJ) genotype, and SCG1 (39.4%), an East African Indian genotype, were dominant. Comparisons between the genotypes of M. tuberculosis isolates causing PTB and EPTB in HIV-negative cases revealed similar prevalence trends although genetic diversity was higher in the PTB patients. The identification of 10 reported sequence types (STs) and three novel STs was hypothesized to indicate preferential expansion of the SCG2 genotype, especially the modern BJ ST10 (15.6%) and ancestral BJ ST19 (13.1%). An association between SCG2 and SCG1 genotypes and particular patient age groups implies the existence of different genetic advantages among the bacterial populations. The results revealed that increasing numbers of young patients were infected with M. tuberculosis SCGs 2 and 5, which contrasts with the reduction of the SCG1 genotype. Our results indicate the selection and dissemination of potent M. tuberculosis genotypes in this population. The determination of heterogeneity and dynamic population changes of circulating M. tuberculosis strains in countries using the Mycobacterium bovis BCG (bacillus Calmette-Guérin) vaccine are beneficial for vaccine development and control strategies. PMID:25297330

  19. In vitro effect of ursolic acid on the inhibition of Mycobacterium tuberculosis and its cell wall mycolic acid.

    Science.gov (United States)

    Jyoti, Md Anirban; Zerin, Tamanna; Kim, Tae-Hyun; Hwang, Tae-Seon; Jang, Woong Sik; Nam, Kung-Woo; Song, Ho-Yeon

    2015-08-01

    Mycobacterium tuberculosis is a dangerous intracellular pathogen. In order to protect against mycobacterium infection, novel agents with anti-mycobacterial activity should be given emergency priority for evaluation. Ursolic acid (UA), a plant triterpenoid, shows promising bioactivities, including anti-mycobacterial potency. In this study, the action of UA against Mycobacterium tuberculosis H37Ra was evaluated, and the inhibitory concentration was found to range between 10 and 20 μg/ml in a resazurin assay and MGIT 960 instrument. The total mycolic acid in UA-treated H37Ra was detected and compared with INH-treated and non-treated bacterium by LC-MS/MS. Quantitative LC-MS/MS data confirmed that both UA and INH decreased mycolic acid biosynthesis in a dose-dependent manner. Thin-layer chromatogram (TLC) analysis showed that all mycolic acid subtypes were affected by UA treatment in the wild type but not in strains resistant to UA. Electron microscopy images also confirmed that UA treatment affected both H37Ra cell and intracellular content of H37Ra. Altogether, these data confirmed the promise of the inhibitory action of UA in mycolic acid, which might further delineate the mechanistic pathway of mycobacterial inhibition by UA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Mycobacterium tuberculosis Zinc Metalloprotease-1 Elicits Tuberculosis-specific Humoral Immune Response Independent of Mycobacterial Load in Pulmonary and Extra-Pulmonary Tuberculosis Patients

    Directory of Open Access Journals (Sweden)

    Mani Harika eVemula

    2016-03-01

    Full Text Available Conventionally, facultative intracellular pathogen, Mycobacterium tuberculosis (M.tb, the tuberculosis (TB causing bacilli in human is cleared by cell-mediated immunity (CMI with CD4+ T cells playing instrumental role in protective immunity, while antibody-mediated immunity (AMI is considered non-protective. This longstanding convention has been challenged with recent evidences of increased susceptibility of hosts with compromised AMI and monoclonal antibodies conferring passive protection against TB and other intracellular pathogens. Therefore, novel approaches towards vaccine development include strategies aiming at induction of humoral response along with CMI. This necessitates the identification of mycobacterial proteins with properties of immunomodulation and strong immunogenicity. In this study, we determined the immunogenic potential of M.tb Zinc metalloprotease-1 (Zmp1, a secretory protein essential for intracellular survival and pathogenesis of M.tb. We observed that Zmp1 was secreted by in vitro grown M.tb under granuloma-like stress conditions (acidic, oxidative, iron deficiency and nutrient deprivation and generated Th2 cytokine microenvironment upon exogenous treatment of Peripheral Blood Mononulear Cells (PBMCs with recombinant Zmp1 (rZmp1. This was supported by recording specific and robust humoral response in TB patients in a cohort of 295. The anti-Zmp1 titers were significantly higher in TB patients (n=121 as against healthy control (n=62, household contacts (n=89 and non-specific infection controls (n=23. A significant observation of the study is the presence of equally high titers of anti-Zmp1 antibodies in a range of patients with high bacilli load (sputum bacilli load of 300+ per mL to paucibacillary smear-negative pulmonary tuberculosis (PTB cases. This clearly indicated the potential of Zmp1 to evoke an effective humoral response independent of mycobacterial load. Such mycobacterial proteins can be explored as antigen

  1. Mycobacterium tuberculosis induces the miR-33 locus to reprogram autophagy and host lipid metabolism.

    Science.gov (United States)

    Ouimet, Mireille; Koster, Stefan; Sakowski, Erik; Ramkhelawon, Bhama; van Solingen, Coen; Oldebeken, Scott; Karunakaran, Denuja; Portal-Celhay, Cynthia; Sheedy, Frederick J; Ray, Tathagat Dutta; Cecchini, Katharine; Zamore, Philip D; Rayner, Katey J; Marcel, Yves L; Philips, Jennifer A; Moore, Kathryn J

    2016-06-01

    Mycobacterium tuberculosis (Mtb) survives in macrophages by evading delivery to the lysosome and promoting the accumulation of lipid bodies, which serve as a bacterial source of nutrients. We found that by inducing the microRNA (miRNA) miR-33 and its passenger strand miR-33*, Mtb inhibited integrated pathways involved in autophagy, lysosomal function and fatty acid oxidation to support bacterial replication. Silencing of miR-33 and miR-33* by genetic or pharmacological means promoted autophagy flux through derepression of key autophagy effectors (such as ATG5, ATG12, LC3B and LAMP1) and AMPK-dependent activation of the transcription factors FOXO3 and TFEB, which enhanced lipid catabolism and Mtb xenophagy. These data define a mammalian miRNA circuit used by Mtb to coordinately inhibit autophagy and reprogram host lipid metabolism to enable intracellular survival and persistence in the host.

  2. Pathogenicity of Mycobacterium tuberculosis is expressed by regulating metabolic thresholds of the host macrophage.

    Directory of Open Access Journals (Sweden)

    Parul Mehrotra

    2014-07-01

    Full Text Available The success of Mycobacterium tuberculosis as a pathogen derives from its facile adaptation to the intracellular milieu of human macrophages. To explore this process, we asked whether adaptation also required interference with the metabolic machinery of the host cell. Temporal profiling of the metabolic flux, in cells infected with differently virulent mycobacterial strains, confirmed that this was indeed the case. Subsequent analysis identified the core subset of host reactions that were targeted. It also elucidated that the goal of regulation was to integrate pathways facilitating macrophage survival, with those promoting mycobacterial sustenance. Intriguingly, this synthesis then provided an axis where both host- and pathogen-derived factors converged to define determinants of pathogenicity. Consequently, whereas the requirement for macrophage survival sensitized TB susceptibility to the glycemic status of the individual, mediation by pathogen ensured that the virulence properties of the infecting strain also contributed towards the resulting pathology.

  3. 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...

  4. Mycobacterium tuberculosis Infection in a Domesticated Korean Wild Boar ( Sus scrofa coreanus).

    Science.gov (United States)

    Seo, Min-Goo; Ouh, In-Ohk; Kim, Munki; Lee, Jienny; Kim, Young-Hoan; Do, Jae-Cheul; Kwak, Dongmi

    2017-06-01

    Tuberculosis, a chronic progressive disease, has been reported in bovine, swine, and primate species. Here, we report the first case of Mycobacterium tuberculosis infection in a Korean wild boar ( Sus scrofa coreanus). The owners this domesticated boar brought it to the Gyeongbuk Veterinary Service Laboratory in Korea after it was found dead and severely emaciated. Demarcated yellowish white nodules were found around the larynx and retropharyngeal lymph node during necropsy. The lungs had diffuse fibrinous pleuritis, severe congestion, and scattered nodules. More nodules were found in the spleen. Tuberculosis is characterized by massive macrophage infiltration and central caseous necrosis; both characteristics were found in the lungs. Histopathologic examination revealed that the alveolar lumen had marked fibrosis and exudates. Examination of the fluid revealed extensive macrophage permeation. To confirm a Mycobacterium infection, PCR was performed using two primer sets specific to the rpoB gene of Mycobacterium; Mycobacterium was detected in the lungs and spleen. To identify the species of Mycobacterium, immunohistochemical evaluation was performed using antibodies against Mycobacterium tuberculosis and Mycobacterium bovis . The results revealed immunoreactivity against M. tuberculosis but not against M. bovis . The consumption of undercooked or raw meat from game animals may expose humans and other animals to sylvatic infection. Consequently, Koreans who ingest wild boar may be at risk of a tuberculosis infection. To reduce the risk of foodborne infection and maintain public health, continuous monitoring and control strategies are required.

  5. In vitro anti-tuberculosis activity of azole drugs against Mycobacterium tuberculosis clinical isolates.

    Science.gov (United States)

    Imperiale, Belén R; Cataldi, Ángel A; Morcillo, Nora S

    Latent tuberculosis has been associated with the persistence of dormant Mycobacterium tuberculosis in the organism of infected individuals, who are reservoirs of the bacilli and the source for spreading the disease in the community. New active anti-TB drugs exerting their metabolic action at different stages and on latent/dormant bacilli are urgently required to avoid endogenous reactivations and to be part of treatments of multi- and extensively-drug resistant tuberculosis (M/XDR-TB). It was previously reported that azole drugs are active against M. tuberculosis. For that reason, the aims of this study were to determine the in vitro activity of azole drugs, imidazole (clotrimazole, CLO and econazole, ECO) and nitroimidazole (metronidazole, MZ and ipronidazole, IPZ), against a collection of MDR M. tuberculosis clinical isolates; and to analyze their potential use in both the LTB and the active forms of M/XDR-TB treatments. A total of 55 MDR M. tuberculosis isolates and H37Rv were included. MZ and IPZ activity against M. tuberculosis isolates were tested using anaerobic culture conditions. The activity of ECO and CLO was measured by the minimal inhibitory concentration (MIC) using a microdilution colorimetric method. MZ and IPZ showed bacteriostatic activity against M. tuberculosis strains. MIC 50 and MIC 90 to ECO was 4.0μg/ml, while MIC 50 to CLO was 4.0μg/ml and MIC 90 was 8.0μg/ml respectively. All azole compounds tested in the study showed inhibitory activity against MDR M. tuberculosis clinical isolates. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Structure of HsaD, a steroid-degrading hydrolase, from Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Lack, Nathan; Lowe, Edward D.; Liu, Jie; Eltis, Lindsay D.; Noble, Martin E. M.; Sim, Edith; Westwood, Isaac M.

    2007-01-01

    The structure of HsaD, a carbon–carbon bond serine hydrolase involved in steroid catabolism that is critical for the survival of M. tuberculosis inside human macrophages, has been solved by X-ray crystallography. Data were collected at the Diamond Light Source in Oxfordshire, England: this paper describes one of the first structures determined at the new synchrotron. Tuberculosis is a major cause of death worldwide. Understanding of the pathogenicity of Mycobacterium tuberculosis has been advanced by gene analysis and has led to the identification of genes that are important for intracellular survival in macrophages. One of these genes encodes HsaD, a meta-cleavage product (MCP) hydrolase that catalyzes the hydrolytic cleavage of a carbon–carbon bond in cholesterol metabolism. This paper describes the production of HsaD as a recombinant protein and, following crystallization, the determination of its three-dimensional structure to 2.35 Å resolution by X-ray crystallography at the Diamond Light Source in Oxfordshire, England. To the authors’ knowledge, this study constitutes the first report of a structure determined at the new synchrotron facility. The volume of the active-site cleft of the HsaD enzyme is more than double the corresponding active-site volumes of related MCP hydrolases involved in the catabolism of aromatic compounds, consistent with the specificity of HsaD for steroids such as cholesterol. Knowledge of the structure of the enzyme facilitates the design of inhibitors

  7. Comparative metabolic profiling of mce1 operon mutant vs wild-type Mycobacterium tuberculosis strains.

    Science.gov (United States)

    Queiroz, Adriano; Medina-Cleghorn, Daniel; Marjanovic, Olivera; Nomura, Daniel K; Riley, Lee W

    2015-11-01

    Mycobacterium tuberculosis disrupted in a 13-gene operon (mce1) accumulates free mycolic acids (FM) in its cell wall and causes accelerated death in mice. Here, to more comprehensively analyze differences in their cell wall lipid composition, we used an untargeted metabolomics approach to compare the lipid profiles of wild-type and mce1 operon mutant strains. By liquid chromatography-mass spectrometry, we identified >400 distinct lipids significantly altered in the mce1 mutant compared to wild type. These lipids included decreased levels of saccharolipids and glycerophospholipids, and increased levels of alpha-, methoxy- and keto mycolic acids (MA), and hydroxyphthioceranic acid. The mutant showed reduced expression of mmpL8, mmpL10, stf0, pks2 and papA2 genes involved in transport and metabolism of lipids recognized to induce proinflammatory response; these lipids were found to be decreased in the mutant. In contrast, the transcripts of mmpL3, fasI, kasA, kasB, acpM and RV3451 involved in MA transport and metabolism increased; MA inhibits inflammatory response in macrophages. Since the mce1 operon is known to be regulated in intracellular M. tuberculosis, we speculate that the differences we observed in cell wall lipid metabolism and composition may affect host response to M. tuberculosis infection and determine the clinical outcome of such an infection. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. A systems biology framework for modeling metabolic enzyme inhibition of Mycobacterium tuberculosis

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    Reifman Jaques

    2009-09-01

    Full Text Available Abstract Background Because metabolism is fundamental in sustaining microbial life, drugs that target pathogen-specific metabolic enzymes and pathways can be very effective. In particular, the metabolic challenges faced by intracellular pathogens, such as Mycobacterium tuberculosis, residing in the infected host provide novel opportunities for therapeutic intervention. Results We developed a mathematical framework to simulate the effects on the growth of a pathogen when enzymes in its metabolic pathways are inhibited. Combining detailed models of enzyme kinetics, a complete metabolic network description as modeled by flux balance analysis, and a dynamic cell population growth model, we quantitatively modeled and predicted the dose-response of the 3-nitropropionate inhibitor on the growth of M. tuberculosis in a medium whose carbon source was restricted to fatty acids, and that of the 5'-O-(N-salicylsulfamoyl adenosine inhibitor in a medium with low-iron concentration. Conclusion The predicted results quantitatively reproduced the experimentally measured dose-response curves, ranging over three orders of magnitude in inhibitor concentration. Thus, by allowing for detailed specifications of the underlying enzymatic kinetics, metabolic reactions/constraints, and growth media, our model captured the essential chemical and biological factors that determine the effects of drug inhibition on in vitro growth of M. tuberculosis cells.

  9. Mycobacterium tuberculosis and Copper: A Newly Appreciated Defense against an Old Foe?*

    Science.gov (United States)

    Darwin, K. Heran

    2015-01-01

    Several independent studies have recently converged upon the conclusion that the human bacterial pathogen Mycobacterium tuberculosis encounters copper during infections. At least three independently regulated pathways respond to excess copper and are required for the full virulence of M. tuberculosis in animals. In this review, I will discuss the functions of the best-characterized copper-responsive proteins in M. tuberculosis, the potential sources of copper during an infection, and remaining questions about the interface between copper and tuberculosis. PMID:26055711

  10. 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 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.

  11. Effect of common and experimental anti-tuberculosis treatments on Mycobacterium tuberculosis growing as biofilms

    Directory of Open Access Journals (Sweden)

    James P. Dalton

    2016-11-01

    Full Text Available Much is known regarding the antibiotic susceptibility of planktonic cultures of Mycobacterium tuberculosis, the bacterium responsible for the lung disease tuberculosis (TB. As planktonically-grown M. tuberculosis are unlikely to be entirely representative of the bacterium during infection, we set out to determine how effective a range of anti-mycobacterial treatments were against M. tuberculosis growing as a biofilm, a bacterial phenotype known to be more resistant to antibiotic treatment. Light levels from bioluminescently-labelled M. tuberculosis H37Rv (strain BSG001 were used as a surrogate for bacterial viability, and were monitored before and after one week of treatment. After treatment, biofilms were disrupted, washed and inoculated into fresh broth and plated onto solid media to rescue any surviving bacteria. We found that in this phenotypic state M. tuberculosis was resistant to the majority of the compounds tested. Minimum inhibitory concentrations (MICs increased by 20-fold to greater than 1,000-fold, underlying the potential of this phenotype to cause significant problems during treatment.

  12. A case report of vascular catheter-associated bacteremia caused by Mycobacterium tuberculosis in a non-immunosuppressed patient

    Directory of Open Access Journals (Sweden)

    PETRILLO Victor Flávio

    1999-01-01

    Full Text Available Mycobacterium tuberculosis was isolated from a central venous catheter in a non-immunosuppressed patient with systemic tuberculosis. This case report represents a very uncommon form of isolation of Mycobacterium tuberculosis. A total improvement was obtained after treatment.

  13. How dormant is Mycobacterium tuberculosis during latency? A study integrating genomics and molecular epidemiology

    DEFF Research Database (Denmark)

    Yang, Zhenhua; Rosenthal, Mariana; Rosenberg, Noah A

    2011-01-01

    Mycobacterium tuberculosis may survive for decades in the human body in a state termed latent tuberculosis infection (LTBI). We investigated the occurrence during LTBI of insertion/deletion events in a selected set of mononucleotide simple sequence repeats, DNA sequence changes in four M. tubercu......Mycobacterium tuberculosis may survive for decades in the human body in a state termed latent tuberculosis infection (LTBI). We investigated the occurrence during LTBI of insertion/deletion events in a selected set of mononucleotide simple sequence repeats, DNA sequence changes in four M...

  14. Mycobacterium tuberculosis Transcription Machinery: Ready To Respond to Host Attacks

    Science.gov (United States)

    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

  15. First molecular epidemiology study of Mycobacterium tuberculosis in Kiribati.

    Directory of Open Access Journals (Sweden)

    Eman Aleksic

    Full Text Available Tuberculosis incidence rates in Kiribati are among the highest in the Western Pacific Region, however the genetic diversity of circulating Mycobacterium tuberculosis complex strains (MTBC and transmission dynamics are unknown. Here, we analysed MTBC strains isolated from culture positive pulmonary tuberculosis (TB cases from the main TB referral centre between November 2007 and October 2009. Strain genotyping (IS6110 typing, spoligotyping, 24-loci MIRU-VNTR and SNP typing was performed and demographic information collected. Among 73 MTBC strains analysed, we identified seven phylogenetic lineages, dominated by Beijing strains (49%. Beijing strains were further differentiated in two main branches, Beijing-A (n = 8 and -B (n = 28, that show distinct genotyping patterns and are characterized by specific deletion profiles (Beijing A: only RD105, RD207 deleted; Beijing B: RD150 and RD181 additionally deleted. Many Kiribati strains (59% based on IS6110 typing of all strains occurred in clusters, suggesting ongoing local transmission. Beijing-B strains and over-crowded living conditions were associated with strain clustering (likely recent transmission, however little evidence of anti-tuberculous drug resistance was observed. We suggest enhanced case finding amongst close contacts and continued supervised treatment of all identified cases using standard first-line drugs to reduce TB burden in Kiribati. Beijing strains can be subdivided in different principle branches that might be associated with differential spreading patterns in the population.

  16. PolyTB: A genomic variation map for Mycobacterium tuberculosis

    KAUST Repository

    Coll, Francesc

    2014-02-15

    Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is the second major cause of death from an infectious disease worldwide. Recent advances in DNA sequencing are leading to the ability to generate whole genome information in clinical isolates of M. tuberculosis complex (MTBC). The identification of informative genetic variants such as phylogenetic markers and those associated with drug resistance or virulence will help barcode Mtb in the context of epidemiological, diagnostic and clinical studies. Mtb genomic datasets are increasingly available as raw sequences, which are potentially difficult and computer intensive to process, and compare across studies. Here we have processed the raw sequence data (>1500 isolates, eight studies) to compile a catalogue of SNPs (n = 74,039, 63% non-synonymous, 51.1% in more than one isolate, i.e. non-private), small indels (n = 4810) and larger structural variants (n = 800). We have developed the PolyTB web-based tool (http://pathogenseq.lshtm.ac.uk/polytb) to visualise the resulting variation and important meta-data (e.g. in silico inferred strain-types, location) within geographical map and phylogenetic views. This resource will allow researchers to identify polymorphisms within candidate genes of interest, as well as examine the genomic diversity and distribution of strains. PolyTB source code is freely available to researchers wishing to develop similar tools for their pathogen of interest. 2014 Elsevier Ltd. All rights reserved.

  17. Origin, spread and demography of the Mycobacterium tuberculosis complex.

    Directory of Open Access Journals (Sweden)

    Thierry Wirth

    Full Text Available The evolutionary timing and spread of the Mycobacterium tuberculosis complex (MTBC, one of the most successful groups of bacterial pathogens, remains largely unknown. Here, using mycobacterial tandem repeat sequences as genetic markers, we show that the MTBC consists of two independent clades, one composed exclusively of M. tuberculosis lineages from humans and the other composed of both animal and human isolates. The latter also likely derived from a human pathogenic lineage, supporting the hypothesis of an original human host. Using Bayesian statistics and experimental data on the variability of the mycobacterial markers in infected patients, we estimated the age of the MTBC at 40,000 years, coinciding with the expansion of "modern" human populations out of Africa. Furthermore, coalescence analysis revealed a strong and recent demographic expansion in almost all M. tuberculosis lineages, which coincides with the human population explosion over the last two centuries. These findings thus unveil the dynamic dimension of the association between human host and pathogen populations.

  18. In silico design of Mycobacterium tuberculosis epitope ensemble vaccines.

    Science.gov (United States)

    Shah, Preksha; Mistry, Jaymisha; Reche, Pedro A; Gatherer, Derek; Flower, Darren R

    2018-03-19

    Effective control of Mycobacterium tuberculosis is a global necessity. In 2015, tuberculosis (TB) caused more deaths than HIV. Considering the increasing prevalence of multi-drug resistant forms of M. tuberculosis, the need for effective TB vaccines becomes imperative. Currently, the only licensed TB vaccine is Bacillus Calmette-Guérin (BCG). Yet, BCG has many drawbacks limiting its efficacy and applicability. We applied advanced computational procedures to derive a universal TB vaccine and one targeting East Africa. Our approach selects an optimal set of highly conserved, experimentally validated epitopes, with high projected population coverage (PPC). Through rigorous data analysis, five different potential vaccine combinations were selected each with PPC above 80% for East Africa and above 90% for the World. Two potential vaccines only contained CD8+ epitopes, while the others included both CD4+ and CD8+ epitopes. Our prime vaccine candidate was a putative seven-epitope ensemble comprising: SRGWSLIKSVRLGNA, KPRIITLTMNPALDI, AAHKGLMNIALAISA, FPAGGSTGSL, MLLAVTVSL, QSSFYSDW and KMRCGAPRY, with a 97.4% global PPC and a 92.7% East African PPC. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. 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%.

  20. Interferon-¿ production by human T cells and natural killer cells in vitro in response to antigens from the two intracellular pathogens Mycobacterium tuberculosis and Leishmania major

    DEFF Research Database (Denmark)

    Kemp, K; Hviid, L; Kharazmi, A

    1997-01-01

    Acquired resistance to both mycobacteria and Leishmania is primarily mediated by interferon-gamma (IFN-gamma), which triggers mechanisms leading to the death of the microorganism in macrophages. In this study, cell activation and IFN-gamma production was investigated in human peripheral blood...... mononuclear cells (PBMC) from individuals previously sensitized to tuberculin and without known exposure to Leishmania parasites. Immune staining for intracellular IFN-gamma and surface markers allowed flow cytometric identification of the cellular sources of IFN-gamma in cell cultures incubated with purified...

  1. Comprehensive insights into transcriptional adaptation of intracellular mycobacteria by microbe-enriched dual RNA sequencing

    NARCIS (Netherlands)

    Rienksma, R.A.; Suarez Diez, M.; Mollenkopf, H.J.; Dolganov, G.M.; Dorhoi, A.; Schoolnik, G.K.; Martins Dos Santos, V.A.P.; Kaufmann, S.; Schaap, P.J.; Gengenbacher, M.

    2015-01-01

    BackgroundThe human pathogen Mycobacterium tuberculosis has the capacity to escape eradication by professional phagocytes. During infection, M. tuberculosis resists the harsh environment of phagosomes and actively manipulates macrophages and dendritic cells to ensure prolonged intracellular

  2. Identification and survival studies of Mycobacterium tuberculosis within Laboratory-Fermented bovine milk

    OpenAIRE

    Mariam, Solomon H

    2014-01-01

    Background Mycobacterium tuberculosis and Mycobacterium bovis are the classic agents causing tuberculosis (TB) in humans and animals respectively. Transmission of tuberculous bacteria to humans usually occurs by inhalation of aerosols containing droplets of tubercle bacilli or via consumption of contaminated foods and drinks, primarily milk. The practice of milk pooling, including from cows with TB of the udder, further exacerbates the situation by rendering the whole milk supply infective. T...

  3. 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.

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

    Science.gov (United States)

    Badr, Hesham M.

    2011-11-01

    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 °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.

  5. Prevalence of latent Mycobacterium tuberculosis infection in prisoners.

    Science.gov (United States)

    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

  6. Molecular typing of Mycobacterium tuberculosis by mycobacterial interspersed repetitive unit-variable-number tandem repeat analysis, a more accurate method for identifying epidemiological links between patients with tuberculosis

    NARCIS (Netherlands)

    van Deutekom, Henk; Supply, Philip; de Haas, Petra E. W.; Willery, Eve; Hoijng, Susan P.; Locht, Camille; Coutinho, Roel A.; van Soolingen, Dick

    2005-01-01

    IS6110 fingerprinting of Mycobacterium tuberculosis is the standard identification method in studies on transmission of tuberculosis. However, intensive epidemiological investigation may fail to confirm transmission links between patients clustered by IS6110-restriction fragment length polymorphism

  7. 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,

  8. Systems-based approaches to probing metabolic variation within the Mycobacterium tuberculosis complex.

    Directory of Open Access Journals (Sweden)

    Emma K Lofthouse

    Full Text Available The Mycobacterium tuberculosis complex includes bovine and human strains of the tuberculosis bacillus, including Mycobacterium tuberculosis, Mycobacterium bovis and the Mycobacterium bovis BCG vaccine strain. M. bovis has evolved from a M. tuberculosis-like ancestor and is the ancestor of the BCG vaccine. The pathogens demonstrate distinct differences in virulence, host range and metabolism, but the role of metabolic differences in pathogenicity is poorly understood. Systems biology approaches have been used to investigate the metabolism of M. tuberculosis, but not to probe differences between tuberculosis strains. In this study genome scale metabolic networks of M. bovis and M. bovis BCG were constructed and interrogated, along with a M. tuberculosis network, to predict substrate utilisation, gene essentiality and growth rates. The models correctly predicted 87-88% of high-throughput phenotype data, 75-76% of gene essentiality data and in silico-predicted growth rates matched measured rates. However, analysis of the metabolic networks identified discrepancies between in silico predictions and in vitro data, highlighting areas of incomplete metabolic knowledge. Additional experimental studies carried out to probe these inconsistencies revealed novel insights into the metabolism of these strains. For instance, that the reduction in metabolic capability observed in bovine tuberculosis strains, as compared to M. tuberculosis, is not reflected by current genetic or enzymatic knowledge. Hence, the in silico networks not only successfully simulate many aspects of the growth and physiology of these mycobacteria, but also provide an invaluable tool for future metabolic studies.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Characterisation of methionine adenosyltransferase from Mycobacterium smegmatis and M. tuberculosis

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    Knodel Marvin H

    2003-06-01

    Full Text Available Abstract Background Tuberculosis remains a serious world-wide health threat which requires the characterisation of novel drug targets for the development of future antimycobacterials. One of the key obstacles in the definition of new targets is the large variety of metabolic alterations that occur between cells in the active growth and chronic/dormant phases of tuberculosis. The ideal biochemical target should be active in both growth phases. Methionine adenosyltransferase, which catalyses the formation of S-adenosylmethionine from methionine and ATP, is involved in polyamine biosynthesis during active growth and is also required for the methylation and cyclopropylation of mycolipids necessary for survival in the chronic phase. Results The gene encoding methionine adenosyltransferase has been cloned from Mycobacterium tuberculosis and the model organism M. smegmatis. Both enzymes retained all amino acids known to be involved in catalysing the reaction. While the M. smegmatis enzyme could be functionally expressed, the M. tuberculosis homologue was insoluble and inactive under a large variety of expression conditions. For the M. smegmatis enzyme, the Vmax for S-adenosylmethionine formation was 1.30 μmol/min/mg protein and the Km for methionine and ATP was 288 μM and 76 μM respectively. In addition, the enzyme was competitively inhibited by 8-azaguanine and azathioprine with a Ki of 4.7 mM and 3.7 mM respectively. Azathioprine inhibited the in vitro growth of M. smegmatis with a minimal inhibitory concentration (MIC of 500 μM, while the MIC for 8-azaguanine was >1.0 mM. Conclusion The methionine adenosyltransferase from both organisms had a primary structure very similar those previously characterised in other prokaryotic and eukaryotic organisms. The kinetic properties of the M. smegmatis enzyme were also similar to known prokaryotic methionine adenosyltransferases. Inhibition of the enzyme by 8-azaguanine and azathioprine provides a starting

  11. Biosynthesis and Recycling of Nicotinamide Cofactors in Mycobacterium tuberculosis

    Science.gov (United States)

    Boshoff, Helena I. M.; Xu, Xia; Tahlan, Kapil; Dowd, Cynthia S.; Pethe, Kevin; Camacho, Luis R.; Park, Tae-Ho; Yun, Chang-Soo; Schnappinger, Dirk; Ehrt, Sabine; Williams, Kerstin J.; Barry, Clifton E.

    2008-01-01

    Despite the presence of genes that apparently encode NAD salvage-specific enzymes in its genome, it has been previously thought that Mycobacterium tuberculosis can only synthesize NAD de novo. Transcriptional analysis of the de novo synthesis and putative salvage pathway genes revealed an up-regulation of the salvage pathway genes in vivo and in vitro under conditions of hypoxia. [14C]Nicotinamide incorporation assays in M. tuberculosis isolated directly from the lungs of infected mice or from infected macrophages revealed that incorporation of exogenous nicotinamide was very efficient in in vivo-adapted cells, in contrast to cells grown aerobically in vitro. Two putative nicotinic acid phosphoribosyltransferases, PncB1 (Rv1330c) and PncB2 (Rv0573c), were examined by a combination of in vitro enzymatic activity assays and allelic exchange studies. These studies revealed that both play a role in cofactor salvage. Mutants in the de novo pathway died upon removal of exogenous nicotinamide during active replication in vitro. Cell death is induced by both cofactor starvation and disruption of cellular redox homeostasis as electron transport is impaired by limiting NAD. Inhibitors of NAD synthetase, an essential enzyme common to both recycling and de novo synthesis pathways, displayed the same bactericidal effect as sudden NAD starvation of the de novo pathway mutant in both actively growing and nonreplicating M. tuberculosis. These studies demonstrate the plasticity of the organism in maintaining NAD levels and establish that the two enzymes of the universal pathway are attractive chemotherapeutic targets for active as well as latent tuberculosis. PMID:18490451

  12. Diversity of Mycobacterium tuberculosis Isolates from New Pulmonary Tuberculosis Cases in Addis Ababa, Ethiopia

    Directory of Open Access Journals (Sweden)

    Adane Mihret

    2012-01-01

    Full Text Available Understanding the genetic diversity of Mycobacterium tuberculosis is needed for a better understanding of the epidemiology of TB and could have implications for the development of new diagnostics, drugs, and vaccines. M. tuberculosis isolates were characterized using spoligotyping and were compared with the SpoIDB4 database of the Pasteur Institute of Guadeloupe. A total of 53 different patterns were identified among 192 isolates examined. 169 of the isolates were classified into one of the 33 shared SITs, whereas the remaining 23 corresponded to 20 orphan patterns. 54% of the isolates were ascribed to the T family, a family which has not been well defined to date. Other prominent families were CAS, Haarlem, LAM, Beijing, and Unknown comprising 26%, 13%, 2.6%, 0.5%, and 2.1%, respectively. Among HIV-positive patients, 10 patterns were observed among 25 isolates. The T (38.5%, H (26.9%, and CAS (23.1% families were the most common among HIV-positive individuals. The diversity of the M. tuberculosis strains found in this study is very high, and there was no difference in the distribution of families in HIV-positive and HIV-negative TB patients except the H family. Tuberculosis transmission in Addis Ababa is due to only the modern M. tuberculosis families (CAS, LAM, T, Beijing, Haarlem, and U.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Susceptibility of a panel of virulent strains of Mycobacterium tuberculosis to reactive nitrogen intermediates.

    Science.gov (United States)

    Rhoades, E R; Orme, I M

    1997-04-01

    Murine bone marrow-derived macrophages were infected with a panel of virulent isolates of Mycobacterium tuberculosis including laboratory strains Erdman and H37Rv and various clinical isolates in order to determine the sensitivity of each of these strains to the antimycobacterial activities of macrophage-generated reactive nitrogen intermediates (RNI). All of the M. tuberculosis strains grew in murine bone marrow-derived macrophages; however, gamma interferon-primed macrophages limited the initial growth of intracellular bacilli. Some of the mycobacterial strains, including Erdman, were killed over the first 4 days of infection, as evidenced by significant decreases in the number of viable intracellular bacilli determined by a CFU assay. Other mycobacterial strains were not killed during this same period, and some isolates, including CSU 24 and CSU 31, grew steadily in activated macrophages. The accumulation of nitrite on infected monolayers was measured, and it was found that inhibitory levels of RNI did not vary among infections with the different strains. Nitrite tolerance was determined in a cell-free system for each of the strains in order to compare susceptibilities of the strains to RNI. All of the strains tested were killed by levels of RNI generated by the acidification of 10 mM NaNO2 to pH 6.5 or 5.5, and the strains exhibited a range of tolerance to lower concentrations of RNI. No correlations were observed between such cell-free RNI tolerances and the capacity of bacilli to resist macrophage RNI-mediated killing. These results indicate that under stringent conditions, RNI can kill M. tuberculosis, but that under less harsh, more physiological conditions, the effects of RNI range from partial to negligible inhibition.

  15. Profiling the Proteome of Mycobacterium tuberculosis during Dormancy and Reactivation.

    Science.gov (United States)

    Gopinath, Vipin; Raghunandanan, Sajith; Gomez, Roshna Lawrence; Jose, Leny; Surendran, Arun; Ramachandran, Ranjit; Pushparajan, Akhil Raj; Mundayoor, Sathish; Jaleel, Abdul; Kumar, Ramakrishnan Ajay

    2015-08-01

    Tuberculosis, caused by Mycobacterium tuberculosis, still remains a major global health problem. The main obstacle in eradicating this disease is the ability of this pathogen to remain dormant in macrophages, and then reactivate later under immuno-compromised conditions. The physiology of hypoxic nonreplicating M. tuberculosis is well-studied using many in vitro dormancy models. However, the physiological changes that take place during the shift from dormancy to aerobic growth (reactivation) have rarely been subjected to a detailed investigation. In this study, we developed an in vitro reactivation system by re-aerating the virulent laboratory strain of M. tuberculosis that was made dormant employing Wayne's dormancy model, and compared the proteome profiles of dormant and reactivated bacteria using label-free one-dimensional LC/MS/MS analysis. The proteome of dormant bacteria was analyzed at nonreplicating persistent stage 1 (NRP1) and stage 2 (NRP2), whereas that of reactivated bacteria was analyzed at 6 and 24 h post re-aeration. Proteome of normoxially grown bacteria served as the reference. In total, 1871 proteins comprising 47% of the M. tuberculosis proteome were identified, and many of them were observed to be expressed differentially or uniquely during dormancy and reactivation. The number of proteins detected at different stages of dormancy (764 at NRP1, 691 at NRP2) and reactivation (768 at R6 and 983 at R24) was very low compared with that of the control (1663). The number of unique proteins identified during normoxia, NRP1, NRP2, R6, and R24 were 597, 66, 56, 73, and 94, respectively. We analyzed various biological functions during these conditions. Fluctuation in the relative quantities of proteins involved in energy metabolism during dormancy and reactivation was the most significant observation we made in this study. Proteins that are up-regulated or uniquely expressed during reactivation from dormancy offer to be attractive targets for therapeutic

  16. Ready Experimental Translocation of Mycobacterium canettii Yields Pulmonary Tuberculosis.

    Science.gov (United States)

    Bouzid, Fériel; Brégeon, Fabienne; Lepidi, Hubert; Donoghue, Helen D; Minnikin, David E; Drancourt, Michel

    2017-12-01

    Mycobacterium canettii , which has a smooth colony morphology, is the tuberculous organism retaining the most genetic traits from the putative last common ancestor of the rough-morphology Mycobacterium tuberculosis complex. To explore whether M. canettii can infect individuals by the oral route, mice were fed phosphate-buffered saline or 10 6 M. canettii mycobacteria and sacrificed over a 28-day experiment. While no M. canettii was detected in negative controls, M. canettii -infected mice yielded granuloma-like lesions for 4/4 lungs at days 14 and 28 postinoculation (p.i.) and positive PCR detection of M. canettii for 5/8 mesenteric lymph nodes at days 1 and 3 p.i. and 5/6 pooled stools collected from day 1 to day 28 p.i. Smooth M. canettii colonies grew from 68% of lungs and 36% of spleens and cervical lymph nodes but fewer than 20% of axillary lymph nodes, livers, brown fat samples, kidneys, or blood samples throughout the 28-day experiment. Ready translocation in mice after digestive tract challenge demonstrates the potential of ingested M. canettii organisms to relocate to distant organs and lungs. The demonstration of this relocation supports the possibility that populations may be infected by environmental M. canettii . Copyright © 2017 American Society for Microbiology.

  17. Mycobacterium tuberculosis infection in a canary (Serinus canana L.) and a blue-fronted Amazon parrot (Amazona amazona aestiva).

    Science.gov (United States)

    Hoop, Richard K

    2002-01-01

    I report two cases of mycobacteriosis in pet birds due to Mycobacterium tuberculosis and discuss the zoonotic implications. The canary with a tuberculous knot in the lung is the first description of M. tuberculosis in a nonpsittacine bird species.

  18. 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

  19. ST2 deficient mice display a normal host defense against pulmonary infection with Mycobacterium tuberculosis

    NARCIS (Netherlands)

    Wieland, Catharina W.; van der Windt, Gerritje J. W.; Florquin, Sandrine; McKenzie, Andrew N. J.; van der Poll, Tom

    2009-01-01

    Tuberculosis, caused by Mycobacterium (M.) tuberculosis, is a devastating infectious disease causing many deaths world-wide every year. Successful host defense mainly depends on a strong Th type I response. We investigated the role of T1/ST2 (recently identified as the receptor for IL-33), a typical

  20. 3-Ketosteroid 9 alpha-hydroxylase is an essential factor in the pathogenesis of Mycobacterium tuberculosis

    NARCIS (Netherlands)

    Hu, Yanmin; van der Geize, Robert; Besra, Gurdyal S.; Gurcha, Sudagar S.; Liu, Alexander; Rohde, Manfred; Singh, Mahavir; Coates, Anthony

    Mycobacterium tuberculosis H37Rv contains the kshA (Rv3526) and kshB (Rv3571) genes, encoding 3-ketosteroid 9a-hydroxylase (KSH). Consistent with their predicted roles, the Delta kshA and Delta kshB deletion mutants of M. tuberculosis H37Rv were unable to use cholesterol and 4-androstene-3,17-dione

  1. The effect of hyperglycaemia on in vitro cytokine production and macrophage infection with Mycobacterium tuberculosis

    NARCIS (Netherlands)

    Lachmandas, E.; Vrieling, F.; Wilson, L.G.; Joosten, S.A.; Netea, M.G.; Ottenhoff, T.H.; Crevel, R. van

    2015-01-01

    Type 2 diabetes mellitus is an established risk factor for tuberculosis but the underlying mechanisms are largely unknown. We examined the effects of hyperglycaemia, a hallmark of diabetes, on the cytokine response to and macrophage infection with Mycobacterium tuberculosis. Increasing in vitro

  2. Role of Granulocyte-Macrophage Colony-Stimulating Factor Production by T Cells duringMycobacterium tuberculosisInfection.

    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

    Mice deficient for granulocyte-macrophage colony-stimulating factor (GM-CSF -/- ) are highly susceptible to infection with Mycobacterium tuberculosis , and clinical data have shown that anti-GM-CSF neutralizing antibodies can lead to increased susceptibility to tuberculosis in otherwise healthy people. GM-CSF activates human and murine macrophages to inhibit intracellular M. tuberculosis growth. We have previously shown that GM-CSF produced by iNKT cells inhibits growth of M. tuberculosis However, the more general role of T cell-derived GM-CSF during infection has not been defined and how GM-CSF activates macrophages to inhibit bacterial growth is unknown. Here we demonstrate that, in addition to nonconventional T cells, conventional T cells also produce GM-CSF during M. tuberculosis infection. Early during infection, nonconventional iNKT cells and γδ T cells are the main source of GM-CSF, a role subsequently assumed by conventional CD4 + T cells as the infection progresses. M. tuberculosis -specific T cells producing GM-CSF are also detected in the peripheral blood of infected people. Under conditions where nonhematopoietic production of GM-CSF is deficient, T cell production of GM-CSF is protective and required for control of M. tuberculosis infection. However, GM-CSF is not required for T cell-mediated protection in settings where GM-CSF is produced by other cell types. Finally, using an in vitro macrophage infection model, we demonstrate that GM-CSF inhibition of M. tuberculosis growth requires the expression of peroxisome proliferator-activated receptor gamma (PPARγ). Thus, we identified GM-CSF production as a novel T cell effector function. These findings suggest that a strategy augmenting T cell production of GM-CSF could enhance host resistance against M. tuberculosis IMPORTANCE Mycobacterium tuberculosis is the bacterium that causes tuberculosis, the leading cause of death by any infection worldwide. T cells are critical components of the immune

  3. Palatal Actinomycosis and Kaposi Sarcoma in an HIV-Infected Subject with Disseminated Mycobacterium avium-intracellulare Infection

    Directory of Open Access Journals (Sweden)

    Yuria Ablanedo-Terrazas

    2012-01-01

    Full Text Available Actinomyces and Mycobacterium avium-intracellulare are facultative intracellular organisms, members of the bacterial order actinomycetales. Although Actinomyces can behave as copathogen when anatomic barriers are compromised, its coinfection with Mycobacterium avium-intracellulare has not previously been reported. We present the first reported case of palatal actinomycosis co-infection with disseminated MAC, in an HIV-infected subject with Kaposi sarcoma and diabetes. We discuss the pathogenesis of the complex condition of this subject.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Molecular epidemiology of Mycobacterium tuberculosis clinical isolates in Southwest Ireland.

    LENUS (Irish Health Repository)

    Ojo, Olabisi O

    2010-10-01

    Tuberculosis has had significant effects on Ireland over the past two centuries, causing persistently higher morbidity and mortality than in neighbouring countries until the last decade. This study describes the results of genotyping and drug susceptibility testing of 171 strains of Mycobacterium tuberculosis complex isolated between January 2004 and December 2006 in a region of Ireland centred on the city of Cork. Spoligotype comparisons were made with the SpolDB4 database and clustered 130 strains in 23 groups, forty-one strains showed unique Spoligotyping patterns. The commonest spoligotypes detected were ST0137 (X2) (16.9%), and ST0351 (15.8%) (\\'U\\' clade). The major spoligotype clades were X (26.2%), U (19.3%), T (15.2%), Beijing (5.9%), Haarlem (4.7%), LAM (4.1%), BOVIS (1.75%), with 12.9% unassigned strains. A 24-locus VNTR genotyping produced 15 clusters containing 49 isolates, with high discrimination index (HGDI>0.99). A combination of Spoligotyping and VNTR reduced the number of clustered isolates to 47 in 15 clusters (27.5%). This study identified ST351 as common among Irish nationals, and found a low rate of drug resistance with little evidence of transmission of drug resistant strains. Strain clustering was significantly associated with age under 55 years and Irish nationality. Only strains of Euro-American lineage formed clusters. Molecular typing did not completely coincide with the results of contact investigations.

  6. Amperometric immunosensor for rapid detection of Mycobacterium tuberculosis

    Science.gov (United States)

    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.

  7. Biochemical characterization of uracil phosphoribosyltransferase from Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Anne Drumond Villela

    Full Text Available Uracil phosphoribosyltransferase (UPRT catalyzes the conversion of uracil and 5-phosphoribosyl-α-1-pyrophosphate (PRPP to uridine 5'-monophosphate (UMP and pyrophosphate (PP(i. UPRT plays an important role in the pyrimidine salvage pathway since UMP is a common precursor of all pyrimidine nucleotides. Here we describe cloning, expression and purification to homogeneity of upp-encoded UPRT from Mycobacterium tuberculosis (MtUPRT. Mass spectrometry and N-terminal amino acid sequencing unambiguously identified the homogeneous protein as MtUPRT. Analytical ultracentrifugation showed that native MtUPRT follows a monomer-tetramer association model. MtUPRT is specific for uracil. GTP is not a modulator of MtUPRT ativity. MtUPRT was not significantly activated or inhibited by ATP, UTP, and CTP. Initial velocity and isothermal titration calorimetry studies suggest that catalysis follows a sequential ordered mechanism, in which PRPP binding is followed by uracil, and PP(i product is released first followed by UMP. The pH-rate profiles indicated that groups with pK values of 5.7 and 8.1 are important for catalysis, and a group with a pK value of 9.5 is involved in PRPP binding. The results here described provide a solid foundation on which to base upp gene knockout aiming at the development of strategies to prevent tuberculosis.

  8. Roles of Mucosal Immunity against Mycobacterium tuberculosis Infection

    Directory of Open Access Journals (Sweden)

    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.

  9. Characterization and transcriptome analysis of Mycobacterium tuberculosis persisters.

    Science.gov (United States)

    Keren, Iris; Minami, Shoko; Rubin, Eric; Lewis, Kim

    2011-01-01

    Tuberculosis continues to be a major public health problem in many parts of the world. Significant obstacles in controlling the epidemic are the length of treatment and the large reservoir of latently infected people. Bacteria form dormant, drug-tolerant persister cells, which may be responsible for the difficulty in treating both acute and latent infections. We find that in Mycobacterium tuberculosis, low numbers of drug-tolerant persisters are present in lag and early exponential phases, increasing sharply at late exponential and stationary phases to make up ~1% of the population. This suggests that persister formation is governed by both stochastic and deterministic mechanisms. In order to isolate persisters, an exponentially growing population was treated with d-cycloserine, and cells surviving lysis were collected by centrifugation. A transcriptome of persisters was obtained by using hybridization to an Affymetrix array. The transcriptome shows downregulation of metabolic and biosynthetic pathways, consistent with a certain degree of dormancy. A set of genes was upregulated in persisters, and these are likely involved in persister formation and maintenance. A comparison of the persister transcriptome with transcriptomes obtained for several in vitro dormancy models identified a small number of genes upregulated in all cases, which may represent a core dormancy response. © 2011 Keren et al.

  10. Biochemical Characterization of Uracil Phosphoribosyltransferase from Mycobacterium tuberculosis

    Science.gov (United States)

    Villela, Anne Drumond; Ducati, Rodrigo Gay; Rosado, Leonardo Astolfi; Bloch, Carlos Junior; Prates, Maura Vianna; Gonçalves, Danieli Cristina; Ramos, Carlos Henrique Inacio; Basso, Luiz Augusto; Santos, Diogenes Santiago

    2013-01-01

    Uracil phosphoribosyltransferase (UPRT) catalyzes the conversion of uracil and 5-phosphoribosyl-α-1-pyrophosphate (PRPP) to uridine 5′-monophosphate (UMP) and pyrophosphate (PPi). UPRT plays an important role in the pyrimidine salvage pathway since UMP is a common precursor of all pyrimidine nucleotides. Here we describe cloning, expression and purification to homogeneity of upp-encoded UPRT from Mycobacterium tuberculosis (MtUPRT). Mass spectrometry and N-terminal amino acid sequencing unambiguously identified the homogeneous protein as MtUPRT. Analytical ultracentrifugation showed that native MtUPRT follows a monomer-tetramer association model. MtUPRT is specific for uracil. GTP is not a modulator of MtUPRT ativity. MtUPRT was not significantly activated or inhibited by ATP, UTP, and CTP. Initial velocity and isothermal titration calorimetry studies suggest that catalysis follows a sequential ordered mechanism, in which PRPP binding is followed by uracil, and PPi product is released first followed by UMP. The pH-rate profiles indicated that groups with pK values of 5.7 and 8.1 are important for catalysis, and a group with a pK value of 9.5 is involved in PRPP binding. The results here described provide a solid foundation on which to base upp gene knockout aiming at the development of strategies to prevent tuberculosis. PMID:23424660

  11. 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...

  12. Networked T cell death following macrophage infection by Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Stephen H-F Macdonald

    Full Text Available BACKGROUND: Depletion of T cells following infection by Mycobacterium tuberculosis (Mtb impairs disease resolution, and interferes with clinical test performance that relies on cell-mediated immunity. A number of mechanisms contribute to this T cell suppression, such as activation-induced death and trafficking of T cells out of the peripheral circulation and into the diseased lungs. The extent to which Mtb infection of human macrophages affects T cell viability however, is not well characterised. METHODOLOGY/PRINCIPAL FINDINGS: We found that lymphopenia (<1.5 × 10(9 cells/l was prevalent among culture-positive tuberculosis patients, and lymphocyte counts significantly improved post-therapy. We previously reported that Mtb-infected human macrophages resulted in death of infected and uninfected bystander macrophages. In the current study, we sought to examine the influence of infected human alveolar macrophages on T cells. We infected primary human alveolar macrophages (the primary host cell for Mtb or PMA-differentiated THP-1 cells with Mtb H37Ra, then prepared cell-free supernatants. The supernatants of Mtb-infected macrophages caused dose-dependent, caspase-dependent, T cell apoptosis. This toxic effect of infected macrophage secreted factors did not require TNF-α or Fas. The supernatant cytotoxic signal(s were heat-labile and greater than 50 kDa in molecular size. Although ESAT-6 was toxic to T cells, other Mtb-secreted factors tested did not influence T cell viability; nor did macrophage-free Mtb bacilli or broth from Mtb cultures. Furthermore, supernatants from Mycobacterium bovis Bacille de Calmette et Guerin (BCG- infected macrophages also elicited T cell death suggesting that ESAT-6 itself, although cytotoxic, was not the principal mediator of T cell death in our system. CONCLUSIONS: Mtb-Infected macrophages secrete heat-labile factors that are toxic to T cells, and may contribute to the immunosuppression seen in tuberculosis as well as

  13. 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.

  14. First insight into Mycobacterium tuberculosis genetic diversity in Paraguay

    Directory of Open Access Journals (Sweden)

    Barrera Lucia

    2007-08-01

    Full Text Available Abstract Background We present a picture of the biodiversity of Mycobacterium tuberculosis in Paraguay, an inland South American country harboring 5 million inhabitants with a tuberculosis notification rate of 38/100,000. Results A total of 220 strains collected throughout the country in 2003 were classified by spoligotyping into 79 different patterns. Spoligopatterns of 173 strains matched 51 shared international types (SITs already present in an updated version of SpolDB4, the global spoligotype database at Pasteur Institute, Guadeloupe. Our study contributed to the database 13 new SITs and 15 orphan spoligopatterns. Frequencies of major M. tuberculosis spoligotype lineages in our sample were as follows: Latin-American & Mediterranean (LAM 52.3%, Haarlem 18.2%, S clade 9.5%, T superfamily 8.6%, X clade 0.9% and Beijing clade 0.5%. Concordant clustering by IS6110 restriction fragment length polymorphism (RFLP and spoligotyping identified transmission in specific settings such as the Tacumbu jail in Asuncion and aboriginal communities in the Chaco. LAM genotypes were ubiquitous and predominated among both RFLP clusters and new patterns, suggesting ongoing transmission and adaptative evolution in Paraguay. We describe a new and successfully evolving clone of the Haarlem 3 sub-lineage, SIT2643, which is thus far restricted to Paraguay. We confirmed its clonality by RFLP and mycobacterial interspersed repetitive unit (MIRU typing; we named it "Tacumbu" after the jail where it was found to be spreading. One-fifth of the spoligopatterns in our study are rarely or never seen outside Paraguay and one-tenth do not fit within any of the major phylogenetic clades in SpolDB4. Conclusion Lineages currently thriving in Paraguay may reflect local host-pathogen adaptation of strains introduced during past migrations from Europe.

  15. First insight into Mycobacterium tuberculosis genetic diversity in Paraguay

    Science.gov (United States)

    Candia, Norma; Lopez, Beatriz; Zozio, Thierry; Carrivale, Marcela; Diaz, Chyntia; Russomando, Graciela; de Romero, Nilda J; Jara, Juan C; Barrera, Lucia; Rastogi, Nalin; Ritacco, Viviana

    2007-01-01

    Background We present a picture of the biodiversity of Mycobacterium tuberculosis in Paraguay, an inland South American country harboring 5 million inhabitants with a tuberculosis notification rate of 38/100,000. Results A total of 220 strains collected throughout the country in 2003 were classified by spoligotyping into 79 different patterns. Spoligopatterns of 173 strains matched 51 shared international types (SITs) already present in an updated version of SpolDB4, the global spoligotype database at Pasteur Institute, Guadeloupe. Our study contributed to the database 13 new SITs and 15 orphan spoligopatterns. Frequencies of major M. tuberculosis spoligotype lineages in our sample were as follows: Latin-American & Mediterranean (LAM) 52.3%, Haarlem 18.2%, S clade 9.5%, T superfamily 8.6%, X clade 0.9% and Beijing clade 0.5%. Concordant clustering by IS6110 restriction fragment length polymorphism (RFLP) and spoligotyping identified transmission in specific settings such as the Tacumbu jail in Asuncion and aboriginal communities in the Chaco. LAM genotypes were ubiquitous and predominated among both RFLP clusters and new patterns, suggesting ongoing transmission and adaptative evolution in Paraguay. We describe a new and successfully evolving clone of the Haarlem 3 sub-lineage, SIT2643, which is thus far restricted to Paraguay. We confirmed its clonality by RFLP and mycobacterial interspersed repetitive unit (MIRU) typing; we named it "Tacumbu" after the jail where it was found to be spreading. One-fifth of the spoligopatterns in our study are rarely or never seen outside Paraguay and one-tenth do not fit within any of the major phylogenetic clades in SpolDB4. Conclusion Lineages currently thriving in Paraguay may reflect local host-pathogen adaptation of strains introduced during past migrations from Europe. PMID:17686181

  16. Pyrosequencing identification of Mycobacterium tuberculosis W-Beijing

    Directory of Open Access Journals (Sweden)

    Drancourt Michel

    2009-12-01

    Full Text Available Abstract Background The worldwide expanding Mycobacterium tuberculosis W-Beijing family is associated with treatment failure and relapse. Its identification currently relies on spoligotyping and conventional sequencing. We developed pyrosequencing as an alternative method for its identification. Findings Pyrosequencing found a G/A substitution in the Rv0927c-pstS3 intergenic spacer and a RD105 deletion, identifying 8/104 M. tuberculosis isolates as W-Beijing isolates. In addition, pyrosequencing found a previously unreported TGC deletion in the Rv0927c gene of W-Beijing isolates. Total concordance was found between the pyrosequencing data and conventional sequencing, as well as reference molecular identification. Multispacer Sequence Typing assigned the W-Beijing isolates to the Asian lineage and the 96 non-W-Beijing isolates to the Euro-American lineage (P -5. The W-Beijing isolates were all susceptible to streptomycin, rifampin, isoniazid, ethambutol, and pyrazinamide; no resistance-associated mutations were detected in these eight W-Beijing isolates. There were no statistically significant differences in the antibiotic susceptibility of W-Beijing and non-W-Beijing isolates (p = 0.2, X2 test. Pyrosequencing correctly identified M. tuberculosis organisms in 26/26 sputum specimens exhibiting acid-fast bacilli. Pyrosequencing results were obtained within four hours, incurring an estimated cost of 1.86 €/test. Conclusion Pyrosequencing of the Rv0927c gene and adjacent intergenic spacer is an efficient, low-cost technique for the rapid identification of W-Beijing isolates.

  17. Assessment of trends of ofloxacin resistance in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    J S Verma

    2011-01-01

    Full Text Available Purpose: Ofloxacin (OFX is one of the potent fluoroquinolone (FQ recommended to treat MDR-TB. Over a decade, the preexposure of this drug for the treatment of other bacterial infections has resulted in acquisition of FQ resistance among Mycobacterium tuberculosis strains. Considering this possibility, a study was undertaken in a tertiary care center in the capital city (India to assess the drug resistance trends of OFX among susceptible and multidrug resistant (MDR strains of M. tuberculosis. Materials and Methods: A total of 102 M. tuberculosis isolates (47 susceptible to first-line drugs and 55 MDR isolates were screened for susceptibility testing of OFX with a critical concentration of 2 μg/ml by Lowenstein Jensen (LJ proportion method. Results: The results showed 40 (85.1% isolates among 47 susceptible isolates and 34 (61.8% isolates among 55 MDR isolates, were found to be susceptible to OFX. Fisher′s exact test showed significant P-value (0.0136 demonstrating 1.377 fold (95% confidence interval increased risk to become resistant to OFX than susceptible isolates. These finding shows decreased OFX susceptibility is not only limited to MDR isolates but also increasingly seen in susceptible strains as a result of drug abuse. Conclusions: Our finding were not alarming, but highlights the general risk of acquiring resistance to OFX, jeopardizing the potential for these drugs to be used as second-line anti-TB agents in the management of drug-resistant TB and creating incurable TB strains .

  18. Optimising Mycobacterium tuberculosis detection in resource limited settings.

    Science.gov (United States)

    Alfred, Nwofor; Lovette, Lawson; Aliyu, Gambo; Olusegun, Obasanya; Meshak, Panwal; Jilang, Tunkat; Iwakun, Mosunmola; Nnamdi, Emenyonu; Olubunmi, Onuoha; Dakum, Patrick; Abimiku, Alash'le

    2014-03-03

    The light-emitting diode (LED) fluorescence microscopy has made acid-fast bacilli (AFB) detection faster and efficient although its optimal performance in resource-limited settings is still being studied. We assessed the optimal performances of light and fluorescence microscopy in routine conditions of a resource-limited setting and evaluated the digestion time for sputum samples for maximum yield of positive cultures. Cross-sectional study. Facility-based involving samples of routine patients receiving tuberculosis treatment and care from the main tuberculosis case referral centre in northern Nigeria. The study included 450 sputum samples from 150 new patients with clinical diagnosis of pulmonary tuberculosis. The 450 samples were pooled into 150 specimens, examined independently with mercury vapour lamp (FM), LED CysCope (CY) and Primo Star iLED (PiLED) fluorescence microscopies, and with the Ziehl-Neelsen (ZN) microscopy to assess the performance of each technique compared with liquid culture. The cultured specimens were decontaminated with BD Mycoprep (4% NaOH-1% NLAC and 2.9% sodium citrate) for 10, 15 and 20 min before incubation in Mycobacterium growth incubator tube (MGIT) system and growth examined for acid-fast bacilli (AFB). Of the 150 specimens examined by direct microscopy: 44 (29%), 60 (40%), 49 (33%) and 64 (43%) were AFB positive by ZN, FM, CY and iLED microscopy, respectively. Digestion of sputum samples for 10, 15 and 20 min yielded mycobacterial growth in 72 (48%), 81 (54%) and 68 (45%) of the digested samples, respectively, after incubation in the MGIT system. In routine laboratory conditions of a resource-limited setting, our study has demonstrated the superiority of fluorescence microscopy over the conventional ZN technique. Digestion of sputum samples for 15 min yielded more positive cultures.

  19. The structure of a resuscitation-promoting factor domain from Mycobacterium tuberculosis shows homology to lysozymes

    OpenAIRE

    Cohen Gonsaud, M.; Barthe, P.; Bagneris, Claire; Henderson, B.; Ward, J.M.; Roumestand, C.; Keep, Nicholas H.

    2005-01-01

    Resuscitation-promoting factor (RPF) proteins reactivate stationary-phase cultures of (G+C)-rich Gram-positive bacteria including the causative agent of tuberculosis, Mycobacterium tuberculosis. We report the solution structure of the RPF domain from M. tuberculosis Rv1009 (RpfB) solved by heteronuclear multidimensional NMR. Structural homology with various glycoside hydrolases suggested that RpfB cleaved oligosaccharides. Biochemical studies indicate that a conserved active site glutamate is...

  20. Structural insights into the quinolone resistance mechanism of Mycobacterium tuberculosis DNA gyrase.

    OpenAIRE

    Piton , Jérémie; Petrella , Stéphanie; Delarue , Marc; André-Leroux , Gwénaëlle; Jarlier , Vincent; Aubry , Alexandra; Mayer , Claudine

    2010-01-01

    International audience; Mycobacterium tuberculosis DNA gyrase, an indispensable nanomachine involved in the regulation of DNA topology, is the only type II topoisomerase present in this organism and is hence the sole target for quinolone action, a crucial drug active against multidrug-resistant tuberculosis. To understand at an atomic level the quinolone resistance mechanism, which emerges in extensively drug resistant tuberculosis, we performed combined functional, biophysical and structural...

  1. Potassium availability triggers Mycobacterium tuberculosis transition to, and resuscitation from, non-culturable (dormant) states

    OpenAIRE

    Salina, Elena G.; Waddell, Simon J.; Hoffmann, Nadine; Rosenkrands, Ida; Butcher, Philip D.; Kaprelyants, Arseny S.

    2014-01-01

    Dormancy in non-sporulating bacteria is an interesting and underexplored phenomenon with significant medical implications. In particular, latent tuberculosis may result from the maintenance of Mycobacterium tuberculosis bacilli in non-replicating states in infected individuals. Uniquely, growth of M. tuberculosis in aerobic conditions in potassium-deficient media resulted in the generation of bacilli that were non-culturable (NC) on solid media but detectable in liquid media. These bacilli we...

  2. Mycobacterium tuberculosis Mce2E suppresses the macrophage innate immune response and promotes epithelial cell proliferation.

    Science.gov (United States)

    Qiang, Lihua; Wang, Jing; Zhang, Yong; Ge, Pupu; Chai, Qiyao; Li, Bingxi; Shi, Yi; Zhang, Lingqiang; Gao, George Fu; Liu, Cui Hua

    2018-03-23

    The intracellular pathogen Mycobacterium tuberculosis (Mtb) can survive in the host and cause disease by interfering with a variety of cellular functions. The mammalian cell entry 2 (mce2) operon of Mtb has been shown to contribute to tuberculosis pathogenicity. However, little is known about the regulatory roles of Mtb Mce2 family proteins towards host cellular functions. Here we show that the Mce2 family protein Mce2E suppressed the macrophage innate immune response and promoted epithelial cell proliferation. Mce2E inhibited activation of the extracellular signal-regulated kinase (ERK) and Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) signaling pathways in a non-canonical D motif (a MAPK-docking motif)-dependent manner, leading to reduced expression of TNF and IL-6 in macrophages. Furthermore, Mce2E promoted proliferation of human lung epithelium-derived lung adenoma A549 cells by inhibiting K48-linked polyubiquitination of eEF1A1 in a β strand region-dependent manner. In summary, Mce2E is a novel multifunctional Mtb virulence factor that regulates host cellular functions in a niche-dependent manner. Our data suggest a potential novel target for TB therapy.

  3. The development, evaluation and performance of molecular diagnostics for detection of Mycobacterium tuberculosis.

    Science.gov (United States)

    Bates, Matthew; Zumla, Alimuddin

    2016-01-01

    The unique pathogenesis of tuberculosis (TB) poses several barriers to the development of accurate diagnostics: a) the establishment of life-long latency by Mycobacterium tuberculosis (M.tb) after primary infection confounds the development of classical antibody or antigen based assays; b) our poor understanding of the molecular pathways that influence progression from latent to active disease; c) the intracellular nature of M.tb infection in tissues means that M.tb and/or its components, are not readily detectable in peripheral specimens; and d) the variable presence of M.tb bacilli in specimens from patients with extrapulmonary TB or children. The literature on the current portfolio of molecular diagnostics tests for TB is reviewed here and the developmental pipeline is summarized. Also reviewed are data from recently published operational research on the GeneXpert MTB/RIF assay and discussed are the lessons that can be taken forward for the design of studies to evaluate the impact of TB diagnostics.

  4. Tuberculosis in Goats and Sheep in Afar Pastoral Region of Ethiopia and Isolation of Mycobacterium tuberculosis from Goat

    Directory of Open Access Journals (Sweden)

    Gezahegne Mamo Kassa

    2012-01-01

    epidemiology of tuberculosis in goats and sheep using comparative intradermal tuberculin skin test, postmortem examination, mycobacteriological culture and molecular typing methods. The overall animal prevalence of TB in small ruminants was 0.5% (95% CI: 0.2%–0.7% at ≥4 mm and 3.8% (95% CI: 3%–4.7% at cutoff ≥2 mm. The herd prevalence was 20% (95% CI: 12–28% and 47% (95% CI: 37–56% at ≥4 mm and ≥2 mm cut-off points, respectively. The overall animal prevalence of Mycobacterium avium complex infection was 2.8% (95% CI: 2.1–3.5% and 6.8% (95% CI: 5.8–7.9% at ≥4 mm and ≥2 mm cut-off points, respectively. Mycobacteriological culture and molecular characterization of isolates from tissue lesions of tuberculin reactor goats resulted in isolation of Mycobacterium tuberculosis (SIT149 and non-tuberculosis mycobacteria as causative agents of tuberculosis and tuberculosis-like diseases in goats, respectively. The isolation of Mycobacterium tuberculosis in goat suggests a potential transmission of the causative agent from human and warrants further investigation in the role of small ruminants in epidemiology of human tuberculosis in the region.

  5. 2-(Quinolin-4-yloxy)acetamides Are Active against Drug-Susceptible and Drug-Resistant Mycobacterium tuberculosis Strains.

    Science.gov (United States)

    Pissinate, Kenia; Villela, Anne Drumond; Rodrigues-Junior, Valnês; Giacobbo, Bruno Couto; Grams, Estêvão Silveira; Abbadi, Bruno Lopes; Trindade, Rogério Valim; Roesler Nery, Laura; Bonan, Carla Denise; Back, Davi Fernando; Campos, Maria Martha; Basso, Luiz Augusto; Santos, Diógenes Santiago; Machado, Pablo

    2016-03-10

    2-(Quinolin-4-yloxy)acetamides have been described as potent in vitro inhibitors of Mycobacterium tuberculosis growth. Herein, additional chemical modifications of lead compounds were carried out, yielding highly potent antitubercular agents with minimum inhibitory concentration (MIC) values as low as 0.05 μM. Further, the synthesized compounds were active against drug-resistant strains and were devoid of apparent toxicity to Vero and HaCat cells (IC50s ≥ 20 μM). In addition, the 2-(quinolin-4-yloxy)acetamides showed intracellular activity against the bacilli in infected macrophages with action similar to rifampin, low risk of drug-drug interactions, and no sign of cardiac toxicity in zebrafish (Danio rerio) at 1 and 5 μM. Therefore, these data indicate that this class of compounds may furnish candidates for future development to, hopefully, provide drug alternatives for tuberculosis treatment.

  6. Putative in vitro expressed gene fragments unique to Mycobacterium avium subspecies para tuberculosis

    DEFF Research Database (Denmark)

    Nielsen, Kirstine Klitgaard; Ahrens, Peter

    2002-01-01

    By a suppression subtractive hybridization based method, nine novel Mycobacterium avium subsp. para tuberculosis (M. para tuberculosis) fragments of between 318 and 596 bp have been identified and characterized. Database search revealed little or no similarity with other mycobacteria. The uniquen......By a suppression subtractive hybridization based method, nine novel Mycobacterium avium subsp. para tuberculosis (M. para tuberculosis) fragments of between 318 and 596 bp have been identified and characterized. Database search revealed little or no similarity with other mycobacteria....... The uniqueness and diagnostic potential of seven of these fragments in relation to M. paratuberculosis closest relative Mycobacterium avium subsp. avium (M. avium) was confirmed by species-specific PCR and Southern blot. Furthermore, RT-PCR indicated that eight of the nine fragments originate from areas...

  7. 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.

  8. Mycobacterium tuberculosis inhibits macrophage responses to IFN-gamma through myeloid differentiation factor 88-dependent and -independent mechanisms.

    Science.gov (United States)

    Fortune, Sarah M; Solache, Alejandra; Jaeger, Alejandra; Hill, Preston J; Belisle, John T; Bloom, Barry R; Rubin, Eric J; Ernst, Joel D

    2004-05-15

    Mycobacterium tuberculosis overcomes macrophage bactericidal activities and persists intracellularly. One mechanism by which M. tuberculosis avoids macrophage killing might be through inhibition of IFN-gamma-mediated signaling. In this study we provide evidence that at least two distinct components of M. tuberculosis, the 19-kDa lipoprotein and cell wall peptidoglycan (contained in the mycolylarabinogalactan peptidoglycan (mAGP) complex), inhibit macrophage responses to IFN-gamma at a transcriptional level. Moreover, these components engage distinct proximal signaling pathways to inhibit responses to IFN-gamma: the 19-kDa lipoprotein inhibits IFN-gamma signaling in a Toll-like receptor (TLR)2-dependent and myeloid differentiation factor 88-dependent fashion whereas mAGP inhibits independently of TLR2, TLR4, and myeloid differentiation factor 88. In addition to inhibiting the induction of specific IFN-gamma responsive genes, the 19-kDa lipoprotein and mAGP inhibit the ability of IFN-gamma to activate murine macrophages to kill virulent M. tuberculosis without inhibiting production of NO. These results imply that inhibition of macrophage responses to IFN-gamma may contribute to the inability of an apparently effective immune response to eradicate M. tuberculosis.

  9. 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

  10. New insights into the SAR and drug combination synergy of 2-(quinolin-4-yloxy)acetamides against Mycobacterium tuberculosis.

    Science.gov (United States)

    Giacobbo, Bruno Couto; Pissinate, Kenia; Rodrigues-Junior, Valnês; Villela, Anne Drumond; Grams, Estêvão Silveira; Abbadi, Bruno Lopes; Subtil, Fernanda Teixeira; Sperotto, Nathalia; Trindade, Rogério Valim; Back, Davi Fernando; Campos, Maria Martha; Basso, Luiz Augusto; Machado, Pablo; Santos, Diógenes Santiago

    2017-01-27

    2-(Quinolin-4-yloxy)acetamides have been described as potent and selective in vitro inhibitors of Mycobacterium tuberculosis (Mtb) growth. Herein, a new series of optimized compounds were found to demonstrate highly potent antitubercular activity, with minimum inhibitory concentration (MIC) values against drug-susceptible and drug-resistant Mycobacterium tuberculosis strains in the submicromolar range. Furthermore, the most active compounds had no apparent toxicity to mammalian cells, and they showed intracellular activities similar to those of isoniazid and rifampin in a macrophage model of Mtb infection. Use of the checkerboard method to investigate the association profiles of lead compounds with first- and second-line antituberculosis drugs showed that 2-(quinolin-4-yloxy)acetamides have a synergistic effect with rifampin. Ultimately, the good permeability, moderate rates of metabolism and low risk of drug-drug interactions displayed by some of the synthesized compounds indicate that 2-(quinolin-4-yloxy)acetamides may yield candidates to use in the development of novel alternative therapeutics for tuberculosis treatment. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Bacterial subversion of cAMP signalling inhibits cathelicidin expression, which is required for innate resistance to Mycobacterium tuberculosis.

    Science.gov (United States)

    Gupta, Shashank; Winglee, Kathryn; Gallo, Richard; Bishai, William R

    2017-05-01

    Antimicrobial peptides such as cathelicidins are important components of innate immune defence against inhaled microorganisms, and have shown antimicrobial activity against Mycobacterium tuberculosis in in vitro models. Despite this, little is known about the regulation and expression of cathelicidin during tuberculosis in vivo. We sought to determine whether the cathelicidin-related antimicrobial peptide gene (Cramp), the murine functional homologue of the human cathelicidin gene (CAMP or LL-37), is required for regulation of protective immunity during M. tuberculosis infection in vivo. We used Cramp -/- mice in a validated model of pulmonary tuberculosis, and conducted cell-based assays with macrophages from these mice. We evaluated the in vivo susceptibility of Cramp -/- mice to infection, and also dissected various pro-inflammatory immune responses against M. tuberculosis. We observed increased susceptibility of Cramp -/- mice to M. tuberculosis as compared with wild-type mice. Macrophages from Cramp -/- mice were unable to control M. tuberculosis growth in an in vitro infection model, were deficient in intracellular calcium influx, and were defective in stimulating T cells. Additionally, CD4 + and CD8 + T cells from Cramp -/- mice produced less interferon-β upon stimulation. Furthermore, bacterial-derived cAMP modulated cathelicidin expression in macrophages. Our results demonstrate that cathelicidin is required for innate resistance to M. tuberculosis in a relevant animal model and is a key mediator in regulation of the levels of pro-inflammatory cytokines by calcium and cyclic nucleotides. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  13. System-wide coordinates of higher order functions in host-pathogen environment upon Mycobacterium tuberculosis infection.

    Science.gov (United States)

    Parvati Sai Arun, P V; Miryala, Sravan Kumar; Rana, Aarti; Kurukuti, Sreenivasulu; Akhter, Yusuf; Yellaboina, Sailu

    2018-03-22

    Molecular signatures and their interactions behind the successful establishment of infection of Mycobacterium tuberculosis (Mtb) inside macrophage are largely unknown. In this work, we present an inter-system scale atlas of the gene expression signatures, their interactions and higher order gene functions of macrophage-Mtb environment at the time of infection. We have carried out large-scale meta-analysis of previously published gene expression microarray studies andhave identified a ranked list of differentially expressed genes and their higher order functions in intracellular Mtb as well as the infected macrophage. Comparative analysis of gene expression signatures of intracellular Mtb with the in vitro dormant Mtb at different hypoxic and oxidative stress conditions led to the identification of the large number of Mtb functional groups, namely operons, regulons and pathways that were common and unique to the intracellular environment and dormancy state. Some of the functions that are specific to intracellular Mtb are cholesterol degradation and biosynthesis of immunomodulatory phenolic compounds. The molecular signatures we have identified to be involved in adaptation to different stress conditions in macrophage environment may be critical for designing therapeutic interventions against tuberculosis. And, our approach may be broadly applicable for investigating other host-pathogen interactions.

  14. Tuberculosis por Mycobacterium bovis en una mujer con SIDA Mycobacterium bovis tuberculosis in a female patient with AIDS

    Directory of Open Access Journals (Sweden)

    M. Valerga

    2005-06-01

    Full Text Available Mycobacterium bovis, también llamado bacilo de la tuberculosis (TBC bovina, fue en otras épocas el principal agente etiológico de la TBC en países industrializados. Actualmente, los casos humanos se han vuelto poco frecuentes, excepto en aquellas naciones donde la enfermedad es aún endémica en el ganado. En pacientes inmunodeficientes, suele presentarse como una enfermedad sistémica. Presentamos el caso de una mujer con SIDA y TBC diseminada por M. bovis. La micobacteria aislada resultó ser resistente a la rifampicina y a la pirazinamida. Se realizó tratamiento con isoniacida, etambutol y ofloxacina con buena respuesta clínica. Este caso resultó ser el primer aislamiento de M. bovis en una paciente con SIDA, en el Hospital Muñiz.M. bovis, the agent of bovine tuberculosis, was in other times, the main ethiological agent of tuberculosis (TBC in industrialized countries. At the moment, the human cases have become not very frequent, except in those countries where the illness is even endemic. In patients with immunodeficiency syndrome, it usually presents as a systemic illness. We present the case of a woman with AIDS and disseminated TBC caused by M. bovis. The isolated micobacteria turned out to be resistant to rifampin and pyrazinamide. She was treated with isoniazid, ethambutol and ofloxacin with good clinical evolution. This case turned out to be the first isolation of M. bovis in a patient with AIDS, in Muñiz hospital.

  15. 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)

  16. Detection of Mycobacterium tuberculosis and Mycobacterium avium Complexes by Real-Time PCR in Bovine Milk from Brazilian Dairy Farms.

    Science.gov (United States)

    Bezerra, André Vinícius Andrade; Dos Reis, Emily Marques; Rodrigues, Rogério Oliveira; Cenci, Alexander; Cerva, Cristine; Mayer, Fabiana Quoos

    2015-05-01

    Foodborne diseases are a public health problem worldwide. The consumption of contaminated raw milk has been recognized as a major cause of transmission of bovine tuberculosis to humans. Other mycobacteria that may be present in raw milk and may cause diseases are those belonging to the Mycobacterium avium complex. In this study, molecular biology tools were applied to investigate raw milk contamination with Mycobacterium spp. in family dairy farms from Rio Grande do Sul, southern Brazil. Furthermore, different variables related to the source of the milk, herd characteristics, and management were evaluated for their effect on milk contamination. Five hundred and two samples were analyzed, of which 354 were from the Northwest region (102 farms with samples from 93 bulk tanks and 261 animals) and 148 from the South region of the state (22 farms with samples from 23 bulk tanks and 125 animals). Among them, 10 (1.99%) and 7 (1.39%) were positive for Mycobacterium tuberculosis (9 confirmed as Mycobacterium bovis) and M. avium complexes, respectively. There was no difference in the frequencies of positive samples between the regions or the sample sources. Of the positive samples, 4 were collected from a bulk tank (1 positive for M. avium and 3 for M. tuberculosis). Moreover, 1 sample was positive concomitantly for M. tuberculosis and M. avium complexes. On risk analysis, no variable was associated with raw milk contamination by M. tuberculosis complex species. However, washing the udders of all animals and drying them with paper towels were weakly classified as risk factors for M. avium contamination. Positive samples were obtained from both animals and bulk tanks, which emphasizes the importance of tuberculosis control programs and provides evidence that milk monitoring can be used as a control practice. Moreover, the findings of this study reinforce the need for awareness of the problems of raw milk consumption among the general population.

  17. Ubiquilin 1 Promotes IFN-γ-Induced Xenophagy of Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Erik T Sakowski

    2015-07-01

    Full Text Available The success of Mycobacterium tuberculosis (Mtb as a pathogen rests upon its ability to grow intracellularly in macrophages. Interferon-gamma (IFN-γ is critical in host defense against Mtb and stimulates macrophage clearance of Mtb through an autophagy pathway. Here we show that the host protein ubiquilin 1 (UBQLN1 promotes IFN-γ-mediated autophagic clearance of Mtb. Ubiquilin family members have previously been shown to recognize proteins that aggregate in neurodegenerative disorders. We find that UBQLN1 can interact with Mtb surface proteins and associates with the bacilli in vitro. In IFN-γ activated macrophages, UBQLN1 co-localizes with Mtb and promotes the anti-mycobacterial activity of IFN-γ. The association of UBQLN1 with Mtb depends upon the secreted bacterial protein, EsxA, which is involved in permeabilizing host phagosomes. In autophagy-deficient macrophages, UBQLN1 accumulates around Mtb, consistent with the idea that it marks bacilli that traffic through the autophagy pathway. Moreover, UBQLN1 promotes ubiquitin, p62, and LC3 accumulation around Mtb, acting independently of the E3 ligase parkin. In summary, we propose a model in which UBQLN1 recognizes Mtb and in turn recruits the autophagy machinery thereby promoting intracellular control of Mtb. Thus, polymorphisms in ubiquilins, which are known to influence susceptibility to neurodegenerative illnesses, might also play a role in host defense against Mtb.

  18. Contrasting transcriptional responses of a virulent and an attenuated strain of Mycobacterium tuberculosis infecting macrophages.

    Directory of Open Access Journals (Sweden)

    Alice H Li

    2010-06-01

    Full Text Available H37Rv and H37Ra are well-described laboratory strains of Mycobacterium tuberculosis derived from the same parental strain, H37, that show dramatically different pathogenic phenotypes.In this study, the transcriptomes of the two strains during axenic growth in broth and during intracellular growth within murine bone-marrow macrophages were compared by whole genome expression profiling. We identified and compared adaptations of either strain upon encountering an intracellular environment, and also contrasted the transcriptomes of the two strains while inside macrophages. In the former comparison, both strains induced genes that would facilitate intracellular survival including those involved in mycobactin synthesis and fatty acid metabolism. However, this response was stronger and more extensive for H37Rv than for H37Ra. This was manifested as the differential expression of a greater number of genes and an increased magnitude of expression for these genes in H37Rv. In comparing intracellular transcriptional signatures, fifty genes were found to be differentially expressed between the strains. Of these fifty, twelve were under control of the PhoPR regulon. Further differences between strains included genes whose products were members of the ESAT-6 family of proteins, or were associated with their secretion.Along with the recent identification of single nucleotide polymorphisms in H37Ra when compared to H37Rv, our demonstration of differential expression of PhoP-regulated and ESX-1 region-related genes during macrophage infection further highlights the significance of these genes in the attenuation of H37Ra.

  19. The Guinea-Bissau Family of Mycobacterium tuberculosis Complex Revisited

    Science.gov (United States)

    Groenheit, Ramona; Ghebremichael, Solomon; Svensson, Jenny; Rabna, Paulo; Colombatti, Raffaella; Riccardi, Fabio; Couvin, David; Hill, Véronique; Rastogi, Nalin; Koivula, Tuija; Källenius, Gunilla

    2011-01-01

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

  20. The Guinea-Bissau family of Mycobacterium tuberculosis complex revisited.

    Directory of Open Access Journals (Sweden)

    Ramona Groenheit

    2011-04-01

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

  1. 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.

  2. [Usefulness of the variable numbers of tandem repeats (VNTR) analysis for complex infections of Mycobacterium avium and Mycobacterium intracellulare].

    Science.gov (United States)

    Tsunematsu, Noriko; Goto, Mieko; Saiki, Yumiko; Baba, Michiko; Udagawa, Tadashi; Kazumi, Yuko

    2008-09-01

    The bacilli which were isolated from a patient suspected of the mixed infections with Mycobacterium avium and Mycobacterium intracellulare, were analyzed. The genotypes of M. avium in the sedimented fractions of treated sputum and in some colonies isolated from Ogawa medium were compared by the Variable Numbers of Tandem Repeats (VNTR). A woman, aged 57. Mycobacterial species isolated from some colonies by culture in 2004 and 2006 and from the treated sputum in 2006, were determined by DNA sequencing analysis of the 16S rRNA gene. Also, by using VNTR, the genotype of mycobacteria was analyzed. [Results] (1) The colony isolated from Ogawa medium in 2004 was monoclonal M. avium. (2) By VNTR analyses of specimens in 2006, multiple acid-fast bacteria were found in the sputum sediment and in isolated bacteria from Ogawa medium. (3) By analyses of 16S rRNA DNA sequence, M. avium and M. intracellulare were found in the colonies isolated from the sputum sediment and the Ogawa medium in 2006. (4) The same VNTR patterns were obtained in M. avium in 2004 and 2006 when single colony was analyzed. (5) From the showerhead and culvert of the bathroom in the patient's house, M. avium was not detected. By VNTR analyses, it was considered that the mixed infections of M. avium and M. intracellulare had been generated during treatment in this case. Therefore, in the case of suspected complex infection, VNTR analysis would be a useful genotyping method in M. avium complex infection.

  3. Implication of the RD(Rio) Mycobacterium tuberculosis sublineage in multidrug resistant tuberculosis in Portugal.

    Science.gov (United States)

    David, Susana; Duarte, Elsa L; Leite, Clarice Queico Fugimura; Ribeiro, João-Nuno; Maio, José-Nuno; Paixão, Eleonora; Portugal, Clara; Sancho, Luísa; Germano de Sousa, José

    2012-10-01

    Multidrug and extensively drug resistant Mycobacterium tuberculosis are a threat to tuberculosis control programs. Genotyping methods, such as spoligotyping and MIRU-VNTR typing (Mycobacterial Interspersed Repetitive Units), are useful in monitoring potentially epidemic strains and estimating strain phylogenetic lineages and/or genotypic families. M. tuberculosis Latin American Mediterranean (LAM) family is a major worldwide contributor to tuberculosis (TB). LAM specific molecular markers, Ag85C(103) single nucleotide polymorphism (SNP) and RD(Rio) long-sequence polymorphism (LSP), were used to characterize spoligotype signatures from 859 patient isolates from Portugal. LAM strains were found responsible for 57.7% of all tuberculosis cases. Strains with the RD(Rio) deletion (referred to as RD(Rio)) were estimated to represent 1/3 of all the strains and over 60% of the multidrug resistant (MDR) strains. The major spoligotype signature SIT20 belonging to the LAM1 RD(Rio) sublineage, represented close to 1/5th of all the strains, over 20% of which were MDR. Analysis of published datasets according to stipulated 12loci MIRU-VNTR RD(Rio) signatures revealed that 96.3% (129/134) of MDR and extensively drug resistant (XDR) clusters were RD(Rio). This is the first report associating the LAM RD(Rio) sublineage with MDR. These results are an important contribution to the monitoring of these strains with heightened transmission for future endeavors to arrest MDR-TB and XDR-TB. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Rosales, Senia; Pineda-García, Lelany; Ghebremichael, Solomon; Rastogi, Nalin; Hoffner, Sven E

    2010-08-03

    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. 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. The findings obtained in this study show that tuberculosis transmission in Honduras is due to modern M. tuberculosis lineages with high level of biodiversity.

  5. 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.

  6. 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

  7. 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)

  8. Mycobacterium tuberculosis transcriptional adaptation, growth arrest and dormancy phenotype development is triggered by vitamin C.

    Science.gov (United States)

    Taneja, Neetu Kumra; Dhingra, Sakshi; Mittal, Aditya; Naresh, Mohit; Tyagi, Jaya Sivaswami

    2010-05-27

    Tubercle bacilli are thought to persist in a dormant state during latent tuberculosis (TB) infection. Although little is known about the host factors that induce and maintain Mycobacterium tuberculosis (M. tb) within latent lesions, O(2) depletion, nutrient limitation and acidification are some of the stresses implicated in bacterial dormancy development/growth arrest. Adaptation to hypoxia and exposure to NO/CO is implemented through the DevRS/DosT two-component system which induces the dormancy regulon. Here we show that vitamin C (ascorbic acid/AA) can serve as an additional signal to induce the DevR regulon. Physiological levels of AA scavenge O(2) and rapidly induce the DevR regulon at an estimated O(2) saturation of vitamin C induces the expression of selected genes previously shown to be responsive to low pH and oxidative stress, triggers bacterial growth arrest and promotes dormancy phenotype development in M. tb grown in axenic culture and intracellularly in THP-1 cells. Vitamin C mimics multiple intracellular stresses and has wide-ranging regulatory effects on gene expression and physiology of M. tb which leads to growth arrest and a 'dormant' drug-tolerant phenotype, but in a manner independent of the DevRS/DosT system. The 'AA-dormancy infection model' offers a potential alternative to other models of non-replicating persistence of M. tb and may be useful for investigating host-'dormant' M. tb interactions. Our findings offer a new perspective on the role of nutritional factors in TB and suggest a possible role for vitamin C in TB.

  9. 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...

  10. SUSCEPTIBILITY OF RIFAMPICIN-ISONIAZID RESISTANT MYCOBACTERIUM TUBERCULOSIS ISOLATES AGAINST LEVOFLOXACIN

    Directory of Open Access Journals (Sweden)

    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.

  11. Clinical significance and epidemiologic analyses of Mycobacterium avium and Mycobacterium intracellulare lung disease from post-marketing surveillance.

    Science.gov (United States)

    Suzuki, Katsuhiro; Kurashima, Atsuyuki; Tatsuno, Kinji; Kadota, Jun-Ichi

    2018-01-01

    In Japan, nontuberculous mycobacterial lung disease is mostly attributable to Mycobacterium avium complex (MAC), i.e., M. avium or M. intracellulare. However, clinical features of the disease caused by these two pathogens have not been studied sufficiently yet. A post-marketing survey of clarithromycin was performed at 130 facilities across Japan. The data on patients with M. avium infection and patients with M. intracellulare infection were selected from this survey for comparison of background variables and clinical features of the two pathogens. Among the patients analyzed (n = 368), 67.4% had M. avium infection and 32.6% had M. intracellulare infection. Stratified analysis revealed no significant differences between the ratio of the two pathogens based on gender, disease type, complication, past medical history, or smoking history. However, the percentage of patients with M. intracellulare infection was significantly higher among those with underlying lung disease than among those without lung disease (p = 0.0217). The percentage of patients with M. intracellulare infection rose significantly with age (p = 0.0296). This age-related change was more significant in women (p = 0.0018). When district-wise analysis was performed for Japan, the percentage of M. intracellulare infection was higher in the Chugoku/Shikoku and Kyushu districts whereas the percentage of M. avium infection was higher in the other districts. This survey revealed some differences in the clinical and epidemiologic features of M. avium and M. intracellulare infection. The significant predominance of M. avium infection among relatively young women is suggestive of an increase in the M. avium/M. intracellulare infection ratio among women in the future. Copyright © 2017 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.

  12. 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.

  13. 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

  14. 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.

  15. Prevalence of drug resistant Mycobacterium tuberculosis among children in China.

    Science.gov (United States)

    Jiao, Wei-wei; Liu, Zhi-guang; Han, Rui; Zhao, Xiu-qin; Dong, Fang; Dong, Hai-yan; Huang, Hai-rong; Li, Qin-jing; Lin, Nan; Song, Wen-qi; Wan, Kang-lin; Shen, A-dong

    2015-05-01

    The available data on the epidemic of drug resistant tuberculosis (TB) among children in China is limited. This study attempted to clarify the drug resistance profiles of clinical strains isolated from children and estimate risk factors related to acquisition of drug resistance. All Mycobacterium tuberculosis strains from children (age children, 159 from adolescents, and 191 from adults) from all over China. Drug susceptibility testing was performed by a proportion method. As a result, the drug resistance and multi-drug resistance (MDR) rates in children were 55% (55/100) and 22% (22/100), respectively. In children with MDR-TB, new cases accounted for 40.9% (9/22). Compared with adults, the drug resistance rates were similar in all subgroups (new cases, previously treated cases and all cases) of children (P > 0.05), except for the lower resistance rate to isoniazid in total cases of children (P = 0.011). Patient related information was included in the MDR-TB association analysis. The treatment history was found to be strongly associated with MDR-TB in all three age groups (P children in China is alarmingly high and similar to that seen in adults. In contrast, in adolescents, the drug resistance rate to most tested drugs was lower than in adults. Primary transmission and inadequate treatment are two equally important factors for the high MDR-TB rate in children. Thus, major efforts in the TB control in children should focus on decreasing the transmission of drug resistant TB and early testing of drug resistance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Deciphering an outbreak of drug-resistant Mycobacterium tuberculosis.

    Science.gov (United States)

    Dahle, Ulf R; Sandven, Per; Heldal, Einar; Mannsaaker, Turid; Caugant, Dominique A

    2003-01-01

    There have been ample warnings that multidrug-resistant (MDR) tuberculosis (TB) will continue to emerge if countries do not strengthen their control of TB. In low-incidence European countries, however, these warnings have been substantiated mainly by outbreaks in association with human immunodeficiency virus (HIV)-positive patients. The aim of this study was to investigate an outbreak of infection with MDR and drug-resistant Mycobacterium tuberculosis that was diagnosed among 20 HIV-negative patients living in Norway. Of these, 19 were immigrants from East Africa and one was an ethnic Norwegian. We wanted to find out if transmission had taken place in Norway or abroad and to identify the genetic basis of drug resistance. The strains were analyzed by IS6110 restriction fragment length polymorphism, antibiotic susceptibility tests, spoligotyping, reverse hybridization to regions of the rpoB gene, and sequencing of the katG gene. Epidemiological links between the patients were mapped, and the strains were compared to those isolated in 36 other countries and regions. All strains were resistant to isoniazid and carried Ala234Gly, Ser315Thr, and Arg463Leu substitutions in the katG gene. Eleven strains were MDR and carried a Ser531Leu substitution in the rpoB gene. MDR was acquired in the index patient after arrival in Norway. Links were found among 14 patients. The strain was imported from Somalia but acquired MDR and was transmitted in Norway. This demonstrated that MDR strains are not necessarily imported from high-incidence countries and can be highly communicable. The outbreak underscores a deficiency in the TB control measures employed in many countries and challenges the adequacy of the policy of screening immigrants for TB only on arrival.

  17. Molecular characterization of Mycobacterium tuberculosis isolates from North Indian patients with extrapulmonary tuberculosis.

    Science.gov (United States)

    Sankar, Manimuthu Mani; Singh, Jitendra; Diana, Selvaraj Cynthiya Angelin; Singh, Sarman

    2013-01-01

    Genotypic studies are important to understand the molecular epidemiology and transmission routes of Mycobacterium tuberculosis. In the first and largest study from India, spoligotyping and 24 loci mycobacterial interspersed repetitive units (MIRU) were performed to find genetic profiles of 125 M. tuberculosis strains isolated from patients with extrapulmonary tuberculosis (EPTB) and their drug susceptibility test was performed using BACTEC-MGIT 960. Spoligotyping results were compared with the world Spoligotyping Database of Institute Pasteur de Guadeloupe (SpolDB4). The spoligotyping results showed that 110 (88%) displayed known patterns while 15 (12%) isolates had no matching database. Predominant spoligotypes belonged to CAS family (57.27%). The largest clade comprised of 38 isolates belonging to the CAS1_DEL lineage. Though there was no significant association between specific mycobacterial lineage and extrapulmonary site, a significantly high (p < 0.001) number of Beijing type isolates (28.6%) were isolated from bone and joint samples as compared to cerebrospinal fluid (5%). There was a significant association between Beijing family isolates and multi-drug-resistance, while all MANU genotypes were pan-drug sensitive. The CAS family lineage was most prevalent genotype in the EPTB cases in our population. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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 Jr, 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 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. PMID:26405286

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

    Directory of Open Access Journals (Sweden)

    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.

  20. LIGAND-BINDING SITES ON THE MYCOBACTERIUM TUBERCULOSIS UREASE

    Directory of Open Access Journals (Sweden)

    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

  1. Probing host pathogen cross-talk by transcriptional profiling of both Mycobacterium tuberculosis and infected human dendritic cells and macrophages.

    Directory of Open Access Journals (Sweden)

    Ludovic Tailleux

    2008-01-01

    Full Text Available Transcriptional profiling using microarrays provides a unique opportunity to decipher host pathogen cross-talk on the global level. Here, for the first time, we have been able to investigate gene expression changes in both Mycobacterium tuberculosis, a major human pathogen, and its human host cells, macrophages and dendritic cells.In addition to common responses, we could identify eukaryotic and microbial transcriptional signatures that are specific to the cell type involved in the infection process. In particular M. tuberculosis shows a marked stress response when inside dendritic cells, which is in accordance with the low permissivity of these specialized phagocytes to the tubercle bacillus and to other pathogens. In contrast, the mycobacterial transcriptome inside macrophages reflects that of replicating bacteria. On the host cell side, differential responses to infection in macrophages and dendritic cells were identified in genes involved in oxidative stress, intracellular vesicle trafficking and phagosome acidification.This study provides the proof of principle that probing the host and the microbe transcriptomes simultaneously is a valuable means to accessing unique information on host pathogen interactions. Our results also underline the extraordinary plasticity of host cell and pathogen responses to infection, and provide a solid framework to further understand the complex mechanisms involved in immunity to M. tuberculosis and in mycobacterial adaptation to different intracellular environments.

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

    Science.gov (United States)

    Philip, Noraini; Rodrigues, Kenneth Francis; William, Timothy; John, Daisy Vanitha

    2016-09-01

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Mycobacterium tuberculosis and Copper: A Newly Appreciated Defense against an Old Foe?

    Science.gov (United States)

    Darwin, K Heran

    2015-07-31

    Several independent studies have recently converged upon the conclusion that the human bacterial pathogen Mycobacterium tuberculosis encounters copper during infections. At least three independently regulated pathways respond to excess copper and are required for the full virulence of M. tuberculosis in animals. In this review, I will discuss the functions of the best-characterized copper-responsive proteins in M. tuberculosis, the potential sources of copper during an infection, and remaining questions about the interface between copper and tuberculosis. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. 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....

  6. Kinetics and inhibition of nicotinamidase from Mycobacterium tuberculosis.

    Science.gov (United States)

    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).

  7. Oligomeric state of hypoxanthine-guanine phosphoribosyltransferase from Mycobacterium tuberculosis.

    Science.gov (United States)

    Eng, Wai Soon; Keough, Dianne T; Hockova, Dana; Winzor, Donald J; Guddat, Luke W

    2017-04-01

    Sedimentation equilibrium and size-exclusion chromatography experiments on Mycobacterium tuberculosis hypoxanthine-guanine phosphoribosyltransferase (MtHGPRT) have established the existence of this enzyme as a reversibly associating mixture of dimeric and tetrameric species in 0.1 M Tris-HCl-0.012 M MgCl 2 , pH 7.4. Displacement of the equilibrium position towards the larger oligomer by phosphate signifies the probable existence of MtHGPRT as a tetramer in the biological environment. These data thus add credibility to the relevance of considering enzyme function in the light of a published tetrameric structure deduced from X-ray crystallography. Failure of 5-phospho-α-d-ribosyl-1-pyrophosphate (PRib-PP) to perturb the dimer-tetramer equilibrium position indicates the equivalence and independence of binding for this substrate (the first to bind in an ordered sequential mechanism) to the two oligomers. By virtue of the displacement of the equilibrium position towards dimer that is affected by removing MgCl 2 from the Tris-HCl buffer, it can be concluded that divalent metal ions, as well as phosphate, can affect the oligomerization. These characteristics of MtHGPRT in solution are correlated with published crystal structures of four enzyme-ligand complexes. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  8. Detecting robust time-delayed regulation in Mycobacterium tuberculosis

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    Rajapakse Jagath C

    2009-12-01

    Full Text Available Abstract Background Time delays are often found in gene regulation though most techniques of building gene regulatory networks are not capable of capturing such phenomena. Here we look at the delays in the DNA repair system of Mycobacterium tuberculosis which is unusually slow in the bacteria. We propose a method based on a skip-chain model to study this phenomena in gene networks. The Viterbi paths of the underlying Markov chains find the most likely regulatory interactions among genes, taking care of very long delays. Using the derived networks, we discuss the delayed regulations and robustness of the DNA damage seen in the bacterium. Results We evaluated our method on time-course gene expressions after DNA damage with Mitocyin C. Several time-delayed interactions were observed with our analysis. The presence of hubs in the networks indicates that a small number of transcriptional factors regulate the rest of the system. We demonstrate the use of priors to overcome over-fitting problem in the generation of networks. We compare our results with the gene networks derived with dynamic Bayesian networks (DBN. Conclusion Different transcription networks are active at different stages, and constant feedback and regulation is maintained throughout the activities of a biological pathway. Skip-chain models are capable of capturing, long distant and the time-delayed regulations. Use of a Dirichlet prior over parameters and Gibbs prior over structure can greatly reduce the over-fitting in the new model.

  9. A robust SNP barcode for typing Mycobacterium tuberculosis complex strains

    KAUST Repository

    Coll, Francesc

    2014-09-01

    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 to classify MTBC strains into distinct lineages and families. Here, we investigate single-nucleotide polymorphisms (SNPs) as robust (stable) markers of genetic variation for phylogenetic analysis. We identify ∼92k SNP across a global collection of 1,601 genomes. The SNP-based phylogeny is consistent with the gold-standard regions of difference (RD) classification system. Of the ∼7k strain-specific SNPs identified, 62 markers are proposed to discriminate known circulating strains. This SNP-based barcode is the first to cover all main lineages, and classifies a greater number of sublineages than current alternatives. It may be used to classify clinical isolates to evaluate tools to control the disease, including therapeutics and vaccines whose effectiveness may vary by strain type. © 2014 Macmillan Publishers Limited.

  10. [Identification of the Mycobacterium tuberculosis Beijing lineage in Ecuador].

    Science.gov (United States)

    Jiménez, Patricia; Calvopiña, Karina; Herrera, Diana; Rojas, Carlos; Pérez-Lago, Laura; Grijalva, Marcelo; Guna, Remedios; García-de Viedma, Darío

    2017-06-01

    Mycobacterium tuberculosis Beijing lineage isolates are considered to be especially virulent, transmissible and prone to acquire resistances. Beijing strains have been reported worldwide, but studies in Latin America are still scarce. The only multinational study performed in the region indicated a heterogeneous distribution for this lineage, which was absent in Chile, Colombia and Ecuador, although further studies found the lineage in Chile and Colombia. To search for the presence of the Beijing lineage in Ecuador, the only country in the region where it remains unreported. We obtained a convenience sample (2006-2012) from two hospitals covering different populations. The isolates were genotyped using 24-MIRU-VNTR. Lineages were assigned by comparing their patterns to those in the MIRU-VNTRplus platform. Isolates belonging to the Beijing lineage were confirmed by allele-specific PCR. We identified the first Beijing isolate in Ecuador in an unexpected epidemiological scenario: A patient was infected in the Andean region, in a population with low mobility and far from the borders of the neighboring countries where Beijing strains had been previously reported. This is the first report of the presence of the Beijing lineage in Ecuador in an unusual epidemiological context that deserves special attention.

  11. Phylogenetic analysis of vitamin B12-related metabolism in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Douglas B. Young

    2015-03-01

    Full Text Available Comparison of genome sequences from clinical isolates of Mycobacterium tuberculosis with phylogenetically-related pathogens Mycobacterium marinum, Mycobacterium kansasii and Mycobacterium leprae reveals diversity amongst genes associated with vitamin B12-related metabolism. Diversity is generated by gene deletion events, differential acquisition of genes by horizontal transfer, and single nucleotide polymorphisms with predicted impact on protein function and transcriptional regulation. Differences in the B12 synthesis pathway, methionine biosynthesis, fatty acid catabolism, and DNA repair and replication are consistent with adaptations to different environmental niches and pathogenic lifestyles. While there is no evidence of further gene acquisition during expansion of the M. tuberculosis complex, the emergence of other forms of genetic diversity provides insights into continuing host-pathogen co-evolution and has the potential to identify novel targets for disease intervention.

  12. [Case of urinary mycobacterium fortuitum in a patient with urinary tract tuberculosis posttreatment].

    Science.gov (United States)

    Maehana, Takeshi; Takahashi, Satoshi; Hirobe, Megumi; Taguchi, Keisuke

    2008-11-01

    A 70-year-old male who complained of urinary frequency and a feeling of incomplete emptying was admitted to our hospital. Imaging findings showed dilation of the left renal pelvis and ureter. He was diagnosed as having urinary tuberculosis because a positive urinary Mycobacterium tuberculosis result was obtained by polymerase chain reaction (PCR). He was treated with a combination of the antituberculosis agents isoniazid, rifampicin, pyrazinamide and ethambutol for six months. The symptoms and pyuria disappeared and M. tuberculosis was negative by PCR; however, Mycobacterium fortuitum was isolated by culture. Due to asymptomatic urinary tract infection by the multidrug resistant M. fortuitum, he was followed up with observation. Currently, he remains unchanged with regard to symptoms and imaging examination. M. fortuitum is a nontubercular mycobacterium, and clinical relevance between urinary tract infection and M. fortuitum has rarely emerged. However, we should be aware that nontubercular mycobacteria such as M. fortuitum can infect the urinary tract, especially in immunocompromised patients.

  13. 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...

  14. Multiple cytokines for the detection of Mycobacterium tuberculosis infection in children with tuberculosis.

    Science.gov (United States)

    Nausch, N; Lundtoft, C; Schulz, G; Henckel, H; Mayatepek, E; Fleischer, B; Marx, F M; Jacobsen, M

    2017-03-01

    Interferon-gamma (IFN-γ) release assays (IGRAs) play an important role in the diagnosis of Mycobacterium tuberculosis infection. However, in children with tuberculosis (TB), some studies have shown increased frequencies of false-negative or indeterminate IGRA results. To analyse the spectrum of different cytokines to improve the diagnostic accuracy of IGRAs in latent tuberculous infection (LTBI) and active TB. We performed multiplex cytokine expression analysis of QuantiFERON® Gold In-Tube supernatants in children with active TB (n = 21) and disease-free contacts with (n = 15) and without LTBI (n = 12), to determine the sensitivity and specificity of the modified tests. Of 21 initial cytokines analysed, IFN-γ and six other candidates (interleukin [IL] 2, inducible protein 10 [IP-10], IL-13, IL-1α, tumour necrosis factor alpha [TNF-α] and granulocyte-macrophage colony-stimulating factor [GM-CSF]) were significantly more elevated in children with TB and those with LTBI than in the non-infected controls. Sensitivity and specificity were similar for IFN-γ and IL-2, but lower for the remaining candidates. Notably, a subset of candidates, including IP-10, showed M. tuberculosis antigen-induced specific expression in non-infected children. None of the candidates showed differences in expression between children with TB and those with LTBI. Our results did not suggest that alternative IGRA cytokines can distinguish between children with active TB and those with LTBI. IFN-γ and IL-2 showed comparable capacity in diagnosing M. tuberculosis infection in our study groups.

  15. Evidence for activation of a respiratory burst in the interaction of human neutrophils with Mycobacterium tuberculosis.

    OpenAIRE

    May, M E; Spagnuolo, P J

    1987-01-01

    We examined the capacity of human neutrophils to develop a respiratory burst, as monitored by superoxide release, in response to interaction with Mycobacterium tuberculosis. Serum-opsonized, heat-killed mycobacteria induced significant release of superoxide from neutrophils after 30 min of exposure, with a maximum release of 34 +/- 1.7 nmol/30 min per 5 X 10(6) neutrophils occurring with a mycobacterium/neutrophil ratio of 40:1. Similar levels of superoxide release were induced by live mycoba...

  16. Innate Immunity Holding the Flanks until Reinforced by Adaptive Immunity against Mycobacterium tuberculosis Infection

    OpenAIRE

    Khan, Nargis; Vidyarthi, Aurobind; Javed, Shifa; Agrewala, Javed N.

    2016-01-01

    T cells play a cardinal role in imparting adaptive immunity against Mycobacterium tuberculosis (Mtb). However, ample time is required before T-cells are able to evoke efficient effector responses in the lung, where the mycobacterium inflicts disease. This delay in T cells priming, which is termed as lag phase, provides sufficient time for Mtb to replicate and establish itself within the host. In contrast, innate immunity efficiently curb the growth of Mtb during initial phase of infection thr...

  17. [Effects of isocitrate lyase from Mycobacterium tuberculosis on the survival of Mycobacterium smegmatis in macrophage and mechanism thereof].

    Science.gov (United States)

    Li, Jun-Ming; Wan, La-Gen; Zhu, Dao-Yin; Li, Na; He, Yong-Lin; Yang, Chun

    2008-02-26

    To investigate the effects of isocitrate lyase (ICL) from Mycobacterium tuberculosis (MTB-icl) on the survival of Mycobacterium smegmatis (MS) in macrophage and illuminate the possible mechanisms. MTB-icl gene was amplified by PCR and cloned into Ecoli-Mycobacterium shuttle plasmid pUV15 to obtain recombinant shuttle plasmid pUV15-icl expressing ICL-GFP. The recombinant shuttle plasmid pUV15-icl and blank plasmid pUV15 were induced into MS of the line 1-2c so as to obtain rMS-pUV15-icl and rMS-pUV15. Shuttle plasmid rMS-pUV15-IG expressing ICL-green fluorescent protein (GFP) was constructed. rMS-pUV15-IG and MS 1-2c were used to infect the murine macrophages of the line RAW264.7, fluorescence microscopy was used to observe the expression of ICL-GFP. The expression of ICL in the MS swallowed by the macrophages was verified by RT-PCR and Western blotting. Another macrophages RAW264.7 were cultured and infected with rMS-pUV15-icl and rMS-pUV15 respectively. 0, 24, and 48 hours later macrophages were collected and the number of MS colonies was calculated. The interferon (IFN)-gamma and nitrogen oxide (NO) concentrations in the culture supernatants of macrophages infected by rMS-pUV15-icl and rMS-pUV15 were measured by ELISA and Griess assay respectively. The apoptotic rate of the macrophages was assayed by in situ TUNEL technique. Western blotting showed that the MTB ICL protein expression of the rMS-pUV15-icl was significantly higher than that of rMS-pUVI5. Fluorescence microscopy showed green fluorescence in the RAW264.7 cells infected with rMS-pUV15-IG, but not ion the RAW264.7 cells infected with MS 1-2c. 0 h after the infection of the macrophages there was not significant difference in the MS amount in the macrophages between the rMS-pUV15-isl and rMS-pUV15 groups, and 24 h and 48 h later the MS amounts of the rMS-pUV15-icl group were (32.78 +/- 2.90) x 10(3) and (23.33 + 2.34) x 10(3) respectively, both significantly higher than those of the rMS-pUV15 group [(14

  18. Characterization of the major formamidopyrimidine-DNA glycosylase homolog in Mycobacterium tuberculosis and its linkage to variable tandem repeats.

    Science.gov (United States)

    Olsen, Ingrid; Balasingham, Seetha V; Davidsen, Tonje; Debebe, Ephrem; Rødland, Einar A; van Soolingen, Dick; Kremer, Kristin; Alseth, Ingrun; Tønjum, Tone

    2009-07-01

    The ability to repair DNA damage is likely to play an important role in the survival of facultative intracellular parasites because they are exposed to high levels of reactive oxygen species and nitrogen intermediates inside phagocytes. Correcting oxidative damage in purines and pyrimidines is the primary function of the enzymes formamidopyrimidine (faPy)-DNA glycosylase (Fpg) and endonuclease VIII (Nei) of the base excision repair pathway, respectively. Four gene homologs, belonging to the fpg/nei family, have been identified in Mycobacterium tuberculosis H37Rv. The recombinant protein encoded by M. tuberculosis Rv2924c, termed Mtb-Fpg1, was overexpressed, purified and biochemically characterized. The enzyme removed faPy and 5-hydroxycytosine lesions, as well as 8-oxo-7,8-dihydroguanine (8oxoG) opposite to C, T and G. Mtb-Fpg1 thus exhibited substrate specificities typical for Fpg enzymes. Although Mtb-fpg1 showed nearly complete nucleotide sequence conservation in 32 M. tuberculosis isolates, the region upstream of Mtb-fpg1 in these strains contained tandem repeat motifs of variable length. A relationship between repeat length and Mtb-fpg1 expression level was demonstrated in M. tuberculosis strains, indicating that an increased length of the tandem repeats positively influenced the expression levels of Mtb-fpg1. This is the first example of such a tandem repeat region of variable length being linked to the expression level of a bacterial gene.

  19. Experimental Evolution of Mycobacterium tuberculosis in Human Macrophages Results in Low-Frequency Mutations Not Associated with Selective Advantage.

    Directory of Open Access Journals (Sweden)

    Valentina Guerrini

    Full Text Available Isolates of the human pathogen Mycobacterium tuberculosis recovered from clinical samples exhibit genetic heterogeneity. Such variation may result from the stressful environment encountered by the pathogen inside the macrophage, which is the host cell tubercle bacilli parasitize. To study the evolution of the M. tuberculosis genome during growth inside macrophages, we developed a model of intracellular culture in which bacteria were serially passaged in macrophage-like THP-1 cells for about 80 bacterial generations. Genome sequencing of single bacterial colonies isolated before and after the infection cycles revealed that M. tuberculosis developed mutations at a rate of about 5.7 × 10-9 / bp/ generation, consistent with mutation rates calculated during in vivo infection. Analysis of mutant growth in macrophages and in mice showed that the mutations identified after the cyclic infection conferred no advantage to the mutants relative to wild-type. Furthermore, activity testing of the recombinant protein harboring one of these mutations showed that the presence of the mutation did not affect the enzymatic activity. The serial infection protocol developed in this work to study M. tuberculosis genome microevolution can be applied to exposure to stressors to determine their effect on genome remodeling during intra-macrophage growth.

  20. Reduced susceptibility of clinical strains of Mycobacterium tuberculosis to reactive nitrogen species promotes survival in activated macrophages.

    Directory of Open Access Journals (Sweden)

    Jonna Idh

    Full Text Available Drugs such as isoniazid (INH and pretomanid (PRT, used against Mycobacterium tuberculosis are active partly through generation of reactive nitrogen species (RNS. The aim of this study was to explore variability in intracellular susceptibility to nitric oxide (NO in clinical strains of M. tuberculosis.Luciferase-expressing clinical M. tuberculosis strains with or without INH resistance were exposed to RNS donors (DETA/NO and SIN-1 in broth cultures and bacterial survival was analysed by luminometry. NO-dependent intracellular killing in a selection of strains was assessed in interferon gamma/lipopolysaccharide-activated murine macrophages using the NO inhibitor L-NMMA.When M. tuberculosis H37Rv was compared to six clinical isolates and CDC1551, three isolates with inhA mediated INH resistance showed significantly reduced NO-susceptibility in broth culture. All strains showed a variable but dose-dependent susceptibility to RNS donors. Two clinical isolates with increased susceptibility to NO exposure in broth compared to H37Rv were significantly inhibited by activated macrophages whereas there was no effect on growth inhibition when activated macrophages were infected by clinical strains with higher survival to NO exposure in broth. Furthermore, the most NO-tolerant clinical isolate showed increased resistance to PRT both in broth culture and the macrophage model compared to H37Rv in the absence of mutational resistance in genes associated to reduced susceptibility against PRT or NO.In a limited number of clinical M. tuberculosis isolates we found a significant difference in susceptibility to NO between clinical isolates, both in broth cultures and in macrophages. Our results indicate that mycobacterial susceptibility to cellular host defence mechanisms such as NO need to be taken into consideration when designing new therapeutic strategies.

  1. 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.

  2. Absence of the Genetic Marker IS6110 from a Strain of Mycobacterium tuberculosis Isolated in Ontario

    Directory of Open Access Journals (Sweden)

    Susan T Howard

    1998-01-01

    Full Text Available A 35-year-old female patient from Waterloo, Ontario was diagnosed with pulmonary tuberculosis in June 1995. Records indicated that the patient had emigrated from Laos circa 1990. A culture grown from a bronchoalveolar lavage specimen was identified as Mycobacterium tuberculosis by standard biochemical methods. Drug-susceptibility testing indicated the strain was resistant to pyrazinamide (PZA, and a mutation was detected within pncA, a gene associated with PZA resistance. Sequence data from the 16S rRNA gene and the 16S/23S rRNA gene spacer confirmed that the strain was a member of the M tuberculosis complex, and analysis of the mpcA and pncA genes supported the identification of the strain as M tuberculosis rather than Mycobacterium bovis. However, the insertion element IS6110, which is used for epidemiological tracing of M tuberculosis, was not detected in this strain by either restriction fragment length polymorphism analysis or by polymerase chain reaction. Two other genetic markers associated with the M tuberculosis complex, IS1081 and the direct repeat element, were present. The arrival of immigrants with tuberculosis from southeast Asia, where most strains of M tuberculosis lacking IS6110 have been traced, has important implications for epidemiological studies of tuberculosis in North America.

  3. 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...

  4. Mycobacterium avium-intracellulare infection during HIV disease. Persisting problems

    Directory of Open Access Journals (Sweden)

    Roberto Manfredi

    2008-12-01

    Full Text Available Still in the era of combined antiretroviral therapy, late recognition of HIV disease or lack of sufficient immune recovery pose HIV-infected patients at risk to develop opportunistic infections by nontuberculous mycobacteria (NTM, which are environmental organisms commonly retrieved in soil and superficial waters.Among these microorganisms, the most frequent is represented by Mycobacterium avium complex (MAC. Health care professionals who face HIV-infected patients should suspect disseminated mycobacterial disease when a deep immunodeficiency is present, (a CD4+ lymphocyte count below 50 cells/μL often associated with constitutional signs and symptoms, and non-specific laboratory abnormalities. Mycobacterial culture of peripheral blood is a reliable technique for diagnosing disseminated disease. Among drugs active against NTM, as well as some anti-tubercular compounds, the rifampin derivative rifabutin, and some novel fluoroquinolones, the availability of macrolides, has greatly contributed to improve both prophylaxis and treatment outcome of disseminated MAC infections. Although multiple questions remain about which regimens may be regarded as optimal, general recommendations can be expressed on the ground of existing evidences.Treatment should begin with associated clarithromycin (or azithromycin, plus ethambutol and rifabutin (with the rifabutin dose depending on other concomitant medications that might result in drug-drug interactions.A combined three-drug regimen is preferred for patients who cannot be prescribed an effective antiretroviral regimen immediately. Patients with a CD4+ lymphocyte count below 50 cells/μL, who do not have clinical evidence of active mycobacterial disease, should receive a primary prophylaxis with either clarithromycin or azithromycin, with or without rifabutin.

  5. Sputum is a surrogate for bronchoalveolar lavage for monitoring Mycobacterium tuberculosis transcriptional profiles in TB patients.

    Science.gov (United States)

    Garcia, Benjamin J; Loxton, Andre G; Dolganov, Gregory M; Van, Tran T; Davis, J Lucian; de Jong, Bouke C; Voskuil, Martin I; Leach, Sonia M; Schoolnik, Gary K; Walzl, Gerhard; Strong, Michael; Walter, Nicholas D

    2016-09-01

    Pathogen-targeted transcriptional profiling in human sputum may elucidate the physiologic state of Mycobacterium tuberculosis (M. tuberculosis) during infection and treatment. However, whether M. tuberculosis transcription in sputum recapitulates transcription in the lung is uncertain. We therefore compared M. tuberculosis transcription in human sputum and bronchoalveolar lavage (BAL) samples from 11 HIV-negative South African patients with pulmonary tuberculosis. We additionally compared these clinical samples with in vitro log phase aerobic growth and hypoxic non-replicating persistence (NRP-2). Of 2179 M. tuberculosis transcripts assayed in sputum and BAL via multiplex RT-PCR, 194 (8.9%) had a p-value <0.05, but none were significant after correction for multiple testing. Categorical enrichment analysis indicated that expression of the hypoxia-responsive DosR regulon was higher in BAL than in sputum. M. tuberculosis transcription in BAL and sputum was distinct from both aerobic growth and NRP-2, with a range of 396-1020 transcripts significantly differentially expressed after multiple testing correction. Collectively, our results indicate that M. tuberculosis transcription in sputum approximates M. tuberculosis transcription in the lung. Minor differences between M. tuberculosis transcription in BAL and sputum suggested lower oxygen concentrations or higher nitric oxide concentrations in BAL. M. tuberculosis-targeted transcriptional profiling of sputa may be a powerful tool for understanding M. tuberculosis pathogenesis and monitoring treatment responses in vivo. Published by Elsevier Ltd.

  6. Radiometric assessment of the sensitivity to antituberculotics of Mycobacterium avium-intracellulare and Mycobacterium xenopi

    International Nuclear Information System (INIS)

    Kubin, M.; Lindholm-Levy, P.; Heifets, L. B.

    1994-01-01

    The macrodilution radiometric method using Middlebrook's 7H12 liquid medium enriched with 14 C-palmitic acid, where the growth activity is monitored by measuring liberated 14 CO 2 , was applied to 25 strains of the Mycobacterium avium complex and to 20 strains of Mycobacterium xenopi to determine the minimal inhibitory concentrations of the following chemotherapeutical agents: ciprofloxacine, clofazimine, rifampin, cycloserine, kanamycin, etionamide, ethambutol, and amikacin. In the case of the M. avium complex, slightly or completely resistant strains were found for the majority of drugs. The sensitive strain proportion was highest with clofazimine and amikacin. The M. xenopis strains exhibited generally lower minimal inhibitory concentrations than the avian mycobacteria for all drugs except for cycloserine and ethambutol. The radiometric method using the BACTEC system was found suitable for the determination of the sensitivity of mycobacteria to chemotherapeutic agents: the results are obtained rapidly, within 8 days following inoculation, and the minimal inhibitory concentrations can be evaluated quantitatively. 1 tab., 8 refs

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

    Directory of Open Access Journals (Sweden)

    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%.

  8. Comparative analysis of mycobacterium and related actinomycetes yields insight into the evolution of mycobacterium tuberculosis pathogenesis

    Directory of Open Access Journals (Sweden)

    McGuire Abigail

    2012-03-01

    Full Text Available Abstract Background The sequence of the pathogen Mycobacterium tuberculosis (Mtb strain H37Rv has been available for over a decade, but the biology of the pathogen remains poorly understood. Genome sequences from other Mtb strains and closely related bacteria present an opportunity to apply the power of comparative genomics to understand the evolution of Mtb pathogenesis. We conducted a comparative analysis using 31 genomes from the Tuberculosis Database (TBDB.org, including 8 strains of Mtb and M. bovis, 11 additional Mycobacteria, 4 Corynebacteria, 2 Streptomyces, Rhodococcus jostii RHA1, Nocardia farcinia, Acidothermus cellulolyticus, Rhodobacter sphaeroides, Propionibacterium acnes, and Bifidobacterium longum. Results Our results highlight the functional importance of lipid metabolism and its regulation, and reveal variation between the evolutionary profiles of genes implicated in saturated and unsaturated fatty acid metabolism. It also suggests that DNA repair and molybdopterin cofactors are important in pathogenic Mycobacteria. By analyzing sequence conservation and gene expression data, we identify nearly 400 conserved noncoding regions. These include 37 predicted promoter regulatory motifs, of which 14 correspond to previously validated motifs, as well as 50 potential noncoding RNAs, of which we experimentally confirm the expression of four. Conclusions Our analysis of protein evolution highlights gene families that are associated with the adaptation of environmental Mycobacteria to obligate pathogenesis. These families include fatty acid metabolism, DNA repair, and molybdopterin biosynthesis. Our analysis reinforces recent findings suggesting that small noncoding RNAs are more common in Mycobacteria than previously expected. Our data provide a foundation for understanding the genome and biology of Mtb in a comparative context, and are available online and through TBDB.org.

  9. Comparative analysis of Mycobacterium and related Actinomycetes yields insight into the evolution of Mycobacterium tuberculosis pathogenesis.

    Science.gov (United States)

    McGuire, Abigail Manson; Weiner, Brian; Park, Sang Tae; Wapinski, Ilan; Raman, Sahadevan; Dolganov, Gregory; Peterson, Matthew; Riley, Robert; Zucker, Jeremy; Abeel, Thomas; White, Jared; Sisk, Peter; Stolte, Christian; Koehrsen, Mike; Yamamoto, Robert T; Iacobelli-Martinez, Milena; Kidd, Matthew J; Maer, Andreia M; Schoolnik, Gary K; Regev, Aviv; Galagan, James

    2012-03-28

    The sequence of the pathogen Mycobacterium tuberculosis (Mtb) strain H37Rv has been available for over a decade, but the biology of the pathogen remains poorly understood. Genome sequences from other Mtb strains and closely related bacteria present an opportunity to apply the power of comparative genomics to understand the evolution of Mtb pathogenesis. We conducted a comparative analysis using 31 genomes from the Tuberculosis Database (TBDB.org), including 8 strains of Mtb and M. bovis, 11 additional Mycobacteria, 4 Corynebacteria, 2 Streptomyces, Rhodococcus jostii RHA1, Nocardia farcinia, Acidothermus cellulolyticus, Rhodobacter sphaeroides, Propionibacterium acnes, and Bifidobacterium longum. Our results highlight the functional importance of lipid metabolism and its regulation, and reveal variation between the evolutionary profiles of genes implicated in saturated and unsaturated fatty acid metabolism. It also suggests that DNA repair and molybdopterin cofactors are important in pathogenic Mycobacteria. By analyzing sequence conservation and gene expression data, we identify nearly 400 conserved noncoding regions. These include 37 predicted promoter regulatory motifs, of which 14 correspond to previously validated motifs, as well as 50 potential noncoding RNAs, of which we experimentally confirm the expression of four. Our analysis of protein evolution highlights gene families that are associated with the adaptation of environmental Mycobacteria to obligate pathogenesis. These families include fatty acid metabolism, DNA repair, and molybdopterin biosynthesis. Our analysis reinforces recent findings suggesting that small noncoding RNAs are more common in Mycobacteria than previously expected. Our data provide a foundation for understanding the genome and biology of Mtb in a comparative context, and are available online and through TBDB.org.

  10. Dual color fluorescence in situ hybridization (FISH) assays for detecting Mycobacterium tuberculosis and Mycobacterium avium complexes and related pathogens in cultures

    OpenAIRE

    Shah, Jyotsna; Weltman, Helena; Narciso, Patricia; Murphy, Christina; Poruri, Akhila; Baliga, Shrikala; Sharon, Leesha; York, Mary; Cunningham, Gail; Miller, Steve; Caviedes, Luz; Gilman, Robert; Desmond, Edward; Ramasamy, Ranjan

    2017-01-01

    Two rapid dual color fluorescence in situ hybridization (FISH) assays were evaluated for detecting M. tuberculosis and related pathogens in cultures. The MN Genus-MTBC FISH assay uses an orange fluorescent probe specific for the Mycobacterium tuberculosis complex (MTBC) and a green fluorescent probe specific for the Mycobacterium and Nocardia genera (MN Genus) to detect and distinguish MTBC from other Mycobacteria and Nocardia. A complementary MTBC-MAC FISH assay uses green and orange fluores...

  11. 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...

  12. Orbital and external ocular manifestations of Mycobacterium tuberculosis: A review of the literature

    Directory of Open Access Journals (Sweden)

    Lauren A. Dalvin

    2016-08-01

    Full Text Available Tuberculosis (TB is an airborne infectious disease caused by Mycobacterium tuberculosis that most commonly affects the lungs. However, extrapulmonary manifestations of TB can affect the eye and surrounding orbital tissues. TB can affect nearly any tissue in the eye, and a high index of suspicion is required for accurate diagnosis. Systemic anti-tuberculosis treatment is required in cases of ocular TB, and steroids are sometimes necessary to prevent tissue damage secondary to inflammation. Delays in diagnosis are common and can result in morbidities such as loss of an affected eye. It is important for ophthalmologists and infectious disease specialists to work together to accurately diagnose and treat ocular TB in order to prevent vision loss. This article reports the various known presentations of orbital and external ocular TB and reviews important elements of diagnosis and treatment. Keywords: Tuberculosis, Mycobacterium, Orbit, Eye, Ocular

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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...

  15. Evolution and Diversity of Clonal Bacteria: The Paradigm of Mycobacterium tuberculosis

    OpenAIRE

    Dos Vultos, Tiago; Mestre, Olga; Rauzier, Jean; Golec, Marcin; Rastogi, Nalin; Rasolofo, Voahangy; Tonjum, Tone; Sola, Christophe; Matic, Ivan; Gicquel, Brigitte

    2008-01-01

    International audience; BACKGROUND: Mycobacterium tuberculosis complex species display relatively static genomes and 99.9% nucleotide sequence identity. Studying the evolutionary history of such monomorphic bacteria is a difficult and challenging task. PRINCIPAL FINDINGS: We found that single-nucleotide polymorphism (SNP) analysis of DNA repair, recombination and replication (3R) genes in a comprehensive selection of M. tuberculosis complex strains from across the world, yielded surprisingly ...

  16. 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...

  17. Anti-Mycobacterium tuberculosis activity of antituberculosis drugs and amoxicillin/clavulanate combination.

    Science.gov (United States)

    Pagliotto, Aline Daniele Furlan; Caleffi-Ferracioli, Katiany Rizzieri; Lopes, Mariana Aparecida; Baldin, Vanessa Pietrowski; Leite, Clarice Queico Fujimura; Pavan, Fernando Rogério; Scodro, Regiane Bertin de Lima; Siqueira, Vera Lúcia Dias; Cardoso, Rosilene Fressatti

    2016-12-01

    We report the in vitro drugs interaction by the resazurin drugs combination microtiter assay (REDCA) of amoxicillin (AMO)/clavulanate (CLAV) with isoniazid (INH), ethambutol (EMB), and rifampicin (RIF) against susceptible and resistant Mycobacterium tuberculosis isolates. The addition of AMO/CLAV to classical antituberculosis drugs should be explored as a promising alternative for the treatment of resistant tuberculosis (TB). Copyright © 2015. Published by Elsevier B.V.

  18. Antagonistic action of Streptococcus salivarius and Streptococcus faecalis to Mycobacterium tuberculosis.

    Science.gov (United States)

    Darling, C L; Hart, G D

    1976-10-01

    Streptococcus salivarius and Streptococcus faecalis were found to inhibit the growth of Mycobacterium tuberculosis on Löwenstein-Jensen and Middlebrook 7H11 agars, but not on the latter medium when antibacterial drugs were added. S. faecalis was found to be more inhibitory than S. salivarius to 15 strains of M. tuberculosis. S. salivarius produced little or no inhibition of growth of Runyon group III organisms but was very antagonistic to Runyon group I mycobacteria.

  19. Global adaptation to a lipid environment triggers the dormancy- related phenotype of mycobacterium tuberculosis

    OpenAIRE

    Rodríguez, Juan G.; Hernández, Adriana C.; Helguera-Repetto, Cecilia; Ayala, Diana Aguilar; Guadarrama-Medina, Rosalina; Anzóla, Juan M.; Bustos, Jose R.; Zambrano, María M.; González-y-Merchand, Jorge; García, María J.; Portillo, Patricia Del

    2014-01-01

    Strong evidence supports the idea that fatty acids rather than carbohydrates are the main energy source of Mycobacterium tuberculosis during infection and latency. Despite that important role, a complete scenario of the bacterium’s metabolism when lipids are the main energy source is still lacking. Here we report the development of an in vitro model to analyze adaptation of M. tuberculosis during assimilation of long-chain fatty acids as sole carbon sources. The global lipid transcri...

  20. Susceptibility of a panel of virulent strains of Mycobacterium tuberculosis to reactive nitrogen intermediates.

    OpenAIRE

    Rhoades, E R; Orme, I M

    1997-01-01

    Murine bone marrow-derived macrophages were infected with a panel of virulent isolates of Mycobacterium tuberculosis including laboratory strains Erdman and H37Rv and various clinical isolates in order to determine the sensitivity of each of these strains to the antimycobacterial activities of macrophage-generated reactive nitrogen intermediates (RNI). All of the M. tuberculosis strains grew in murine bone marrow-derived macrophages; however, gamma interferon-primed macrophages limited the in...

  1. A Molecular Biological and Biochemical Investigation on Mycobacterium tuberculosis MutT Protein

    OpenAIRE

    Huang, Hsiu-Lin; Su, Ho-Ting; Wu, Chung-Hsiun Herbert; Tsai-Wu, Jyy-Jih

    2014-01-01

    Background: Mycobacterium tuberculosis is a vicious microbe co-existing with the infected host. This pathogen exploited opportunities to spread during periods of urbanization and social upheaval, and got retreated with improved hygiene. Objectives: This investigation was designed to clone and characterize M. tuberculosis mutT gene, a homologue of a DNA repair protein in Escherichia coli. The aim was to depict the possible role of this homologue in the virulent microbe. Materials and Methods: ...

  2. The Response of Mycobacterium Tuberculosis to Reactive Oxygen and Nitrogen Species

    OpenAIRE

    Voskuil, Martin I.; Bartek, Iona L.; Visconti, Kevin; Schoolnik, Gary K.

    2011-01-01

    The bacteriostatic and bactericidal effects and the transcriptional response of Mycobacterium tuberculosis to representative oxidative and nitrosative stresses were investigated by growth and survival studies and whole genome expression analysis. The M. tuberculosis reaction to a range of hydrogen peroxide (H2O2) concentrations fell into three distinct categories: (1) low level exposure resulted in induction of a few highly sensitive H2O2-responsive genes, (2) intermediate exposure resulted i...

  3. 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...

  4. Molecular Targets Related Drug Resistance Mechanisms in MDR-, XDR-, and TDR-Mycobacterium tuberculosis Strains

    Directory of Open Access Journals (Sweden)

    H. M. Adnan Hameed

    2018-04-01

    Full Text Available Tuberculosis (TB is a formidable infectious disease that remains a major cause of death worldwide today. Escalating application of genomic techniques has expedited the identification of increasing number of mutations associated with drug resistance in Mycobacterium tuberculosis. Unfortunately the prevalence of bacillary resistance becomes alarming in many parts of the world, with the daunting scenarios of multidrug-resistant tuberculosis (MDR-TB, extensively drug-resistant tuberculosis (XDR-TB and total drug-resistant tuberculosis (TDR-TB, due to number of resistance pathways, alongside some apparently obscure ones. Recent advances in the understanding of the molecular/ genetic basis of drug targets and drug resistance mechanisms have been steadily made. Intriguing findings through whole genome sequencing and other molecular approaches facilitate the further understanding of biology and pathology of M. tuberculosis for the development of new therapeutics to meet the immense challenge of global health.

  5. Positive interferon-γ release assay leading to a diagnosis of Mycobacterium tuberculosis pericarditis in pregnancy.

    Science.gov (United States)

    Cain, Mary Ashley; Whiteman, Valerie E; Buhari, Mudathiru A; Louis, Judette M

    2014-08-01

    Tuberculosis during pregnancy is associated with increased complications. The wide range of presentations among patients with extrapulmonary tuberculosis can make diagnosis and treatment difficult. We present the case of a patient with Mycobacterium tuberculosis pericarditis presenting in pregnancy with recurrent pericardial effusions. The diagnosis of active tuberculosis was made and treatment initiated after a positive interferon-gamma release assay and granulomatous pericardial pathology despite negative tuberculin skin testing. Culture of pericardial tissue obtained by pericardectomy confirmed the diagnosis 1 month after initiation of treatment. This case report demonstrates the use of interferon-gamma release assay in diagnosing tuberculosis among high-risk pregnant patients. Although limited by expense and minimal experience in pregnancy, these assays may be useful to screen for tuberculosis in high-risk pregnant populations.

  6. Aerosol Mycobacterium tuberculosis infection causes rapid loss of diversity in gut microbiota.

    Science.gov (United States)

    Winglee, Kathryn; Eloe-Fadrosh, Emiley; Gupta, Shashank; Guo, Haidan; Fraser, Claire; Bishai, William

    2014-01-01

    Mycobacterium tuberculosis is an important human pathogen, and yet diagnosis remains challenging. Little research has focused on the impact of M. tuberculosis on the gut microbiota, despite the significant immunological and homeostatic functions of the gastrointestinal tract. To determine the effect of M. tuberculosis infection on the gut microbiota, we followed mice from M. tuberculosis aerosol infection until death, using 16S rRNA sequencing. We saw a rapid change in the gut microbiota in response to infection, with all mice showing a loss and then recovery of microbial community diversity, and found that pre-infection samples clustered separately from post-infection samples, using ecological beta-diversity measures. The effect on the fecal microbiota was observed as rapidly as six days following lung infection. Analysis of additional mice infected by a different M. tuberculosis strain corroborated these results, together demonstrating that the mouse gut microbiota significantly changes with M. tuberculosis infection.

  7. Pulmonary Disease due to Mycobacterium tuberculosis in a Horse: Zoonotic Concerns and Limitations of Antemortem Testing

    Directory of Open Access Journals (Sweden)

    Konstantin P. Lyashchenko

    2012-01-01

    Full Text Available A case of pulmonary tuberculosis caused by Mycobacterium tuberculosis was diagnosed in a horse. Clinical evaluation performed prior to euthanasia did not suggest tuberculosis, but postmortem examination provided pathological and bacteriological evidence of mycobacteriosis. In the lungs, multiple tuberculoid granulomas communicating with the bronchiolar lumen, pleural effusion, and a granulomatous lymphadenitis involving mediastinal and tracheobronchial lymph nodes were found. Serologic response to M. tuberculosis antigens was detected in the infected horse, but not in the group of 42 potentially exposed animals (18 horses, 14 alpacas, 6 donkeys, and 4 dogs which showed no signs of disease. Diagnosis of tuberculosis in live horses remains extremely difficult. Four of 20 animal handlers at the farm were positive for tuberculous infection upon follow-up testing by interferon-gamma release assay, indicating a possibility of interspecies transmission of M. tuberculosis.

  8. 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

  9. 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

    Directory of Open Access Journals (Sweden)

    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.

  10. Detection of mutation in isoniazid-resistant Mycobacterium tuberculosis isolates from tuberculosis patients in Belarus

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    Bostanabad S

    2008-01-01

    Full Text Available The aim of this study was to investigate the frequency, location and type of katG mutations in Mycobacterium tuberculosis strains isolated from patients in Belarus. Forty two isoniazid-resistant isolates were identified from sputum of 163 patients with active pulmonary tuberculosis. Drug susceptibility testing was determined by using CDC standard conventional proportional method and BACTEC system. Standard PCR method for detection of isoniazid resistance associated mutations was performed by katG gene amplification and DNA sequencing. Most mutations were found in katG gene codons 315, 316 and 309. Four types of mutations were identified in codon 315: AGC→ACC ( n = 36 85%, AGC→AGG ( n = 1 2.3%, AGC→AAC ( n = 2 4.7%, AGC→GGC ( n = 1 2.3%. One type of mutation was found in codon 316: GGC→AGC ( n = 1841.4%, four types of mutations were detected in codon 309: GGT→GGT ( n = 716.1%, GGT→GCT ( n = 49.2%, GGT→GTC ( n = 36.9%, GGT→GGG ( n = 12.7%. The highest frequency of mutations sharing between primary and secondary infections was found in codon 315.

  11. IFNG-mediated immune responses enhance autophagy against Mycobacterium tuberculosis antigens in patients with active tuberculosis

    Science.gov (United States)

    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

  12. Strain Diversity of Mycobacterium tuberculosis Isolates from Pulmonary Tuberculosis Patients in Afar Pastoral Region of Ethiopia

    Directory of Open Access Journals (Sweden)

    Mulugeta Belay

    2014-01-01

    Full Text Available Data on genotypic diversity of Mycobacterium tuberculosis complex (MTBC is important to understand its epidemiology, human adaptation, clinical phenotypes, and drug resistance. This study aimed to characterize MTBC clinical isolates circulating in a predominantly pastoralist area in Ethiopia, a country where tuberculosis is the second leading cause of mortality. Culture of sputum samples collected from a total of 325 pulmonary TB suspects was done to isolate MTBC. Spoligotyping was used to characterize 105 isolates from culture positive slopes and the result was compared with an international database. Forty-four spoligotype patterns were observed to correspond to 35 shared-types (SITs containing 96 isolates and 9 orphan patterns; 27 SITs containing 83 isolates matched a preexisting shared-type in the database, whereas 8 SITs (n=13 isolates were newly created. A total of 19 SITs containing 80 isolates were clustered within this study (overall clustering of 76.19%. Three dominant lineages (T, CAS, and Manu accounted for 76.19% of the isolates. SIT149/T3-ETH was one of the two most dominant sublineages. Unlike previous reports, we show that Manu lineage strains not only constitute a dominant lineage, but are also associated with HIV infection in Afar region of Ethiopia. The high level of clustering suggests the presence of recent transmission that should be further studied using additional genotyping markers.

  13. Prevalence and evolution of Mycobacterium tuberculosis infection in tuberculosis case contacts

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    Silvia Paulino Ribeiro Albanese

    2015-06-01

    Full Text Available INTRODUCTION : The tuberculin test is a diagnostic method for detecting latent tuberculosis (TB infection, especially among disease contact cases. The objective of this study was to analyze the prevalence and evolution of Mycobacterium tuberculosis infection among TB contact cases. METHODS : A retrospective cohort study was performed in a reference center for TB. The study population consisted of 2,425 patients who underwent a tuberculin test from 2003 to 2010 and whose results indicated contact with individuals with TB. The data were collected from the registry book of the tuberculin tests, patient files and the Information System Records of Notification Grievance. To verify the evolution of TB, case records through September 2014 were consulted. Data were analyzed using the Statistical Package for the Social Sciences (SPSS. In all hypothesis tests, a significance level of 0.05 was used. RESULTS : From the studied sample, 435 (17.9% contacts did not return for reading. Among the 1,990 contacts that completed the test, the prevalence of latent TB infection was 35.4%. Of these positive cases, 50.6% were referred to treatment; the dropout rate was 42.5%. Among all of the contacts, the TB prevalence was 1.8%, from which 13.2% abandoned treatment. CONCLUSIONS : The collected data indicate the need for more effective public policies to improve TB control, including administering tests that do not require a return visit for reading, enhancing contact tracing and encouraging actions that reinforce full treatment adherence.

  14. Potential Inhibitors for Isocitrate Lyase of Mycobacterium tuberculosis and Non-M. tuberculosis: A Summary

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    Yie-Vern Lee

    2015-01-01

    Full Text Available Isocitrate lyase (ICL is the first enzyme involved in glyoxylate cycle. Many plants and microorganisms are relying on glyoxylate cycle enzymes to survive upon downregulation of tricarboxylic acid cycle (TCA cycle, especially Mycobacterium tuberculosis (MTB. In fact, ICL is a potential drug target for MTB in dormancy. With the urge for new antitubercular drug to overcome tuberculosis treat such as multidrug resistant strain and HIV-coinfection, the pace of drug discovery has to be increased. There are many approaches to discovering potential inhibitor for MTB ICL and we hereby review the updated list of them. The potential inhibitors can be either a natural compound or synthetic compound. Moreover, these compounds are not necessary to be discovered only from MTB ICL, as it can also be discovered by a non-MTB ICL. Our review is categorized into four sections, namely, (a MTB ICL with natural compounds; (b MTB ICL with synthetic compounds; (c non-MTB ICL with natural compounds; and (d non-MTB ICL with synthetic compounds. Each of the approaches is capable of overcoming different challenges of inhibitor discovery. We hope that this paper will benefit the discovery of better inhibitor for ICL.

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

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    Burdo Conny CA

    2009-09-01

    Full Text Available Abstract Background 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 identical DNA fingerprints was used for the development of a visual presentation of epidemiologic links between cases. Results Of 32 cases, 17 (53% were linked to the index case, and 11 (34% to a secondary case. The remaining four (13% could not be linked and were classified as possibly caused by the index patient. Of the 21 cases related to the index case, TB developed within one year of the index diagnosis in 11 patients (52%, within one to two years in four patients (19%, and within two to five years in six patients (29%. Conclusion Cluster analysis underscored several issues for TB control in an urban setting, such as the recognition of the outbreak, the importance of reinfections, the impact of delayed diagnosis, the contribution of pub-related transmissions and its value for decision-making to extend contact investigations. Visualising cases in a cluster diagram was particularly useful in finding transmission locations and the similarities and links between patients.

  16. Utility of polymerase chain reaction for detection of Mycobacterium tuberculosis in suspected cases of tuberculosis lymphadenopathy

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    Khushpreet Kaur

    2016-01-01

    Full Text Available Introduction: There is a need for a rapid and cost-effective technique for reliable diagnosis of tubercular lymphadenopathy, particularly in low-resource setting. In this study, we have used various diagnostic techniques including polymerase chain reaction (PCR to diagnose clinically suspected cases of tubercular lymphadenopathy and compared the results to see which of the techniques are more sensitive, specific, and cost-effective. Materials and Methods: All patients having swelling in the neck, axillary, and inguinal regions were recruited for the study. Sputum for acid-fast Bacillus (AFB, fine-needle aspiration cytology, excision biopsy, DNA-PCR, AFB smear of the same material was done as per standard protocol. Results: 32% patients have granulomas with necrosis, whereas 30% have acute suppurative lesions and 24% and 14% patients were having only granulomas and only necrosis, respectively. A significant difference was observed between the PCR-negative and positive cases with respect to their cytomorphologic features. Positive AFB and tuberculosis-PCR (TB-PCR results were significantly more common in the cases with chronic granulomatous inflammation in comparison to the cases showing chronic inflammation only. Sensitivity and specificity of TB-PCR were found to be 71.4% and 28.4%, respectively. Conclusion: PCR is a sensitive and rapid technique in the demonstration of Mycobacterium tuberculosis. It should be done in clinically suspected patients of tuberculous lymphadenopathy when their AFB stain is even negative.

  17. Role of fused Mycobacterium tuberculosis immunogens and adjuvants in modern tuberculosis vaccines

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    Ana Paula eJunqueira-Kipnis

    2014-04-01

    Full Text Available Several approaches have been developed to improve or replace the only available vaccine for tuberculosis (TB, BCG (Bacille Calmette Guerin. The development of subunit protein vaccines is a promising strategy because it combines specificity and safety. In addition, subunit protein vaccines can be designed to have selected immune epitopes associated with immunomodulating components to drive the appropriate immune response. However, the limited antigens present in subunit vaccines reduce their capacity to stimulate a complete immune response compared with vaccines composed of live attenuated or killed microorganisms. This deficiency can be compensated by the incorporation of adjuvants in the vaccine formulation. The fusion of adjuvants with Mycobacterium tuberculosis (Mtb proteins or immune epitopes has the potential to become the new frontier in the TB vaccine development field. Researchers have addressed this approach by fusing the immune epitopes of their vaccines with molecules such as interleukins, lipids, lipoproteins, and immune stimulatory peptides, which have the potential to enhance the immune response. The fused molecules are being tested as subunit vaccines alone or within live attenuated vector contexts. Therefore, the objectives of this review are to discuss the association of Mtb fusion proteins with adjuvants; Mtb immunogens fused with adjuvants; and cytokine fusion with Mtb proteins and live recombinant vectors expressing cytokines. The incorporation of adjuvant molecules in a vaccine can be complex, and developing a stable fusion with proteins is a challenging task. Overall, the fusion of adjuvants with Mtb epitopes, despite the limited number of studies, is a promising field in vaccine development.

  18. Mycobacterium tuberculosis bacteremia in adults and children: a systematic review and meta-analysis.

    Science.gov (United States)

    Pavlinac, P B; Lokken, E M; Walson, J L; Richardson, B A; Crump, J A; John-Stewart, G C

    2016-07-01

    SETTINGp: Among human immunodeficiency virus (HIV) infected adults living in tuberculosis (TB) endemic settings, Mycobacterium tuberculosis is a common cause of bloodstream infections. Although young children have an increased propensity for M. tuberculosis dissemination, M. tuberculosis bacteremia is infrequently described in children. To determine the prevalence of M. tuberculosis bacteremia in adult and pediatric patients and to examine sources of heterogeneity between estimates. Systematic review and meta-analysis. Of 1077 reviewed abstracts, 27 publications met the inclusion criteria, yielding 29 independent M. tuberculosis bacteremia prevalence estimates: 22 in adults, 6 in children, and 1 not stratified by age group. The random effects pooled M. tuberculosis bacteremia prevalence in adults was 13.5% (95%CI 10.8-16.2) and 0.4% (95%CI 0-0.9) in children (P for difference = 0.004). Restricting analyses to HIV-infected participants, pooled M. tuberculosis bacteremia prevalence from 21 adult studies was 15.5% (95%CI 12.5-18.5) and 0.8% (95%CI 0-1.8) in three pediatric studies (P = 0.001). Inclusion of pre-determined study-level confounders did not account for observed differences in M. tuberculosis bacteremia prevalence between age groups. While M. tuberculosis bacteremia appears relatively common in adults, particularly those with HIV infection, bloodstream M. tuberculosis appears to be rare in children.

  19. iNKT cell production of GM-CSF controls Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Alissa C Rothchild

    2014-01-01

    Full Text Available Invariant natural killer T (iNKT cells are activated during infection, but how they limit microbial growth is unknown in most cases. We investigated how iNKT cells suppress intracellular Mycobacterium tuberculosis (Mtb replication. When co-cultured with infected macrophages, iNKT cell activation, as measured by CD25 upregulation and IFNγ production, was primarily driven by IL-12 and IL-18. In contrast, iNKT cell control of Mtb growth was CD1d-dependent, and did not require IL-12, IL-18, or IFNγ. This demonstrated that conventional activation markers did not correlate with iNKT cell effector function during Mtb infection. iNKT cell control of Mtb replication was also independent of TNF and cell-mediated cytotoxicity. By dissociating cytokine-driven activation and CD1d-restricted effector function, we uncovered a novel mediator of iNKT cell antimicrobial activity: GM-CSF. iNKT cells produced GM-CSF in vitro and in vivo in a CD1d-dependent manner during Mtb infection, and GM-CSF was both necessary and sufficient to control Mtb growth. Here, we have identified GM-CSF production as a novel iNKT cell antimicrobial effector function and uncovered a potential role for GM-CSF in T cell immunity against Mtb.

  20. Identification of a Transcription Factor That Regulates Host Cell Exit and Virulence of Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Lalitha Srinivasan

    2016-05-01

    Full Text Available The interaction of Mycobacterium tuberculosis (Mtb with host cell death signaling pathways is characterized by an initial anti-apoptotic phase followed by a pro-necrotic phase to allow for host cell exit of the bacteria. The bacterial modulators regulating necrosis induction are poorly understood. Here we describe the identification of a transcriptional repressor, Rv3167c responsible for regulating the escape of Mtb from the phagosome. Increased cytosolic localization of MtbΔRv3167c was accompanied by elevated levels of mitochondrial reactive oxygen species and reduced activation of the protein kinase Akt, and these events were critical for the induction of host cell necrosis and macroautophagy. The increase in necrosis led to an increase in bacterial virulence as reflected in higher bacterial burden and reduced survival of mice infected with MtbΔRv3167c. The regulon of Rv3167c thus contains the bacterial mediators involved in escape from the phagosome and host cell necrosis induction, both of which are crucial steps in the intracellular lifecycle and virulence of Mtb.

  1. PE_PGRS33 Contributes to Mycobacterium tuberculosis Entry in Macrophages through Interaction with TLR2.

    Directory of Open Access Journals (Sweden)

    Ivana Palucci

    Full Text Available PE_PGRS represent a large family of proteins typical of pathogenic mycobacteria whose members are characterized by an N-terminal PE domain followed by a large Gly-Ala repeat-rich C-terminal domain. Despite the abundance of PE_PGRS-coding genes in the Mycobacterium tuberculosis (Mtb genome their role and function in the biology and pathogenesis still remains elusive. In this study, we generated and characterized an Mtb H37Rv mutant (MtbΔ33 in which the structural gene of PE_PGRS33, a prototypical member of the protein family, was inactivated. We showed that this mutant entered macrophages with an efficiency up to ten times lower than parental or complemented strains, while its efficiency in infecting pneumocytes remained unaffected. Interestingly, the lack of PE_PGRS33 did not affect the intracellular growth of this mutant in macrophages. Using a series of functional deletion mutants of the PE_PGRS33 gene to complement the MtbΔ33 strain, we demonstrated that the PGRS domain is required to mediate cell entry into macrophages, with the key domain encompassing position 140-260 amino acids of PE_PGRS33. PE_PGRS33-mediated entry into macrophages was abolished in TLR2-deficient mice, as well as following treatment with wortmannin or an antibody against the complement receptor 3 (CR3, indicating that PE_PGRS33-mediated entry of Mtb in macrophages occurs through interaction with TLR2.

  2. Molecular analysis of clinical isolates previously diagnosed as Mycobacterium intracellulare reveals incidental findings of "Mycobacterium indicus pranii" genotypes in human lung infection.

    Science.gov (United States)

    Kim, Su-Young; Park, Hye Yun; Jeong, Byeong-Ho; Jeon, Kyeongman; Huh, Hee Jae; Ki, Chang-Seok; Lee, Nam Yong; Han, Seung-Jung; Shin, Sung Jae; Koh, Won-Jung

    2015-09-30

    Mycobacterium intracellulare is a major cause of Mycobacterium avium complex lung disease in many countries. Molecular studies have revealed several new Mycobacteria species that are closely related to M. intracellulare. The aim of this study was to re-identify and characterize clinical isolates from patients previously diagnosed with M. intracellulare lung disease at the molecular level. Mycobacterial isolates from 77 patients, initially diagnosed with M. intracellulare lung disease were re-analyzed by multi-locus sequencing and pattern of insertion sequences. Among the 77 isolates, 74 (96 %) isolates were designated as M. intracellulare based on multigene sequence-based analysis. Interestingly, the three remaining strains (4 %) were re-identified as "Mycobacterium indicus pranii" according to distinct molecular phylogenetic positions in rpoB and hsp65 sequence-based typing. In hsp65 sequevar analysis, code 13 was found in the majority of cases and three unreported codes were identified. In 16S-23S rRNA internal transcribed spacer (ITS) sequevar analysis, all isolates of both species were classified within the Min-A ITS sequevar. Interestingly, four of the M. intracellulare isolates harbored IS1311, a M. avium-specific element. Two of three patients infected with "M. indicus pranii" had persistent positive sputum cultures after antibiotic therapy, indicating the clinical relevance of this study. This analysis highlights the importance of precise identification of clinical isolates genetically close to Mycobacterium species, and suggests that greater attention should be paid to nontuberculous mycobacteria lung disease caused by "M. indicus pranii".

  3. 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)

  4. Analysis of isoniazid, streptomycin and ethambutol resistance in Mycobacterium tuberculosis isolates from Morocco.

    Science.gov (United States)

    Chaoui, Imane; Sabouni, Radia; Kourout, Moussa; Jordaan, Annemie M; Lahlou, Ouafae; Elouad, Rajae; Akrim, Mohammed; Victor, Thomas C; El Mzibri, Mohammed

    2009-05-01

    Drug-resistant tuberculosis is a major problem worldwide. Based on the knowledge of specific mutations occurring in Mycobacterium tuberculosis genome, drug resistance can be detected earlier. The aim of this study was to determine the prevalence of the most common mutations associated with resistance to Isoniazid (INH), Streptomycin (SM) and Ethambutol (EMB) in Mycobacterium tuberculosis isolates from Morocco in order to select target mutations to develop tests for rapid detection of drug-resistant Mycobacterium tuberculosis Moroccan isolates. A total of 199 M. tuberculosis isolates collected from the National Tuberculosis Reference Laboratory in Morocco were subject to katG, inhA, rrs, rpsL and emb mutation analysis by PCR probe-based assay. The genotypic results were then compared to drug susceptibility testing results for the corresponding drugs. Among 66 phenotypically INH resistant isolates, 80.3% (53/66) were found to be genotypically INH resistant from which 77.3% (51/66) and 3% (2/66) had respective mutations in katG315 and inhp-15 codons. Of the 58 phenotypically SM resistant isolates, genotypic SM resistance was confirmed in 17.2% (10/58) cases. Nucleotide mutations at codons 43 and 88 of rpsL gene and at codon 512 of rrs gene were found respectively in 12.1% (7/58); 1.7% (1/58) and 3.4% (2/58) of the phenotypically SM resistant Mycobacterium tuberculosis isolates. Finally, mutations at codon 306 of embB gene were identified in 42.3% (11/26) of Mycobacterium tuberculosis isolates phenotypically EMB resistant. This study showed that a large proportion of Mycobacterium tuberculosis resistant isolates from Morocco carry a large number of mutations in different codons (especially katG315, embB306 and rpsL43) of the corresponding genes associated with drug resistance. Thus, molecular analysis based on the identification of such mutations is useful but not fully sufficient to predict all drug resistance cases. Based on these results, rapid drug resistance

  5. Unexpectedly High Proportion of Ancestral Manu Genotype Mycobacterium tuberculosis Strains Cultured from Tuberculosis Patients in Egypt ▿

    Science.gov (United States)

    Helal, Zeinab H.; El-Din Ashour, Mohamed Seif; Eissa, Somaia A.; Abd-Elatef, Ghanem; Zozio, Thierry; Babapoor, Sankhiros; Rastogi, Nalin; Khan, Mazhar I.

    2009-01-01

    Tuberculosis is one of the important public health problems in Egypt. However, limited information on the Mycobacterium tuberculosis genotypes circulating in Egypt is available. A total of 151 M. tuberculosis strains were characterized by spoligotyping. The results revealed that 74.8% of M. tuberculosis isolates grouped into 13 different clusters, while 25.2% had unique spoligotype patterns. Comparison with an international spoligotyping database (the SITVIT2 database) showed that types SIT53 (T1 variant) and SIT54 (Manu2 variant) were the most common types between cluster groups. In addition, new shared types SIT2977, SIT2978, and SIT2979 were observed. The results identified for the first time an unusually high proportion of ancestral Manu strains of M. tuberculosis from patients in Egypt. The percentage of the Manu clade in this study (27.15%) was significantly higher than its overall representation of 0.4% in the SITVIT2 database. We show that in Egypt tuberculosis is caused by a predominant M. tuberculosis genotype belonging to the ancestral Manu lineage which could be a missing link in the split between ancestral and modern tubercle bacilli during the evolution of M. tuberculosis. PMID:19553569

  6. [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.

  7. Endosomal MR1 Trafficking Plays a Key Role in Presentation of Mycobacterium tuberculosis Ligands to MAIT Cells.

    Directory of Open Access Journals (Sweden)

    Melanie J Harriff

    2016-03-01

    Full Text Available Mucosal-Associated Invariant T (MAIT cells, present in high frequency in airway and other mucosal tissues, have Th1 effector capacity positioning them to play a critical role in the early immune response to intracellular pathogens, including Mycobacterium tuberculosis (Mtb. MR1 is a highly conserved Class I-like molecule that presents vitamin B metabolites to MAIT cells. The mechanisms for loading these ubiquitous small molecules are likely to be tightly regulated to prevent inappropriate MAIT cell activation. To define the intracellular localization of MR1, we analyzed the distribution of an MR1-GFP fusion protein in antigen presenting cells. We found that MR1 localized to endosomes and was translocated to the cell surface upon addition of 6-formyl pterin (6-FP. To understand the mechanisms by which MR1 antigens are presented, we used a lentiviral shRNA screen to identify trafficking molecules that are required for the presentation of Mtb antigen to HLA-diverse T cells. We identified Stx18, VAMP4, and Rab6 as trafficking molecules regulating MR1-dependent MAIT cell recognition of Mtb-infected cells. Stx18 but not VAMP4 or Rab6 knockdown also resulted in decreased 6-FP-dependent surface translocation of MR1 suggesting distinct pathways for loading of exogenous ligands and intracellular mycobacterially-derived ligands. We postulate that endosome-mediated trafficking of MR1 allows for selective sampling of the intracellular environment.

  8. 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

  9. 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

  10. 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

  11. 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...

  12. 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...

  13. 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

    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...

  14. Pathology of the emerging Mycobacterium tuberculosis complex pathogen, M. mungi in the banded mongoose (Mungos mungo)

    Science.gov (United States)

    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...

  15. Resazurin Microtiter Assay Plate: Simple and Inexpensive Method for Detection of Drug Resistance in Mycobacterium tuberculosis

    Science.gov (United States)

    Palomino, Juan-Carlos; Martin, Anandi; Camacho, Mirtha; Guerra, Humberto; Swings, Jean; Portaels, Françoise

    2002-01-01

    A method for detecting multidrug-resistant Mycobacterium tuberculosis by using a reduction of resazurin is described. Eighty clinical isolates were evaluated against isoniazid and rifampin; results at 7 days were compared with those of the proportion method. Specificity and sensitivity were excellent. The method is simple, inexpensive, and rapid and might be used with other antituberculosis drugs. PMID:12121966

  16. Substantial molecular evolution and mutation rates in prolonged latent Mycobacterium tuberculosis infection in humans

    DEFF Research Database (Denmark)

    Lillebaek, Troels; Norman, Anders; Rasmussen, Erik Michael

    2016-01-01

    The genome of Mycobacterium tuberculosis (Mtb) of latently infected individuals may hold the key to understanding the processes that lead to reactivation and progression to clinical disease. We report here analysis of pairs of Mtb isolates from putative prolonged latent TB cases. We identified tw...

  17. Modeling Phenotypic Metabolic Adaptations of Mycobacterium tuberculosis H37Rv under Hypoxia

    Science.gov (United States)

    2012-09-13

    prokaryotic bacteria . In yeast, the observed correlations Figure 6. Genes predicted to be essential for Mycobacterium tuberculosis H37Rv to adapt to...proteome quantification of haploid versus diploid yeast. Nature 455: 1251–1254. 64. Washburn MP, Koller A, Oshiro G, Ulaszek RR, Plouffe D, et al. (2003

  18. 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

  19. Transposition rates of Mycobacterium tuberculosis IS6110 restriction fragment length polymorphism patterns

    NARCIS (Netherlands)

    Eilers, Paul H. C.; van Soolingen, Dick; Thi Ngoc Lan, Nguyen; Warren, Rob M.; Borgdorff, Martien W.

    2004-01-01

    To determine the rate at which IS6110 restriction fragment length polymorphism (RFLP) patterns in Mycobacterium tuberculosis change over time, we applied a smooth nonparametric survival model to several data sets, including data from previous publications on the rate of change. The results strongly

  20. Viral Booster Vaccines Improve Mycobacterium bovis BCG-Induced Protection Against Bovine Tuberculosis

    Science.gov (United States)

    Previous work in small animal laboratory models of tuberculosis have shown that vaccination strategies based on heterologous prime-boost protocols using Mycobacterium bovis bacille Calmette-Guerin (BCG) to prime and Modified Vaccinia Ankara strain (MVA85A) or recombinant attenuated adenoviruses (Ad8...

  1. DNA fingerprinting of Mycobacterium tuberculosis: from phage typing to whole-genome sequencing.

    NARCIS (Netherlands)

    Schurch, A.C.; Soolingen, D. van

    2012-01-01

    Current typing methods for Mycobacterium tuberculosis complex evolved from simple phenotypic approaches like phage typing and drug susceptibility profiling to DNA-based strain typing methods, such as IS6110-restriction fragment length polymorphisms (RFLP) and variable number of tandem repeats (VNTR)

  2. Novel mutation in 16S rRNA associated with streptomycin dependence in Mycobacterium tuberculosis.

    OpenAIRE

    Honoré, N; Marchal, G; Cole, S T

    1995-01-01

    Molecular characterization of a streptomycin-dependent mutant of Mycobacterium tuberculosis revealed the presence of a novel mutation in the rrs gene encoding 16S rRNA. Insertion of an additional cytosine in the 530 loop of 16S rRNA, a region known to be involved in streptomycin susceptibility and resistance, was associated with streptomycin dependence.

  3. Mycobacterium tuberculosis ClpX interacts with FtsZ and interferes with FtsZ assembly.

    Directory of Open Access Journals (Sweden)

    Renata Dziedzic

    2010-07-01

    Full Text Available FtsZ assembly at the midcell division site in the form of a Z-ring is crucial for initiation of the cell division process in eubacteria. It is largely unknown how this process is regulated in the human pathogen Mycobacterium tuberculosis. Here we show that the expression of clpX was upregulated upon macrophage infection and exposure to cephalexin antibiotic, the conditions where FtsZ-ring assembly is delayed. Independently, we show using pull-down, solid-phase binding, bacterial two-hybrid and mycobacterial protein fragment complementation assays, that M. tuberculosis FtsZ interacts with ClpX, the substrate recognition domain of the ClpXP protease. Incubation of FtsZ with ClpX increased the critical concentration of GTP-dependent polymerization of FtsZ. Immunoblotting revealed that the intracellular ratio of ClpX to FtsZ in wild type M. tuberculosis is approximately 1:2. Overproduction of ClpX increased cell length and modulated the localization of FtsZ at midcell sites; however, intracellular FtsZ levels were unaffected. A ClpX-CFP fusion protein localized to the cell poles and midcell sites and colocalized with the FtsZ-YFP protein. ClpX also interacted with FtsZ mutant proteins defective for binding to and hydrolyzing GTP and possibly for interactions with other proteins. Taken together, our results suggest that M. tuberculosis ClpX interacts stoichiometrically with FtsZ protomers, independent of its nucleotide-bound state and negatively regulates FtsZ activities, hence cell division.

  4. The structure of a resuscitation-promoting factor domain from Mycobacterium tuberculosis shows homology to lysozymes.

    Science.gov (United States)

    Cohen-Gonsaud, Martin; Barthe, Philippe; Bagnéris, Claire; Henderson, Brian; Ward, John; Roumestand, Christian; Keep, Nicholas H

    2005-03-01

    Resuscitation-promoting factor (RPF) proteins reactivate stationary-phase cultures of (G+C)-rich Gram-positive bacteria including the causative agent of tuberculosis, Mycobacterium tuberculosis. We report the solution structure of the RPF domain from M. tuberculosis Rv1009 (RpfB) solved by heteronuclear multidimensional NMR. Structural homology with various glycoside hydrolases suggested that RpfB cleaved oligosaccharides. Biochemical studies indicate that a conserved active site glutamate is important for resuscitation activity. These data, as well as the presence of a clear binding pocket for a large molecule, indicate that oligosaccharide cleavage is probably the signal for revival from dormancy.

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

    Science.gov (United States)

    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.

  6. Evaluation of the Commercial Kit SIRE Nitratase for detecting resistant Mycobacterium tuberculosis in Brazil

    Directory of Open Access Journals (Sweden)

    Silvana Spindola de Miranda

    Full Text Available Abstract INTRODUCTION: This study aimed to evaluate a new commercial kit, Kit SIRE Nitratase-PlastLabor, for testing the drug susceptibility of clinical Mycobacterium tuberculosis isolates. METHODS: The accuracy of the Kit SIRE Nitratase was evaluated by examining the susceptibility (streptomycin, isoniazid, rifampicin, and ethambutol of 40 M. tuberculosis isolates, using the proportion method with Lowenstein-Jensen medium or the BACTEC MGIT 960 system. RESULTS: The detection accuracy for streptomycin, isoniazid, rifampicin, and ethambutol was 95%, 97.5%, 100%, and 80%, respectively. CONCLUSIONS: The exceptional accuracy demonstrated by Kit SIRE Nitratase for isoniazid and rifampicin makes the kit an attractive option for screening M. tuberculosis strain resistance.

  7. Differentiation of clinical Mycobacterium tuberculosis complex isolates by their GyrB polymorphism

    Directory of Open Access Journals (Sweden)

    Abass N

    2010-01-01

    Full Text Available Purpose: To evaluate the reliability of the gyrB PCR-RFLP technique in differentiating clinical Mycobacterium tuberculosis complex isolates. Materials and Methods: A primer pair MTUB-f and MTUB-r for M. tuberculosis complex (MTBC was used to differentiate 79 mycobacterial isolates by specific amplification of the 1,020-bp fragment of the gyrB gene (gyrB-PCR1. The MTBC isolates were further differentiated using a set of specific primers MTUB-756-Gf and MTUB-1450-Cr that allowed selective amplification of the gyrB fragment specific for M. tuberculosis (gyrB-PCR2. The DNA polymorphisms in the 1,020-bp gyrB fragment for 7 M. tuberculosis strains confirmed by PCR as well as 2 reference strains; M. tuberculosis H37Rv and M. bovis BCG were analyzed with the restriction enzyme Rsa1. Results: Seventy-seven (97.5% isolates were positive for gyrB-PCR1 and thus identified as members of M. tuberculosis complex (MTBC and two (2.6% isolates were negative and identified as Mycobacteria other than tuberculosis (MOTT. All the M. tuberculosis isolates showed the typical M. tuberculosis specific Rsa1 RFLP patterns (100, 360, 560-bp while 360 and 480-bp fragments were generated from M. bovis BCG. Conclusion: The gyrB PCR-RFLP using the endonuclease Rsa1 can be used to differentiate M. tuberculosis from M. bovis in clinical isolates.

  8. 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...

  9. Mycobacterium tuberculosis induces apoptosis in gamma/delta T lymphocytes from patients with advanced clinical forms of active tuberculosis.

    OpenAIRE

    Duarte, R; Kindlelán, J M; Carracedo, J; Sánchez-Guijo, P; Ramírez, R

    1997-01-01

    Antigens from inactivated Mycobacterium tuberculosis H37Ra induce activation in a subpopulation of gamma/delta (gamma/delta) T lymphocytes in a manner that resembles that of superantigens from alpha/beta T cells. After culture in vitro with H37Ra proteins, gamma/delta T lymphocytes from patients with advanced clinical forms of active tuberculosis (ACF-TBC) display cytotoxic activity against homotypic target cells exposed to H37Ra. Cytotoxicity by gamma/delta T lymphocytes from ACF-TBC patient...

  10. Rapid presumptive identification of the Mycobacterium tuberculosis-bovis complex by radiometric determination of heat stable urease

    International Nuclear Information System (INIS)

    Gandy, J.H.; Pruden, E.L.; Cox, F.R.

    1983-01-01

    Simple and rapid Bactec methodologies for the determination of neat (unaltered) and heat stable urease activity of mycobacteria are presented. Clinical isolates (63) and stock cultures (32)--consisting of: M. tuberculosis (19), M. bovis (5), M. kansasii (15), M. marinum (4), M. simiae (3), M. scrofulaceum (16), M. gordonae (6), M. szulgai (6), M. flavescens (1), M. gastri (1), M. intracellulare (6), M. fortuitum-chelonei complex (12), and M. smegmatis (1)--were tested for neat urease activity by Bactec radiometry. Mycobacterial isolates (50-100 mg wet weight) were incubated at 35 degrees C for 30 minutes with microCi14C-urea. Urease-positive mycobacteria gave Bactec growth index (GI) values greater than 100 units, whereas urease-negative species gave values less than 10 GI units. Eighty-three isolates possessing neat urease activity were heated at 80 degrees C for 30 minutes followed by incubation at 35 degrees C for 30 minutes with 1 microCi14C-urea. Mycobacterium tuberculosis-bovis complex demonstrated heat-stable urease activity (GI more than 130 units) and could be distinguished from mycobacteria other than tuberculosis (MOTT), which gave GI values equal to or less than 40 units

  11. Beijing genotype and other predominant Mycobacterium tuberculosis spoligotypes observed in Mashhad city, Iran

    Directory of Open Access Journals (Sweden)

    Rohani M

    2009-01-01

    Full Text Available Purpose : The purpose of this study was to understand the molecular epidemiology of tuberculosis in Khorasan province of Iran was studied by spoligotyping 113 Mycobacterium tuberculosis isolates. The spoligotyping results were in comparison to the word Spoligotyping Database of Institute Pasteur de Guadeloupe (SpolDB4. Spoligotyping data from Iran has rarely been described and there is limited information on the major circulating clades of M. tuberculosis in Iran. Materials and Methods: Spoligotyping was performed on 113 M. tuberculosis isolates from Mashhad patients between November 2004 and September 2005. Results: The study found 57 spoligopatterns. 17 clusters and 32 true orphan genotype. The biggest cluster with 13 isolates had not been previously reported. The Beijing genotype was seen in eight (7.1% isolates. Conclusions: Genotyping and Spoligotyping gives a unifying framework for both epidemiology and evolutionary analysis of M. tuberculosis populations.

  12. Design and Construction of a Cloning Vector Containing the hspX Gene of Mycobacterium tuberculosis.

    Science.gov (United States)

    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.

  13. Mycobacterium tuberculosis Molecular Determinants of Infection, Survival Strategies, and Vulnerable Targets.

    Science.gov (United States)

    Ferraris, Davide M; Miggiano, Riccardo; Rossi, Franca; Rizzi, Menico

    2018-02-01

    Mycobacterium tuberculosis is the causative agent of tuberculosis, an ancient disease which, still today, represents a major threat for the world population. Despite the advances in medicine and the development of effective antitubercular drugs, the cure of tuberculosis involves prolonged therapies which complicate the compliance and monitoring of drug administration and treatment. Moreover, the only available antitubercular vaccine fails to provide an effective shield against adult lung tuberculosis, which is the most prevalent form. Hence, there is a pressing need for effective antitubercular drugs and vaccines. This review highlights recent advances in the study of selected M. tuberculosis key molecular determinants of infection and vulnerable targets whose structures could be exploited for the development of new antitubercular agents.

  14. 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.

  15. Mycobacterium tuberculosis Universal Stress Protein Rv2623 Regulates Bacillary Growth by ATP Binding: Requirement for Establishing Chronic Persistent Infection

    Energy Technology Data Exchange (ETDEWEB)

    Drumm, J.; Mi, K; Bilder, P; Sun, M; Lim, J; Bielefeldt-Ohmann, H; Basaraba, R; So, M; Zhu, G; et. al.

    2009-01-01

    Tuberculous latency and reactivation play a significant role in the pathogenesis of tuberculosis, yet the mechanisms that regulate these processes remain unclear. The Mycobacterium tuberculosisuniversal stress protein (USP) homolog, rv2623, is among the most highly induced genes when the tubercle bacillus is subjected to hypoxia and nitrosative stress, conditions thought to promote latency. Induction of rv2623 also occurs when M. tuberculosis encounters conditions associated with growth arrest, such as the intracellular milieu of macrophages and in the lungs of mice with chronic tuberculosis. Therefore, we tested the hypothesis that Rv2623 regulates tuberculosis latency. We observed that an Rv2623-deficient mutant fails to establish chronic tuberculous infection in guinea pigs and mice, exhibiting a hypervirulence phenotype associated with increased bacterial burden and mortality. Consistent with this in vivo growth-regulatory role, constitutive overexpression of rv2623 attenuates mycobacterial growth in vitro. Biochemical analysis of purified Rv2623 suggested that this mycobacterial USP binds ATP, and the 2.9-A-resolution crystal structure revealed that Rv2623 engages ATP in a novel nucleotide-binding pocket. Structure-guided mutagenesis yielded Rv2623 mutants with reduced ATP-binding capacity. Analysis of mycobacteria overexpressing these mutants revealed that the in vitro growth-inhibitory property of Rv2623 correlates with its ability to bind ATP. Together, the results indicate that i M. tuberculosis Rv2623 regulates mycobacterial growth in vitro and in vivo, and ii Rv2623 is required for the entry of the tubercle bacillus into the chronic phase of infection in the host; in addition, iii Rv2623 binds ATP; and iv the growth-regulatory attribute of this USP is dependent on its ATP-binding activity. We propose that Rv2623 may function as an ATP-dependent signaling intermediate in a pathway that promotes persistent infection.

  16. Partial and ineffective activation of V gamma 9V delta 2 T cells by Mycobacterium tuberculosis-infected dendritic cells.

    Science.gov (United States)

    Meraviglia, Serena; Caccamo, Nadia; Salerno, Alfredo; Sireci, Guido; Dieli, Francesco

    2010-08-01

    Gammadelta T cells and dendritic cells (DCs) participate in early phases of immune response against Mycobacterium tuberculosis. We investigated whether a close functional relationship exists between these two cell populations using an in vitro coculture in a human system. Vgamma9Vdelta2 T cells induce full maturation of M. tuberculosis-infected immature DCs, as demonstrated by upregulation of the costimulatory CD80, CD86, CD40, and HLA-DR molecules on infected DCs after 24 h of coculture. Reciprocally, infected DCs induced substantial activation of Vgamma9Vdelta2 T cells upon coculture, which was cell-to-cell contact and TCR dependent, as demonstrated in transwell experiments. However, infected DCs selectively induced proliferative, but not cytokine or cytolytic, responses of Vgamma9Vdelta2 T cells, and this was associated with the expansion of phenotypically immature, central memory-type Vgamma9Vdelta2 T cells. Importantly, expansion of central memory Vgamma9Vdelta2 T cells and reduction of the pool of Vgamma9Vdelta2 T cells with immediate effector functions (effector memory and terminally differentiated cells) were also detected in vivo in the peripheral blood of patients with active tuberculosis, which reversed after antimycobacterial therapy. M. tuberculosis-infected DCs produced many different cytokines, but not IL-15, and addition of IL-15 to cocultures of infected DCs and Vgamma9Vdelta2 T cells caused efficient differentiation of these latter with generation of effector memory and terminally differentiated cells, which were capable of reducing the viability of intracellular M. tuberculosis. Overall, this study provides a further piece of information on the complex relationship between important players of innate immunity during mycobacterial infection.

  17. 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...

  18. Cutaneous gallium uptake in patients with AIDS with mycobacterium avium-intracellulare septicemia

    Energy Technology Data Exchange (ETDEWEB)

    Allwright, S.J.; Chapman, P.R.; Antico, V.F.; Gruenewald, S.M.

    1988-07-01

    Gallium imaging is increasingly being used for the early detection of complications in patients with AIDS. A 26-year-old homosexual man who was HIV antibody positive underwent gallium imaging for investigation of possible Pneumocystis carinii pneumonia. Widespread cutaneous focal uptake was seen, which was subsequently shown to be due to mycobacterium avium-intracellulare (MAI) septicemia. This case demonstrates the importance of whole body imaging rather than imaging target areas only, the utility of gallium imaging in aiding the early detection of clinically unsuspected disease, and shows a new pattern of gallium uptake in disseminated MAI infection.

  19. Henoch-Schönlein purpura associated with pulmonary Mycobacterium avium-intracellulare complex.

    Science.gov (United States)

    Yano, Shuichi

    2004-09-01

    A 57-year-old woman presented with bloody sputum and high grade fever. She had been treated for Mycobacterium avium-intracellulare complex (MAC). High grade fever slightly decreased and bloody sputum disappeared after two weeks, but low grade fever persisted. After 3 days of recurrence of bloody sputum, she suddenly complained of palpable pururitic lesions on the bilateral lower extremities with bilateral gonalgia. Although there are some reports of direct skin lesions due to MAC, there are no reports of hypersensitivity vasculitis, Henoch-Schönlein purpura, in MAC. It is necessary to consider MAC infection as a potential cause of Henoch-Schönlein purpura.

  20. Cutaneous gallium uptake in patients with AIDS with mycobacterium avium-intracellulare septicemia

    International Nuclear Information System (INIS)

    Allwright, S.J.; Chapman, P.R.; Antico, V.F.; Gruenewald, S.M.

    1988-01-01

    Gallium imaging is increasingly being used for the early detection of complications in patients with AIDS. A 26-year-old homosexual man who was HIV antibody positive underwent gallium imaging for investigation of possible Pneumocystis carinii pneumonia. Widespread cutaneous focal uptake was seen, which was subsequently shown to be due to mycobacterium avium-intracellulare (MAI) septicemia. This case demonstrates the importance of whole body imaging rather than imaging target areas only, the utility of gallium imaging in aiding the early detection of clinically unsuspected disease, and shows a new pattern of gallium uptake in disseminated MAI infection

  1. 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.

  2. Mycobacterium tuberculosis: just desserts for an ungrateful guest.

    Science.gov (United States)

    Halloran, M E

    1994-02-01

    Myobacterium tuberculosis is the most common infectious cause of death in the world, with up to one-third of the population infected. In industrial countries infection with M. tuberculosis and tuberculosis disease has been decreasing since the 19th century. Now, however, tuberculosis disease is on the increase again, with resistance of the bacillus to available drugs spreading rapidly. This resurgence can be seen from the ecological and evolutionary point of view, where human hosts are the niche of the tuberculosis bacillus. Copyright © 1994. Published by Elsevier Ltd.

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

    Science.gov (United States)

    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.

  4. 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

  5. Tuberculosis

    NARCIS (Netherlands)

    Ankrah, Alfred O; Glaudemans, Andor W J M; Maes, Alex; Van de Wiele, Christophe; Dierckx, Rudi A J O; Vorster, Mariza; Sathekge, Mike M

    Tuberculosis (TB) is currently the world's leading cause of infectious mortality. Imaging plays an important role in the management of this disease. The complex immune response of the human body to Mycobacterium tuberculosis results in a wide array of clinical manifestations, making clinical and

  6. 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.

  7. Clinical evaluation of MPT-64 and MPT-59, two proteins secreted from Mycobacterium tuberculosis, for skin test reagents

    DEFF Research Database (Denmark)

    Wilcke, J T; Jensen, B N; Ravn, P

    1996-01-01

    SETTING: Department of Pulmonary Medicine P, Bispebjerg Hospital, Copenhagen, Denmark. OBJECTIVE: To study the ability of two proteins secreted from Mycobacterium tuberculosis, MPT-64 and MPT-59 to induce delayed type hypersensitivity (DTH) reactions following intradermal administration. DESIGN...

  8. Direct detection of rpoB and katG gene mutations of Mycobacterium tuberculosis in clinical samples

    Directory of Open Access Journals (Sweden)

    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.

  9. The quiet and controversial: Ural family of Mycobacterium tuberculosis.

    Science.gov (United States)

    Mokrousov, Igor

    2012-06-01

    The absence of lateral gene exchange is a characteristic feature defining the genome evolution and clonal population structure of Mycobacterium tuberculosis. Certain of its lineages have justly attracted more attention due to their global dissemination and/or remarkable pathogenic properties. In this critical review, I discuss the population structure and genetic geography of the less 'popular' but in some aspects no less noteworthy M. tuberculosis lineage, Ural family. Its specific signature was initially defined by single copy in MIRU26, and large (>6) copy number in MIRU10 loci, and by 43-spoligotyping as absence of signals 29-31 and 33-36. Here, I suggest to subdivide Ural strains with present and absent spoligosignal 2 into primary Ural-1 and secondary Ural-2 sublineages, respectively, while 1 copy in MIRU26 is specific of Ural-1. Furthermore, three copies were recently described in MIRU10 in Ural-1 strains which highlights a high diversity of this locus in Ural genotype. The data on the two Ural sublineages were extracted from SpolDB4 database and original publications in order to trace their distribution at global and within-country levels. Importantly, the rigorous reanalysis suggested the true rate of the Ural genotype in the Ural area in Russia to be only 7%. In contrast, the frequencies of the Ural sublineages peak elsewhere: in South Ukraine and Georgia/Abkhazia (Ural-1, up to 14-19%), and in southwestern Iran (Ural-2, up to 26%). However, as this name is used since 2005, it seems most parsimonious to continue its use even if misleading. The forest graph was built on the available spoligoprofiles of Ural family strains from Eurasia. It helped to suggest routes of their primary dispersal that are discussed in the context of the known human migrations also influenced by natural barriers. The north/east Pontic area may have been an area of origin and primary dispersal of the Ural (Ural-1) genotype in Eurasia, whereas political and natural borders may have

  10. Comparative roles of free fatty acids with reactive nitrogen intermediates and reactive oxygen intermediates in expression of the anti-microbial activity of macrophages against Mycobacterium tuberculosis

    Science.gov (United States)

    Akaki, T; Tomioka, H; Shimizu, T; Dekio, S; Sato, K

    2000-01-01

    We assessed the role of free fatty acids (FFA) in the expression of the activity of macrophages against Mycobacterium tuberculosis in relation to the roles of two major anti-microbial effectors, reactive nitrogen intermediates (RNI) and reactive oxygen intermediates (ROI). Intracellular growth of M. tuberculosis residing inside macrophages was accelerated by treatments of macrophages with either quinacrine (phospholipase A2 (PLA2) inhibitor), arachidonyl trifuloromethylketone (type IV cytosolic PLA2 inhibitor), NG-monomethyl-l-arginine (nitric oxide synthase inhibitor), and superoxide dismutase plus catalase (ROI scavengers). In addition, M. tuberculosis-infected macrophages produced and/or secreted these effectors sequentially in the order ROI (0–3 h), FFA (0–48 h), and RNI (3 to at least 72 h). Notably, membranous FFA (arachidonic acid) of macrophages translocated to M. tuberculosis residing in the phagosomes of macrophages in phagocytic ability-and PLA2-dependent fashions during cultivation after M. tuberculosis infection. FFA, RNI and H2O2-mediated halogenation system (H2O2-halogenation system) displayed strong activity against M. tuberculosis in cell-free systems, while ROI alone exerted no such effects. Combinations of ‘FFA + RNI’ and ‘RNI + H2O2-halogenation system’ exhibited synergistic and additive effects against M. tuberculosis, respectively, while ‘FFA + H2O2-halogenation system’ had an antagonistic effect. Moreover, a sequential attack of FFA followed by RNI exerted synergistic activity against M. tuberculosis. Since M. tuberculosis-infected macrophages showed simultaneous production of RNI with FFA secretion for relatively long periods (approx. 45 h) and prolonged RNI production was seen thereafter, RNI in combination with FFA appear to play critical roles in the manifestation of the activity of macrophages against M. tuberculosis. PMID:10931146

  11. Tuberculosis

    International Nuclear Information System (INIS)

    Latorre Tortello, Pablo

    1998-01-01

    The tuberculosis is an infection bacterial chronicle of world distribution. Three organisms of the family of the mycobacterium, the m. tuberculosis, the m. bovis and m. africanum, phenotypic and genetically similar, produce it, but only the m. tuberculosis has importance; the others rarely produce illness in the human. By definition, the lung tuberculosis is the localization of the m. tuberculosis in the breathing tract, the most common and main form in the affection and the only able to contaminate to other people. The koch bacillus, transmits the illness directly person to person. The paper Includes topics like pathogenesis, natural history, epidemiology, diagnose, symptomatology and treatment

  12. 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....

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Ei, Phyu Win; Aung, Wah Wah; Lee, Jong Seok; Choi, Go Eun; Chang, Chulhun L

    2016-11-01

    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.

  15. 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.

  16. TUBERCULOSIS

    OpenAIRE

    Tarik Bajrović; Mahmud Nurkić; Šukrija Zvizdić

    2013-01-01

    Tuberculosis, known as the "White Plague" in the early 19th century, is the infectious disease, which is being researched today even in some of the most developed countries in the world. Epidemiological- epizootiological research points to the importance of pasteurizing milk as well as the transmission in aerosolized droplets in humans and animals. Mycobacterium tuberculosis (Mtb), M. bovis, M. africanum and M. microti are the mycobacteria that cause tuberculosis. Other mycobacteria cause dis...

  17. Perturbation of cytochrome c maturation reveals adaptability of the respiratory chain in Mycobacterium tuberculosis.

    Science.gov (United States)

    Small, Jennifer L; Park, Sae Woong; Kana, Bavesh D; Ioerger, Thomas R; Sacchettini, James C; Ehrt, Sabine

    2013-09-17

    Mycobacterium tuberculosis depends on aerobic respiration for growth and utilizes an aa3-type cytochrome c oxidase for terminal electron transfer. Cytochrome c maturation in bacteria requires covalent attachment of heme to apocytochrome c, which occurs outside the cytoplasmic membrane. We demonstrate that in M. tuberculosis the thioredoxin-like protein Rv3673c, which we named CcsX, is required for heme insertion in cytochrome c. Inactivation of CcsX resulted in loss of c-type heme absorbance, impaired growth and virulence of M. tuberculosis, and induced cytochrome bd oxidase. This suggests that the bioenergetically less efficient bd oxidase can compensate for deficient cytochrome c oxidase activity, highlighting the flexibility of the M. tuberculosis respiratory chain. A spontaneous mutation in the active site of vitamin K epoxide reductase (VKOR) suppressed phenotypes of the CcsX mutant and abrogated the activity of the disulfide bond-dependent alkaline phosphatase, which shows that VKOR is the major disulfide bond catalyzing protein in the periplasm of M. tuberculosis. Mycobacterium tuberculosis requires oxygen for growth; however, the biogenesis of respiratory chain components in mycobacteria has not been explored. Here, we identified a periplasmic thioredoxin, CcsX, necessary for heme insertion into cytochrome c. We investigated the consequences of disrupting cytochrome c maturation (CCM) for growth and survival of M. tuberculosis in vitro and for its pathogenesis. Appearance of a second-site suppressor mutation in the periplasmic disulfide bond catalyzing protein VKOR indicates the strong selective pressure for a functional cytochrome c oxidase. The observation that M. tuberculosis is able to partially compensate for defective CCM by upregulation of the cytochrome bd oxidase exposes a functional role of this alternative terminal oxidase under normal aerobic conditions and during pathogenesis. This suggests that targeting both oxidases simultaneously might be

  18. Detection of Mycobacteria, Mycobacterium avium Subspecies, and Mycobacterium tuberculosis Complex by a Novel Tetraplex Real-Time PCR Assay

    Science.gov (United States)

    Molina, Elena; Elguezabal, Natalia; Pérez, Valentín; Garrido, Joseba M.

    2015-01-01

    Mycobacterium tuberculosis complex, Mycobacterium avium, and many other nontuberculous mycobacteria are worldwide distributed microorganisms of major medical and veterinary importance. Considering the growing epidemiologic significance of wildlife-livestock-human interrelation, developing rapid detection tools of high specificity and sensitivity is vital to assess their presence and accelerate the process of diagnosing mycobacteriosis. Here we describe the development and evaluation of a novel tetraplex real-time PCR for simultaneous detection of Mycobacterium genus, M. avium subspecies, and M. tuberculosis complex in an internally monitored single assay. The method was evaluated using DNA from mycobacterial (n = 38) and nonmycobacterial (n = 28) strains, tissues spiked with different CFU amounts of three mycobacterial species (n = 57), archival clinical samples (n = 233), and strains isolated from various hosts (n = 147). The minimum detectable DNA amount per reaction was 50 fg for M. bovis BCG and M. kansasii and 5 fg for M. avium subsp. hominissuis. When spiked samples were analyzed, the method consistently detected as few as 100 to 1,000 mycobacterial CFU per gram. The sensitivity and specificity values for the panel of clinical samples were 97.5 and 100% using a verified culture-based method as the reference method. The assays performed on clinical isolates confirmed these results. This PCR was able to identify M. avium and M. tuberculosis complex in the same sample in one reaction. In conclusion, the tetraplex real-time PCR we designed represents a highly specific and sensitive tool for the detection and identification of mycobacteria in routine laboratory diagnosis with potential additional uses. PMID:25588660

  19. Coexistent Pseudogout and Mycobacterium avium-intracellulare Septic Arthritis in a Patient with HIV and ESRD

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    Wais Afzal

    2016-01-01

    Full Text Available Pseudogout is a crystal-induced arthropathy characterized by the deposition of calcium pyrophosphate dihydrate (CPPD crystals in synovial fluid, menisci, or articular cartilage. Although not very common, this entity can be seen in patients with chronic kidney disease (CKD. Septic arthritis due to Mycobacterium avium-intracellulare (MAI is a rare entity that can affect immunocompromised patients such as those with acquired immunodeficiency syndrome (AIDS or those who are on immunosuppressive drugs. Here, we describe a 51-year-old female who presented with fever, right knee pain, swelling, warmth, and decreased range of motion for several days. The initial assessment was consistent with pseudogout, with negative bacterial and fungal cultures. However, due to high white blood cell (WBC count in the synovial fluid analysis, she was empirically started on intravenous (IV vancomycin and piperacillin-tazobactam and discharged on IV vancomycin and cefepime, while acid-fast bacilli (AFB culture was still in process. Seventeen days later, AFB culture grew Mycobacterium avium-intracellulare (MAI, and she was readmitted for relevant management. This case illustrates that septic arthritis due to MAI should be considered in the differential diagnosis of septic arthritis in immunocompromised patients.

  20. 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.

  1. Identification and survival studies of Mycobacterium tuberculosis within Laboratory-Fermented bovine milk.

    Science.gov (United States)

    Mariam, Solomon H

    2014-03-26

    Mycobacterium tuberculosis and Mycobacterium bovis are the classic agents causing tuberculosis (TB) in humans and animals respectively. Transmission of tuberculous bacteria to humans usually occurs by inhalation of aerosols containing droplets of tubercle bacilli or via consumption of contaminated foods and drinks, primarily milk. The practice of milk pooling, including from cows with TB of the udder, further exacerbates the situation by rendering the whole milk supply infective. The simultaneous presence of indigenous lactic acid bacteria (LAB) in Mycobacterium-contaminated milk is believed to confer protective effect when the milk is adequately fermented. This study assessed the effect of LAB on the viability of mycobacteria in inherently contaminated pool of raw milk during fermentation as a function of time. Growth was obtained in the pooled raw milk culture, and identified to be M. tuberculosis. This M. tuberculosis growth was undetectable in the milk culture by day 7 as assessed by plating serial dilutions of the milk culture for up to 14 days. Some LAB species appear to show inhibitory effect on tubercle bacilli. If proven by more rigorous, controlled experimental results regarding such effect, selected LAB (with proven safety and efficacy) may have potential applications as anti-mycobacterial agents.

  2. Identification and survival studies of Mycobacterium tuberculosis within Laboratory-Fermented bovine milk

    Science.gov (United States)

    2014-01-01

    Background Mycobacterium tuberculosis and Mycobacterium bovis are the classic agents causing tuberculosis (TB) in humans and animals respectively. Transmission of tuberculous bacteria to humans usually occurs by inhalation of aerosols containing droplets of tubercle bacilli or via consumption of contaminated foods and drinks, primarily milk. The practice of milk pooling, including from cows with TB of the udder, further exacerbates the situation by rendering the whole milk supply infective. The simultaneous presence of indigenous lactic acid bacteria (LAB) in Mycobacterium-contaminated milk is believed to confer protective effect when the milk is adequately fermented. This study assessed the effect of LAB on the viability of mycobacteria in inherently contaminated pool of raw milk during fermentation as a function of time. Findings Growth was obtained in the pooled raw milk culture, and identified to be M. tuberculosis. This M. tuberculosis growth was undetectable in the milk culture by day 7 as assessed by plating serial dilutions of the milk culture for up to 14 days. Conclusions Some LAB species appear to show inhibitory effect on tubercle bacilli. If proven by more rigorous, controlled experimental results regarding such effect, selected LAB (with proven safety and efficacy) may have potential applications as anti-mycobacterial agents. PMID:24666844

  3. Comparative Study of Activities of a Diverse Set of Antimycobacterial Agents against Mycobacterium tuberculosis and Mycobacterium ulcerans.

    Science.gov (United States)

    Scherr, Nicole; Pluschke, Gerd; Panda, Manoranjan

    2016-05-01

    A library of compounds covering a broad chemical space was selected from a tuberculosis drug development program and was screened in a whole-cell assay against Mycobacterium ulcerans, the causative agent of the necrotizing skin disease Buruli ulcer. While a number of potent antitubercular agents were only weakly active or inactive against M. ulcerans, five compounds showed high activity (90% inhibitory concentration [IC90], ≤1 μM), making screening of focused antitubercular libraries a good starting point for lead generation against M. ulcerans. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

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

    Science.gov (United States)

    Moghaddam, Roghieh; Mosavari, Nader; Mahalati, Ardeshir Hesampoor

    2016-12-01

    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. Copyright © 2016.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Reactive Nitrogen Intermediates Have a Bacteriostatic Effect on Mycobacterium tuberculosis In Vitro

    OpenAIRE

    Firmani, Marcia A.; Riley, Lee W.

    2002-01-01

    Susceptibility of six isolates of Mycobacterium tuberculosis (CB3.3, CDC1551, RJ2E, C.C.13, H37Rv, and H37Ra) and two isolates of Mycobacterium bovis (Ravenel and BCG) to reactive oxygen intermediates (ROI) and reactive nitrogen intermediates (RNI) was determined by standard in vitro survival assays. After 21 days of incubation, the survival of most strains exposed to either acidified sodium nitrite (ASN) or hydrogen peroxide (H2O2) was significantly lower than the same strains unexposed to t...

  7. 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.

  8. 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

  9. At Baltic crossroads: a molecular snapshot of Mycobacterium tuberculosis population diversity in Kaliningrad, Russia.

    Science.gov (United States)

    Mokrousov, Igor; Otten, Tatiana; Zozio, Thierry; Turkin, Eugeni; Nazemtseva, Vera; Sheremet, Aleksandra; Vishnevsky, Boris; Narvskaya, Olga; Rastogi, Nalin

    2009-01-01

    The Kaliningrad region is the westernmost part of the Russian Federation; it includes an enclave on the Baltic Sea inside the European Union separated from mainland Russia by Lithuania and Poland. The incidence of tuberculosis in Kaliningrad has shown a steady and dramatic increase from 83/100,000 in 2000 to 134/100,000 in 2006; the rate of multidrug-resistant tuberculosis (MDR-tuberculosis) in the Kaliningrad region was reported to be 30.5% among newly diagnosed tuberculosis patients. This study presents a first molecular snapshot of the population diversity of Mycobacterium tuberculosis in this region. A total of 90 drug-resistant and susceptible M. tuberculosis strains from Kaliningrad were subjected to spoligotyping, 12-locus MIRU typing and mutation analysis of the drug resistance genes rpoB and katG. A comparison with international databases showed that the M. tuberculosis population in this region shares a joint pool of strains with the European part of Russia, and also exhibits a certain affinity with those of its northern European neighbours, such as Poland and Germany. Comparison of the genotyping and drug resistance data emphasized that the high prevalence of the MDR Beijing genotype strains is a major cause of the adverse epidemiological situation of MDR-tuberculosis in the Kaliningrad region.

  10. Resazurin reduction assays for screening of anti-tubercular compounds against dormant and actively growing Mycobacterium tuberculosis, Mycobacterium bovis BCG and Mycobacterium smegmatis.

    Science.gov (United States)

    Taneja, Neetu Kumra; Tyagi, Jaya Sivaswami

    2007-08-01

    To develop simple, rapid, low-cost and robust assays for screening drugs against dormant and actively growing mycobacteria. Actively growing aerobic and hypoxia-adapted dormant cultures of Mycobacterium tuberculosis, Mycobacterium bovis BCG and Mycobacterium smegmatis were tested for susceptibility to standard antimicrobial drugs by resazurin reduction assay. The visual and fluorimetric MICs were compared with those obtained by the standard cfu assay. Drug MICs for M. tuberculosis and M. bovis BCG were determined by the aerobic resazurin microplate assay (REMA) and correlated well with those obtained by the cfu assay. Metronidazole and nitrofurans showed comparable bactericidal activity in the hypoxic resazurin reduction assay (HyRRA). The HyRRA assay was noted to be superior to the cfu assay in that it distinguished between metabolically active dormant bacteria and non-viable organisms, unlike the cfu assay that could not differentiate between these two populations. The HyRRA assay performed with good concordance in both fluorimetric and visual formats to distinguish between bactericidal and bacteriostatic effects of a drug. The REMA and HyRRA assays will be useful for anti-tubercular anti-dormancy compound screening and drug susceptibility testing in a safe, reliable, easy and cost-effective manner particularly in low resource countries. The application of the assays in M. smegmatis or M. bovis BCG offers the distinct advantage of rapidly and safely screening anti-tubercular compounds in a high-throughput format.

  11. A rhodanine agent active against non-replicating intracellular Mycobacterium avium subspecies paratuberculosis

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    Bull Tim J

    2009-12-01

    Full Text Available Abstract Background Antibiotic therapy targeting chronic mycobacterial disease is often ineffective due to problems with the emergence of drug resistance and non-replicating persistent intracellular antibiotic resistant phenotypes. Strategies which include agents able to enhance host cell killing mechanisms could represent an alternative to conventional methods with the potential for host clearance if active against dormant phenotypes. Investigations of agents with potential activity against non-replicating mycobacteria however are restricted due to a need for assays that can assess bacterial viability without having to culture. Results This study describes the development and use of a pre16S ribosomal gene RNA/DNA ratio viability assay which is independent of the need for culture, supported by a novel thin layer accelerated mycobacterial colony forming method for determining viability and culturability of MAP in intracellular environments. We describe the use of these tools to demonstrate intracellular killing activity of a novel rhodanine agent (D157070 against the intracellular pathogen Mycobacterium avium subspecies paratuberculosis (MAP and show that the culturability of MAP decreases relative to its viability on intracellular entry suggesting the induction of a non-culturable phenotype. We further demonstrate that D157070, although having no direct activity against the culturability of extracellular MAP, can bind to cultured MAP cells and has significant influence on the MAP transcriptome, particularly with respect of δL associated genes. D157070 is shown to be taken up by bovine and human cells and able to enhance host cell killing, as measured by significant decreases in both culturability and viability of intracellular MAP. Conclusions This work suggests that pre16srRNA gene ratios represent a viable method for studying MAP viability. In addition, the rhodanine agent D157070 tested is non-toxic and enhances cell killing activity

  12. Combined use of Mycobacterium tuberculosis-specific CD4 and CD8 T-cell responses is a powerful diagnostic tool of active tuberculosis.

    Science.gov (United States)

    Rozot, Virginie; Patrizia, Amelio; Vigano, Selena; Mazza-Stalder, Jesica; Idrizi, Elita; Day, Cheryl L; Perreau, Matthieu; Lazor-Blanchet, Catherine; Ohmiti, Khalid; Goletti, Delia; Bart, Pierre-Alexandre; Hanekom, Willem; Scriba, Thomas J; Nicod, Laurent; Pantaleo, Giuseppe; Harari, Alexandre

    2015-02-01

    Immune-based assays are promising tools to help to formulate diagnosis of active tuberculosis. A multiparameter flow cytometry assay assessing T-cell responses specific to Mycobacterium tuberculosis and the combination of both CD4 and CD8 T-cell responses accurately discriminated between active tuberculosis and latent infection. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

  13. Utility of MPT64 antigen detection for rapid confirmation of mycobacterium tuberculosis complex

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    Jyoti Arora

    2015-01-01

    Full Text Available Background: Rapid differentiation of the Mycobacterium tuberculosis complex (MTBC and mycobacteria other than tuberculosis (MOTT is crucial to facilitate early and effective treatment of the patients. Clinical presentation of MTBC and MOTT is not always very clear and routine conventional methods are time consuming. Materials and Methods: In the present study, the MPT64 protein detection-based immunochomatographic test (SD Bioline Kit, Standard Diagnostics, Inc., Korea was compared with the conventional biochemical method. Results: The sensitivity, specificity, positive predictive, and negative predictive values of the SD AgMPT64 kit were found to be 100, 96.4, 98.72, and 100%, respectively. Conclusions: Our results have demonstrated that the SD bioline kit is a rapid, reliable method and it can be used in the Revised National Tuberculosis Control Program (RNTCP of India, for the appropriate management of tuberculosis.

  14. Molecular epidemiology of Mycobacterium tuberculosis strains circulating in the penitentiary system of Kazakhstan.

    Science.gov (United States)

    Ibrayeva, A; Kozhamkulov, U; Raiymbek, D; Alenova, A; Igilikova, S; Zholdybayeva, E; Abildaev, T; Momynaliev, K

    2014-03-01

    A total of 60 Mycobacterium tuberculosis isolates collected from patients in prisons in Kazakhstan and 125 from the civilian sector were examined using mycobacterial interspersed repetitive units-variable number of tandem repeat analysis in 2012. The proportion of tuberculosis strains with unique genotypes isolated from the civilian patients was 50.4%, while that in the prison patients was 31.7%. This difference was statistically significant (χ(2) 4.42, P 0.035), and may reflect a low genetic diversity of M. tuberculosis strains isolated from prison patients. The frequencies of mutations in the rpoB531 and katG315 genes of the M. tuberculosis strains isolated from the civilians and in the penitentiary system were not significantly different (rpoB531: 82.4% vs. 88.3%, and katG315: 98.4% vs. 100%, respectively).

  15. System-level strategies for studying the metabolism of Mycobacterium tuberculosis.

    Science.gov (United States)

    Beste, Dany J V; McFadden, Johnjoe

    2010-12-01

    Despite decades of research many aspects of the biology of Mycobacterium tuberculosis remain unclear and this is reflected in the antiquated tools available to treat and prevent tuberculosis and consequently this disease remains a serious public health problem. Important discoveries linking M. tuberculosis's metabolism and pathogenesis have renewed interest in this area of research. Previous experimental studies were limited to the analysis of individual genes or enzymes whereas recent advances in computational systems biology and high throughput experimental technologies now allow metabolism to be studied on a genome scale. Here we discuss the progress being made in applying system level approaches to studying the metabolism of this important pathogen. The information from these studies will fundamentally change our approach to tuberculosis research and lead to new targets for therapeutic drugs and vaccines.

  16. 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.

  17. Inhibition of glutamine synthetase: a potential drug target in Mycobacterium tuberculosis.

    Science.gov (United States)

    Mowbray, Sherry L; Kathiravan, Muthu K; Pandey, Abhishek A; Odell, Luke R

    2014-08-26

    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.

  18. 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

  19. Detection of Mycobacterium tuberculosis complex by PCR in fresh cheese from local markets in Hidalgo, Mexico.

    Science.gov (United States)

    Pereira-Suárez, Ana Laura; Estrada-Chávez, Yessica; Zúñiga-Estrada, Armidá; Lopez-Rincón, Gonzálo; Hernández, David Ulises Miranda; Padilla-Ramírez, Francisco Javier; Estrada-Chávez, Ciro

    2014-05-01

    The objective of this study was to identify the presence of Mycobacterium tuberculosis complex bacterial DNA in samples extracted from fresh cheeses; 95 samples of fresh cheese were obtained from municipal markets in the state of Hidalgo, in central Mexico, and were analyzed in triplicate. The exogenous control for the amplification was the mitochondrial gene for cytochrome b (cyt-b). M. tuberculosis complex DNA was detected by nested-PCR amplification of a fragment of the mpb70 gene in six samples, four of which were obtained from regions with enzootic bovine tuberculosis. These results suggest that cheeses prepared with raw milk contaminated with M. bovis are being sold and consumed by humans, which may cause tuberculosis.

  20. Mycobacterium tuberculosis and Dual M. tuberculosis/M. bovis Infection as the Cause of Tuberculosis in a Gorilla and a Lioness, Respectively, in Ibadan Zoo, Nigeria

    Directory of Open Access Journals (Sweden)

    Aina Adeogun

    2016-01-01

    Full Text Available Tuberculosis (TB in zoo animals is an important public health problem in places where it occurs. This is even very important in countries where there is little public health awareness about the disease; thus confined animals in the zoo can be infected directly or indirectly by infected humans and vice versa. In Nigeria, the problem of TB is a major concern among both humans and cattle. Here, we present cases of Mycobacterium tuberculosis and M. tuberculosis/M. bovis infections in a female gorilla and a lioness, respectively, in a zoo in Ibadan, Nigeria. These cases were confirmed after bacteriological examinations and DNA from granulomatous lesions of the animals’ carcasses were subjected to the Hain and spoligotyping techniques. Our findings reveal the first documented report of TB infections in a gorilla and a lioness in zoo animals in Nigeria. The public health risks of tuberculosis in zoological settings are therefore reemphasized.

  1. Drug resistance of Mycobacterium tuberculosis in Malawi: a cross-sectional survey.

    Science.gov (United States)

    Abouyannis, Michael; Dacombe, Russell; Dambe, Isaias; Mpunga, James; Faragher, Brian; Gausi, Francis; Ndhlovu, Henry; Kachiza, Chifundo; Suarez, Pedro; Mundy, Catherine; Banda, Hastings T; Nyasulu, Ishmael; Squire, S Bertel

    2014-11-01

    To document the prevalence of multidrug resistance among people newly diagnosed with - and those retreated for - tuberculosis in Malawi. We conducted a nationally representative survey of people with sputum-smear-positive tuberculosis between 2010 and 2011. For all consenting participants, we collected demographic and clinical data, two sputum samples and tested for human immunodeficiency virus (HIV).The samples underwent resistance testing at the Central Reference Laboratory in Lilongwe, Malawi. All Mycobacterium tuberculosis isolates found to be multidrug-resistant were retested for resistance to first-line drugs - and tested for resistance to second-line drugs - at a Supranational Tuberculosis Reference Laboratory in South Africa. Overall, M. tuberculosis was isolated from 1777 (83.8%) of the 2120 smear-positive tuberculosis patients. Multidrug resistance was identified in five (0.4%) of 1196 isolates from new cases and 28 (4.8%) of 581 isolates from people undergoing retreatment. Of the 31 isolates from retreatment cases who had previously failed treatment, nine (29.0%) showed multidrug resistance. Although resistance to second-line drugs was found, no cases of extensive drug-resistant tuberculosis were detected. HIV testing of people from whom M. tuberculosis isolates were obtained showed that 577 (48.2%) of people newly diagnosed and 386 (66.4%) of people undergoing retreatment were positive. The prevalence of multidrug resistance among people with smear-positive tuberculosis was low for sub-Saharan Africa - probably reflecting the strength of Malawi's tuberculosis control programme. The relatively high prevalence of such resistance observed among those with previous treatment failure may highlight a need for a change in the national policy for retreating this subgroup of people with tuberculosis.

  2. The Mycobacterium tuberculosis phagosome is a HLA-I processing competent organelle.

    Directory of Open Access Journals (Sweden)

    Jeff E Grotzke

    2009-04-01

    Full Text Available Mycobacterium tuberculosis (Mtb resides in a long-lived phagosomal compartment that resists maturation. The manner by which Mtb antigens are processed and presented on MHC Class I molecules is poorly understood. Using human dendritic cells and IFN-gamma release by CD8(+ T cell clones, we examined the processing and presentation pathway for two Mtb-derived antigens, each presented by a distinct HLA-I allele (HLA-Ia versus HLA-Ib. Presentation of both antigens is blocked by the retrotranslocation inhibitor exotoxin A. Inhibitor studies demonstrate that, after reaching the cytosol, both antigens require proteasomal degradation and TAP transport, but differ in the requirement for ER-golgi egress and new protein synthesis. Specifically, presentation by HLA-B8 but not HLA-E requires newly synthesized HLA-I and transport through the ER-golgi. Phenotypic analysis of the Mtb phagosome by flow organellometry revealed the presence of Class I and loading accessory molecules, including TAP and PDI. Furthermore, loaded HLA-I:peptide complexes are present within the Mtb phagosome, with a pronounced bias towards HLA-E:peptide complexes. In addition, protein analysis also reveals that HLA-E is enriched within the Mtb phagosome compared to HLA-A2. Together, these data suggest that the phagosome, through acquisition of ER-localized machinery and as a site of HLA-I loading, plays a vital role in the presentation of Mtb-derived antigens, similar to that described for presentation of latex bead-associated antigens. This is, to our knowledge, the first description of this presentation pathway for an intracellular pathogen. Moreover, these data suggest that HLA-E may play a unique role in the presentation of phagosomal antigens.

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

    DEFF Research Database (Denmark)

    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...

  4. Genetic diversity of Mycobacterium tuberculosis isolates from Tochigi prefecture, a local region of Japan.

    Science.gov (United States)

    Mizukoshi, Fuminori; Miyoshi-Akiyama, Tohru; Iwai, Hiroki; Suzuki, Takako; Kiritani, Reiko; Kirikae, Teruo; Funatogawa, Keiji

    2017-05-25

    Foreign-born patients with tuberculosis (TB) may introduce globally disseminated isolates of Mycobacterium tuberculosis into large cities in Japan. The risk of dissemination of these isolates into local regions, however, has not been determined. This study analyzed the molecular epidemiology of M. tuberculosis isolates obtained from TB patients living in a local region of Japan. Whole genome sequences of 169 M. tuberculosis isolates, obtained from 148 Japanese-born and 21 foreign-born patients living in Tochigi, Japan, were analyzed using the Comprehensive analysis server for the Mycobacterium t u b erculosis complex (CASTB). The 169 isolates were clustered into four clades; Lineage 2 (111 isolates 65.7%), Lineage 4 (43 isolates, 25.4%), Lineage 1 (13 isolates, 7.7%), and Lineage 3 (2 isolates, 1.2%). Of the 111 isolates belonging to Lineage 2, 79 (71.2%) were of the atypical Beijing sub-genotype. Of the 13 Lineage 1 isolates, nine (69.2%) were from foreign-born patients. The isolates belonging to Lineage 4 were further clustered into three clades, two containing isolates shared by both Japanese- and foreign-born patients. The two isolates belonging to Lineage 3 were obtained from foreign-born patients. The genotypic diversity of M. tuberculosis in a local region of Japan is increased primarily by the presence of isolates obtained from foreign-born patients.

  5. Validation of an immunochromatographic assay kit for the identification of the Mycobacterium tuberculosis complex

    Directory of Open Access Journals (Sweden)

    Al-Habib Omar Said Toihir

    2011-09-01

    Full Text Available The performance of the immunochromatographic assay, SD BIOLINE TB Ag MPT64 RAPID®, was evaluated in Madagascar. Using mouse anti-MPT64 monoclonal antibodies for rapid discrimination between the Mycobacterium tuberculosis complex and nontuberculous mycobacteria, the kit was tested on mycobacteria and other pathogens using conventional methods as the gold standard. The results presented here indicate that this kit has excellent sensitivity (100% and specificity (100% compared to standard biochemical detection and can be easily used for the rapid identification of M. tuberculosis complex.

  6. 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

    , suggest a potential for fewer missed cases with a combined IFNγ/IP-10 read-out in a 4 generation IGRA.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share......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...

  7. Analytical and Clinical Evaluation of the Epistem Genedrive Assay for Detection of Mycobacterium tuberculosis

    Science.gov (United States)

    Shenai, Shubhada; Armstrong, Derek T.; Valli, Eloise; Dolinger, David L.; Nakiyingi, Lydia; Dietze, Reynaldo; Dalcolmo, Margareth Pretti; Nicol, Mark P.; Zemanay, Widaad; Manabe, Yuka; Hadad, David Jamil; Marques-Rodrigues, Patricia; Palaci, Moises; Peres, Renata L.; Gaeddert, Mary; Armakovitch, Sandra; Nonyane, Bareng A. S.; Denkinger, Claudia M.; Banada, Padmapriya; Joloba, Moses L.; Ellner, Jerrold; Boehme, Catharina; Alland, David

    2016-01-01

    The Epistem Genedrive assay rapidly detects the Mycobacterium tuberculosis complex from sputum and is currently available for clinical use. However, the analytical and clinical performance of this test has not been fully evaluated. The analytical limit of detection (LOD) of the Genedrive PCR amplification was tested with genomic DNA; the performance of the complete (sample processing plus amplification) system was tested by spiking M. tuberculosis mc26030 cells into distilled water and M. tuberculosis-negative sputum. Specificity was tested using common respiratory pathogens and nontuberculosis mycobacteria. A clinical evaluation enrolled adults with suspected pulmonary tuberculosis, obtained three sputum samples from each participant, and compared the accuracy of the Genedrive to that of the Xpert MTB/RIF assay using M. tuberculosis cultures as the reference standard. The Genedrive assay had an LOD of 1 pg/μl (100 genomic DNA copies/reaction). The LODs of the system were 2.5 × 104 CFU/ml and 2.5 × 105 CFU/ml for cells spiked into water and sputum, respectively. False-positive rpoB probe signals were observed in 3/32 (9.4%) of the negative controls and also in few samples containing Mycobacterium abscessus, Mycobacterium gordonae, or Mycobacterium thermoresistibile. In the clinical study, among 336 analyzed participants, the overall sensitivities for the tuberculosis case detection of Genedrive, Xpert, and smear microscopy were 45.4% (95% confidence interval [CI], 35.2% to 55.8%), 91.8% (95% CI, 84.4% to 96.4%), and 77.3% (95% CI, 67.7% to 85.2%), respectively. The sensitivities of Genedrive and Xpert for the detection of smear-microscopy-negative tuberculosis were 0% (95% CI, 0% to 15.4%) and 68.2% (95% CI, 45.1% to 86.1%), respectively. The Genedrive assay did not meet performance standards recommended by the World Health Organization for a smear microscopy replacement tuberculosis test. Epistem is working on modifications to improve the assay. PMID:26865685

  8. Mycobacterium tuberculosis-specific T-cell responses in latent infection and active disease

    OpenAIRE

    Schuck, Sebastian D.

    2009-01-01

    Adaptive Immunantworten gegen Mycobacterium tuberculosis (M. tuberculosis) sind von entscheidender Bedeutung für die effektive Eindämmung des Erregers sowie den Schutz vor einer erneuten, sekundären Tuberkulose (TB). Obwohl Schlüsselfaktoren wie die Th1 Zytokine IFN-gamma und TNF-alpha bekannt sind, blieben Bemühungen zur Identifizierung eindeutiger immunologischer Parameter, welche ausschlaggebend für den Krankheitsverlauf sind, bislang erfolglos. Ein besseres Verständnis der zugrunde liegen...

  9. Purification, crystallization and preliminary X-ray crystallographic studies of Rv3705c from Mycobacterium tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. 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

  11. Genomic diversity of drug-resistant Mycobacterium tuberculosis isolates in Lisbon Portugal: Towards tuberculosis genomic epidemiology

    KAUST Repository

    Perdigão, João

    2015-03-01

    Multidrug- (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) present a challenge to disease control and elimination goals. Lisbon, Portugal, has a high TB incidence rate and unusual and successful XDR-TB strains that have been found in circulation for almost two decades. For the last 20. years, a continued circulation of two phylogenetic clades, Lisboa3 and Q1, which are highly associated with MDR and XDR, have been observed. In recent years, these strains have been well characterized regarding the molecular basis of drug resistance and have been inclusively subjected to whole genome sequencing (WGS). Researchers have been studying the genomic diversity of strains circulating in Lisbon and its genomic determinants through cutting-edge next generation sequencing. An enormous amount of whole genome sequence data are now available for the most prevalent and clinically relevant strains circulating in Lisbon.It is the persistence, prevalence and rapid evolution towards drug resistance that has prompted researchers to investigate the properties of these strains at the genomic level and in the future at a global transcriptomic level. Seventy Mycobacterium tuberculosis (MTB) isolates, mostly recovered in Lisbon, were genotyped by 24-. loci Mycobacterial Interspersed Repetitive Unit - Variable Number of Tandem Repeats (MIRU-VNTR) and the genomes sequenced using a next generation sequencing platform - Illumina HiSeq 2000.The genotyping data revealed three major clusters associated with MDR-TB (Lisboa3-A, Lisboa3-B and Q1), two of which are associated with XDR-TB (Lisboa3-B and Q1), whilst the genomic data contributed to elucidating 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 MTB clinical isolates, revealed two major clades responsible for MDR/XDR-TB in the region: Lisboa3 and Q

  12. A convenient synthesis and screening of benzosuberone bearing 1,2,3-triazoles against Mycobacterium tuberculosis.

    Science.gov (United States)

    Sajja, Yasodakrishna; Vanguru, Sowmya; Jilla, Lavanya; Vulupala, Hanmanth Reddy; Bantu, Rajashaker; Yogeswari, Perumal; Sriram, Dharmarajan; Nagarapu, Lingaiah

    2016-09-01

    A series of benzosuberone bearing 1,2,3-triazoles were rationally designed and alkyl/aryl groups appended on 1,2,3-triazole derivatives 5a-o were synthesized using click chemistry and evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (ATCC27294). Compounds 5h (MIC: 3.125μg/mL) and 5l, 5m, 5o (MIC: 6.25μg/mL) exhibited promising hits. This is the first Letter on the synthesis and in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv of benzosuberone alkyl/aryl groups appended on 1,2,3-triazole derivatives. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Rv2629 Overexpression Delays Mycobacterium smegmatis and Mycobacteria tuberculosis Entry into Log-Phase and Increases Pathogenicity of Mycobacterium smegmatis in Mice

    Directory of Open Access Journals (Sweden)

    Dan Liu

    2017-11-01

    Full Text Available Objective: The aim of the present study was to explore the potential biological role of Rv2629 in Mycobacterium smegmatis and Mycobacterium tuberculosis.Methods: Recombinant wild type and mutant Rv2629 strains were constructed. Rv2629 expression was evaluated by real-time PCR and western blot. Microarray and interaction network analyses were used to identify the gene interactions associated with wild type and mutant Rv2629. Bacterial growth was assessed in Balb/c mice infected with wild type and mutant Rv2629 strains using CFU assay and histological analysis of the organs.Results: Overexpression of Rv2629 could delay the entry of the Mycobacterium tuberculosis cells into the log-phase, while Rv2629 decreased the number of ribosomes and the expression of uridylate kinase in Mycobacterium smegmatis. The Gene Ontology (GO and pathway analysis indicated that 122 genes correlated with wild type Rv2629, whereas the Rv2629 mutation led to decrease in the ribosome production, oxidative phosphorylation, and virulence in Mycobacterium tuberculosis. Overexpression of Rv2629 slightly enhanced the drug resistance of Mycobacterium smegmatis to antibiotics, and increased its survival and pathogenicity in Balb/c mice.Conclusion: It is suggested that Rv2629 is involved in the survival of the clinical drug-resistant strain via bacterial growth repression and bacterial persistence induction.

  15. 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

  16. 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.

  17. High-Throughput CRISPR Typing of Mycobacterium tuberculosis Complex and Salmonella enterica Serotype Typhimurium

    OpenAIRE

    Sola, Christophe; Abadia, Edgar; Le Hello, Simon; Weill, François-Xavier

    2015-01-01

    International audience; Spoligotyping was developed almost 18 years ago and still remains a popular fi rst-lane genotyping technique to identify and subtype Mycobacterium tuberculosis complex (MTC) clinical isolates at a phylogeo-graphic level. For other pathogens, such as Salmonella enterica , recent studies suggest that specifi cally designed spoligotyping techniques could be interesting for public health purposes. Spoligotyping was in its original format a reverse line-blot hybridization m...

  18. Pyrazinamide resistance in Mycobacterium tuberculosis arises after rifampicin and fluoroquinolone resistance

    OpenAIRE

    Alame-Emane , Amel Kevin; Xu , Peng; Pierre-Audigier , C; Cadet-Daniel , Véronique; Shen , X; Sraouia , M; Djoba Siawaya , J F; Takiff , H; Gao , Q; Gicquel , B

    2015-01-01

    International audience; Background: Multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis (TB) constitute a major public health concern. The objective was to determine the timing of pncA mutations that confer pyrazinamide (PZA) resistance in relation to mutations conferring resistance to isoniazid (INH) and rifampicin (RMP). For this goal, isolates from two major urban centres—Paris (101 strains) and Shanghai (171 strains)—were investigated for t...

  19. Mycobacterium tuberculosis induces the miR-33 locus to reprogram autophagy and host lipid metabolism

    OpenAIRE

    Ouimet, Mireille; Koster, Stefan; Sakowski, Erik; Ramkhelawon, Bhama; van Solingen, Coen; Oldebeken, Scott; Karunakaran, Denuja; Celhay, Cynthia Portal; Sheedy, Frederick J.; Ray, Tathagat Dutta; Cecchini, Katharine; Zamore, Philip D; Rayner, Katey J; Marcel, Yves L; Philips, Jennifer A

    2016-01-01

    Mycobacterium tuberculosis (Mtb) survives within macrophages by evading delivery to the lysosome and promoting the accumulation of lipid bodies, which serve as a bacterial source of nutrients. Here we show that by inducing miR-33 and its passenger strand miR-33*, Mtb inhibits integrated pathways involved in autophagy, lysosomal function and fatty acid oxidation to support bacterial replication. Silencing of miR-33 and miR-33* by genetic or pharmacological means promotes autophagy flux through...

  20. High-contrast imaging of mycobacterium tuberculosis using third-harmonic generation microscopy

    Science.gov (United States)

    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.

  1. DNA repair systems and the pathogenesis of Mycobacterium tuberculosis: varying activities at different stages of infection

    OpenAIRE

    Gorna, AE; Bowater, RP; Dziadek, J

    2010-01-01

    Mycobacteria, including most of all MTB (Mycobacterium tuberculosis), cause pathogenic infections in humans and, during the infectious process, are exposed to a range of environmental insults, including the host's immune response. From the moment MTB is exhaled by infected individuals, through an active and latent phase in the body of the new host, until the time they reach the reactivation stage, MTB is exposed to many types of DNA-damaging agents. Like all cellular organisms, MTB has effici...

  2. DNA alkylation damage as a sensor of nitrosative stress in Mycobacterium tuberculosis

    OpenAIRE

    Durbach, S I; Springer, B; Machowski, E E; North, R J; Papavinasasundaram, K G; Colston, M J; Böttger, E C; Mizrahi, V

    2003-01-01

    One of the cellular consequences of nitrosative stress is alkylation damage to DNA. To assess whether nitrosative stress is registered on the genome of Mycobacterium tuberculosis, mutants lacking an alkylation damage repair and reversal operon were constructed. Although hypersensitive to the genotoxic effects of N-methyl-N′-nitro-N-nitrosoguanidine in vitro, the mutants displayed no phenotype in vivo, suggesting that permeation of nitrosative stress to the level of cytotoxic DNA damage is res...

  3. Characterization of DprE1-Mediated Benzothiazinone Resistance in Mycobacterium tuberculosis

    OpenAIRE

    Foo, Caroline Shi-Yan; Lechartier, Benoit; Kolly, Ga?lle S.; Boy-R?ttger, Stefanie; Neres, Jo?o; Rybniker, Jan; Lupien, Andr?anne; Sala, Claudia; Piton, J?r?mie; Cole, Stewart T.

    2016-01-01

    Benzothiazinones (BTZs) are a class of compounds found to be extremely potent against both drug-susceptible and drug-resistant Mycobacterium tuberculosis strains. The potency of BTZs is explained by their specificity for their target decaprenylphosphoryl-d-ribose oxidase (DprE1), in particular by covalent binding of the activated form of the compound to the critical cysteine 387 residue of the enzyme. To probe the role of C387, we used promiscuous site-directed mutagenesis to introduce other ...

  4. Mycobacterium tuberculosis prokaryotic ubiquitin-like protein-deconjugating enzyme is an unusual aspartate amidase.

    Science.gov (United States)

    Burns, Kristin E; McAllister, Fiona E; Schwerdtfeger, Carsten; Mintseris, Julian; Cerda-Maira, Francisca; Noens, Elke E; Wilmanns, Matthias; Hubbard, Stevan R; Melandri, Francesco; Ovaa, Huib; Gygi, Steven P; Darwin, K Heran

    2012-10-26

    Deamidase of Pup (Dop), the prokaryotic ubiquitin-like protein (Pup)-deconjugating enzyme, is critical for the full virulence of Mycobacterium tuberculosis and is unique to bacteria, providing an ideal target for the development of selective chemotherapies. We used a combination of genetics and chemical biology to characterize the mechanism of depupylation. We identified an aspartate as a potential nucleophile in the active site of Dop, suggesting a novel protease activity to target for inhibitor development.

  5. Correlation of molecular resistance mechanisms and phenotypic resistance levels in streptomycin-resistant Mycobacterium tuberculosis.

    OpenAIRE

    Meier, A; Sander, P; Schaper, K J; Scholz, M; Böttger, E C

    1996-01-01

    Quantitative susceptibility testing of clinical isolates of streptomycin-resistant Mycobacterium tuberculosis demonstrated that there is a close correlation between the molecular resistance mechanism and the in vitro activity of streptomycin: mutations in rpsL were mainly associated with high-level resistance, mutations in rrs were associated with an intermediate level of resistance, and streptomycin-resistant isolates with wild-type rpsL and rrs exhibited a low-level resistance phenotype. In...

  6. Impact of pe_pgrs33 Gene Polymorphisms on Mycobacterium tuberculosis Infection and Pathogenesis

    Directory of Open Access Journals (Sweden)

    Giovanni Delogu

    2017-04-01

    Full Text Available PE_PGRS33 is a surface-exposed protein of Mycobacterium tuberculosis (Mtb which exerts its role in macrophages entry and immunomodulation. In this study, we aimed to investigate the polymorphisms in the pe_pgrs33 gene of Mtb clinical isolates and evaluate their impact on protein functions. We sequenced pe_pgrs33 in a collection of 135 clinical strains, genotyped by 15-loci MIRU-VNTR and spoligotyping and belonging to the Mtb complex (MTBC. Overall, an association between pe_pgrs33 alleles and MTBC genotypes was observed and a dN/dS ratio of 0.64 was obtained, suggesting that a purifying selective pressure is acting on pe_pgrs33 against deleterious SNPs. Among a total of 19 pe_pgrs33 alleles identified in this study, 5 were cloned and used to complement the pe_pgrs33 knock-out mutant strain of Mtb H37Rv (MtbΔ33 to assess the functional impact of the respective polymorphisms in in vitro infections of primary macrophages. In human monocyte-derived macrophages (MDMs infection, large in-frame and frameshift mutations were unable to restore the phenotype of Mtb H37Rv, impairing the cell entry capacity of Mtb, but neither its intracellular replication rate nor its immunomodulatory properties. In vivo studies performed in the murine model of tuberculosis (TB demonstrated that the MtbΔ33 mutant strain was not impaired in the ability to infect and replicate in the lung tissue compared to the parental strain. Interestingly, MtbΔ33 showed an enhanced virulence during the chronic steps of infection compared to Mtb H37Rv. Similarly, the complementation of MtbΔ33 with a frameshift allele also resulted in a Mtb strain capable of causing a surprisingly enhanced tissue damage in murine lungs, during the chronic steps of infection. Together, these results further support the role of PE_PGRS33 in the pathogenesis and virulence of Mtb.

  7. Small Molecule-directed Immunotherapy against Recurrent Infection by Mycobacterium tuberculosis*

    Science.gov (United States)

    Bhattacharya, Debapriya; Dwivedi, Ved Prakash; Maiga, Mamoudou; Maiga, Mariama; Van Kaer, Luc; Bishai, William R.; Das, Gobardhan

    2014-01-01

    Tuberculosis remains the biggest infectious threat to humanity with one-third of the population infected and 1.4 million deaths and 8.7 million new cases annually. Current tuberculosis therapy is lengthy and consists of multiple antimicrobials, which causes poor compliance and high treatment dropout, resulting in the development of drug-resistant variants of tuberculosis. Therefore, alternate methods to treat tuberculosis are urgently needed. Mycobacterium tuberculosis evades host immune responses by inducing T helper (Th)2 and regulatory T (Treg) cell responses, which diminish protective Th1 responses. Here, we show that animals (Stat-6−/−CD4-TGFβRIIDN mice) that are unable to generate both Th2 cells and Tregs are highly resistant to M. tuberculosis infection. Furthermore, simultaneous inhibition of these two subsets of Th cells by therapeutic compounds dramatically reduced bacterial burden in different organs. This treatment was associated with the generation of protective Th1 immune responses. As these therapeutic agents are not directed to the harbored organisms, they should avoid the risk of promoting the development of drug-resistant M. tuberculosis variants. PMID:24711459

  8. Molecular epidemiology and drug resistance of widespread genotypes of Mycobacterium tuberculosis in northwestern Russia.

    Science.gov (United States)

    Baranov, A A; Mariandyshev, A O; Mannsåker, T; Dahle, U R; Bjune, G A

    2009-10-01

    Four administrative territories (Archangel Oblast, Murmansk Oblast, Republic of Karelia, Republic of Komi) in the northwestern federal region of Russia. To describe the genetic diversity and level of drug resistance in Mycobacterium tuberculosis isolates from new cases of pulmonary tuberculosis. A total of 176 isolates of M. tuberculosis were tested for drug susceptibility and typed with insertion sequence (IS) 6110 restriction fragment length polymorphism (RFLP) and spoligotyping. The Beijing family was found to be the most prevalent (47.1%), most frequently clustered and significantly associated with drug resistance to all first-line anti-tuberculosis drugs (isoniazid, rifampicin, ethambutol, streptomycin and pyrazinamide) and ethionamide, when compared to the T and Haarlem families of M. tuberculosis, which were also prevalent in the study population. Some RFLP clusters (4/10) included isolates that originated from patients residing in different territories, and cases infected with multiple strains of M. tuberculosis were apparently present in the collection. The M. tuberculosis population in northwestern Russia appears to be genetically diverse and geographically widespread. Although dominated by isolates assigned to the Beijing family, other families also contribute to the current epidemic, and multiple strain infections may represent a problem in many cases. Extended genetic studies should be encouraged.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Cutaneous Squamous Cell Carcinoma in Lupus Vulgaris Caused by Drug Resistant Mycobacterium Tuberculosis.

    Science.gov (United States)

    Kumaran, Muthu S; Narang, Tarun; Jitendriya, Madhukara; Tirumale, Rajalakshmi; Manjunath, Suraj; Savio, Jayanthi

    2017-01-01

    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.

  11. 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

  12. Low rate of fluoroquinolone resistance in Mycobacterium tuberculosis isolates from northern Tanzania.

    Science.gov (United States)

    van den Boogaard, Jossy; Semvua, Hadija H; van Ingen, Jakko; Mwaigwisya, Solomon; van der Laan, Tridia; van Soolingen, Dick; Kibiki, Gibson S; Boeree, Martin J; Aarnoutse, Rob E

    2011-08-01

    Fluoroquinolones are used in second-line treatment of tuberculosis (TB) and have a potential role in shortening TB treatment duration. The wide use of fluoroquinolones in the treatment of other infections, including respiratory tract infections in patients with (undiagnosed) active TB, could result in fluoroquinolone-resistant Mycobacterium tuberculosis. We determined the rate of fluoroquinolone resistance in M. tuberculosis isolates obtained from Tanzanian patients and linked this to previous fluoroquinolone exposure and mycobacterial resistance to rifampicin and isoniazid. A total of 291 M. tuberculosis isolates were obtained between April 2009 and June 2010 from patients with smear-positive pulmonary TB and tested for susceptibility to ciprofloxacin, moxifloxacin, rifampicin and isoniazid. Information on previous fluoroquinolone use was obtained by interviewing patients and checking their medical files. Only 2 (0.7%) of the 291 M. tuberculosis isolates were resistant to ciprofloxacin; 1 of which was intermediately resistant to moxifloxacin as well. These two isolates were susceptible to rifampicin and isoniazid. Twenty-two (8%) of the 291 patients had a history of fluoroquinolone use (median: 7 days; interquartile range: 5-10 days). The patients from whom the fluoroquinolone-resistant M. tuberculosis isolates were obtained had no known history of previous fluoroquinolone use. Our findings indicate that the rate of fluoroquinolone-resistant M. tuberculosis in Tanzanian patients with TB is low and not related to previous, brief episodes of exposure to fluoroquinolones. The findings favour future application of fluoroquinolones in TB treatment regimens of shorter duration.

  13. Genetic Diversity of Mycobacterium tuberculosis Isolates from Tibetans in Tibet, China

    Science.gov (United States)

    Zhao, Xiuqin; Sang, Ba; Lv, Bing; Liu, Zhiguang; Wan, Kanglin

    2012-01-01

    Background Tuberculosis (TB) is a serious health problem in Tibet where Tibetans are the major ethnic group. Although genotyping of Mycobacterium tuberculosis (M. tuberculosis) isolates is a valuable tool for TB control, our knowledge of population structure of M. tuberculosis circulating in Tibet is limited. Methodology/Principal Findings In our study, a total of 576 M. tuberculosis isolates from Tibetans in Tibet, China, were analyzed via spoligotyping and 24-locus MIRU-VNTR. The Beijing genotype was the most prevalent family (90.63%, n = 522). Shared-type (ST) 1 was the most dominant genotype (88.89%, n = 512). We found that there was no association between the Beijing genotype and sex, age and treatment status. In this sample collection, 7 of the 24 MIRU-VNTR loci were highly or moderately discriminative according to their Hunter-Gaston discriminatory index. An informative set of 12 loci had similar discriminatory power with 24 loci set. Conclusions/Significance The population structure of M. tuberculosis isolates in Tibetans is homogeneous and dominated by Beijing genotype. The analysis of 24-locus MIRU-VNTR data might be useful to select appropriate VNTR loci for the genotyping of M. tuberculosis. PMID:22479472

  14. Delayed onset Mycobacterium intracellulare keratitis after laser in situ keratomileusis: A case report and literature review.

    Science.gov (United States)

    Ko, JaeSang; Kim, Se Kyung; Yong, Dong Eun; Kim, Tae-Im; Kim, Eung Kweon

    2017-12-01

    Infectious keratitis is a relatively uncommon but potentially sight-threatening complication of laser in situ keratomileusis (LASIK). Mycobacterial keratitis is usually regarded as late onset keratitis among post-LASIK keratitis. There has been no documented case of Mycobacterium intracellulare post-LASIK keratitis of a long-latent period. A 36-year-old man was referred to our out-patient clinic, for persistent corneal epithelial defect with intrastromal infiltration. He had undergone uneventful bilateral LASIK procedure 4 years before. He complained decreased vision, accompanied by ocular pain, photophobia, and redness in his left eye for 7 months. Lamellar keratectomy was taken using femtosecond laser. Bacterial culture with sequenced bacterial 16s ribosomal DNA confirmed the organism to be M intracellulare. After 3 months of administration of topical clarithromycin, amikacin, and moxifloxacin, the corneal epithelial defect was resolved and the infiltration was much improved. However, newly developed diffuse haziness with surrounding granular infiltration in the central cornea was noted. Drug toxicity was suspected and topical moxifloxacin was discontinued, resulting in resolution of the diffuse haze with infiltration. The patient was followed up regularly without medication thereafter and recurrence was not found for 7 years. This case presents the first case of M intracellulare keratitis after LASIK. LASIK surgeons should aware that post-LASIK keratitis can develop long after the operation and careful suspicion of infectious disease with meticulous diagnostic test is needed. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  15. Vitamin D enhances IL-1β secretion and restricts growth of Mycobacterium tuberculosis in macrophages from TB patients

    Directory of Open Access Journals (Sweden)

    Daniel Eklund

    2013-01-01

    Full Text Available The emergence of multidrug-resistant strains of Mycobacterium tuberculosis (MTB, the bacterium responsible for tuberculosis (TB, has rekindled the interest in the role of nutritional supplementation of micronutrients, such as vitamin D, as adjuvant treatment. Here, the growth of virulent MTB in macrophages obtained from the peripheral blood of patients with and without TB was studied. The H37Rv strain genetically modified to express Vibrio harveyi luciferase was used to determine the growth of MTB by luminometry in the human monocyte-derived macrophages (hMDMs from study subjects. Determination of cytokine levels in culture supernatants was performed using a flow cytometry-based bead array technique. No differences in intracellular growth of MTB were observed between the different study groups. However, stimulation with 100nM 1,25-dihydroxyvitamin D significantly enhanced the capacity of hMDMs isolated from TB patients to control the infection. This effect was not observed in hMDMs from the other groups. The interleukin (IL-1β and IL-10 release by hMDMs was clearly increased upon stimulation with 1,25-dihydroxyvitamin D. Furthermore, the 1,25-dihydroxyvitamin D stimulation also led to elevated levels of TNF-α (tumor necrosis factor-alpha and IL-12p40. It was concluded that vitamin D triggers an inflammatory response in human macrophages with enhanced secretion of cytokines, as well as enhancing the capacity of hMDMs from patients with active TB to restrict mycobacterial growth.

  16. Mycobacterium tuberculosis Cpn60.2 (GroEL2 blocks macrophage apoptosis via interaction with mitochondrial mortalin

    Directory of Open Access Journals (Sweden)

    Sunil Joseph

    2017-04-01

    Full Text Available Earlier studies suggested that Mycobacterium tuberculosis (Mtb proteins exported within the host macrophage play an essential role in tuberculosis pathogenesis. In fact, Mtb proteins interact with and deactivate key regulators of many macrophage functions such as phago-lysosome fusion and antigen presentation, resulting in the intracellular persistence of pathogenic mycobacteria. Cpn60.2 is an abundant Mtb chaperone protein, restricted to cell cytoplasm and surface, that was reported to be essential for bacterial growth. Here, we provide evidence that once Mtb is ingested by the macrophage, Cpn60.2 is able to detach from the bacterial surface and crosses the phagosomal membrane towards mitochondria organelles. Once there, Cpn60.2 interacts with host mortalin, a member of the HSP 70 gene family that contributes to apoptosis modulation. In this regard, we showed that Cpn60.2 blocks macrophage apoptosis, a phenotype that is reversed when cells are pretreated with a specific mortalin inhibitor. Our findings have extended the current knowledge of the Mtb Cpn60.2 functions to add a strong anti-apoptotic activity dependent on its interaction with mitochondrial mortalin, which otherwise promotes Mtb survival in the hostile macrophage environment.

  17. Multifaceted remodeling by vitamin C boosts sensitivity of Mycobacterium tuberculosis subpopulations to combination treatment by anti-tubercular drugs

    Directory of Open Access Journals (Sweden)

    Kriti Sikri

    2018-05-01

    Full Text Available Bacterial dormancy is a major impediment to the eradication of tuberculosis (TB, because currently used drugs primarily target actively replicating bacteria. Therefore, decoding of the critical survival pathways in dormant tubercle bacilli is a research priority to formulate new approaches for killing these bacteria. Employing a network-based gene expression analysis approach, we demonstrate that redox active vitamin C (vit C triggers a multifaceted and robust adaptation response in Mycobacterium tuberculosis (Mtb involving ~ 67% of the genome. Vit C-adapted bacteria display well-described features of dormancy, including growth stasis and progression to a viable but non-culturable (VBNC state, loss of acid-fastness and reduction in length, dissipation of reductive stress through triglyceride (TAG accumulation, protective response to oxidative stress, and tolerance to first line TB drugs. VBNC bacteria are reactivatable upon removal of vit C and they recover drug susceptibility properties. Vit C synergizes with pyrazinamide, a unique TB drug with sterilizing activity, to kill dormant and replicating bacteria, negating any tolerance to rifampicin and isoniazid in combination treatment in both in-vitro and intracellular infection models. Finally, the vit C multi-stress redox models described here also offer a unique opportunity for concurrent screening of compounds/combinations active against heterogeneous subpopulations of Mtb. These findings suggest a novel strategy of vit C adjunctive therapy by modulating bacterial physiology for enhanced efficacy of combination chemotherapy with existing drugs, and also possible synergies to guide new therapeutic combinations towards accelerating TB treatment.

  18. NOD2, RIP2 and IRF5 Play a Critical Role in the Type I Interferon Response to Mycobacterium tuberculosis

    Science.gov (United States)

    Jiang, Zhaozhao; Fortune, Sarah M.; Coulombe, Francois; Behr, Marcel A.; Fitzgerald, Katherine A.; Sassetti, Christopher M.; Kelliher, Michelle A.

    2009-01-01

    While the recognition of microbial infection often occurs at the cell surface via Toll-like receptors, the cytosol of the cell is also under surveillance for microbial products that breach the cell membrane. An important outcome of cytosolic recognition is the induction of IFNα and IFNβ, which are critical mediators of immunity against both bacteria and viruses. Like many intracellular pathogens, a significant fraction of the transcriptional response to Mycobacterium tuberculosis infection depends on these type I interferons, but the recognition pathways responsible remain elusive. In this work, we demonstrate that intraphagosomal M. tuberculosis stimulates the cytosolic Nod2 pathway that responds to bacterial peptidoglycan, and this event requires membrane damage that is actively inflicted by the bacterium. Unexpectedly, this recognition triggers the expression of type I interferons in a Tbk1- and Irf5-dependent manner. This response is only partially impaired by the loss of Irf3 and therefore, differs fundamentally from those stimulated by bacterial DNA, which depend entirely on this transcription factor. This difference appears to result from the unusual peptidoglycan produced by mycobacteria, which we show is a uniquely potent agonist of the Nod2/Rip2/Irf5 pathway. Thus, the Nod2 system is specialized to recognize bacteria that actively perturb host membranes and is remarkably sensitive to mycobacteria, perhaps reflecting the strong evolutionary pressure exerted by these pathogens on the mammalian immune system. PMID:19578435

  19. Revaccination of Guinea Pigs With the Live Attenuated Mycobacterium tuberculosis Vaccine MTBVAC Improves BCG's Protection Against Tuberculosis.

    Science.gov (United States)

    Clark, Simon; Lanni, Faye; Marinova, Dessislava; Rayner, Emma; Martin, Carlos; Williams, Ann

    2017-09-01

    The need for an effective vaccine against human tuberculosis has driven the development of different candidates and vaccination strategies. Novel live attenuated vaccines are being developed that promise greater safety and efficacy than BCG against tuberculosis. We combined BCG with the vaccine MTBVAC to evaluate whether the efficacy of either vaccine would be affected upon revaccination. In a well-established guinea pig model of aerosol infection with Mycobacterium tuberculosis, BCG and MTBVAC delivered via various prime-boost combinations or alone were compared. Efficacy was determined by a reduction in bacterial load 4 weeks after challenge. Efficacy data suggests MTBVAC-associated immunity is longer lasting than that of BCG when given as a single dose. Long and short intervals between BCG prime and MTBVAC boost resulted in improved efficacy in lungs, compared with BCG given alone. A shorter interval between MTBVAC prime and BCG boost resulted in improved efficacy in lungs, compared with BCG given alone. A longer interval resulted in protection equivalent to that of BCG given alone. These data indicate that, rather than boosting the waning efficacy of BCG, a vaccination schedule involving a combination of the 2 vaccines yielded stronger immunity to M. tuberculosis infection. This work supports development of MTBVAC use as a revaccination strategy to improve on the effects of BCG in vaccinated people living in tuberculosis-endemic countries. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  20. 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)