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Sample records for complexo mycobacterium tuberculosis

  1. Immune Responses in Cattle Inoculated with Mycobacterium bovis, Mycobacterium tuberculosis, or Mycobacterium kansasii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cattle were inoculated with Mycobacterium bovis, Mycobacterium tuberculosis, or Mycobacterium kansasii to compare antigen-specific immune responses to varied patterns of mycobacterial disease. Disease expression ranged from colonization with associated pathology (M. bovis), colonization without path...

  2. Peritoneal tuberculosis due to Mycobacterium caprae

    PubMed Central

    Nebreda, T.; Álvarez-Prida, E.; Blanco, B.; Remacha, M.A.; Samper, S.; Jiménez, M.S.

    2016-01-01

    The incidence of tuberculosis in humans due to Mycobacterium caprae is very low and is almost confined to Europe. We report a case of a previously healthy 41-year-old Moroccan with a 6 month history of abdominal pain, weight loss, fatigue and diarrhea. A diagnosis of peritoneal tuberculosis due to M. caprae was made. PMID:27134824

  3. Mycobacterium tuberculosis and the host response

    PubMed Central

    Kaufmann, Stefan H.E.; Cole, Stewart T.; Mizrahi, Valerie; Rubin, Eric; Nathan, Carl

    2005-01-01

    Mycobacterium tuberculosis remains a leading cause of morbidity and mortality worldwide. Advances reported at a recent international meeting highlight insights and controversies in the genetics of M. tuberculosis and the infected host, the nature of protective immune responses, adaptation of the bacillus to host-imposed stresses, animal models, and new techniques. PMID:15939785

  4. Drug Resistance Mechanisms in Mycobacterium tuberculosis

    PubMed Central

    Palomino, Juan Carlos; Martin, Anandi

    2014-01-01

    Tuberculosis (TB) is a serious public health problem worldwide. Its situation is worsened by the presence of multidrug resistant (MDR) strains of Mycobacterium tuberculosis, the causative agent of the disease. In recent years, even more serious forms of drug resistance have been reported. A better knowledge of the mechanisms of drug resistance of M. tuberculosis and the relevant molecular mechanisms involved will improve the available techniques for rapid drug resistance detection and will help to explore new targets for drug activity and development. This review article discusses the mechanisms of action of anti-tuberculosis drugs and the molecular basis of drug resistance in M. tuberculosis. PMID:27025748

  5. Pathway Profiling in Mycobacterium tuberculosis

    PubMed Central

    Thomas, Suzanne T.; VanderVen, Brian C.; Sherman, David R.; Russell, David G.; Sampson, Nicole S.

    2011-01-01

    Mycobacterium tuberculosis, the bacterium that causes tuberculosis, imports and metabolizes host cholesterol during infection. This ability is important in the chronic phase of infection. Here we investigate the role of the intracellular growth operon (igr), which has previously been identified as having a cholesterol-sensitive phenotype in vitro and which is important for intracellular growth of the mycobacteria. We have employed isotopically labeled low density lipoproteins containing either [1,7,15,22,26-14C]cholesterol or [1,7,15,22,26-13C]cholesterol and high resolution LC/MS as tools to profile the cholesterol-derived metabolome of an igr operon-disrupted mutant (Δigr) of M. tuberculosis. A partially metabolized cholesterol species accumulated in the Δigr knock-out strain that was absent in the complemented and parental wild-type strains. Structural elucidation by multidimensional 1H and 13C NMR spectroscopy revealed the accumulated metabolite to be methyl 1β-(2′-propanoate)-3aα-H-4α-(3′-propanoic acid)-7aβ-methylhexahydro-5-indanone. Heterologously expressed and purified FadE28-FadE29, an acyl-CoA dehydrogenase encoded by the igr operon, catalyzes the dehydrogenation of 2′-propanoyl-CoA ester side chains in substrates with structures analogous to the characterized metabolite. Based on the structure of the isolated metabolite, enzyme activity, and bioinformatic annotations, we assign the primary function of the igr operon to be degradation of the 2′-propanoate side chain. Therefore, the igr operon is necessary to completely metabolize the side chain of cholesterol metabolites. PMID:22045806

  6. Dormancy models for Mycobacterium tuberculosis: A minireview.

    PubMed

    Alnimr, Amani M

    2015-01-01

    Dormancy models for Mycobacterium tuberculosis play important roles in understanding various aspects of tuberculosis pathogenesis and in the testing of novel therapeutic regimens. By simulating the latent tuberculosis infection, in which the bacteria exist in a non-replicative state, the models demonstrate reduced susceptibility to antimycobacterial agents. This minireview outlines the models available for simulating latent tuberculosis both in vitro and in several animal species. Additionally, this minireview discusses the advantages and disadvantages of these models for investigating the bacterial subpopulations and susceptibilities to sterilization by various antituberculosis drugs. PMID:26413043

  7. Dormancy models for Mycobacterium tuberculosis: A minireview

    PubMed Central

    Alnimr, Amani M.

    2015-01-01

    Dormancy models for Mycobacterium tuberculosis play important roles in understanding various aspects of tuberculosis pathogenesis and in the testing of novel therapeutic regimens. By simulating the latent tuberculosis infection, in which the bacteria exist in a non-replicative state, the models demonstrate reduced susceptibility to antimycobacterial agents. This minireview outlines the models available for simulating latent tuberculosis both in vitro and in several animal species. Additionally, this minireview discusses the advantages and disadvantages of these models for investigating the bacterial subpopulations and susceptibilities to sterilization by various antituberculosis drugs. PMID:26413043

  8. Macrophage infection models for Mycobacterium tuberculosis.

    PubMed

    Johnson, Benjamin K; Abramovitch, Robert B

    2015-01-01

    Mycobacterium tuberculosis colonizes, survives, and grows inside macrophages. In vitro macrophage infection models, using both primary macrophages and cell lines, enable the characterization of the pathogen response to macrophage immune pressure and intracellular environmental cues. We describe methods to propagate and infect primary murine bone marrow-derived macrophages and J774 and THP-1 macrophage-like cell lines. We also present methods on the characterization of M. tuberculosis intracellular survival and the preparation of infected macrophages for imaging. PMID:25779326

  9. Mycobacterium tuberculosis wears what it eats

    PubMed Central

    Russell, David G.; VanderVen, Brian C.; Lee, Wonsik; Abramovitch, Robert B.; Kim, Mijeong; Homolka, Susanne; Niemann, Stefan; Rohde, Kyle H.

    2010-01-01

    Mycobacterium tuberculosis remains one of the most pernicious of human pathogens. Current vaccines are ineffective and drugs, although efficacious, require prolonged treatment with constant medical oversight. Overcoming these problems requires a greater appreciation of M. tuberculosis in the context of its host. Upon infection of either macrophages in culture or animal models, the bacterium re-aligns its metabolism in response to the new environments it encounters. Understanding these environments, and the stresses that they place on M. tuberculosis, should provide insights invaluable for the development of new chemo- and immuno-therapeutic strategies. PMID:20638643

  10. Radioimmunoassay of tuberculoprotein derived from Mycobacterium tuberculosis.

    PubMed Central

    Straus, E; Wu, N

    1980-01-01

    A radioimmunoassay was developed for constituent of the purified-protein derivative obtained from cultures of Mycobacterium tuberculosis. Crossreacting immunoreactive material was detected in cultures of other mycobacterial species, but no immunoreactivity was present in cultures of various fungal and bacterial species. The development of specific radioimmunoassays for tuberculoproteins offers a new research and diagnostic approach. Images PMID:6933481

  11. The Mycobacterium tuberculosis Cytochrome P450 System

    PubMed Central

    Ouellet, Hugues; Johnston, Jonathan B.; Ortiz de Montellano, Paul R.

    2009-01-01

    Tuberculosis remains a leading cause of human mortality. The emergence of strains of Mycobacterium tuberculosis, the causative agent, that are resistant to the major frontline antitubercular drugs increases the urgency for the development of new therapeutic agents. Sequencing of the M. tuberculosis genome revealed the existence of twenty cytochrome P450 enzymes, some of which are potential candidates for drug targeting. The recent burst of studies reporting microarray-based gene essentiality and transcriptome analyses under in vitro, ex vivo and in vivo conditions highlight the importance of selected P450 isoforms for M. tuberculosis viability and pathogenicity. Current knowledge of the structural and biochemical properties of the M. tuberculosis P450 enzymes and their putative redox partners is reviewed, with an emphasis on findings related to their physiological function(s) as well as their potential as drug targets. PMID:19635450

  12. [Coinfection of Mycobacterium malmoense and Mycobacterium tuberculosis in a patient with acquired inmune deficiency syndrome].

    PubMed

    Mederos Cuervo, Lilian María; Reyes Pérez, Angélica; Valdes Alonso, Lidunka; Rodríguez Delgado, Francisco; Sardiñas Aragón, Misleydis; Martínez Romero, María Rosarys; Díaz Romero, Raúl

    2014-01-01

    A case is presented of coinfection with Mycobacterium malmoense and Mycobacterium tuberculosis in a Cuban patient with AIDS which produced respiratory and liver disease respectively. Cultures done from sputum samples showed the presence of a non-pigmented, slow growing mycobacterial strain belonging to Runyon group III and identified as Mycobacterium malmoense. From cultures of liver tissue removed laparoscopically, a strain was isolated and subsequently identified as Mycobacterium tuberculosis. Anatomapathologic examination confirmed the diagnosis of tuberculosis, the patient received specific treatment and had a favorable clinical course. This report of a rare case of coinfection of Mycobacterium describes the first report of hepatic tuberculosis in a patient with AIDS in Cuba. PMID:25597735

  13. Porins increase copper susceptibility of Mycobacterium tuberculosis.

    PubMed

    Speer, Alexander; Rowland, Jennifer L; Haeili, Mehri; Niederweis, Michael; Wolschendorf, Frank

    2013-11-01

    Copper resistance mechanisms are crucial for many pathogenic bacteria, including Mycobacterium tuberculosis, during infection because the innate immune system utilizes copper ions to kill bacterial intruders. Despite several studies detailing responses of mycobacteria to copper, the pathways by which copper ions cross the mycobacterial cell envelope are unknown. Deletion of porin genes in Mycobacterium smegmatis leads to a severe growth defect on trace copper medium but simultaneously increases tolerance for copper at elevated concentrations, indicating that porins mediate copper uptake across the outer membrane. Heterologous expression of the mycobacterial porin gene mspA reduced growth of M. tuberculosis in the presence of 2.5 μM copper by 40% and completely suppressed growth at 15 μM copper, while wild-type M. tuberculosis reached its normal cell density at that copper concentration. Moreover, the polyamine spermine, a known inhibitor of porin activity in Gram-negative bacteria, enhanced tolerance of M. tuberculosis for copper, suggesting that copper ions utilize endogenous outer membrane channel proteins of M. tuberculosis to gain access to interior cellular compartments. In summary, these findings highlight the outer membrane as the first barrier against copper ions and the role of porins in mediating copper uptake in M. smegmatis and M. tuberculosis. PMID:24013632

  14. Virulence factors of the Mycobacterium tuberculosis complex

    PubMed Central

    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

  15. Mycobacterium tuberculosis produces pili during human infection

    PubMed Central

    Alteri, Christopher J.; Xicohténcatl-Cortes, Juan; Hess, Sonja; Caballero-Olín, Guillermo; Girón, Jorge A.; Friedman, Richard L.

    2007-01-01

    Mycobacterium tuberculosis is responsible for nearly 3 million human deaths worldwide every year. Understanding the mechanisms and bacterial factors responsible for the ability of M. tuberculosis to cause disease in humans is critical for the development of improved treatment strategies. Many bacterial pathogens use pili as adherence factors to colonize the host. We discovered that M. tuberculosis produces fine (2- to 3-nm-wide), aggregative, flexible pili that are recognized by IgG antibodies contained in sera obtained from patients with active tuberculosis, indicating that the bacilli produce pili or pili-associated antigen during human infection. Purified M. tuberculosis pili (MTP) are composed of low-molecular-weight protein subunits encoded by the predicted M. tuberculosis H37Rv ORF, designated Rv3312A. MTP bind to the extracellular matrix protein laminin in vitro, suggesting that MTP possess adhesive properties. Isogenic mtp mutants lost the ability to produce Mtp in vitro and demonstrated decreased laminin-binding capabilities. MTP shares morphological, biochemical, and functional properties attributed to bacterial pili, especially with curli amyloid fibers. Thus, we propose that MTP are previously unidentified host-colonization factors of M. tuberculosis. PMID:17360408

  16. Mycobacterium tuberculosis Serine/Threonine Protein Kinases

    PubMed Central

    PRISIC, SLADJANA; HUSSON, ROBERT N.

    2014-01-01

    The Mycobacterium tuberculosis genome encodes 11 serine/threonine protein kinases (STPKs). A similar number of two-component systems are also present, indicating that these two signal transduction mechanisms are both important in the adaptation of this bacterial pathogen to its environment. The M. tuberculosis phosphoproteome includes hundreds of Ser- and Thr-phosphorylated proteins that participate in all aspects of M. tuberculosis biology, supporting a critical role for the STPKs in regulating M. tuberculosis physiology. Nine of the STPKs are receptor type kinases, with an extracytoplasmic sensor domain and an intracellular kinase domain, indicating that these kinases transduce external signals. Two other STPKs are cytoplasmic and have regulatory domains that sense changes within the cell. Structural analysis of some of the STPKs has led to advances in our understanding of the mechanisms by which these STPKs are activated and regulated. Functional analysis has provided insights into the effects of phosphorylation on the activity of several proteins, but for most phosphoproteins the role of phosphorylation in regulating function is unknown. Major future challenges include characterizing the functional effects of phosphorylation for this large number of phosphoproteins, identifying the cognate STPKs for these phosphoproteins, and determining the signals that the STPKs sense. Ultimately, combining these STPK-regulated processes into larger, integrated regulatory networks will provide deeper insight into M. tuberculosis adaptive mechanisms that contribute to tuberculosis pathogenesis. Finally, the STPKs offer attractive targets for inhibitor development that may lead to new therapies for drug-susceptible and drug-resistant tuberculosis. PMID:25429354

  17. Comparative Mycobacterium tuberculosis spoligotype distribution in Mexico.

    PubMed

    Vera-Cabrera, Lucio; Ramos-Alvarez, Jessica; Molina-Torres, Carmen A; Rivera-Morales, Lydia Guadalupe; Rendón, Adrian; Quiñones-Falconi, Francisco; Ocampo-Candiani, Jorge

    2014-08-01

    In the present work, we studied the genetic diversity of Mycobacterium tuberculosis clinical isolates from patients according to their gender, age, and geographic location in Mexico. We did not observe any statistically significant differences in regard to age or gender. We found that spoligo international type 53 (SIT53) is more frequent in the northern states and that SIT119 predominates in central Mexico. PMID:24850349

  18. Comparative Mycobacterium tuberculosis Spoligotype Distribution in Mexico

    PubMed Central

    Ramos-Alvarez, Jessica; Molina-Torres, Carmen A.; Rivera-Morales, Lydia Guadalupe; Rendón, Adrian; Quiñones-Falconi, Francisco; Ocampo-Candiani, Jorge

    2014-01-01

    In the present work, we studied the genetic diversity of Mycobacterium tuberculosis clinical isolates from patients according to their gender, age, and geographic location in Mexico. We did not observe any statistically significant differences in regard to age or gender. We found that spoligo international type 53 (SIT53) is more frequent in the northern states and that SIT119 predominates in central Mexico. PMID:24850349

  19. Mycobacterium tuberculosis: Manipulator of Protective Immunity

    PubMed Central

    Korb, Vanessa C.; Chuturgoon, Anil A.; Moodley, Devapregasan

    2016-01-01

    Mycobacterium tuberculosis (MTB) is one of the most successful pathogens in human history and remains a global health challenge. MTB has evolved a plethora of strategies to evade the immune response sufficiently to survive within the macrophage in a bacterial-immunological equilibrium, yet causes sufficient immunopathology to facilitate its transmission. This review highlights MTB as the driver of disease pathogenesis and presents evidence of the mechanisms by which MTB manipulates the protective immune response into a pathological productive infection. PMID:26927066

  20. Targeting the histidine pathway in Mycobacterium tuberculosis.

    PubMed

    Lunardi, Juleane; Nunes, José Eduardo S; Bizarro, Cristiano V; Basso, Luiz Augusto; Santos, Diógenes Santiago; Machado, Pablo

    2013-01-01

    Worldwide, tuberculosis is the leading cause of morbidity and mortality due to a single bacterial pathogen, Mycobacterium tuberculosis (Mtb). The increasing prevalence of this disease, the emergence of multi-, extensively, and totally drug-resistant strains, complicated by co-infection with the human immunodeficiency virus, and the length of tuberculosis chemotherapy have led to an urgent and continued need for the development of new and more effective antitubercular drugs. Within this context, the L-histidine biosynthetic pathway, which converts 5-phosphoribosyl 1-pyrophosphate to L-histidine in ten enzymatic steps, has been reported as a promising target of antimicrobial agents. This pathway is found in bacteria, archaebacteria, lower eukaryotes, and plants but is absent in mammals, making these enzymes highly attractive targets for the drug design of new antimycobacterial compounds with selective toxicity. Moreover, the biosynthesis of L-histidine has been described as essential for Mtb growth in vitro. Accordingly, a comprehensive overview of Mycobacterium tuberculosis histidine pathway enzymes as attractive targets for the development of new antimycobacterial agents is provided, mainly summarizing the previously reported inhibition data for Mtb or orthologous proteins. PMID:24111909

  1. Efficacies of selected disinfectants against Mycobacterium tuberculosis.

    PubMed

    Best, M; Sattar, S A; Springthorpe, V S; Kennedy, M E

    1990-10-01

    The activities of 10 formulations as mycobactericidal agents in Mycobacterium tuberculosis-contaminated suspensions (suspension test) and stainless steel surfaces (carrier test) were investigated with sputum as the organic load. The quaternary ammonium compound, chlorhexidine gluconate, and an iodophor were ineffective in all tests. Ethanol (70%) was effective against M. tuberculosis only in suspension in the absence of sputum. Povidone-iodine was not as efficacious when the test organism was dried on a surface as it was in suspension, and its activity was further reduced in the presence of sputum. Sodium hypochlorite required a higher concentration of available chlorine to achieve an effective level of disinfection than did sodium dichloroisocyanurate. Phenol (5%) was effective under all test conditions, producing at least a 4-log10 reduction in CFU. The undiluted glutaraldehyde-phenate solution was effective against M. tuberculosis and a second test organism, Mycobacterium smegmatis, even in the presence of dried sputum, whereas the diluted solution (1:16) was only effective against M. smegmatis in the suspension test. A solution of 2% glutaraldehyde was effective against M. tuberculosis. This investigation presents tuberculocidal efficacy data generated by methods simulating actual practices of routine disinfection. PMID:2121783

  2. Mycobacterium tuberculosis infection and vaccine development.

    PubMed

    Tang, Jiansong; Yam, Wing-Cheong; Chen, Zhiwei

    2016-05-01

    Following HIV/AIDS, tuberculosis (TB) continues to be the second most deadly infectious disease in humans. The global TB prevalence has become worse in recent years due to the emergence of multi-drug resistant (MDR) and extensively-drug resistant (XDR) strains, as well as co-infection with HIV. Although Bacillus Calmette-Guérin (BCG) vaccine has nearly been used for a century in many countries, it does not protect adult pulmonary tuberculosis and even causes disseminated BCG disease in HIV-positive population. It is impossible to use BCG to eliminate the Mycobacterium tuberculosis (M. tb) infection or to prevent TB onset and reactivation. Consequently, novel vaccines are urgently needed for TB prevention and immunotherapy. In this review, we discuss the TB prevalence, interaction between M. tb and host immune system, as well as recent progress of TB vaccine research and development. PMID:27156616

  3. High Persister Mutants in Mycobacterium tuberculosis

    PubMed Central

    Torrey, Heather L.; Keren, Iris; Via, Laura E.; Lee, Jong Seok; Lewis, Kim

    2016-01-01

    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. PMID:27176494

  4. High Persister Mutants in Mycobacterium tuberculosis.

    PubMed

    Torrey, Heather L; Keren, Iris; Via, Laura E; Lee, Jong Seok; Lewis, Kim

    2016-01-01

    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. PMID:27176494

  5. Peptide mimotopes of Mycobacterium tuberculosis carbohydrate immunodeterminants

    PubMed Central

    2004-01-01

    Cell-surface saccharides of Mycobacterium tuberculosis appear to be crucial factors in tuberculosis pathogenicity and could be useful antigens in tuberculosis immunodiagnosis. In the present study, we report the successful antigenic and immunogenic mimicry of mannose-containing cell-wall compounds of M. tuberculosis by dodecamer peptides identified by phage-display technology. Using a rabbit antiserum raised against M. tuberculosis cell-surface saccharides as a target for biopanning, peptides with three different consensus sequences were identified. Phage-displayed and chemically synthesized peptides bound to the anticarbohydrate antiserum. Rabbit antibodies elicited against the peptide QEPLMGTVPIRAGGGS recognize the mannosylated M. tuberculosis cell-wall antigens arabinomannan and lipoarabinomannan, and the glycosylated recombinant protein alanine/proline-rich antigen. Furthermore, antibodies were also able to react with mannan from Saccharomyces cerevisiae, but not with phosphatidylinositol dimannosides or arabinogalactan from mycobacteria. These results suggest that the immunogenic peptide mimics oligomannosidic epitopes. Interestingly, this report provides evidence that, in contrast with previously known carbohydrate mimotopes, no aromatic residues are necessary in a peptide sequence for mimicking unusual glycoconjugates synthesized by mycobacteria. The possible usefulness of the identified peptide mimotopes as surrogate reagents for immunodiagnosis and for the study of functional roles of the native non-peptide epitopes is discussed. PMID:15560754

  6. Consequences of genomic diversity in Mycobacterium tuberculosis.

    PubMed

    Coscolla, Mireia; Gagneux, Sebastien

    2014-12-01

    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

  7. Mycobacterium tuberculosis expresses two chaperonin-60 homologs.

    PubMed Central

    Kong, T H; Coates, A R; Butcher, P D; Hickman, C J; Shinnick, T M

    1993-01-01

    A 65-kDa protein and a 10-kDa protein are two of the more strongly immunoreactive components of Mycobacterium tuberculosis, the causative agent of tuberculosis. The 65-kDa antigen has homology with members of the GroEL or chaperonin-60 (Cpn60) family of heat shock proteins. The 10-kDa antigen has homology with the GroES or chaperonin-10 family of heat shock proteins. These two proteins are encoded by separate genes in M. tuberculosis. The studies reported here reveal that M. tuberculosis contains a second Cpn60 homolog located 98 bp downstream of the 10-kDa antigen gene. The second Cpn60 homolog (Cpn60-1) displays 61% amino acid sequence identity with the 65-kDa antigen (Cpn60-2) and 53% and 41% identity with the Escherichia coli GroEL protein and the human P60 protein, respectively. Primer-extension analysis revealed that transcription starts 29 bp upstream of the translation start of the Cpn60-1 homolog and protein purification studies indicate that the cpn60-1 gene is expressed as an approximately 60-kDa polypeptide. Images Fig. 3 Fig. 5 PMID:7681982

  8. Mycobacterium tuberculosis is resistant to streptolydigin.

    PubMed

    Speer, Alexander; Rowland, Jennifer L; Niederweis, Michael

    2013-07-01

    Drug resistant strains of Mycobacterium tuberculosis (Mtb) undermine tuberculosis (TB) control. Streptolydigin is a broadly effective antibiotic which inhibits RNA polymerase, similarly to rifampicin, a key drug in current TB chemotherapeutic regimens. Due to a vastly improved chemical synthesis streptolydigin and derivatives are being promoted as putative TB drugs. The microplate Alamar Blue assay revealed that Streptococcus salivarius and Mycobacterium smegmatis were susceptible to streptolydigin with minimum inhibitory concentrations (MICs) of 1.6 mg/L and 6.25 mg/L, respectively. By contrast, the MICs of streptolydigin and two derivatives, streptolydiginone and dihydrostreptolydigin, against Mtb were ≥ 100 mg/L demonstrating that Mtb is resistant to streptolydigin in contrast to previous reports. Further, a porin mutant of M. smegmatis is resistant to streptolydigin indicating that porins mediate uptake of streptolydigin across the outer membrane. Since the RNA polymerase is a validated drug target in Mtb and porins are required for susceptibility of M. smegmatis, the absence of MspA-like porins probably contributes to the resistance of Mtb to streptolydigin. This study shows that streptolydigin is not a suitable drug in TB treatment regimens. PMID:23591156

  9. Tenosynovitis caused by a novel nontuberculous Mycobacterium species initially misidentified as a member of the Mycobacterium tuberculosis complex.

    PubMed

    Simner, Patricia J; Hyle, Emily P; Buckwalter, Seanne P; Branda, John A; Brown-Elliott, Barbara A; Franklin, Jameelah; Toney, Nadege C; de Man, Tom J B; Wallace, Richard J; Vasireddy, Ravikiran; Gandhi, Rajesh T; Wengenack, Nancy L

    2014-12-01

    We present a case of tenosynovitis caused by a novel, slowly growing, nonchromogenic, nontuberculous mycobacterium (NTM). Originally misidentified as Mycobacterium tuberculosis complex, the NTM cross-reacts with the M. tuberculosis complex nucleic acid hybridization probe, a M. tuberculosis gamma interferon release assay, and is closely related to M. tuberculosis by 16S rRNA gene sequencing. PMID:25253791

  10. The 65-kilodalton antigen of Mycobacterium tuberculosis.

    PubMed Central

    Shinnick, T M

    1987-01-01

    The immune response of the host to the antigens of Mycobacterium tuberculosis plays the key role in determining immunity from infection with as well as the pathogenicity of this organism. A 65-kilodalton (kDa) protein has been identified as one of the medically important antigens of M. tuberculosis. The gene encoding this antigen was isolated from a lambda gt11-M. tuberculosis recombinant DNA library using monoclonal antibodies directed against the 65-kDa antigen as the specific probes. The nucleotide sequence of this gene was determined, and a 540-amino-acid sequence was deduced. This sequence was shown to correspond to that of the 65-kDa antigen by constructing a plasmid in which this open reading frame was fused to the lacZ gene. The resulting fusion protein reacted specifically with the anti-65-kDa protein antibodies. A second long open reading frame was found downstream of the 65-kDa antigen gene which could encode a protein of 517 amino acids. This putative protein contained 29 tandemly arranged partial or complete matches to a pentapeptide sequence. Images PMID:3029018

  11. Genome Sequencing and Annotation of Mycobacterium tuberculosis PR08 strain.

    PubMed

    Jaafar, Mohammad Maaruf; Halim, Mohd Zakihalani A; Ismail, Mohamad Izwan; Shien, Lee Lian; Kek, Teh Lay; Fong, Ngeow Yun; Nor, Norazmi Mohd; Zainuddin, Zainul Fadziruddin; Hock, Tang Thean; Najimudin, Mohd Nazalan Mohd; Salleh, Mohd Zaki

    2016-03-01

    Mycobacterium tuberculosis is an acid fast bacterial species in the family Mycobacteriaceae and is the causative agent of most cases of tuberculosis. Here, we report the genomic features of Mycobacterium tuberculosis isolated from the cerebrospinal fluid (CSF) of a patient diagnosed with both pulmonary and extrapulmonary tuberculosis (TB). The isolated strain was identified as Mycobacterium tuberculosis PR08 (MTB PR08). Genomic DNA of the MTB PR08 strain was extracted and subjected to whole genome sequencing using MiSeq (Illumina, CA,USA). The draft genome size of MTB PR08 strain is 4,292,364 bp with a G + C content of 65.2%. This strain was annotated to have 4723 genes and 48 RNAs. This whole genome shotgun project has been deposited at DDBJ/EMBL/GenBank under the accession number CP010895. PMID:26981383

  12. Mycobacterium tuberculosis supports protein tyrosine phosphorylation

    PubMed Central

    Kusebauch, Ulrike; Ortega, Corrie; Ollodart, Anja; Rogers, Richard S.; Sherman, David R.; Moritz, Robert L.; Grundner, Christoph

    2014-01-01

    Reversible protein phosphorylation determines growth and adaptive decisions in Mycobacterium tuberculosis (Mtb). At least 11 two-component systems and 11 Ser/Thr protein kinases (STPKs) mediate phosphorylation on Asp, His, Ser, and Thr. In contrast, protein phosphorylation on Tyr has not been described previously in Mtb. Here, using a combination of phospho-enrichment and highly sensitive mass spectrometry, we show extensive protein Tyr phosphorylation of diverse Mtb proteins, including STPKs. Several STPKs function as dual-specificity kinases that phosphorylate Tyr in cis and in trans, suggesting that dual-specificity kinases have a major role in bacterial phospho-signaling. Mutation of a phosphotyrosine site of the essential STPK PknB reduces its activity in vitro and in live Mtb, indicating that Tyr phosphorylation has a functional role in bacterial growth. These data identify a previously unrecognized phosphorylation system in a human pathogen that claims ∼1.4 million lives every year. PMID:24927537

  13. Characterization of Mycobacterium orygis as M. tuberculosis complex subspecies.

    PubMed

    van Ingen, Jakko; Rahim, Zeaur; Mulder, Arnout; Boeree, Martin J; Simeone, Roxane; Brosch, Roland; van Soolingen, Dick

    2012-04-01

    The oryx bacilli are Mycobacterium tuberculosis complex organisms for which phylogenetic position and host range are unsettled. We characterized 22 isolates by molecular methods and propose elevation to subspecies status as M. orygis. M. orygis is a causative agent of tuberculosis in animals and humans from Africa and South Asia. PMID:22469053

  14. The cell envelope glycoconjugates of Mycobacterium tuberculosis

    PubMed Central

    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

  15. Human immune response to Mycobacterium tuberculosis antigens.

    PubMed Central

    Havlir, D V; Wallis, R S; Boom, W H; Daniel, T M; Chervenak, K; Ellner, J J

    1991-01-01

    Little is known about the immunodominant or protective antigens of Mycobacterium tuberculosis in humans. Cell-mediated immunity is necessary for protection, and healthy tuberculin-positive individuals are relatively resistant to exogenous reinfection. We compared the targets of the cell-mediated immune response in healthy tuberculin-positive individuals to those of tuberculosis patients and tuberculin-negative persons. By using T-cell Western blotting (immunoblotting) of nitrocellulose-bound M. tuberculosis culture filtrate, peaks of T-cell blastogenic activity were identified in the healthy tuberculin reactors at 30, 37, 44, 57, 64, 71 and 88 kDa. Three of these fractions (30, 64, and 71 kDa) coincided with previously characterized proteins: antigen 6/alpha antigen, HSP60, and HSP70, respectively. The blastogenic responses to purified M. tuberculosis antigen 6/alpha antigen and BCG HSP60 were assessed. When cultured with purified antigen 6/alpha antigen, lymphocytes of healthy tuberculin reactors demonstrated greater [3H]thymidine incorporation than either healthy tuberculin-negative controls or tuberculous patients (8,113 +/- 1,939 delta cpm versus 645 +/- 425 delta cpm and 1,019 +/- 710 delta cpm, respectively; P less than 0.01). Healthy reactors also responded to HSP60, although to a lesser degree than antigen 6/alpha antigen (4,276 +/- 1,095 delta cpm; P less than 0.05). Partially purified HSP70 bound to nitrocellulose paper elicited a significant lymphocyte blastogenic response in two of six of the tuberculous patients but in none of the eight healthy tuberculin reactors. Lymphocytes of none of five tuberculin-negative controls responded to recombinant antigens at 14 or 19 kDa or to HSP70. Antibody reactivity generally was inversely correlated with blastogenic response: tuberculous sera had high titer antibody to M. tuberculosis culture filtrate in a range from 35 to 180 kDa. This is the first systematic evaluation of the human response to a panel of native

  16. Fate of Mycobacterium tuberculosis inside rat peritoneal macrophages in vitro.

    PubMed

    Vishwanath, V; Meera, R; Puvanakrishnan, R; Narayanan, P R

    1997-10-01

    Rat peritoneal macrophages in vitro were infected with Mycobacterium tuberculosis and the fate of M. tuberculosis inside macrophages was monitored. Alteration in the levels of nitric oxide (NO) measured in terms of nitrite formed, hydrogen peroxide (H2O2) and lysosomal enzymes such as acid phosphatase, cathepsin-D and beta-glucuronidase in macrophages following M. tuberculosis infection was also studied. Elevation in the levels of nitrite were observed from 72 h of M. tuberculosis infection. Irrespective of the time point, M. tuberculosis infected macrophages produced elevated levels of H2O2. Maximum increase in the level of acid phosphatase was observed from 72 h of M. tuberculosis infection, whereas maximum elevation in the level of beta-glucuronidase was observed 48 h after M. tuberculosis infection. However these microbicidal agents did not alter the intracellular viability of M. tuberculosis. PMID:9350049

  17. Insights from the complete genome sequence of Mycobacterium marinum on the evolution of Mycobacterium tuberculosis

    PubMed Central

    Stinear, Timothy P.; Seemann, Torsten; Harrison, Paul F.; Jenkin, Grant A.; Davies, John K.; Johnson, Paul D.R.; Abdellah, Zahra; Arrowsmith, Claire; Chillingworth, Tracey; Churcher, Carol; Clarke, Kay; Cronin, Ann; Davis, Paul; Goodhead, Ian; Holroyd, Nancy; Jagels, Kay; Lord, Angela; Moule, Sharon; Mungall, Karen; Norbertczak, Halina; Quail, Michael A.; Rabbinowitsch, Ester; Walker, Danielle; White, Brian; Whitehead, Sally; Small, Pamela L.C.; Brosch, Roland; Ramakrishnan, Lalita; Fischbach, Michael A.; Parkhill, Julian; Cole, Stewart T.

    2008-01-01

    Mycobacterium marinum, a ubiquitous pathogen of fish and amphibia, is a near relative of Mycobacterium tuberculosis, the etiologic agent of tuberculosis in humans. The genome of the M strain of M. marinum comprises a 6,636,827-bp circular chromosome with 5424 CDS, 10 prophages, and a 23-kb mercury-resistance plasmid. Prominent features are the very large number of genes (57) encoding polyketide synthases (PKSs) and nonribosomal peptide synthases (NRPSs) and the most extensive repertoire yet reported of the mycobacteria-restricted PE and PPE proteins, and related-ESX secretion systems. Some of the NRPS genes comprise a novel family and seem to have been acquired horizontally. M. marinum is used widely as a model organism to study M. tuberculosis pathogenesis, and genome comparisons confirmed the close genetic relationship between these two species, as they share 3000 orthologs with an average amino acid identity of 85%. Comparisons with the more distantly related Mycobacterium avium subspecies paratuberculosis and Mycobacterium smegmatis reveal how an ancestral generalist mycobacterium evolved into M. tuberculosis and M. marinum. M. tuberculosis has undergone genome downsizing and extensive lateral gene transfer to become a specialized pathogen of humans and other primates without retaining an environmental niche. M. marinum has maintained a large genome so as to retain the capacity for environmental survival while becoming a broad host range pathogen that produces disease strikingly similar to M. tuberculosis. The work described herein provides a foundation for using M. marinum to better understand the determinants of pathogenesis of tuberculosis. PMID:18403782

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

    PubMed Central

    Tian, Wei-wei; Wang, Qian-qiu; Liu, Wei-da; Shen, Jian-ping; Wang, Hong-sheng

    2013-01-01

    Purpose 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 higher levels of chemokine (C-X-C motif) ligand (CXCL) 8 and chemokine (C motif) ligand (XCL) 1 on day 3 (CXCL8: P = 0.012 and 0.014, respectively; XCL1: P = 0.000 and 0.000, respectively). The M. marinum stimulated coculture group also secreted more tumor necrosis factor (TNF)-α, IL-1β, and IL-10 on day 1 (TNF-α: P = 0.000 and 0.000, respectively; IL-1β: P = 0.000 and 0.000, respectively; IL-10: P = 0.002 and 0.019, respectively) and day 3 (TNF-α: P = 0.000 and 0.000, respectively; IL-1β: P = 0.000 and 0.001, respectively; IL-10: P = 0.000 and 0.000, respectively). In addition, the

  19. Evaluation of the results of Mycobacterium tuberculosis direct test (MTD) and Mycobacterial culture in urine samples

    PubMed Central

    Sener, Asli Gamze; Kurultay, Nukhet; Afsar, Ilhan

    2008-01-01

    Tuberculosis remains a public health problem in Turkey. Rapid detection of Mycobacterium tuberculosis plays a key role in control of infection. In this article, the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD) was evaluated for detection of M. tuberculosis in urine samples. The performance of the MTD was very good and appropriate for routine laboratory diagnosis. PMID:24031287

  20. Characterization of Lipoyl Synthase from Mycobacterium tuberculosis.

    PubMed

    Lanz, Nicholas D; Lee, Kyung-Hoon; Horstmann, Abigail K; Pandelia, Maria-Eirini; Cicchillo, Robert M; Krebs, Carsten; Booker, Squire J

    2016-03-01

    The prevalence of multiple and extensively drug-resistant strains of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, is on the rise, necessitating the identification of new targets to combat an organism that has infected one-third of the world's population, according to the World Health Organization. The biosynthesis of the lipoyl cofactor is one possible target, given its critical importance in cellular metabolism and the apparent lack of functional salvage pathways in Mtb that are found in humans and many other organisms. The lipoyl cofactor is synthesized de novo in two committed steps, involving the LipB-catalyzed transfer of an octanoyl chain derived from fatty acid biosynthesis to a lipoyl carrier protein and the LipA-catalyzed insertion of sulfur atoms at C6 and C8 of the octanoyl chain. A number of in vitro studies of lipoyl synthases from Escherichia coli, Sulfolobus solfataricus, and Thermosynechococcus elongatus have been conducted, but the enzyme from Mtb has not been characterized. Herein, we show that LipA from Mtb contains two [4Fe-4S] clusters and converts an octanoyl peptide substrate to the corresponding lipoyl peptide product via the same C6-monothiolated intermediate as that observed in the E. coli LipA reaction. In addition, we show that LipA from Mtb forms a complex with the H protein of the glycine cleavage system and that the strength of association is dependent on the presence of S-adenosyl-l-methionine. We also show that LipA from Mtb can complement a lipA mutant of E. coli, demonstrating the commonalities of the two enzymes. Lastly, we show that the substrate for LipA, which normally acts on a post-translationally modified protein, can be reduced to carboxybenzyl-octanoyllysine. PMID:26841001

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. MTBreg: The Database of Conditionally Regulated Proteins in Mycobacterium Tuberculosis

    DOE Data Explorer

    Kaufman, Markus; Pal, Debnath; Eisenberg, David

    Proteins up- and down- regulated in Mycobacterium tuberculosis grown under conditions mimicking infection are included in this database. It also includes information on proteins that are regulated by selected transcription factors or other regulatory proteins. The literature data provided here is complimentary to the databases provided by Michael Strong that include recent TB computational functional linkages and the Prolinks Database by Peter Bowers. The experimental condition, the experimental dataset and a literature reference will be displayed, including links to the computationally linked proteins in the Prolinks Database and the entry in the Mycobacterium tuberculosis Structural Genomics Database.[Copied from information at http://www.doe-mbi.ucla.edu/Services/MTBreg/

  3. Two Cases of Pulmonary Tuberculosis Caused by Mycobacterium tuberculosis subsp. canetti

    PubMed Central

    Morillon, Marc; Koeck, Jean-Louis; Varnerot, Anne; Briant, Jean-François; Nguyen, Gilbert; Verrot, Denis; Bonnet, Daniel; Vincent, Véronique

    2002-01-01

    We identified an unusual strain of mycobacteria from two patients with pulmonary tuberculosis by its smooth, glossy morphotype and, primarily, its genotypic characteristics. Spoligotyping and restriction fragment length polymorphism typing were carried out with the insertion sequence IS6110 patterns. All known cases of tuberculosis caused by Mycobacterium canetti have been contracted in the Horn of Africa. PMID:12453369

  4. Human Xenobiotic Nuclear Receptor PXR Augments Mycobacterium tuberculosis Survival.

    PubMed

    Bhagyaraj, Ella; Nanduri, Ravikanth; Saini, Ankita; Dkhar, Hedwin Kitdorlang; Ahuja, Nancy; Chandra, Vemika; Mahajan, Sahil; Kalra, Rashi; Tiwari, Drishti; Sharma, Charu; Janmeja, Ashok Kumar; Gupta, Pawan

    2016-07-01

    Mycobacterium tuberculosis can evade host defense processes, thereby ensuring its survival and pathogenesis. In this study, we investigated the role of nuclear receptor, pregnane X receptor (PXR), in M. tuberculosis infection in human monocyte-derived macrophages. In this study, we demonstrate that PXR augments M. tuberculosis survival inside the host macrophages by promoting the foamy macrophage formation and abrogating phagolysosomal fusion, inflammation, and apoptosis. Additionally, M. tuberculosis cell wall lipids, particularly mycolic acids, crosstalk with human PXR (hPXR) by interacting with its promiscuous ligand binding domain. To confirm our in vitro findings and to avoid the reported species barrier in PXR function, we adopted an in vivo mouse model expressing hPXR, wherein expression of hPXR in mice promotes M. tuberculosis survival. Therefore, pharmacological intervention and designing antagonists to hPXR may prove to be a promising adjunct therapy for tuberculosis. PMID:27233963

  5. Dramatic reduction of culture time of Mycobacterium tuberculosis

    NASA Astrophysics Data System (ADS)

    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.

  6. Genomic signal analysis of Mycobacterium tuberculosis

    NASA Astrophysics Data System (ADS)

    Cristea, Paul Dan; Banica, Dorina; Tuduce, Rodica

    2007-02-01

    As previously shown the conversion of nucleotide sequences into digital signals offers the possibility to apply signal processing methods for the analysis of genomic data. Genomic Signal Analysis (GSA) has been used to analyze large scale features of DNA sequences, at the scale of whole chromosomes, including both coding and non-coding regions. The striking regularities of genomic signals reveal restrictions in the way nucleotides and pairs of nucleotides are distributed along nucleotide sequences. Structurally, a chromosome appears to be less of a "plain text", corresponding to certain semantic and grammar rules, but more of a "poem", satisfying additional symmetry restrictions that evoke the "rhythm" and "rhyme". Recurrent patterns in nucleotide sequences are reflected in simple mathematical regularities observed in genomic signals. GSA has also been used to track pathogen variability, especially concerning their resistance to drugs. Previous work has been dedicated to the study of HIV-1, Clade F and Avian Flu. The present paper applies GSA methodology to study Mycobacterium tuberculosis (MT) rpoB gene variability, relevant to its resistance to antibiotics. Isolates from 50 Romanian patients have been studied both by rapid LightCycler PCR and by sequencing of a segment of 190-250 nucleotides covering the region of interest. The variability is caused by SNPs occurring at specific sites along the gene strand, as well as by inclusions. Because of the mentioned symmetry restrictions, the GS variations tend to compensate. An important result is that MT can act as a vector for HIV virus, which is able to retrotranscribe its specific genes both into human and MT genomes.

  7. Detection of Mycobacterium tuberculosis in clinical specimens by polymerase chain reaction and Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test.

    PubMed Central

    Abe, C; Hirano, K; Wada, M; Kazumi, Y; Takahashi, M; Fukasawa, Y; Yoshimura, T; Miyagi, C; Goto, S

    1993-01-01

    The polymerase chain reaction (PCR) using oligonucleotides based on the repetitive sequence (IS986) of Mycobacterium tuberculosis as a primer and the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD), which combines an M. tuberculosis rRNA amplification method with the hybridization protection assay format, were evaluated for detection of M. tuberculosis in clinical samples. The detection limits of these two assay systems based on nucleic acid amplification for cultured M. tuberculosis were less than 10 cells per reaction. A total of 135 sputum specimens were examined by the two assay systems. The PCR and the MTD systems for detection of M. tuberculosis gave overall positivity rates of 84.2% (32 of 38) and 91.9% (34 of 37), respectively, as compared with 71.9% (23 of 32) by smear and 96.9% (31 of 32) by culture in the liquid medium MB-Check. Procedures for sample preparation used in the two methods were different. Although the sensitivities of the PCR and MTD appeared to be similar to that of culture with the MB-Check system, the two methods based on nucleic acid amplification should be very useful for rapid detection of M. tuberculosis infections without the long time required for culture of M. tuberculosis. Images PMID:8308121

  8. Novel Cephalosporins Selectively Active on Nonreplicating Mycobacterium tuberculosis.

    PubMed

    Gold, Ben; Smith, Robert; Nguyen, Quyen; Roberts, Julia; Ling, Yan; Lopez Quezada, Landys; Somersan, Selin; Warrier, Thulasi; Little, David; Pingle, Maneesh; Zhang, David; Ballinger, Elaine; Zimmerman, Matthew; Dartois, Véronique; Hanson, Paul; Mitscher, Lester A; Porubsky, Patrick; Rogers, Steven; Schoenen, Frank J; Nathan, Carl; Aubé, Jeffrey

    2016-07-14

    We report two series of novel cephalosporins that are bactericidal to Mycobacterium tuberculosis alone of the pathogens tested, which only kill M. tuberculosis when its replication is halted by conditions resembling those believed to pertain in the host, and whose bactericidal activity is not dependent upon or enhanced by clavulanate, a β-lactamase inhibitor. The two classes of cephalosporins bear an ester or alternatively an oxadiazole isostere at C-2 of the cephalosporin ring system, a position that is almost exclusively a carboxylic acid in clinically used agents in the class. Representatives of the series kill M. tuberculosis within macrophages without toxicity to the macrophages or other mammalian cells. PMID:27144688

  9. Novel Cephalosporins Selectively Active on Nonreplicating Mycobacterium tuberculosis

    PubMed Central

    2016-01-01

    We report two series of novel cephalosporins that are bactericidal to Mycobacterium tuberculosis alone of the pathogens tested, which only kill M. tuberculosis when its replication is halted by conditions resembling those believed to pertain in the host, and whose bactericidal activity is not dependent upon or enhanced by clavulanate, a β-lactamase inhibitor. The two classes of cephalosporins bear an ester or alternatively an oxadiazole isostere at C-2 of the cephalosporin ring system, a position that is almost exclusively a carboxylic acid in clinically used agents in the class. Representatives of the series kill M. tuberculosis within macrophages without toxicity to the macrophages or other mammalian cells. PMID:27144688

  10. Co-evolution of Mycobacterium tuberculosis and Homo sapiens

    PubMed Central

    Brites, Daniela; Gagneux, Sebastien

    2015-01-01

    The causative agent of human tuberculosis (TB), Mycobacterium tuberculosis, is an obligate pathogen that evolved to exclusively persist in human populations. For M. tuberculosis to transmit from person to person, it has to cause pulmonary disease. Therefore, M. tuberculosis virulence has likely been a significant determinant of the association between M. tuberculosis and humans. Indeed, the evolutionary success of some M. tuberculosis genotypes seems at least partially attributable to their increased virulence. The latter possibly evolved as a consequence of human demographic expansions. If co-evolution occurred, humans would have counteracted to minimize the deleterious effects of M. tuberculosis virulence. The fact that human resistance to infection has a strong genetic basis is a likely consequence of such a counter-response. The genetic architecture underlying human resistance to M. tuberculosis remains largely elusive. However, interactions between human genetic polymorphisms and M. tuberculosis genotypes have been reported. Such interactions are consistent with local adaptation and allow for a better understanding of protective immunity in TB. Future ‘genome-to-genome’ studies, in which locally associated human and M. tuberculosis genotypes are interrogated in conjunction, will help identify new protective antigens for the development of better TB vaccines. PMID:25703549

  11. Can Molecular Methods Detect 1% Isoniazid Resistance in Mycobacterium tuberculosis?

    PubMed Central

    Folkvardsen, Dorte Bek; Thomsen, Vibeke Ø.; Rasmussen, Erik Michael; Bang, Didi; Werngren, Jim; Hoffner, Sven; Hillemann, Doris; Rigouts, Leen

    2013-01-01

    Patients may harbor both drug-susceptible and -resistant bacteria, representing heteroresistance. We studied mixtures of isoniazid-resistant and -susceptible Mycobacterium tuberculosis strains. Conventional drug susceptibility testing was the most sensitive method of detection, whereas the line probe assay and sequencing were not able to detect the clinically relevant 1% proportion of resistant bacteria. PMID:23447641

  12. A case of Manila type Mycobacterium tuberculosis infection in Japan

    PubMed Central

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

    2015-01-01

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

  13. 21 CFR 866.3370 - Mycobacterium tuberculosis immunofluorescent reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Mycobacterium tuberculosis immunofluorescent reagents. 866.3370 Section 866.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological...

  14. 21 CFR 866.3370 - Mycobacterium tuberculosis immunofluorescent reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mycobacterium tuberculosis immunofluorescent reagents. 866.3370 Section 866.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological...

  15. 21 CFR 866.3370 - Mycobacterium tuberculosis immunofluorescent reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Mycobacterium tuberculosis immunofluorescent reagents. 866.3370 Section 866.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological...

  16. 21 CFR 866.3370 - Mycobacterium tuberculosis immunofluorescent reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Mycobacterium tuberculosis immunofluorescent reagents. 866.3370 Section 866.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological...

  17. 21 CFR 866.3370 - Mycobacterium tuberculosis immunofluorescent reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Mycobacterium tuberculosis immunofluorescent reagents. 866.3370 Section 866.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological...

  18. Insights into redox sensing metalloproteins in Mycobacterium tuberculosis.

    PubMed

    Chim, Nicholas; Johnson, Parker M; Goulding, Celia W

    2014-04-01

    Mycobacterium tuberculosis, the pathogen that causes tuberculosis, has evolved sophisticated mechanisms for evading assault by the human host. This review focuses on M. tuberculosis regulatory metalloproteins that are sensitive to exogenous stresses attributed to changes in the levels of gaseous molecules (i.e., molecular oxygen, carbon monoxide and nitric oxide) to elicit an intracellular response. In particular, we highlight recent developments on the subfamily of Whi proteins, redox sensing WhiB-like proteins that contain iron-sulfur clusters, sigma factors and their cognate anti-sigma factors of which some are zinc-regulated, and the dormancy survival regulon DosS/DosT-DosR heme sensory system. Mounting experimental evidence suggests that these systems contribute to a highly complex and interrelated regulatory network that controls M. tuberculosis biology. This review concludes with a discussion of strategies that M. tuberculosis has developed to maintain redox homeostasis, including mechanisms to regulate endogenous nitric oxide and carbon monoxide levels. PMID:24314844

  19. Biosensing Technologies for Mycobacterium tuberculosis Detection: Status and New Developments

    PubMed Central

    Zhou, Lixia; He, Xiaoxiao; He, Dinggeng; Wang, Kemin; Qin, Dilan

    2011-01-01

    Biosensing technologies promise to improve Mycobacterium tuberculosis (M. tuberculosis) detection and management in clinical diagnosis, food analysis, bioprocess, and environmental monitoring. A variety of portable, rapid, and sensitive biosensors with immediate “on-the-spot” interpretation have been developed for M. tuberculosis detection based on different biological elements recognition systems and basic signal transducer principles. Here, we present a synopsis of current developments of biosensing technologies for M. tuberculosis detection, which are classified on the basis of basic signal transducer principles, including piezoelectric quartz crystal biosensors, electrochemical biosensors, and magnetoelastic biosensors. Special attention is paid to the methods for improving the framework and analytical parameters of the biosensors, including sensitivity and analysis time as well as automation of analysis procedures. Challenges and perspectives of biosensing technologies development for M. tuberculosis detection are also discussed in the final part of this paper. PMID:21437177

  20. Rapid diagnosis of Mycobacterium tuberculosis bacteremia by PCR.

    PubMed Central

    Folgueira, L; Delgado, R; Palenque, E; Aguado, J M; Noriega, A R

    1996-01-01

    A method based on DNA amplification and hybridization has been used for the rapid detection of Mycobacterium tuberculosis in blood samples from 38 hospitalized patients (15 human immunodeficiency virus [HIV] positive and 23 HIV negative) in whom localized or disseminated forms of tuberculosis were suspected. In 32 of these patients, the diagnosis of tuberculosis was eventually confirmed by conventional bacteriological or histological procedures. M. tuberculosis DNA was detected with the PCR technique in the peripheral blood mononuclear cells from 9 of 11 (82%) HIV-infected patients and in 7 of 21 (33%) HIV-negative patients (P < 0.01), while M. tuberculosis blood cultures were positive in 1 of 8 (12.5%) and 1 of 18 (5.5%) patients, respectively. PCR was positive in all cases with disseminated disease in both HIV-negative and HIV-positive patients and also in the HIV-positive patients with extrapulmonary tuberculosis. Seven samples from patients with documented illness other than tuberculosis and 12 specimens from healthy volunteers, including seven volunteers with a recent positive purified protein derivative test, were used as controls and had a negative PCR. These results suggest that detection of M. tuberculosis DNA in peripheral blood mononuclear cells may be a useful tool for rapid diagnosis of disseminated and extrapulmonary forms of tuberculosis, especially in an HIV-positive population. PMID:8904404

  1. Mycobacterium tuberculosis resistance to antituberculosis drugs in Mozambique*, **

    PubMed Central

    Pires, Germano Manuel; Folgosa, Elena; Nquobile, Ndlovu; Gitta, Sheba; Cadir, Nureisha

    2014-01-01

    OBJECTIVE: To determine the drug resistance profile of Mycobacterium tuberculosis in Mozambique. METHODS: We analyzed secondary data from the National Tuberculosis Referral Laboratory, in the city of Maputo, Mozambique, and from the Beira Regional Tuberculosis Referral Laboratory, in the city of Beira, Mozambique. The data were based on culture-positive samples submitted to first-line drug susceptibility testing (DST) between January and December of 2011. We attempted to determine whether the frequency of DST positivity was associated with patient type or provenance. RESULTS: During the study period, 641 strains were isolated in culture and submitted to DST. We found that 374 (58.3%) were resistant to at least one antituberculosis drug and 280 (43.7%) were resistant to multiple antituberculosis drugs. Of the 280 multidrug-resistant tuberculosis cases, 184 (65.7%) were in previously treated patients, most of whom were from southern Mozambique. Two (0.71%) of the cases of multidrug-resistant tuberculosis were confirmed to be cases of extensively drug-resistant tuberculosis. Multidrug-resistant tuberculosis was most common in males, particularly those in the 21-40 year age bracket. CONCLUSIONS: M. tuberculosis resistance to antituberculosis drugs is high in Mozambique, especially in previously treated patients. The frequency of M. tuberculosis strains that were resistant to isoniazid, rifampin, and streptomycin in combination was found to be high, particularly in samples from previously treated patients. PMID:24831398

  2. Proteome Analysis of the Plasma Membrane of Mycobacterium Tuberculosis

    PubMed Central

    Arora, Shalini; Kosalai, K.; Namane, Abdelkader; Pym, Alex S.; Cole, Stewart T.

    2002-01-01

    The plasma membrane of Mycobacterium tuberculosis is likely to contain proteins that could serve as novel drug targets, diagnostic probes or even components of a vaccine against tuberculosis. With this in mind, we have undertaken proteome analysis of the membrane of M. tuberculosis H37Rv. Isolated membrane vesicles were extracted with either a detergent (Triton X114) or an alkaline buffer (carbonate) following two of the protocols recommended for membrane protein enrichment. Proteins were resolved by 2D-GE using immobilized pH gradient (IPG) strips, and identified by peptide mass mapping utilizing the M. tuberculosis genome database. The two extraction procedures yielded patterns with minimal overlap. Only two proteins, both HSPs, showed a common presence. MALDI–MS analysis of 61 spots led to the identification of 32 proteins, 17 of which were new to the M. tuberculosis proteome database. We classified 19 of the identified proteins as ‘membrane-associated’; 14 of these were further classified as ‘membrane-bound’, three of which were lipoproteins. The remaining proteins included four heat-shock proteins and several enzymes involved in energy or lipid metabolism. Extraction with Triton X114 was found to be more effective than carbonate for detecting ‘putative’ M. tuberculosis membrane proteins. The protocol was also found to be suitable for comparing BCG and M. tuberculosis membranes, identifying ESAT-6 as being expressed selectively in M. tuberculosis. While this study demonstrates for the first time some of the membrane proteins of M. tuberculosis, it also underscores the problems associated with proteomic analysis of a complex membrane such as that of a mycobacterium. PMID:18629250

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

    PubMed

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

    2005-01-01

    The study was designed to compare immune responses to Mycobacterium tuberculosis bacilli and antigens in healthy Portuguese subjects and pulmonary tuberculosis patients (TB), and to correlate immune status with clinical severity of tuberculosis disease. PBMC were cultured and stimulated with live and killed M. tuberculosis H37Rv and purified protein derivative (PPD) and lymphoproliferation and production of IFN-gamma and IL-5/IL-4 by these cultures were evaluated by the use of ELISA and multi-parameter flow cytometry. PBMC from 30 tuberculosis patients demonstrated significantly reduced amounts of proliferation and IFN-gamma when stimulated with live M. tuberculosis compared the control group. Of 15 tuberculosis patients tested for intracellular IL-4 following stimulation with M. tuberculosis, 7 showed greatly increased IL-4 production in CD8+ and gammadelta+ T cells. Tuberculosis patients demonstrated an increase of intracellular IL-4 after PBMC were stimulated with live M. tuberculosis in the CD4+ phenotype, but more notably in CD8+ and gammadelta TCR+ subsets. Increased production of IL-4 in tuberculosis patients was primarily in individuals with advanced involvement of lung parenchymal with high bacterial loads in sputum. These results suggest that an alteration in type 1 and type 2 cytokine balance can occur in patients with tuberculosis at an advanced clinical stage of disease. PMID:16202332

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

    PubMed Central

    Eisenhut, Michael; Hargreaves, Dougal S.; Scott, Anne; Housley, David; Walters, Andrew; Mulla, Rohinton

    2016-01-01

    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. PMID:27433370

  5. Transmission of Mycobacterium orygis (M. tuberculosis complex species) from a tuberculosis patient to a dairy cow in New Zealand.

    PubMed

    Dawson, Kara L; Bell, Anita; Kawakami, R Pamela; Coley, Kathryn; Yates, Gary; Collins, Desmond M

    2012-09-01

    Mycobacterium orygis, previously called the oryx bacillus, is a member of the Mycobacterium tuberculosis complex and has been reported only recently as a cause of human tuberculosis in patients of South Asian origin. We present the first case documenting the transmission of this organism from a human to a cow. PMID:22785186

  6. Identification of proteins from Mycobacterium tuberculosis missing in attenuated Mycobacterium bovis BCG strains.

    PubMed

    Mattow, J; Jungblut, P R; Schaible, U E; Mollenkopf, H J; Lamer, S; Zimny-Arndt, U; Hagens, K; Müller, E C; Kaufmann, S H

    2001-08-01

    A proteome approach, combining high-resolution two-dimensional electrophoresis (2-DE) with mass spectrometry, was used to compare the cellular protein composition of two virulent strains of Mycobacterium tuberculosis with two attenuated strains of Mycobacterium bovis Bacillus Calmette-Guerin (BCG), in order to identify unique proteins of these strains. Emphasis was given to the identification of M. tuberculosis specific proteins, because we consider these proteins to represent putative virulence factors and interesting candidates for vaccination and diagnosis of tuberculosis. The genome of M. tuberculosis strain H37Rv comprises nearly 4000 predicted open reading frames. In contrast, the separation of proteins from whole mycobacterial cells by 2-DE resulted in silver-stained patterns comprising about 1800 distinct protein spots. Amongst these, 96 spots were exclusively detected either in the virulent (56 spots) or in the attenuated (40 spots) mycobacterial strains. Fifty-three of these spots were analyzed by mass spectrometry, of which 41 were identified, including 32 M. tuberculosis specific spots. Twelve M. tuberculosis specific spots were identified as proteins, encoded by genes previously reported to be deleted in M. bovis BCG. The remaining 20 spots unique for M. tuberculosis were identified as proteins encoded by genes that are not known to be missing in M. bovis BCG. PMID:11565788

  7. Phospholipase C in Beijing strains of Mycobacterium tuberculosis

    PubMed Central

    Mirsamadi, ES; Farnia, P; Jahani Sherafat, S; Esfahani, M; Faramarzi, N

    2010-01-01

    Background and Objectives Phospholipase of Mycobacterium tuberculosis plays an important role in pathogenesis through breaking up phospholipids and production of diacylglycerol. In this study, we examined the Beijing strains of Mycobacterium tuberculosis isolated from Iranian patients for the genes encoding this enzyme. Materials and Methods DNA extraction was performed using CTAB (cetyltrimethylammonium bromide) from positive culture specimens in tuberculosis patients. PCR was then used to amplify the plcA, plcB, plcC genes of Beijing strain, and non-Beijing strains were identified by spoligotyping. Results Of 200 specimens, 19 (9.5%) were Beijing strain and 181 (90.5%) were non-Beijing strains. The results of PCR for Beijing strains were as follows: 16 strains (84.2%) were positive for plcA, 17 (89.4%) were positive for plcB and 17 (89.4%) were positive for plcC genes. The standard strain (H37RV) was used as control. Conclusion The majority of Beijing strains have phospholipase C genes which can contribute to their pathogenesis but we need complementary studies to confirm the role of phospholipase C in pathogenecity of Mycobacterium tuberculosis. PMID:22347572

  8. Identification of Mycobacterium tuberculosis antigens in Seibert fractions by immunoblotting.

    PubMed Central

    Coates, S R; Hansen, D; Schecter, G; Slutkin, G; Hopewell, P; Affronti, L; Echenberg, D F

    1986-01-01

    Seibert fractions prepared from Mycobacterium tuberculosis culture filtrates were evaluated by immunoblotting with a serum pool from patients with active pulmonary tuberculosis. Antibody activity was observed primarily with antigens in the polysaccharide II and A protein fractions; these fractions were further evaluated by immunoblotting with sera from individual patients with tuberculosis, from individuals without tuberculosis and positive for the purified protein derivative antigen skin test, and from individuals negative for the purified protein derivative antigen skin test. The antigens identified in the protein A fraction, a 32,000-molecular-weight antigen and a heterogeneous high-molecular-weight antigen, reacted with antibody found in sera from all patients with tuberculosis and with antibody from over 25% of the control individuals. A 10,000-molecular-weight antigen, a 30,000- to 44,000-molecular-weight antigen, and a heterogeneous high-molecular-weight antigen were observed in the polysaccharide II fraction; these antigens reacted with serum antibody from 70% or more of the patients with tuberculosis and with antibody from 20 to 70% of the control individuals. One of the antigens, with a molecular weight ranging from 17,000 to 28,000 in the polysaccharide II fraction, reacted with antibody in 64% of the sera from patients with tuberculosis but with only 1 of 15 control normal sera. This antigen may elicit an antibody response specifically associated with tuberculosis. Images PMID:3088029

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

    PubMed Central

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

    2013-01-01

    In this cross-sectional study, mycobacteria specimens from 189 tuberculosis (TB) patients living in an urban area in Brazil were characterised from 2008-2010 using phenotypic and molecular speciation methods (pncA gene and oxyR pseudogene analysis). Of these samples, 174 isolates simultaneously grew on Löwenstein-Jensen (LJ) and Stonebrink (SB)-containing media and presented phenotypic and molecular profiles of Mycobacterium tuberculosis, whereas 12 had molecular profiles of M. tuberculosis based on the DNA analysis of formalin-fixed paraffin wax-embedded tissue samples (paraffin blocks). One patient produced two sputum isolates, the first of which simultaneously grew on LJ and SB media and presented phenotypic and molecular profiles of M. tuberculosis, and the second of which only grew on SB media and presented phenotypic profiles of Mycobacterium bovis. One patient provided a bronchial lavage isolate, which simultaneously grew on LJ and SB media and presented phenotypic and molecular profiles of M. tuberculosis, but had molecular profiles of M. bovis from paraffin block DNA analysis, and one sample had molecular profiles of M. tuberculosis and M. bovis identified from two distinct paraffin blocks. Moreover, we found a low prevalence (1.6%) of M. bovis among these isolates, which suggests that local health service procedures likely underestimate its real frequency and that it deserves more attention from public health officials. PMID:23778657

  10. Evasion and subversion of antigen presentation by Mycobacterium tuberculosis

    PubMed Central

    Baena, Andres; Porcelli, Steven A.

    2009-01-01

    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 reveal the multiple potential mechanisms by which M. tuberculosis may actively inhibit, subvert or otherwise modulate antigen presentation by MHC 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. PMID:19563525

  11. Draft Genome Sequence of Mycobacterium tuberculosis KT-0184, Isolated in South Korea.

    PubMed

    Kwon, Taesoo; Han, Seung Jung; Yoo, Won Gi; Yun, Mi-Ran; Lee, Sanghyun; Lee, Jong Seok; Kim, Dae-Won

    2016-01-01

    Here, we describe the draft genome sequence of Mycobacterium tuberculosis KT-0184, from the Beijing family. This genome will provide insight into the evolution and adaptation of M. tuberculosis KT-0184 in human hosts. PMID:26893431

  12. Draft Genome Sequence of Mycobacterium tuberculosis KT-0204, Isolated in South Korea.

    PubMed

    Yun, Mi-Ran; Han, Seung Jung; Yoo, Won Gi; Kwon, Taesoo; Lee, Sanghyun; Lee, Jong Seok; Kim, Dae-Won

    2016-01-01

    Here, we describe the draft genome sequence of Mycobacterium tuberculosis KT-0204, non-Beijing family. This sequence will reveal genes related to the evolution and adaptation of M. tuberculosis KT-0204 in human hosts. PMID:26847902

  13. Draft Genome Sequence of a New Zealand Rangipo Strain of Mycobacterium tuberculosis

    PubMed Central

    Gautam, Sanjay S.; Bower, James E.; Basu, Indira

    2016-01-01

    The Rangipo genotype of the Mycobacterium tuberculosis complex has been associated with a number of tuberculosis (TB) outbreaks in New Zealand. We report here the draft whole-genome sequence of a representative isolate of this strain. PMID:27389273

  14. Dispersal of Mycobacterium tuberculosis via the Canadian fur trade.

    PubMed

    Pepperell, Caitlin S; Granka, Julie M; Alexander, David C; Behr, Marcel A; Chui, Linda; Gordon, Janet; Guthrie, Jennifer L; Jamieson, Frances B; Langlois-Klassen, Deanne; Long, Richard; Nguyen, Dao; Wobeser, Wendy; Feldman, Marcus W

    2011-04-19

    Patterns of gene flow can have marked effects on the evolution of populations. To better understand the migration dynamics of Mycobacterium tuberculosis, we studied genetic data from European M. tuberculosis lineages currently circulating in Aboriginal and French Canadian communities. A single M. tuberculosis lineage, characterized by the DS6(Quebec) genomic deletion, is at highest frequency among Aboriginal populations in Ontario, Saskatchewan, and Alberta; this bacterial lineage is also dominant among tuberculosis (TB) cases in French Canadians resident in Quebec. Substantial contact between these human populations is limited to a specific historical era (1710-1870), during which individuals from these populations met to barter furs. Statistical analyses of extant M. tuberculosis minisatellite data are consistent with Quebec as a source population for M. tuberculosis gene flow into Aboriginal populations during the fur trade era. Historical and genetic analyses suggest that tiny M. tuberculosis populations persisted for ∼100 y among indigenous populations and subsequently expanded in the late 19th century after environmental changes favoring the pathogen. Our study suggests that spread of TB can occur by two asynchronous processes: (i) dispersal of M. tuberculosis by minimal numbers of human migrants, during which small pathogen populations are sustained by ongoing migration and slow disease dynamics, and (ii) expansion of the M. tuberculosis population facilitated by shifts in host ecology. If generalizable, these migration dynamics can help explain the low DNA sequence diversity observed among isolates of M. tuberculosis and the difficulties in global elimination of tuberculosis, as small, widely dispersed pathogen populations are difficult both to detect and to eradicate. PMID:21464295

  15. Dispersal of Mycobacterium tuberculosis via the Canadian fur trade

    PubMed Central

    Pepperell, Caitlin S.; Granka, Julie M.; Alexander, David C.; Behr, Marcel A.; Chui, Linda; Gordon, Janet; Guthrie, Jennifer L.; Jamieson, Frances B.; Langlois-Klassen, Deanne; Long, Richard; Nguyen, Dao; Wobeser, Wendy; Feldman, Marcus W.

    2011-01-01

    Patterns of gene flow can have marked effects on the evolution of populations. To better understand the migration dynamics of Mycobacterium tuberculosis, we studied genetic data from European M. tuberculosis lineages currently circulating in Aboriginal and French Canadian communities. A single M. tuberculosis lineage, characterized by the DS6Quebec genomic deletion, is at highest frequency among Aboriginal populations in Ontario, Saskatchewan, and Alberta; this bacterial lineage is also dominant among tuberculosis (TB) cases in French Canadians resident in Quebec. Substantial contact between these human populations is limited to a specific historical era (1710–1870), during which individuals from these populations met to barter furs. Statistical analyses of extant M. tuberculosis minisatellite data are consistent with Quebec as a source population for M. tuberculosis gene flow into Aboriginal populations during the fur trade era. Historical and genetic analyses suggest that tiny M. tuberculosis populations persisted for ∼100 y among indigenous populations and subsequently expanded in the late 19th century after environmental changes favoring the pathogen. Our study suggests that spread of TB can occur by two asynchronous processes: (i) dispersal of M. tuberculosis by minimal numbers of human migrants, during which small pathogen populations are sustained by ongoing migration and slow disease dynamics, and (ii) expansion of the M. tuberculosis population facilitated by shifts in host ecology. If generalizable, these migration dynamics can help explain the low DNA sequence diversity observed among isolates of M. tuberculosis and the difficulties in global elimination of tuberculosis, as small, widely dispersed pathogen populations are difficult both to detect and to eradicate. PMID:21464295

  16. Zirconia based nucleic acid sensor for Mycobacterium tuberculosis detection

    NASA Astrophysics Data System (ADS)

    Das, Maumita; Sumana, Gajjala; Nagarajan, R.; Malhotra, B. D.

    2010-03-01

    Nanostructured zirconium oxide (ZrO2) film (particle size˜35 nm), electrochemically deposited onto gold(Au) surface, has been used to immobilize 21-mer oligonucleotide probe (ssDNA) specific to Mycobacterium tuberculosis by utilizing affinity between oxygen atom of phosphoric group and zirconium to fabricate DNA biosensor. This DNA-ZrO2/Au bioelectrode, characterized using x-ray diffraction, Fourier transform infrared spectroscopy, cyclic voltammetry, and scanning electron microscopy techniques, can be used for early and rapid diagnosis of M. tuberculosis with detection limit of 0.065 ng/μL within 60s.

  17. Efficacy of Nitazoxanide against Clinical Isolates of Mycobacterium tuberculosis

    PubMed Central

    Shigyo, Kristina; Ocheretina, Oksana; Merveille, Yves Mary; Johnson, Warren D.; Pape, Jean William; Nathan, Carl F.

    2013-01-01

    Nitazoxanide (NTZ) has bactericidal activity against the H37Rv laboratory strain of Mycobacterium tuberculosis with a MIC of 16 μg/ml. However, its efficacy against clinical isolates of M. tuberculosis has not been determined. We found that NTZ's MIC against 50 clinical isolates ranged from 12 to 28 μg/ml with a median of 16 μg/ml and was unaffected by resistance to first- or second-line antituberculosis drugs or a diversity of spoligotypes. PMID:23507275

  18. Identification of new diamine scaffolds with activity against Mycobacterium tuberculosis

    PubMed Central

    Bogatcheva, Elena; Hanrahan, Colleen; Nikonenko, Boris; Samala, Rowena; Chen, Ping; Gearhart, Jacqueline; Barbosa, Francis; Einck, Leo; Nacy, Carol A.; Protopopova, Marina

    2015-01-01

    A diverse 5,000-compound library was synthesized from commercially available diamines and screened for activity against Mycobacterium tuberculosis in vitro, revealing 143 hits with MIC equal to or less than 12.5 µM. New prospective scaffolds with antitubercular activity derived from homopiperazine, phenyl- and benzyl substituted piperazines, 4-aminomethylpiperidine, 4-aminophenylethylamine, 4,4'-methylenebiscyclohexylamine were identified. Compound SQ775 derived from homopiperazine, and compound SQ786 derived from benzylpiperazine had potent antimicrobial activity against M. tuberculosis in experimental animals in vivo. PMID:16722620

  19. Inactivation of Mycobacterium tuberculosis for DNA Typing Analysis

    PubMed Central

    Bemer-Melchior, P.; Drugeon, H. B.

    1999-01-01

    DNA fingerprinting analysis of Mycobacterium tuberculosis is used for epidemiological studies and the control of laboratory cross-contamination. Because standardized procedures are not entirely safe for mycobacteriology laboratory staff, the paper proposes a new technique for the processing of specimens. The technique ensures the inactivation of M. tuberculosis before DNA extraction without the loss of DNA integrity. The control of inactivated cultures should be rigorous and should involve the use of two different culture media incubated for at least 4 months. PMID:10364613

  20. Cholesterol catabolism as a therapeutic target in Mycobacterium tuberculosis

    PubMed Central

    Ouellet, Hugues; Johnston, Jonathan B.; Ortiz de Montellano, Paul R.

    2011-01-01

    Mycobacterium tuberculosis (Mtb) is an intracellular pathogen that infects 10 million worldwide and kills 2 million people every year. The uptake and utilization of nutrients by Mtb within the host cell is still poorly understood, although lipids play an important role in Mtb persistence. The recent identification of a large regulon of cholesterol catabolic genes suggests that Mtb can use host sterol for infection and persistence. In this review, we report on recent progress in elucidation of the Mtb cholesterol catabolic reactions and their potential utility as targets for tuberculosis therapeutic agents. PMID:21924910

  1. Mycobacterium tuberculosis virulence: insights and impact on vaccine development.

    PubMed

    Delogu, Giovanni; Provvedi, Roberta; Sali, Michela; Manganelli, Riccardo

    2015-01-01

    The existing TB vaccine, the attenuated Mycobacterium bovis strain BCG, is effective in protecting infants from severe forms of the disease, while its efficacy in protecting adults from pulmonary TB is poor. In the last two decades, a renewed interest in TB resulted in the development of several candidate vaccines that are now entering clinical trials. However, most of these vaccines are based on a common rationale and aim to induce a strong T-cell response against Mycobacterium tuberculosis. Recent advancements in the understanding of M. tuberculosis virulence determinants and associated pathogenic strategies are opening a new and broader view of the complex interaction between this remarkable pathogen and the human host, providing insights at molecular level that could lead to a new rationale for the design of novel antitubercular vaccines. A vaccination strategy that simultaneously targets different steps in TB pathogenesis may result in improved protection and reduced TB transmission. PMID:26119086

  2. Complete Genome Sequence of Mycobacterium tuberculosis Clinical Isolate Spoligotype SIT745/EAI1-MYS.

    PubMed

    Suraiya, S; Semail, N; Ismail, M F; Abdullah, J M

    2016-01-01

    Mycobacterium tuberculosis is known to cause pulmonary and extrapulmonary tuberculosis. This organism showed special phylogeographical specificity. Here, we report the complete genome sequence of M. tuberculosis clinical isolate spoligotype SIT745/EAI1-MYS, which was isolated from a Malaysian tuberculosis patient. PMID:27198011

  3. Lymphatic endothelial cells are a replicative niche for Mycobacterium tuberculosis.

    PubMed

    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

    2016-03-01

    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

  4. Lymphatic endothelial cells are a replicative niche for Mycobacterium tuberculosis

    PubMed Central

    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

  5. Mycobacterium tuberculosis Infection of Domesticated Asian Elephants, Thailand

    PubMed Central

    Angkawanish, Taweepoke; Sirimalaisuwan, Anucha; Kaewsakhorn, Thattawan; Boonsri, Kittikorn; Rutten, Victor P.M.G.

    2010-01-01

    Four Asian elephants were confirmed to be infected with Mycobacterium tuberculosis by bacterial culture, other diagnostic procedures, and sequencing of 16S–23S rDNA internal transcribed spacer region, 16S rRNA, and gyrase B gene sequences. Genotyping showed that the infectious agents originated from 4 sources in Thailand. To identify infections, a combination of diagnostic assays is essential. PMID:21122228

  6. Mycobacterium tuberculosis Mutations Associated with Reduced Susceptibility to Linezolid.

    PubMed

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

    2016-04-01

    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 ofMycobacterium tuberculosiswith reduced susceptibility to LZD, which was accounted for byrrlandrplCmutations 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

  7. Carbapenems and Rifampin Exhibit Synergy against Mycobacterium tuberculosis and Mycobacterium abscessus

    PubMed Central

    Kaushik, Amit; Makkar, Nayani; Pandey, Pooja; Parrish, Nicole; Singh, Urvashi

    2015-01-01

    An effective regimen for treatment of tuberculosis (TB) is comprised of multiple drugs that inhibit a range of essential cellular activities in Mycobacterium tuberculosis. The effectiveness of a regimen is further enhanced if constituent drugs act with synergy. Here, we report that faropenem (a penem) or biapenem, doripenem, or meropenem (carbapenems), which belong to the β-lactam class of antibiotics, and rifampin, one of the drugs that forms the backbone of TB treatment, act with synergy when combined. One of the reasons (carba)penems are seldom used for treatment of TB is the high dosage levels required, often at the therapeutic limits. The synergistic combination of rifampin and these (carba)penems indicates that (carba)penems can be administered at dosages that are therapeutically relevant. The combination of faropenem and rifampin also limits the frequency of resistant mutants, as we were unable to obtain spontaneous mutants in the presence of these two drugs. The combinations of rifampin and (carba)penems were effective not only against drug-sensitive Mycobacterium tuberculosis but also against drug-resistant clinical isolates that are otherwise resistant to rifampin. A combination of doripenem or biapenem and rifampin also exhibited synergistic activity against Mycobacterium abscessus. Although the MICs of these three drugs alone against M. abscessus are too high to be of clinical relevance, their concentrations in combinations are therapeutically relevant; therefore, they warrant further evaluation for clinical utility to treat Mycobacterium abscessus infection, especially in cystic fibrosis patients. PMID:26259792

  8. Carbapenems and Rifampin Exhibit Synergy against Mycobacterium tuberculosis and Mycobacterium abscessus.

    PubMed

    Kaushik, Amit; Makkar, Nayani; Pandey, Pooja; Parrish, Nicole; Singh, Urvashi; Lamichhane, Gyanu

    2015-10-01

    An effective regimen for treatment of tuberculosis (TB) is comprised of multiple drugs that inhibit a range of essential cellular activities in Mycobacterium tuberculosis. The effectiveness of a regimen is further enhanced if constituent drugs act with synergy. Here, we report that faropenem (a penem) or biapenem, doripenem, or meropenem (carbapenems), which belong to the β-lactam class of antibiotics, and rifampin, one of the drugs that forms the backbone of TB treatment, act with synergy when combined. One of the reasons (carba)penems are seldom used for treatment of TB is the high dosage levels required, often at the therapeutic limits. The synergistic combination of rifampin and these (carba)penems indicates that (carba)penems can be administered at dosages that are therapeutically relevant. The combination of faropenem and rifampin also limits the frequency of resistant mutants, as we were unable to obtain spontaneous mutants in the presence of these two drugs. The combinations of rifampin and (carba)penems were effective not only against drug-sensitive Mycobacterium tuberculosis but also against drug-resistant clinical isolates that are otherwise resistant to rifampin. A combination of doripenem or biapenem and rifampin also exhibited synergistic activity against Mycobacterium abscessus. Although the MICs of these three drugs alone against M. abscessus are too high to be of clinical relevance, their concentrations in combinations are therapeutically relevant; therefore, they warrant further evaluation for clinical utility to treat Mycobacterium abscessus infection, especially in cystic fibrosis patients. PMID:26259792

  9. Mycobacterium thermoresistibile as a source of thermostable orthologs of Mycobacterium tuberculosis proteins.

    PubMed

    Edwards, Thomas E; Liao, Reiling; Phan, Isabelle; Myler, Peter J; Grundner, Christoph

    2012-07-01

    The genus Mycobacterium comprises major human pathogens such as the causative agent of tuberculosis, Mycobacterium tuberculosis (Mtb), and many environmental species. Tuberculosis claims ~1.5 million lives every year, and drug resistant strains of Mtb are rapidly emerging. To aid the development of new tuberculosis drugs, major efforts are currently under way to determine crystal structures of Mtb drug targets and proteins involved in pathogenicity. However, a major obstacle to obtaining crystal structures is the generation of well-diffracting crystals. Proteins from thermophiles can have better crystallization and diffraction properties than proteins from mesophiles, but their sequences and structures are often divergent. Here, we establish a thermophilic mycobacterial model organism, Mycobacterium thermoresistibile (Mth), for the study of Mtb proteins. Mth tolerates higher temperatures than Mtb or other environmental mycobacteria such as M. smegmatis. Mth proteins are on average more soluble than Mtb proteins, and comparison of the crystal structures of two pairs of orthologous proteins reveals nearly identical folds, indicating that Mth structures provide good surrogates for Mtb structures. This study introduces a thermophile as a source of protein for the study of a closely related human pathogen and marks a new approach to solving challenging mycobacterial protein structures. PMID:22544630

  10. Rapid drug susceptibility test of mycobacterium tuberculosis by bioluminescence sensor

    NASA Astrophysics Data System (ADS)

    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.

  11. Uracil excision repair in Mycobacterium tuberculosis cell-free extracts.

    PubMed

    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. PMID:21371942

  12. Laboratory Diagnosis of Mycobacterium tuberculosis Infection and Disease in Children.

    PubMed

    Dunn, James J; Starke, Jeffrey R; Revell, Paula A

    2016-06-01

    Diagnosis of tuberculosis in children is challenging; even with advanced technologies, the diagnosis is often difficult to confirm microbiologically in part due to the paucibacillary nature of the disease. Clinical diagnosis lacks standardization, and traditional and molecular microbiologic methods lack sensitivity, particularly in children. Immunodiagnostic tests may improve sensitivity, but these tests cannot distinguish tuberculosis disease from latent infection and some lack specificity. While molecular tools like Xpert MTB/RIF have advanced our ability to detect Mycobacterium tuberculosis and to determine antimicrobial resistance, decades old technologies remain the standard in most locales. Today, the battle against this ancient disease still poses one of the primary diagnostic challenges in pediatric laboratory medicine. PMID:26984977

  13. The efficacy of the heat killing of Mycobacterium tuberculosis.

    PubMed

    Doig, C; Seagar, A L; Watt, B; Forbes, K J

    2002-10-01

    There is concern that current procedures for the heat inactivation of Mycobacterium tuberculosis may not be adequate. This raises serious safety issues for laboratory staff performing molecular investigations such as IS6110 restriction fragment length polymorphism typing. This paper confirms that the protocol of van Embden et al, as performed routinely in this laboratory, is safe and effective for the heat inactivation of M tuberculosis. This procedure involves complete immersion of a tube containing a suspension of one loopfull of growth in a water bath at 80 degrees C for 20 minutes. Seventy four isolates were included in this investigation. Despite prolonged incubation for 20 weeks, none of the heat killed M tuberculosis suspensions produced visible colonies or gave a positive growth signal from liquid culture. This method did not affect the integrity of the DNA for subsequent molecular investigations. PMID:12354807

  14. Direct identification and typing of Mycobacterium tuberculosis by PCR.

    PubMed Central

    Neimark, H; Ali Baig, M; Carleton, S

    1996-01-01

    We have developed a rapid PCR assay that types strains of Mycobacterium tuberculosis by generating distinct DNA fingerprints directly from primary cultures. This assay allows strain identification analogous to that achieved by the standard restriction fragment length polymorphism method, and fingerprints are obtained in less than 8 h. This assay does not require subculturing, DNA purification, restriction digestion, Southern blotting, or nucleic acid hybridization. Rapid and precise identification of M. tuberculosis strains permits immediate molecular epidemiologic studies. The assay can be converted to a computer-automated system by employing fluorescently labeled PCR primers and the Perkin-Elmer DNA sequencer so that unknown-specimen fingerprints are identified by computer comparison to a database of M. tuberculosis strain fingerprints. PMID:8880499

  15. The efficacy of the heat killing of Mycobacterium tuberculosis

    PubMed Central

    Doig, C; Seagar, A L; Watt, B; Forbes, K J

    2002-01-01

    There is concern that current procedures for the heat inactivation of Mycobacterium tuberculosis may not be adequate. This raises serious safety issues for laboratory staff performing molecular investigations such as IS6110 restriction fragment length polymorphism typing. This paper confirms that the protocol of van Embden et al, as performed routinely in this laboratory, is safe and effective for the heat inactivation of M tuberculosis. This procedure involves complete immersion of a tube containing a suspension of one loopfull of growth in a water bath at 80°C for 20 minutes. Seventy four isolates were included in this investigation. Despite prolonged incubation for 20 weeks, none of the heat killed M tuberculosis suspensions produced visible colonies or gave a positive growth signal from liquid culture. This method did not affect the integrity of the DNA for subsequent molecular investigations. PMID:12354807

  16. Advances in Mycobacterium tuberculosis therapeutics discovery utlizing structural biology

    PubMed Central

    Chim, Nicholas; Owens, Cedric P.; Contreras, Heidi; Goulding, Celia W.

    2013-01-01

    In 2012, tuberculosis (TB) remains a global health threat and is exacerbated both by the emergence of drug resistant Mycobacterium tuberculosis strains and its synergy with HIV infection. The waning effectiveness of current treatment regimens necessitates the development of new or repurposed anti-TB therapeutics for improved combination therapies against the disease. Exploiting atomic resolution structural information of proteins in complex with their substrates and/or inhibitors can facilitate structure-based rational drug design. Since our last review in 2009, there has been a wealth of new M. tuberculosis protein structural information. Once again, we have compiled the most promising structures with regards to potential anti-TB drug development and present them in this updated review. PMID:23167715

  17. Development of a new DNA extraction protocol for PFGE typing of Mycobacterium tuberculosis complex.

    PubMed

    Ghodousi, Arash; Arash, Ghodousi A; Vatani, S; Darban-Sarokhalil, Davood; Omrani, Maryam; Fooladi, A; Fooladi, Aa; Khosaravi, A; Khosaravi, Ad; Feizabadi, Mohammad Mehdi

    2012-03-01

    A modified pulsed-field gel electrophoresis (PFGE) protocol was developed and applied to clinical isolates of Mycobacterium tuberculosis complex to reduce the cost of using lyticase. This protocol reduces the expense of PFGE typing of Mycobacterium tuberculosis complex as it removes the use of lyticase during the spheroplast formation from these bacteria. PMID:22783461

  18. Development of a new DNA extraction protocol for PFGE typing of Mycobacterium tuberculosis complex

    PubMed Central

    Arash, Ghodousi A; Vatani, S; Darban-Sarokhalil, Davood; Omrani, Maryam; Fooladi, AA; Khosaravi, AD; Feizabadi, Mohammad Mehdi

    2012-01-01

    A modified pulsed-field gel electrophoresis (PFGE) protocol was developed and applied to clinical isolates of Mycobacterium tuberculosis complex to reduce the cost of using lyticase. This protocol reduces the expense of PFGE typing of Mycobacterium tuberculosis complex as it removes the use of lyticase during the spheroplast formation from these bacteria. PMID:22783461

  19. Proteogenomic analysis of Mycobacterium tuberculosis by high resolution mass spectrometry.

    PubMed

    Kelkar, Dhanashree S; Kumar, Dhirendra; Kumar, Praveen; Balakrishnan, Lavanya; Muthusamy, Babylakshmi; Yadav, Amit Kumar; Shrivastava, Priyanka; Marimuthu, Arivusudar; Anand, Sridhar; Sundaram, Hema; Kingsbury, Reena; Harsha, H C; Nair, Bipin; Prasad, T S Keshava; Chauhan, Devendra Singh; Katoch, Kiran; Katoch, Vishwa Mohan; Kumar, Prahlad; Chaerkady, Raghothama; Ramachandran, Srinivasan; Dash, Debasis; Pandey, Akhilesh

    2011-12-01

    The genome sequencing of H37Rv strain of Mycobacterium tuberculosis was completed in 1998 followed by the whole genome sequencing of a clinical isolate, CDC1551 in 2002. Since then, the genomic sequences of a number of other strains have become available making it one of the better studied pathogenic bacterial species at the genomic level. However, annotation of its genome remains challenging because of high GC content and dissimilarity to other model prokaryotes. To this end, we carried out an in-depth proteogenomic analysis of the M. tuberculosis H37Rv strain using Fourier transform mass spectrometry with high resolution at both MS and tandem MS levels. In all, we identified 3176 proteins from Mycobacterium tuberculosis representing ~80% of its total predicted gene count. In addition to protein database search, we carried out a genome database search, which led to identification of ~250 novel peptides. Based on these novel genome search-specific peptides, we discovered 41 novel protein coding genes in the H37Rv genome. Using peptide evidence and alternative gene prediction tools, we also corrected 79 gene models. Finally, mass spectrometric data from N terminus-derived peptides confirmed 727 existing annotations for translational start sites while correcting those for 33 proteins. We report creation of a high confidence set of protein coding regions in Mycobacterium tuberculosis genome obtained by high resolution tandem mass-spectrometry at both precursor and fragment detection steps for the first time. This proteogenomic approach should be generally applicable to other organisms whose genomes have already been sequenced for obtaining a more accurate catalogue of protein-coding genes. PMID:21969609

  20. Granuloma Correlates of Protection Against Tuberculosis and Mechanisms of Immune Modulation by Mycobacterium tuberculosis

    PubMed Central

    Mehra, Smriti; Alvarez, Xavier; Didier, Peter J.; Doyle, Lara A.; Blanchard, James L.; Lackner, Andrew A.; Kaushal, Deepak

    2013-01-01

    Background. The BCG vaccine is ineffective against adult tuberculosis. Hence, new antituberculosis vaccines are needed. Correlates of protection against tuberculosis are not known. We studied the effects of BCG vaccination on gene expression in tuberculosis granulomas using macaques. Methods. Macaques were BCG-vaccinated or sham-vaccinated and then challenged with virulent Mycobacterium tuberculosis. Lung lesions were used for comparative transcriptomics. Results. Vaccinated macaques were protected with lower bacterial burden and immunopathology. Lesions from BCG-vaccinated nonhuman primates (NHPs) showed a better balance of α- and β-chemokine gene expression with higher levels of β-chemokine expression relative to nonvaccinated animals. Consistent with this, sham-vaccinated macaques recruited fewer macrophages relative to neutrophils in their lungs. The expression of indoleamine 2,3-dioxygenase (IDO), a known immunosuppressor, was significantly higher in both week 5 and 10 lesions from sham-vaccinated, relative to BCG-vaccinated, NHPs. IDO expression was primarily limited to the nonlymphocytic region of the lesions, within the inner ring structure surrounding the central necrosis. Conclusions. Our study defines lung gene expression correlates of protective response against tuberculosis, relative to disease, which can potentially be employed to assess the efficacy of candidate antituberculosis vaccines. Mycobacterium tuberculosis may modulate protective immune responses using diverse mechanisms, including increased recruitment of inflammatory neutrophils and the concomitant use of IDO to modulate inflammation. PMID:23255564

  1. Synthetic Long Peptide Derived from Mycobacterium tuberculosis Latency Antigen Rv1733c Protects against Tuberculosis

    PubMed Central

    Coppola, Mariateresa; van den Eeden, Susan J. F.; Wilson, Louis; Franken, Kees L. M. C.; Ottenhoff, Tom H. M.

    2015-01-01

    Responsible for 9 million new cases of active disease and nearly 2 million deaths each year, tuberculosis (TB) remains a global health threat of overwhelming dimensions. Mycobacterium bovis BCG, the only licensed vaccine available, fails to confer lifelong protection and to prevent reactivation of latent infection. Although 15 new vaccine candidates are now in clinical trials, an effective vaccine against TB remains elusive, and new strategies for vaccination are vital. BCG vaccination fails to induce immunity against Mycobacterium tuberculosis latency antigens. Synthetic long peptides (SLPs) combined with adjuvants have been studied mostly for therapeutic cancer vaccines, yet not for TB, and proved to induce efficient antitumor immunity. This study investigated an SLP derived from Rv1733c, a major M. tuberculosis latency antigen which is highly expressed by “dormant” M. tuberculosis and well recognized by T cells from latently M. tuberculosis-infected individuals. In order to assess its in vivo immunogenicity and protective capacity, Rv1733c SLP in CpG was administered to HLA-DR3 transgenic mice. Immunization with Rv1733c SLP elicited gamma interferon-positive/tumor necrosis factor-positive (IFN-γ+/TNF+) and IFN-γ+ CD4+ T cells and Rv1733c-specific antibodies and led to a significant reduction in the bacterial load in the lungs of M. tuberculosis-challenged mice. This was observed both in a pre- and in a post-M. tuberculosis challenge setting. Moreover, Rv1733c SLP immunization significantly boosted the protective efficacy of BCG, demonstrating the potential of M. tuberculosis latency antigens to improve BCG efficacy. These data suggest a promising role for M. tuberculosis latency antigen Rv1733c-derived SLPs as a novel TB vaccine approach, both in a prophylactic and in a postinfection setting. PMID:26202436

  2. The progress made in determining the Mycobacterium tuberculosis structural proteome

    PubMed Central

    Hecker, Michael

    2011-01-01

    Mycobacterium tuberculosis is a highly infectious pathogen that is still responsible for millions of deaths annually. Effectively treating this disease typically requires a course of antibiotics, most of which were developed decades ago. These drugs are, however, not effective against persistent tubercle bacilli and the emergence of drug-resistant stains threatens to make many of them obsolete. The identification of new drug targets, allowing the development of new potential drugs, is therefore imperative. Both proteomics and structural biology have important roles to play in this process, the former as a means of identifying promising drug targets and the latter allowing understanding of protein function and protein–drug interactions at atomic resolution. The determination of M. tuberculosis protein structures has been a goal of the scientific community for the last decade, who have aimed to supply a large amount of structural data that can be used in structure-based approaches for drug discovery and design. Only since the genome sequence of M. tuberculosis has been available has the determination of large numbers of tuberculosis protein structures been possible. Currently, the molecular structures of 8.5% of all the pathogen's protein-encoding ORFs have been determined. In this review, we look at the progress made in determining the M. tuberculosis structural proteome and the impact this has had on the development of potential new drugs, as well as the discovery of the function of crucial mycobaterial proteins. PMID:21674801

  3. Structural and functional characterization of Mycobacterium tuberculosis triosephosphate isomerase

    SciTech Connect

    Connor, Sean E.; Capodagli, Glenn C.; Deaton, Michelle K.; Pegan, Scott D.

    2012-04-18

    Tuberculosis (TB) is a major infectious disease that accounts for over 1.7 million deaths every year. Mycobacterium tuberculosis, the causative agent of tuberculosis, enters the human host by the inhalation of infectious aerosols. Additionally, one third of the world's population is likely to be infected with latent TB. The incidence of TB is on the rise owing in part to the emergence of multidrug-resistant strains. As a result, there is a growing need to focus on novel M. tuberculosis enzyme targets. M. tuberculosis triosephosphate isomerase (MtTPI) is an essential enzyme for gluconeogenetic pathways, making it a potential target for future therapeutics. In order to determine its structure, the X-ray crystal structure of MtTPI has been determined, as well as that of MtTPI bound with a reaction-intermediate analog. As a result, two forms of the active site were revealed. In conjunction with the kinetic parameters obtained for the MtTPI-facilitated conversion of dihydroxyacetone phosphate (DHAP) to D-glyceraldehyde-3-phosphate (D-GAP), this provides a greater structural and biochemical understanding of this enzyme. Additionally, isothermal titration calorimetry was used to determine the binding constant for a reaction-intermediate analog bound to the active site of MtTPI.

  4. TIM3 Mediates T Cell Exhaustion during Mycobacterium tuberculosis Infection

    PubMed Central

    Jayaraman, Pushpa; Jacques, Miye K.; Zhu, Chen; Steblenko, Katherine M.; Stowell, Britni L.; Madi, Asaf; Anderson, Ana C.; Kuchroo, Vijay K.; Behar, Samuel M.

    2016-01-01

    While T cell immunity initially limits Mycobacterium tuberculosis infection, why T cell immunity fails to sterilize the infection and allows recrudescence is not clear. One hypothesis is that T cell exhaustion impairs immunity and is detrimental to the outcome of M. tuberculosis infection. Here we provide functional evidence for the development T cell exhaustion during chronic TB. Second, we evaluate the role of the inhibitory receptor T cell immunoglobulin and mucin domain–containing-3 (TIM3) during chronic M. tuberculosis infection. We find that TIM3 expressing T cells accumulate during chronic infection, co-express other inhibitory receptors including PD1, produce less IL-2 and TNF but more IL-10, and are functionally exhausted. Finally, we show that TIM3 blockade restores T cell function and improves bacterial control, particularly in chronically infected susceptible mice. These data show that T cell immunity is suboptimal during chronic M. tuberculosis infection due to T cell exhaustion. Moreover, in chronically infected mice, treatment with anti-TIM3 mAb is an effective therapeutic strategy against tuberculosis. PMID:26967901

  5. Genetic diversity of Mycobacterium tuberculosis isolates from central India

    PubMed Central

    Desikan, Prabha; Chauhan, D.S.; Sharma, Pragya; Panwalkar, Nikita; Chourey, Manju; Patidar, Mohan Lal; Yadav, Priyanka; Chandrasekaran, V.; Ohri, B.S.

    2016-01-01

    Background & objectives: There is a paucity of data available on genetic biodiversity of Mycobacterium tuberculosis isolates from central India. The present study was carried out on isolates of M. tuberculosis cultured from diagnostic clinical samples of patients from Bhopal, central India, using spoligotyping as a method of molecular typing. Methods: DNA was extracted from 340 isolates of M. tuberculosis from culture, confirmed as M. tuberculosis by molecular and biochemical methods and subjected to spoligotyping. The results were compared with the international SITVIT2 database. Results: Sixty five different spoligo international type (SIT) patterns were observed. A total of 239 (70.3%) isolates could be clustered into 25 SITs. The Central Asian (CAS) and East African Indian (EAI) families were found to be the two major circulating families in this region. SIT26/CAS1_DEL was identified as the most predominant type, followed by SIT11/EAI3_IND and SIT288/CAS2. Forty (11.8%) unique (non-clustered) and 61 (17.9%) orphan isolates were identified in the study. There was no significant association of clustering with clinical and demographic characteristics of patients. Interpretation & conclusions: Well established SITs were found to be predominant in our study. SIT26/CAS1_DEL was the most predominant type. However, the occurrence of a substantial number of orphan isolates may indicate the presence of active spatial and temporal evolutionary dynamics within the isolates of M. tuberculosis. PMID:27377505

  6. Bystander Macrophage Apoptosis after Mycobacterium tuberculosis H37Ra Infection▿

    PubMed Central

    Kelly, Deirdre M.; ten Bokum, Annemieke M. C.; O'Leary, Seonadh M.; O'Sullivan, Mary P.; Keane, Joseph

    2008-01-01

    Human macrophages infected with Mycobacterium tuberculosis may undergo apoptosis. Macrophage apoptosis contributes to the innate immune response against M. tuberculosis by containing and limiting the growth of mycobacteria and also by depriving the bacillus of its niche cell. Apoptosis of infected macrophages is well documented; however, bystander apoptosis of uninfected macrophages has not been described in the setting of M. tuberculosis. We observed that uninfected human macrophages underwent significant bystander apoptosis 48 and 96 h after they came into contact with macrophages infected with avirulent M. tuberculosis. The bystander apoptosis was significantly greater than the background apoptosis observed in uninfected control cells cultured for the same length of time. There was no evidence of the involvement of tumor necrosis factor alpha, Fas, tumor necrosis factor-related apoptosis-inducing ligand, transforming growth factor β, Toll-like receptor 2, or MyD88 in contact-mediated bystander apoptosis. This newly described phenomenon may further limit the spread of M. tuberculosis by eliminating the niche cells on which the bacillus relies. PMID:17954721

  7. Gene Transfer in Mycobacterium tuberculosis: Shuttle Phasmids to Enlightenment

    PubMed Central

    JACOBS, WILLIAM R.

    2016-01-01

    Infectious diseases have plagued humankind throughout history and have posed serious public health problems. Yet vaccines have eradicated smallpox and antibiotics have drastically decreased the mortality rate of many infectious agents. These remarkable successes in the control of infections came from knowing the causative agents of the diseases, followed by serendipitous discoveries of attenuated viruses and antibiotics. The discovery of DNA as genetic material and the understanding of how this information translates into specific phenotypes have changed the paradigm for developing new vaccines, drugs, and diagnostic tests. Knowledge of the mechanisms of immunity and mechanisms of action of drugs has led to new vaccines and new antimicrobial agents. The key to the acquisition of the knowledge of these mechanisms has been identifying the elemental causes (i.e., genes and their products) that mediate immunity and drug resistance. The identification of these genes is made possible by being able to transfer the genes or mutated forms of the genes into causative agents or surrogate hosts. Such an approach was limited in Mycobacterium tuberculosis by the difficulty of transferring genes or alleles into M. tuberculosis or a suitable surrogate mycobacterial host. The construction of shuttle phasmids—chimeric molecules that replicate in Escherichia coli as plasmids and in mycobacteria as mycobacteriophages—was instrumental in developing gene transfer systems for M. tuberculosis. This review will discuss M. tuberculosis genetic systems and their impact on tuberculosis research. “I had to know my enemy in order to prevail against him.”Nelson Mandela PMID:26105819

  8. Resistance to cellular autophagy by Mycobacterium tuberculosis Beijing strains.

    PubMed

    Haque, Md Fazlul; Boonhok, Rachasak; Prammananan, Therdsak; Chaiprasert, Angkana; Utaisincharoen, Pongsak; Sattabongkot, Jetsumon; Palittapongarnpim, Prasit; Ponpuak, Marisa

    2015-10-01

    Autophagy represents a key pathway in innate immune defense to restrict Mycobacterium tuberculosis growth inside host macrophages. Induction of autophagy has been shown to promote mycobacterial phagosome acidification and acquisition of lysosomal hydrolases, resulting in the elimination of intracellular M. tuberculosis reference strains such as H37Rv. The notorious Beijing genotype has been previously shown to be hyper-virulent and associated with increased survival in host cells and a high mortality rate in animal models, but the underlying mechanism that renders this family to have such advantages remains unclear. We hypothesize that autophagic control against M. tuberculosis Beijing strains may be altered. Here, we discovered that the Beijing strains can resist autophagic killing by host cells compared with that of the reference strain H37Rv and a strain belonging to the East African Indian genotype. Moreover, we have determined a possible underlying mechanism and found that the greater ability to evade autophagic elimination possessed by the Beijing strains stems from their higher capacity to inhibit autophagolysosome biogenesis upon autophagy induction. In summary, a previously unrecognized ability of the M. tuberculosis Beijing strains to evade host autophagy was identified, which may have important implications for tuberculosis treatment, especially in regions prevalent by the Beijing genotype. PMID:26160686

  9. Mycobacterium tuberculosis Pathogenesis and Molecular Determinants of Virulence

    PubMed Central

    Smith, Issar

    2003-01-01

    Tuberculosis (TB), one of the oldest known human diseases. is still is one of the major causes of mortality, since two million people die each year from this malady. TB has many manifestations, affecting bone, the central nervous system, and many other organ systems, but it is primarily a pulmonary disease that is initiated by the deposition of Mycobacterium tuberculosis, contained in aerosol droplets, onto lung alveolar surfaces. From this point, the progression of the disease can have several outcomes, determined largely by the response of the host immune system. The efficacy of this response is affected by intrinsic factors such as the genetics of the immune system as well as extrinsic factors, e.g., insults to the immune system and the nutritional and physiological state of the host. In addition, the pathogen may play a role in disease progression since some M. tuberculosis strains are reportedly more virulent than others, as defined by increased transmissibility as well as being associated with higher morbidity and mortality in infected individuals. Despite the widespread use of an attenuated live vaccine and several antibiotics, there is more TB than ever before, requiring new vaccines and drugs and more specific and rapid diagnostics. Researchers are utilizing information obtained from the complete sequence of the M. tuberculosis genome and from new genetic and physiological methods to identify targets in M. tuberculosis that will aid in the development of these sorely needed antitubercular agents. PMID:12857778

  10. Mycobacterium tuberculosis infection in women with unexplained infertility

    PubMed Central

    Eftekhar, Maryam; Pourmasumi, Soheila; Sabeti, Parvin; Aflatoonian, Abbas; Sheikhha, Mohammad Hasan

    2015-01-01

    Background: Genital tuberculosis (GTB) is an important cause of female infertility, especially in developing countries. The positive results of polymerase chain reaction (PCR) in endometrial GTB in the absence of tubal damage raise the possibility of the detection of sub-clinical or latent disease, with doubtful benefits of treatment. Objective: To evaluate the mycobacterium tuberculosis infection in endometrial biopsy samples collected from unexplained infertile women attending Yazd Research and Clinical Center for Infertility by using PCR techniques. Materials and Methods: In this cross sectional study, 144 infertile women with unexplained infertility aged 20-35 years old and normal Histro-saplango graphy findings were enrolled. Endometrial biopsy samples from each participant were tested for mycobacterium tuberculosis detecting by PCR. In 93 patients, peritoneal fluid was also taken for culture and PCR. Results: The PCR results of endometrial specimens were negative in all cases, demonstrating that there was no GTB infection among our patients. Conclusion: Our results showed that GTB could not be considered as a major problem in women with unexplained infertility. Although, studies have indicated that PCR is a useful method in diagnosing early GTB disease in infertile women with no demonstrable evidence of tubal or endometrial involvement. PMID:27141534

  11. Dielectrophoretic characterization of antibiotic-treated Mycobacterium tuberculosis complex cells.

    PubMed

    Inoue, Shinnosuke; Lee, Hyun-Boo; Becker, Annie L; Weigel, Kris M; Kim, Jong-Hoon; Lee, Kyong-Hoon; Cangelosi, Gerard A; Chung, Jae-Hyun

    2015-10-01

    Multi-drug resistant tuberculosis (MDR-TB) has become a serious concern for proper treatment of patients. As a phenotypic method, dielectrophoresis can be useful but is yet to be attempted to evaluate Mycobacterium tuberculosis complex cells. This paper investigates the dielectrophoretic behavior of Mycobacterium bovis (Bacillus Calmette-Guérin, BCG) cells that are treated with heat or antibiotics rifampin (RIF) or isoniazid (INH). The experimental parameters are designed on the basis of our sensitivity analysis. The medium conductivity (σ(m)) and the frequency (f) for a crossover frequency (f(xo1)) test are decided to detect the change of σ(m)-f(xo1) in conjunction with the drug mechanism. Statistical modeling is conducted to estimate the distributions of viable and nonviable cells from the discrete measurement of f (xo1). Finally, the parameters of the electrophysiology of BCG cells, C(envelope) and σ(cyto), are extracted through a sampling algorithm. This is the first evaluation of the dielectrophoresis (DEP) approach as a means to assess the effects of antimicrobial drugs on M. tuberculosis complex cells. PMID:26231690

  12. Structural and Biochemical Characterization of Mycobacterium tuberculosis CYP142

    PubMed Central

    Driscoll, Max D.; McLean, Kirsty J.; Levy, Colin; Mast, Natalia; Pikuleva, Irina A.; Lafite, Pierre; Rigby, Stephen E. J.; Leys, David; Munro, Andrew W.

    2010-01-01

    The Mycobacterium tuberculosis cytochrome P450 enzyme CYP142 is encoded in a large gene cluster involved in metabolism of host cholesterol. CYP142 was expressed and purified as a soluble, low spin P450 hemoprotein. CYP142 binds tightly to cholesterol and its oxidized derivative cholest-4-en-3-one, with extensive shift of the heme iron to the high spin state. High affinity for azole antibiotics was demonstrated, highlighting their therapeutic potential. CYP142 catalyzes either 27-hydroxylation of cholesterol/cholest-4-en-3-one or generates 5-cholestenoic acid/cholest-4-en-3-one-27-oic acid from these substrates by successive sterol oxidations, with the catalytic outcome dependent on the redox partner system used. The CYP142 crystal structure was solved to 1.6 Å, revealing a similar active site organization to the cholesterol-metabolizing M. tuberculosis CYP125, but having a near-identical organization of distal pocket residues to the branched fatty acid oxidizing M. tuberculosis CYP124. The cholesterol oxidizing activity of CYP142 provides an explanation for previous findings that ΔCYP125 strains of Mycobacterium bovis and M. bovis BCG cannot grow on cholesterol, because these strains have a defective CYP142 gene. CYP142 is revealed as a cholesterol 27-oxidase with likely roles in host response modulation and cholesterol metabolism. PMID:20889498

  13. Overview and phylogeny of Mycobacterium tuberculosis complex organisms: implications for diagnostics and legislation of bovine tuberculosis.

    PubMed

    Rodriguez-Campos, Sabrina; Smith, Noel H; Boniotti, Maria B; Aranaz, Alicia

    2014-10-01

    Members of the Mycobacterium tuberculosis complex (MTBC) cause a serious disease with similar pathology, tuberculosis; in this review, bovine tuberculosis will be considered as disease caused by any member of the MTBC in bovids. Bovine tuberculosis is responsible for significant economic loss due to costly eradication programs and trade limitations and poses a threat to both endangered and protected species as well as to public health. We here give an overview on all members of the MTBC, focusing on their isolation from different animal hosts. We also review the recent advances made in elucidating the evolutionary and phylogenetic relationships of members of the MTBC. Because the nomenclature of the MTBC is controversial, its members have been considered species, subspecies or ecotypes, this review discusses the possible implications for diagnostics and the legal consequences of naming of new species. PMID:24630673

  14. Zoonotic tuberculosis due to Mycobacterium bovis in developing countries.

    PubMed Central

    Cosivi, O.; Grange, J. M.; Daborn, C. J.; Raviglione, M. C.; Fujikura, T.; Cousins, D.; Robinson, R. A.; Huchzermeyer, H. F.; de Kantor, I.; Meslin, F. X.

    1998-01-01

    The World Health Organization (WHO) estimates that human tuberculosis (TB) incidence and deaths for 1990 to 1999 will be 88 million and 30 million, respectively, with most cases in developing countries. Zoonotic TB (caused by Mycobacterium bovis) is present in animals in most developing countries where surveillance and control activities are often inadequate or unavailable; therefore, many epidemiologic and public health aspects of infection remain largely unknown. We review available information on zoonotic TB in developing countries, analyze risk factors that may play a role in the disease, review recent WHO activities, and recommend actions to assess the magnitude of the problem and control the disease in humans and animals. PMID:9452399

  15. Antimicrobial Resistance in Mycobacterium tuberculosis: The Odd One Out.

    PubMed

    Eldholm, Vegard; Balloux, François

    2016-08-01

    Antimicrobial resistance (AMR) threats are typically represented by bacteria capable of extensive horizontal gene transfer (HGT). One clear exception is Mycobacterium tuberculosis (Mtb). It is an obligate human pathogen with limited genetic diversity and a low mutation rate which lacks any evidence for HGT. Such features should, in principle, reduce its ability to rapidly evolve AMR. We identify key features in its biology and epidemiology that allow it to overcome its low adaptive potential. We focus in particular on its innate resistance to drugs, its unusual life cycle, including an often extensive latent phase, and its ability to shelter from exposure to antimicrobial drugs within cavities it induces in the lungs. PMID:27068531

  16. Anti-Mycobacterium tuberculosis activity of fungus Phomopsis stipata

    PubMed Central

    de Prince, Karina Andrade; Sordi, Renata; Pavan, Fernando Rogério; Barreto Santos, Adolfo Carlos; Araujo, Angela R.; Leite, Sergio R.A.; Leite, Clarice Q. F.

    2012-01-01

    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. PMID:24031821

  17. Autolysis and Secondary Growth of Mycobacterium tuberculosis in Submerged Culture

    PubMed Central

    Wayne, Lawrence G.; Diaz, Gilbert A.

    1967-01-01

    Mycobacterium tuberculosis has been found to exhibit autolysis and spontaneous secondary growth in modified Sauton medium. The phenomenon is a function of high glycerol concentration of the medium and limitation of air in test tubes. It is not a function of depletion of nutrients and is probably not a manifestation of lysogeny or spheroplast formation. The cycle of growth, autolysis, and secondary growth is related to development of lethal conditions during a period of severe oxygen limitation followed by a metabolic change associated with slower depletion of glycerol. PMID:4962059

  18. Genetic regulation of vesiculogenesis and immunomodulation in Mycobacterium tuberculosis

    PubMed Central

    Rath, Poonam; Huang, Chengdong; Wang, Tao; Wang, Tianzhi; Li, Huilin; Prados-Rosales, Rafael; Elemento, Olivier; Casadevall, Arturo; Nathan, Carl F.

    2013-01-01

    Mycobacterium tuberculosis (Mtb) restrains immune responses well enough to escape eradication but elicits enough immunopathology to ensure its transmission. Here we provide evidence that this host–pathogen relationship is regulated in part by a cytosolic, membrane-associated protein with a unique structural fold, encoded by the Mtb gene rv0431. The protein acts by regulating the quantity of Mtb-derived membrane vesicles bearing Toll-like receptor 2 ligands, including the lipoproteins LpqH and SodC. We propose that rv0431 be named “vesiculogenesis and immune response regulator.” PMID:24248369

  19. Interaction of Mycobacterium tuberculosis with Host Cell Death Pathways

    PubMed Central

    Srinivasan, Lalitha; Ahlbrand, Sarah; Briken, Volker

    2014-01-01

    Mycobacterium tuberculosis (Mtb) has coevolved with humans for tens of thousands of years. It is thus highly adapted to its human host and has evolved multiple mechanisms to manipulate host immune responses to its advantage. One central host pathogen interaction modality is host cell death pathways. Host cell apoptosis is associated with a protective response to Mtb infection, whereas a necrotic response favors the pathogen. Consistently, Mtb inhibits host cell apoptosis signaling but promotes induction of programmed necrosis. The molecular mechanisms involved in Mtb-mediated host cell death manipulation, the consequences for host immunity, and the potential for therapeutic and preventive approaches will be discussed. PMID:24968864

  20. Mycobacterium terrae: a potential surrogate for Mycobacterium tuberculosis in a standard disinfectant test.

    PubMed

    Griffiths, P A; Babb, J R; Fraise, A P

    1998-03-01

    The susceptibility of Mycobacterium tuberculosis and Mycobacterium avium-intracellulare to the disinfections used for spillage and heat sensitive instruments has received much attention in recent years. The use of clinical isolates of M. tuberculosis and M. avium-intracellulare as test organisms is considered unsuitable for standard tests due to their hazardous nature (category 3 pathogens and slow growth rates). This has led to much debate in standards committees on the selection and use of a possible surrogate which would be safer and more practical to use and yet mimic the susceptibility of clinical isolates. This study compared the susceptibility of one possible surrogate Mycobacterium terrae NCTC 10856, with that of clinical isolates of M. tuberculosis H37 Rv and M. avium-intracellulare using a quantitative suspension test. The instrument and environmental disinfectants tested were a chlorine-releasing agent, sodium dichloroisocyanyurate (NaDCC) at 1000 ppm and 10,000 ppm av. Cl, chlorine dioxide at 1100 ppm av. ClO2 (Tristel, HayMan MediChem), 0.35% peracetic acid (NuCidex, Johnson & Johnson), 70% industrial methylated spirit (IMS), 2% alkaline glutaraldehyde (Asep, Galen), 10% succine dialdehyde and formaldehyde mixture (Gigasept, Schulke and Mayr). Results showed that the clinical isolate of M. avium-intracellulare was the most resistant of the three test organisms. M. terrae, which is not a category 3 pathogen, was slightly more resistant than M. tuberculosis and this would appear to be a suitable surrogate for establishing tuberculocidal activity. However, with an increase in the clinical significance of M. avium-intracellulare, particularly in human immunodeficiency virus (HIV) and immunocompromised patients, a more resistant surrogate is required. In the absence of such a surrogate, testing with M. avium-intracellulare in a clinical laboratory equipped for handling category 3 pathogens is still advised to establish mycobactericidal activity. PMID

  1. Mycobacterium tuberculosis Infection following Kidney Transplantation

    PubMed Central

    Boubaker, Karima; Gargah, Tahar; Abderrahim, Ezzedine; Ben Abdallah, Taieb; Kheder, Adel

    2013-01-01

    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. PMID:24222903

  2. Mycobacterium tuberculosis infection of the 'non-classical immune cell'.

    PubMed

    Randall, Philippa J; Hsu, Nai-Jen; Quesniaux, Valerie; Ryffel, Bernhard; Jacobs, Muazzam

    2015-10-01

    Mycobacterium tuberculosis can infect 'non-classical immune cells', which comprise a significant constituency of cells that reside outside of those defined as 'classical immune cells' from myeloid or lymphoid origin. Here we address the influence of specific 'non-classical immune cells' in host responses and their effects in controlling mycobacterial growth or enabling an environment conducive for bacilli persistence. The interaction of M. tuberculosis with epithelial cells, endothelial cells, fibroblasts, adipocytes, glia and neurons and downstream cellular responses that often dictate immune regulation and disease outcome are discussed. Functional integration and synergy between 'classical' and 'non-classical immune cells' are highlighted as critical for determining optimal immune outcomes that favour the host. PMID:25801479

  3. Selective Mycobacterium tuberculosis Shikimate Kinase Inhibitors as Potential Antibacterials.

    PubMed

    Gordon, Sara; Simithy, Johayra; Goodwin, Douglas C; Calderón, Angela I

    2015-01-01

    Owing to the persistence of tuberculosis (TB) as well as the emergence of multidrug-resistant and extensively drug-resistant (XDR) forms of the disease, the development of new antitubercular drugs is crucial. Developing inhibitors of shikimate kinase (SK) in the shikimate pathway will provide a selective target for antitubercular agents. Many studies have used in silico technology to identify compounds that are anticipated to interact with and inhibit SK. To a much more limited extent, SK inhibition has been evaluated by in vitro methods with purified enzyme. Currently, there are no data on in vivo activity of Mycobacterium tuberculosis shikimate kinase (MtSK) inhibitors available in the literature. In this review, we present a summary of the progress of SK inhibitor discovery and evaluation with particular attention toward development of new antitubercular agents. PMID:25861218

  4. Selective Mycobacterium tuberculosis Shikimate Kinase Inhibitors as Potential Antibacterials

    PubMed Central

    Gordon, Sara; Simithy, Johayra; Goodwin, Douglas C; Calderón, Angela I

    2015-01-01

    Owing to the persistence of tuberculosis (TB) as well as the emergence of multidrug-resistant and extensively drug-resistant (XDR) forms of the disease, the development of new antitubercular drugs is crucial. Developing inhibitors of shikimate kinase (SK) in the shikimate pathway will provide a selective target for antitubercular agents. Many studies have used in silico technology to identify compounds that are anticipated to interact with and inhibit SK. To a much more limited extent, SK inhibition has been evaluated by in vitro methods with purified enzyme. Currently, there are no data on in vivo activity of Mycobacterium tuberculosis shikimate kinase (MtSK) inhibitors available in the literature. In this review, we present a summary of the progress of SK inhibitor discovery and evaluation with particular attention toward development of new antitubercular agents. PMID:25861218

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

    PubMed Central

    Samuchiwal, Sachin Kumar; Tousif, Sultan; Singh, Dhiraj Kumar; Kumar, Arun; Ghosh, Anamika; Bhalla, Kuhulika; Prakash, Prem; Kumar, Sushil; Trivedi, Ashish Chandra; Bhattacharyya, Maitree; Das, Gobardhan; Ranganathan, Anand

    2014-01-01

    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. PMID:25349777

  6. Disinfecting endoscopes: how not to transmit Mycobacterium tuberculosis by bronchoscopy.

    PubMed Central

    Leers, W D

    1980-01-01

    Mycobacterium tuberculosis was cultured from the bronchial washings of two patients who underwent bronchoscopy consecutively with the same bronchoscope. Active pulmonary tuberculosis was later confirmed in the first patient, whereas the second patient had clinical and serologic evidence of infection with respiratory syncytial virus. The bronchoscope had been cleaned with an iodophor disinfectant, which had not destroyed the tubercle bacilli. The agent recommended for chemical disinfection of fibreoptic bronchoscopes is 2% glutaraldehyde solution; the instrument should be immersed in it for 10 to 30 minutes. Five hours' exposure to ethylene oxide is recommended for sterilization of instruments. These procedures must be preceded by adequate mechanical cleaning. Then transmission of pathogenic organisms during endoscopy, which can result in nosocomial disease, misdiagnosis or inappropriate treatment, will be avoided. Images FIG. 1 FIG. 2 FIG. 3 PMID:6790150

  7. The transmission of Mycobacterium tuberculosis in high burden settings.

    PubMed

    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

    2016-02-01

    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 transmission in populations and trials and describe the Wells-Riley equation, which is used to estimate transmission risk in indoor spaces. Present research priorities include the identification of effective strategies for tuberculosis infection control, improved understanding of where transmission occurs and the transmissibility of drug-resistant strains, and estimates of the effect of HIV and antiretroviral therapy on transmission dynamics. When research is planned and interventions are designed to interrupt transmission, resource constraints that are common in high burden settings-including shortages of health-care workers-must be considered. PMID:26867464

  8. Microfold Cells Actively Translocate Mycobacterium tuberculosis to Initiate Infection.

    PubMed

    Nair, Vidhya R; Franco, Luis H; Zacharia, Vineetha M; Khan, Haaris S; Stamm, Chelsea E; You, Wu; Marciano, Denise K; Yagita, Hideo; Levine, Beth; Shiloh, Michael U

    2016-08-01

    The prevailing paradigm is that tuberculosis infection is initiated when patrolling alveolar macrophages and dendritic cells within the terminal alveolus ingest inhaled Mycobacterium tuberculosis (Mtb). However, definitive data for this model are lacking. Among the epithelial cells of the upper airway, a specialized epithelial cell known as a microfold cell (M cell) overlies various components of mucosa-associated lymphatic tissue. Here, using multiple mouse models, we show that Mtb invades via M cells to initiate infection. Intranasal Mtb infection in mice lacking M cells either genetically or by antibody depletion resulted in reduced invasion and dissemination to draining lymph nodes. M cell-depleted mice infected via aerosol also had delayed dissemination to lymph nodes and reduced mortality. Translocation of Mtb across two M cell transwell models was rapid and transcellular. Thus, M cell translocation is a vital entry mechanism that contributes to the pathogenesis of Mtb. PMID:27452467

  9. Proposing Low-Similarity Peptide Vaccines against Mycobacterium tuberculosis

    PubMed Central

    Lucchese, Guglielmo; Stufano, Angela; Kanduc, Darja

    2010-01-01

    Using the currently available proteome databases and based on the concept that a rare sequence is a potential epitope, epitopic sequences derived from Mycobacterium tuberculosis were examined for similarity score to the proteins of the host in which the epitopes were defined. We found that: (i) most of the bacterial linear determinants had peptide fragment(s) that were rarely found in the host proteins and (ii) the relationship between low similarity and epitope definition appears potentially applicable to T-cell determinants. The data confirmed the hypothesis that low-sequence similarity shapes or determines the epitope definition at the molecular level and provides a potential tool for designing new approaches to prevent, diagnose, and treat tuberculosis and other infectious diseases. PMID:20625421

  10. Benzothiazinones Kill Mycobacterium tuberculosis by Blocking Arabinan Synthesis

    PubMed Central

    Makarov, Vadim; Manina, Giulia; Mikusova, Katarina; Möllmann, Ute; Ryabova, Olga; Saint-Joanis, Brigitte; Dhar, Neeraj; Pasca, Maria Rosalia; Buroni, Silvia; Lucarelli, Anna Paola; Milano, Anna; De Rossi, Edda; Belanova, Martina; Bobovska, Adela; Dianiskova, Petronela; Kordulakova, Jana; Sala, Claudia; Fullam, Elizabeth; Schneider, Patricia; McKinney, John D.; Brodin, Priscille; Christophe, Thierry; Waddell, Simon; Butcher, Philip; Albrethsen, Jakob; Rosenkrands, Ida; Brosch, Roland; Nandi, Vrinda; Bharath, Sowmya; Gaonkar, Sheshagiri; Shandil, Radha K.; Balasubramanian, Venkataraman; Balganesh, Tanjore; Tyagi, Sandeep; Grosset, Jacques; Riccardi, Giovanna; Cole, Stewart T.

    2011-01-01

    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 and biochemistry, we identified the enzyme decaprenylphosphoryl-β-d-ribose 2′-epimerase as a major BTZ target. Inhibition of this enzymatic activity abolishes the formation of decaprenylphosphoryl arabinose, a key precursor that is required for the synthesis of the cell-wall arabinans, thus provoking cell lysis and bacterial death. The most advanced compound, BTZ043, is a candidate for inclusion in combination therapies for both drug-sensitive and extensively drug-resistant TB. PMID:19299584

  11. Benzothiazinones kill Mycobacterium tuberculosis by blocking arabinan synthesis.

    PubMed

    Makarov, Vadim; Manina, Giulia; Mikusova, Katarina; Möllmann, Ute; Ryabova, Olga; Saint-Joanis, Brigitte; Dhar, Neeraj; Pasca, Maria Rosalia; Buroni, Silvia; Lucarelli, Anna Paola; Milano, Anna; De Rossi, Edda; Belanova, Martina; Bobovska, Adela; Dianiskova, Petronela; Kordulakova, Jana; Sala, Claudia; Fullam, Elizabeth; Schneider, Patricia; McKinney, John D; Brodin, Priscille; Christophe, Thierry; Waddell, Simon; Butcher, Philip; Albrethsen, Jakob; Rosenkrands, Ida; Brosch, Roland; Nandi, Vrinda; Bharath, Sowmya; Gaonkar, Sheshagiri; Shandil, Radha K; Balasubramanian, Venkataraman; Balganesh, Tanjore; Tyagi, Sandeep; Grosset, Jacques; Riccardi, Giovanna; Cole, Stewart T

    2009-05-01

    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 and biochemistry, we identified the enzyme decaprenylphosphoryl-beta-d-ribose 2'-epimerase as a major BTZ target. Inhibition of this enzymatic activity abolishes the formation of decaprenylphosphoryl arabinose, a key precursor that is required for the synthesis of the cell-wall arabinans, thus provoking cell lysis and bacterial death. The most advanced compound, BTZ043, is a candidate for inclusion in combination therapies for both drug-sensitive and extensively drug-resistant TB. PMID:19299584

  12. Iron Acquisition Mechanisms: Promising Target Against Mycobacterium tuberculosis

    PubMed Central

    Hameed, Saif; Pal, Rahul; Fatima, Zeeshan

    2015-01-01

    Continuous deployment of antitubercular drugs in treating Tuberculosis (TB) caused by Mycobacterium tuberculosis (MTB) has led to the emergence of drug resistance resulting in cross-resistance to many unrelated drugs, a phenomenon termed as Multi-Drug Resistance (MDR-TB). Despite reasonable documentation of major factors which contribute to MDR mechanisms, it appears unavoidable to consider novel mechanisms combating MDR. The ability of pathogenic MTB, to sense and become accustomed to changes in the host environment is essential for its survival and confers the basis of their success as dreadful pathogen. One such significant environmental factor that MTB must surmount is iron limitation, since they encounter diverse anatomical sites during the establishment of infection within the host. Considering the importance of MTB, being the second most common cause of mortality, this review focuses on gaining insights of iron acquisition mechanisms in MTB and how it can be exploited as efficient anti-mycobacterial drug target. PMID:26464608

  13. Progress in targeting cell envelope biogenesis in Mycobacterium tuberculosis

    PubMed Central

    Jackson, Mary; McNeil, Michael R; Brennan, Patrick J

    2013-01-01

    Most of the newly discovered compounds showing promise for the treatment of TB, notably multidrug-resistant TB, inhibit aspects of Mycobacterium tuberculosis cell envelope metabolism. This review reflects on the evolution of the knowledge that many of the front-line and emerging products inhibit aspects of cell envelope metabolism and in the process are bactericidal not only against actively replicating M. tuberculosis, but contrary to earlier impressions, are effective against latent forms of the disease. While mycolic acid and arabinogalactan synthesis are still primary targets of existing and new drugs, peptidoglycan synthesis, transport mechanisms and the synthesis of the decaprenyl-phosphate carrier lipid all show considerable promise as targets for new products, older drugs and new combinations. The advantages of whole cell- versus target-based screening in the perpetual search for new targets and products to counter multidrug-resistant TB are discussed. PMID:23841633

  14. Tuberculosis

    MedlinePlus

    Tuberculosis (TB) is a disease caused by bacteria called Mycobacterium tuberculosis. The bacteria usually attack the lungs, but they can also damage other parts of the body. TB spreads through the air when a person with ...

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

    PubMed Central

    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

  16. Native New Zealand plants with inhibitory activity towards Mycobacterium tuberculosis

    PubMed Central

    2010-01-01

    Background Plants have long been investigated as a source of antibiotics and other bioactives for the treatment of human disease. New Zealand contains a diverse and unique flora, however, few of its endemic plants have been used to treat tuberculosis. One plant, Laurelia novae-zelandiae, was reportedly used by indigenous Maori for the treatment of tubercular lesions. Methods Laurelia novae-zelandiae and 44 other native plants were tested for direct anti-bacterial activity. Plants were extracted with different solvents and extracts screened for inhibition of the surrogate species, Mycobacterium smegmatis. Active plant samples were then tested for bacteriostatic activity towards M. tuberculosis and other clinically-important species. Results Extracts of six native plants were active against M. smegmatis. Many of these were also inhibitory towards M. tuberculosis including Laurelia novae-zelandiae (Pukatea). M. excelsa (Pohutukawa) was the only plant extract tested that was active against Staphylococcus aureus. Conclusions Our data provide support for the traditional use of Pukatea in treating tuberculosis. In addition, our analyses indicate that other native plant species possess antibiotic activity. PMID:20537175

  17. Crosstalk between Mycobacterium tuberculosis and the host cell

    PubMed Central

    Dey, Bappaditya; Bishai, William R.

    2014-01-01

    The successful establishment and maintenance of a bacterial infection depends on the pathogen’s ability to subvert the host cell’s defense response and successfully survive, proliferate, or persist within the infected cell. To circumvent host defense systems, bacterial pathogens produce a variety of virulence factors that potentiate bacterial adherence and invasion and usurp host cell signaling cascades that regulate intracellular microbial survival and trafficking. Mycobacterium tuberculosis, probably one of the most successful pathogens on earth, has coexisted with humanity for centuries, and this intimate and persistent connection between these two organisms suggests that the pathogen has evolved extensive mechanisms to evade the human immune system at multiple levels. While some of these mechanisms are mediated by factors released by M. tuberculosis, others rely on host components that are hijacked to prevent the generation of an effective immune response thus benefiting the survival of M. tuberculosis within the host cell. Here, we describe several of these mechanisms, with an emphasis on the cyclic nucleotide signaling and subversion of host responses that occur at the intracellular level when tubercle bacilli encounter macrophages, a cell that becomes a safe-house for M. tuberculosis although it is specialized to kill most microbes. PMID:25303934

  18. An acidic sphingomyelinase Type C activity from Mycobacterium tuberculosis.

    PubMed

    Castro-Garza, Jorge; González-Salazar, Francisco; Quinn, Frederick D; Karls, Russell K; De La Garza-Salinas, Laura Hermila; Guzmán-de la Garza, Francisco J; Vargas-Villarreal, Javier

    2016-01-01

    Sphingomyelinases (SMases) catalyze the hydrolysis of sphingomyelin to ceramide and phosphorylcholine. Sphingolipids are recognized as diverse and dynamic regulators of a multitude of cellular processes mediating cell cycle control, differentiation, stress response, cell migration, adhesion, and apoptosis. Bacterial SMases are virulence factors for several species of pathogens. Whole cell extracts of Mycobacterium tuberculosis strains H37Rv and CDC1551 were assayed using [N-methyl-(14)C]-sphingomyelin as substrate. Acidic Zn(2+)-dependent SMase activity was identified in both strains. Peak SMase activity was observed at pH 5.5. Interestingly, overall SMase activity levels from CDC1551 extracts are approximately 1/3 of those of H37Rv. The presence of exogenous SMase produced by M. tuberculosis during infection may interfere with the normal host inflammatory response thus allowing the establishment of infection and disease development. This Type C activity is different from previously identified M. tuberculosis SMases. Defining the biochemical characteristics of M. tuberculosis SMases helps to elucidate the roles that these enzymes play during infection and disease. PMID:26948102

  19. LAG3 Expression in Active Mycobacterium tuberculosis Infections

    PubMed Central

    Phillips, Bonnie L.; Mehra, Smriti; Ahsan, Muhammad H.; Selman, Moises; Khader, Shabaana A.; Kaushal, Deepak

    2016-01-01

    Mycobacterium tuberculosis (MTB) is a highly successful pathogen because of its ability to persist in human lungs for long periods of time. MTB modulates several aspects of the host immune response. Lymphocyte-activation gene 3 (LAG3) is a protein with a high affinity for the CD4 receptor and is expressed mainly by regulatory T cells with immunomodulatory functions. To understand the function of LAG3 during MTB infection, a nonhuman primate model of tuberculosis, which recapitulates key aspects of natural human infection in rhesus macaques (Macaca mulatta), was used. We show that the expression of LAG3 is highly induced in the lungs and particularly in the granulomatous lesions of macaques experimentally infected with MTB. Furthermore, we show that LAG3 expression is not induced in the lungs and lung granulomas of animals exhibiting latent tuberculosis infection. However, simian immunodeficiency virus–induced reactivation of latent tuberculosis infection results in an increased expression of LAG3 in the lungs. This response is not observed in nonhuman primates infected with non-MTB bacterial pathogens, nor with simian immunodeficiency virus alone. Our data show that LAG3 was expressed primarily on CD4+ T cells, presumably by regulatory T cells but also by natural killer cells. The expression of LAG3 coincides with high bacterial burdens and changes in the host type 1 helper T-cell response. PMID:25549835

  20. Gamma Interferon Release Assays for Detection of Mycobacterium tuberculosis Infection

    PubMed Central

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

    2014-01-01

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

  1. Thioridazine Alters the Cell-Envelope Permeability of Mycobacterium tuberculosis.

    PubMed

    de Keijzer, Jeroen; Mulder, Arnout; de Haas, Petra E W; de Ru, Arnoud H; Heerkens, Evy M; Amaral, Leonard; van Soolingen, Dick; van Veelen, Peter A

    2016-06-01

    The increasing occurrence of multidrug resistant tuberculosis exerts a major burden on treatment of this infectious disease. Thioridazine, previously used as a neuroleptic, is active against extensively drug resistant tuberculosis when added to other second- and third-line antibiotics. By quantitatively studying the proteome of thioridazine-treated Mycobacterium tuberculosis, we discovered the differential abundance of several proteins that are involved in the maintenance of the cell-envelope permeability barrier. By assessing the accumulation of fluorescent dyes in mycobacterial cells over time, we demonstrate that long-term drug exposure of M. tuberculosis indeed increased the cell-envelope permeability. The results of the current study demonstrate that thioridazine induced an increase in cell-envelope permeability and thereby the enhanced uptake of compounds. These results serve as a novel explanation to the previously reported synergistic effects between thioridazine and other antituberculosis drugs. This new insight in the working mechanism of this antituberculosis compound could open novel perspectives of future drug-administration regimens in combinational therapy. PMID:27068340

  2. Prospective Genotyping of Mycobacterium tuberculosis from Fresh Clinical Samples

    PubMed Central

    Bidovec-Stojkovič, Urška; Seme, Katja; Žolnir-Dovč, Manca; Supply, Philip

    2014-01-01

    Shorter time-to-result is key for improving molecular-guided epidemiological investigation of tuberculosis (TB) cases. We performed a prospective study to evaluate the use of standardized MIRU-VNTR (mycobacterial interspersed repetitive-unit-variable-number tandem-repeat) typing of Mycobacterium tuberculosis directly on 79 fresh clinical samples from 26 TB patients consecutively enrolled over a 17-month period. Overall, complete 24-locus types were obtained for 18 out of the 26 (69.2%) patients and 14 of the 16 grade 3+ and grade 2+ samples (87.5%). The degree of completion of the genotypes obtained significantly correlated with smear microscopy grade both for 26 first samples (p = 0.0003) and for 53 follow-up samples (p = 0.002). For 20 of the 26 patients for whom complete or even incomplete M. tuberculosis isolate genotypes were obtained, typing applied to the clinical samples allowed the same unambiguous conclusions regarding case clustering or uniqueness as those that could have been drawn based on the corresponding cultured isolates. Standard 24 locus MIRU-VNTR typing of M. tuberculosis can be applied directly to fresh clinical samples, with typeability depending on the bacterial load in the sample. PMID:25313883

  3. Essential Metabolites of Mycobacterium tuberculosis and Their Mimics

    PubMed Central

    Lamichhane, Gyanu; Freundlich, Joel S.; Ekins, Sean; Wickramaratne, Niluka; Nolan, Scott T.; Bishai, William R.

    2011-01-01

    An organism requires a range of biomolecules for its growth. By definition, these are essential molecules which constitute the basic metabolic requirements of an organism. A small organic molecule with chemical similarity to that of an essential metabolite may bind to the enzyme that catalyzes its production and inhibit it, likely resulting in the stasis or death of the organism. Here, we report a high-throughput approach for identifying essential metabolites of an organism using genetic and biochemical approaches and then implement computational approaches to identify metabolite mimics. We generated and genotyped 5,126 Mycobacterium tuberculosis mutants and performed a statistical analysis to determine putative essential genes. The essential molecules of M. tuberculosis were classified as products of enzymes that are encoded by genes in this list. Although incomplete, as many enzymes of M. tuberculosis have yet to be identified and characterized, this is the first report of a large number of essential molecules of the organism. We identified essential metabolites of three distinct metabolic pathways in M. tuberculosis and selected molecules with chemical similarity using cheminformatics strategies that illustrate a variety of different pharmacophores. Our approach is aimed at systematic identification of essential molecules and their mimics as a blueprint for development of effective chemical probes of M. tuberculosis metabolism, with the ultimate goal of seeking drugs that can kill this pathogen. As an illustration of this approach, we report that compounds JFD01307SC and l-methionine-S-sulfoximine, which share chemical similarity with an essential molecule of M. tuberculosis, inhibited the growth of this organism at micromolar concentrations. PMID:21285434

  4. Energy Metabolism and Drug Efflux in Mycobacterium tuberculosis

    PubMed Central

    Black, Philippa A.; Warren, Robin M.; Louw, Gail E.; van Helden, Paul D.; Victor, Thomas C.

    2014-01-01

    The inherent drug susceptibility of microorganisms is determined by multiple factors, including growth state, the rate of drug diffusion into and out of the cell, and the intrinsic vulnerability of drug targets with regard to the corresponding antimicrobial agent. Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), remains a significant source of global morbidity and mortality, further exacerbated by its ability to readily evolve drug resistance. It is well accepted that drug resistance in M. tuberculosis is driven by the acquisition of chromosomal mutations in genes encoding drug targets/promoter regions; however, a comprehensive description of the molecular mechanisms that fuel drug resistance in the clinical setting is currently lacking. In this context, there is a growing body of evidence suggesting that active extrusion of drugs from the cell is critical for drug tolerance. M. tuberculosis encodes representatives of a diverse range of multidrug transporters, many of which are dependent on the proton motive force (PMF) or the availability of ATP. This suggests that energy metabolism and ATP production through the PMF, which is established by the electron transport chain (ETC), are critical in determining the drug susceptibility of M. tuberculosis. In this review, we detail advances in the study of the mycobacterial ETC and highlight drugs that target various components of the ETC. We provide an overview of some of the efflux pumps present in M. tuberculosis and their association, if any, with drug transport and concomitant effects on drug resistance. The implications of inhibiting drug extrusion, through the use of efflux pump inhibitors, are also discussed. PMID:24614376

  5. Population genomics of Mycobacterium tuberculosis in the Inuit.

    PubMed

    Lee, Robyn S; Radomski, Nicolas; Proulx, Jean-Francois; Levade, Ines; Shapiro, B Jesse; McIntosh, Fiona; Soualhine, Hafid; Menzies, Dick; Behr, Marcel A

    2015-11-01

    Nunavik, Québec suffers from epidemic tuberculosis (TB), with an incidence 50-fold higher than the Canadian average. Molecular studies in this region have documented limited bacterial genetic diversity among Mycobacterium tuberculosis isolates, consistent with a founder strain and/or ongoing spread. We have used whole-genome sequencing on 163 M. tuberculosis isolates from 11 geographically isolated villages to provide a high-resolution portrait of bacterial genetic diversity in this setting. All isolates were lineage 4 (Euro-American), with two sublineages present (major, n = 153; minor, n = 10). Among major sublineage isolates, there was a median of 46 pairwise single-nucleotide polymorphisms (SNPs), and the most recent common ancestor (MRCA) was in the early 20th century. Pairs of isolates within a village had significantly fewer SNPs than pairs from different villages (median: 6 vs. 47, P < 0.00005), indicating that most transmission occurs within villages. There was an excess of nonsynonymous SNPs after the diversification of M. tuberculosis within Nunavik: The ratio of nonsynonymous to synonymous substitution rates (dN/dS) was 0.534 before the MRCA but 0.777 subsequently (P = 0.010). Nonsynonymous SNPs were detected across all gene categories, arguing against positive selection and toward genetic drift with relaxation of purifying selection. Supporting the latter possibility, 28 genes were partially or completely deleted since the MRCA, including genes previously reported to be essential for M. tuberculosis growth. Our findings indicate that the epidemiologic success of M. tuberculosis in this region is more likely due to an environment conducive to TB transmission than a particularly well-adapted strain. PMID:26483462

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

    PubMed

    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

  7. Identification of outer membrane proteins of Mycobacterium tuberculosis.

    PubMed

    Song, Houhui; Sandie, Reatha; Wang, Ying; Andrade-Navarro, Miguel A; Niederweis, Michael

    2008-11-01

    The cell wall of mycobacteria includes an unusual outer membrane of extremely low permeability. While Escherichia coli uses more than 60 proteins to functionalize its outer membrane, only two mycobacterial outer membrane proteins (OMPs) are known. The porin MspA of Mycobacterium smegmatis provided the proof of principle that integral mycobacterial OMPs share the beta-barrel structure, the absence of hydrophobic alpha-helices and the presence of a signal peptide with OMPs of gram-negative bacteria. These properties were exploited in a multi-step bioinformatic approach to predict OMPs of M. tuberculosis. A secondary structure analysis was performed for 587 proteins of M. tuberculosis predicted to be exported. Scores were calculated for the beta-strand content and the amphiphilicity of the beta-strands. Reference OMPs of gram-negative bacteria defined threshold values for these parameters that were met by 144 proteins of unknown function of M. tuberculosis. Two of them were verified as OMPs by a novel two-step experimental approach. Rv1698 and Rv1973 were detected only in the total membrane fraction of M. bovis BCG in Western blot experiments, while proteinase K digestion of whole cells showed the surface accessibility of these proteins. These findings established that Rv1698 and Rv1973 are indeed localized in the outer membrane and tripled the number of known OMPs of M. tuberculosis. Significantly, these results provide evidence for the usefulness of the bioinformatic approach to predict mycobacterial OMPs and indicate that M. tuberculosis likely has many OMPs with beta-barrel structure. Our findings pave the way to identify the set of proteins which functionalize the outer membrane of M. tuberculosis. PMID:18439872

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

    PubMed Central

    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

  9. Population genomics of Mycobacterium tuberculosis in the Inuit

    PubMed Central

    Lee, Robyn S.; Radomski, Nicolas; Proulx, Jean-Francois; Levade, Ines; Shapiro, B. Jesse; McIntosh, Fiona; Soualhine, Hafid; Menzies, Dick; Behr, Marcel A.

    2015-01-01

    Nunavik, Québec suffers from epidemic tuberculosis (TB), with an incidence 50-fold higher than the Canadian average. Molecular studies in this region have documented limited bacterial genetic diversity among Mycobacterium tuberculosis isolates, consistent with a founder strain and/or ongoing spread. We have used whole-genome sequencing on 163 M. tuberculosis isolates from 11 geographically isolated villages to provide a high-resolution portrait of bacterial genetic diversity in this setting. All isolates were lineage 4 (Euro-American), with two sublineages present (major, n = 153; minor, n = 10). Among major sublineage isolates, there was a median of 46 pairwise single-nucleotide polymorphisms (SNPs), and the most recent common ancestor (MRCA) was in the early 20th century. Pairs of isolates within a village had significantly fewer SNPs than pairs from different villages (median: 6 vs. 47, P < 0.00005), indicating that most transmission occurs within villages. There was an excess of nonsynonymous SNPs after the diversification of M. tuberculosis within Nunavik: The ratio of nonsynonymous to synonymous substitution rates (dN/dS) was 0.534 before the MRCA but 0.777 subsequently (P = 0.010). Nonsynonymous SNPs were detected across all gene categories, arguing against positive selection and toward genetic drift with relaxation of purifying selection. Supporting the latter possibility, 28 genes were partially or completely deleted since the MRCA, including genes previously reported to be essential for M. tuberculosis growth. Our findings indicate that the epidemiologic success of M. tuberculosis in this region is more likely due to an environment conducive to TB transmission than a particularly well-adapted strain. PMID:26483462

  10. Mean Platelet Volume in Mycobacterium tuberculosis Infection

    PubMed Central

    Lee, Min Young; Kim, Young Jin; Lee, Hee Joo; Park, Tae Sung

    2016-01-01

    Introduction. Mean platelet volume (MPV) has been thought as a useful index of platelet activation. It is supposed that MPV is also associated with several inflammatory and infectious diseases. Korea still has a high incidence of tuberculosis (TB). The aim of this study was to investigate MPV as an inflammatory marker in TB patients. Materials and Methods. MPV were determined in 221 patients with TB and 143 individuals for control group. MPV was estimated by an Advia 2120 (Siemens Healthcare Diagnostics, Tarrytown, NY, USA). Results. In the TB patient group, a positive correlation was found between CRP and MPV. Age and MPV had a positive correlation in TB patient group. Conclusions. We conclude that there is a significant relation between MPV and inflammatory conditions. MPV can be an inflammatory marker to determine the disease activity in TB patients. PMID:27419136

  11. Prime–Boost with Mycobacterium smegmatis Recombinant Vaccine Improves Protection in Mice Infected with Mycobacterium tuberculosis

    PubMed Central

    Junqueira-Kipnis, Ana Paula; de Oliveira, Fábio Muniz; Trentini, Monalisa Martins; Tiwari, Sangeeta; Chen, Bing; Resende, Danilo Pires; Silva, Bruna D. S.; Chen, Mei; Tesfa, Lydia; Jacobs, William R.; Kipnis, André

    2013-01-01

    The development of a new vaccine as a substitute for Bacillus Calmette–Guerin or to improve its efficacy is one of the many World Health Organization goals to control tuberculosis. Mycobacterial vectors have been used successfully in the development of vaccines against tuberculosis. To enhance the potential utility of Mycobacterium smegmatis as a vaccine, it was transformed with a recombinant plasmid containing the partial sequences of the genes Ag85c, MPT51, and HspX (CMX) from M. tuberculosis. The newly generated recombinant strain mc2-CMX was tested in a murine model of infection. The recombinant vaccine induced specific IgG1 or IgG2a responses to CMX. CD4+ and CD8+ T cells from the lungs and spleen responded ex vivo to CMX, producing IFN-γ, IL17, TNF-α, and IL2. The vaccine thus induced a significant immune response in mice. Mice vaccinated with mc2-CMX and challenged with M. tuberculosis showed better protection than mice immunized with wild-type M. smegmatis or BCG. To increase the safety and immunogenicity of the CMX antigens, we used a recombinant strain of M. smegmatis, IKE (immune killing evasion), to express CMX. The recombinant vaccine IKE-CMX induced a better protective response than mc2-CMX. The data presented here suggest that the expression of CMX antigens improves the immune response and the protection induced in mice when M. smegmatis is used as vaccine against tuberculosis. PMID:24250805

  12. A High-Throughput Cidality Screen for Mycobacterium Tuberculosis

    PubMed Central

    Kaur, Parvinder; Ghosh, Anirban; Krishnamurthy, Ramya Vadageri; Bhattacharjee, Deepa Gagwani; Achar, Vijayashree; Datta, Santanu; Narayanan, Shridhar; Anbarasu, Anand; Ramaiah, Sudha

    2015-01-01

    Exposure to Mycobacterium tuberculosis (Mtb) aerosols is a major threat to tuberculosis (TB) researchers, even in bio-safety level-3 (BSL-3) facilities. Automation and high-throughput screens (HTS) in BSL3 facilities are essential for minimizing manual aerosol-generating interventions and facilitating TB research. In the present study, we report the development and validation of a high-throughput, 24-well ‘spot-assay’ for selecting bactericidal compounds against Mtb. The bactericidal screen concept was first validated in the fast-growing surrogate Mycobacterium smegmatis (Msm) and subsequently confirmed in Mtb using the following reference anti-tubercular drugs: rifampicin, isoniazid, ofloxacin and ethambutol (RIOE, acting on different targets). The potential use of the spot-assay to select bactericidal compounds from a large library was confirmed by screening on Mtb, with parallel plating by the conventional gold standard method (correlation, r2 = 0.808). An automated spot-assay further enabled an MBC90 determination on resistant and sensitive Mtb clinical isolates. The implementation of the spot-assay in kinetic screens to enumerate residual Mtb after either genetic silencing (anti-sense RNA, AS-RNA) or chemical inhibition corroborated its ability to detect cidality. This relatively simple, economical and quantitative HTS considerably minimized the bio-hazard risk and enabled the selection of novel vulnerable Mtb targets and mycobactericidal compounds. Thus, spot-assays have great potential to impact the TB drug discovery process. PMID:25693161

  13. Accurate Detection of Rifampicin-Resistant Mycobacterium Tuberculosis Strains.

    PubMed

    Song, Keum-Soo; Nimse, Satish Balasaheb; Kim, Hee Jin; Yang, Jeongseong; Kim, Taisun

    2016-01-01

    In 2013 alone, the death rate among the 9.0 million people infected with Mycobacterium tuberculosis (TB) worldwide was around 14%, which is unacceptably high. An empiric treatment of patients infected with TB or drug-resistant Mycobacterium tuberculosis (MDR-TB) strain can also result in the spread of MDR-TB. The diagnostic tools which are rapid, reliable, and have simple experimental protocols can significantly help in decreasing the prevalence rate of MDR-TB strain. We report the evaluation of the 9G technology based 9G DNAChips that allow accurate detection and discrimination of TB and MDR-TB-RIF. One hundred and thirteen known cultured samples were used to evaluate the ability of 9G DNAChip in the detection and discrimination of TB and MDR-TB-RIF strains. Hybridization of immobilized probes with the PCR products of TB and MDR-TB-RIF strains allow their detection and discrimination. The accuracy of 9G DNAChip was determined by comparing its results with sequencing analysis and drug susceptibility testing. Sequencing analysis showed 100% agreement with the results of 9G DNAChip. The 9G DNAChip showed very high sensitivity (95.4%) and specificity (100%). PMID:26999135

  14. Accurate Detection of Rifampicin-Resistant Mycobacterium Tuberculosis Strains

    PubMed Central

    Song, Keum-Soo; Nimse, Satish Balasaheb; Kim, Hee Jin; Yang, Jeongseong; Kim, Taisun

    2016-01-01

    In 2013 alone, the death rate among the 9.0 million people infected with Mycobacterium tuberculosis (TB) worldwide was around 14%, which is unacceptably high. An empiric treatment of patients infected with TB or drug-resistant Mycobacterium tuberculosis (MDR-TB) strain can also result in the spread of MDR-TB. The diagnostic tools which are rapid, reliable, and have simple experimental protocols can significantly help in decreasing the prevalence rate of MDR-TB strain. We report the evaluation of the 9G technology based 9G DNAChips that allow accurate detection and discrimination of TB and MDR-TB-RIF. One hundred and thirteen known cultured samples were used to evaluate the ability of 9G DNAChip in the detection and discrimination of TB and MDR-TB-RIF strains. Hybridization of immobilized probes with the PCR products of TB and MDR-TB-RIF strains allow their detection and discrimination. The accuracy of 9G DNAChip was determined by comparing its results with sequencing analysis and drug susceptibility testing. Sequencing analysis showed 100% agreement with the results of 9G DNAChip. The 9G DNAChip showed very high sensitivity (95.4%) and specificity (100%). PMID:26999135

  15. Acquired Drug Resistance in Mycobacterium tuberculosis and Poor Outcomes among Patients with Multidrug-Resistant Tuberculosis

    PubMed Central

    Kipiani, Maia; Mirtskhulava, Veriko; Tukvadze, Nestani; Magee, Matthew J.; Blumberg, Henry M.

    2015-01-01

    Rates and risk factors for acquired drug resistance and association with outcomes among patients with multidrug-resistant tuberculosis (MDR TB) are not well defined. In an MDR TB cohort from the country of Georgia, drug susceptibility testing for second-line drugs (SLDs) was performed at baseline and every third month. Acquired resistance was defined as any SLD whose status changed from susceptible at baseline to resistant at follow-up. Among 141 patients, acquired resistance in Mycobacterium tuberculosis was observed in 19 (14%); prevalence was 9.1% for ofloxacin and 9.8% for capreomycin or kanamycin. Baseline cavitary disease and resistance to >6 drugs were associated with acquired resistance. Patients with M. tuberculosis that had acquired resistance were at significantly increased risk for poor treatment outcome compared with patients without these isolates (89% vs. 36%; p<0.01). Acquired resistance occurs commonly among patients with MDR TB and impedes successful treatment outcomes. PMID:25993036

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

    PubMed Central

    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

  17. Mycobacterium tuberculosis Infection in a Green-Winged Macaw (Ara chloroptera): Report with Public Health Implications

    PubMed Central

    Washko, Rita M.; Hoefer, Heidi; Kiehn, Timothy E.; Armstrong, Donald; Dorsinville, Guy; Frieden, Thomas R.

    1998-01-01

    Mycobacterium tuberculosis was isolated from the eyelid, skin, tongue, and lungs of a green-winged macaw (Ara chloroptera). Two persons living in the same household were culture positive for pulmonary tuberculosis 3 to 4 years before tuberculosis was diagnosed in the bird. Although humans have not been shown to acquire tuberculosis from birds, an infected bird may be a sentinel for human infection. PMID:9542945

  18. Analysis of the Mycobacterium tuberculosis 85A antigen promoter region.

    PubMed Central

    Kremer, L; Baulard, A; Estaquier, J; Content, J; Capron, A; Locht, C

    1995-01-01

    A mycobacterial expression-secretion vector was constructed in which the Escherichia coli alkaline phosphatase (phoA) reporter gene was placed under the control of the Mycobacterium tuberculosis 85A promoter and secretion signal sequences. In recombinant Mycobacterium smegmatis and Mycobacterium bovis BCG, PhoA activity could readily be detected on the mycobacterial cell surface and in the culture supernatant, indicating that the 85A signals can drive heterologous expression and secretion in both species. In contrast to the mycobacteria, the 85A promoter did not function in E. coli. We mapped the promoter region by progressive deletions using BAL 31 exonuclease and by primer extension analysis. Insertion and deletion mutations within the promoter region indicated that, unlike most E. coli promoters but similar to Streptomyces promoters, the position of the putative -35 region was not critical for efficient promoter activity. In addition, we investigated the ability of the identified signals to drive the production and secretion in BCG of recombinant Schistosoma mansoni glutathione S-transferase (Sm28GST), a protective antigen against schistosomiasis. BALB/c mice immunized with the recombinant BCG by a single dose exhibited a weak but specific T-cell response to Sm28GST. PMID:7836298

  19. Novel Multiplex Real-Time PCR Diagnostic Assay for Identification and Differentiation of Mycobacterium tuberculosis, Mycobacterium canettii, and Mycobacterium tuberculosis Complex Strains▿†

    PubMed Central

    Reddington, Kate; O'Grady, Justin; Dorai-Raj, Siobhan; Maher, Majella; van Soolingen, Dick; Barry, Thomas

    2011-01-01

    Tuberculosis (TB) in humans is caused by members of the Mycobacterium tuberculosis complex (MTC). Rapid detection of the MTC is necessary for the timely initiation of antibiotic treatment, while differentiation between members of the complex may be important to guide the appropriate antibiotic treatment and provide epidemiological information. In this study, a multiplex real-time PCR diagnostics assay using novel molecular targets was designed to identify the MTC while simultaneously differentiating between M. tuberculosis and M. canettii. The lepA gene was targeted for the detection of members of the MTC, the wbbl1 gene was used for the differentiation of M. tuberculosis and M. canettii from the remainder of the complex, and a unique region of the M. canettii genome, a possible novel region of difference (RD), was targeted for the specific identification of M. canettii. The multiplex real-time PCR assay was tested using 125 bacterial strains (64 MTC isolates, 44 nontuberculosis mycobacteria [NTM], and 17 other bacteria). The assay was determined to be 100% specific for the mycobacteria tested. Limits of detection of 2.2, 2.17, and 0.73 cell equivalents were determined for M. tuberculosis/M. canettii, the MTC, and M. canettii, respectively, using probit regression analysis. Further validation of this diagnostics assay, using clinical samples, should demonstrate its potential for the rapid, accurate, and sensitive diagnosis of TB caused by M. tuberculosis, M. canettii, and the other members of the MTC. PMID:21123525

  20. Molecular Epidemiology of Mycobacterium tuberculosis Isolates in 100 Patients With Tuberculosis Using Pulsed Field Gel Electrophoresis

    PubMed Central

    Pooideh, Mohammad; Jabbarzadeh, Ismail; Ranjbar, Reza; Saifi, Mahnaz

    2015-01-01

    Background: Tuberculosis (TB) is a widespread infectious disease. Today, TB has created a public health crisis in the world. Genotyping of Mycobacterium tuberculosis isolates is useful for surveying the dynamics of TB infection, identifying new outbreaks, and preventing the disease. Different molecular methods for clustering of M. tuberculosis isolates have been used. Objectives: During a one year study of genotyping, 100 M. tuberculosis isolates from patients referred to Pasteur Institute of Iran were collected and their genotyping was accomplished using pulsed field gel electrophoresis (PFGE) method. Materials and Methods: Identification of all M. tuberculosis isolates was accomplished using standard biochemical and species-specific polymerase chain reaction (PCR) methods. Antibiotic susceptibility tests were performed using proportional method. After preparing PFGE plaques for each isolate of M. tuberculosis, XbaI restriction enzyme was applied for genome digestion. Finally, the digested DNA fragments were separated on 1% agarose gel and analyzed with GelCompar II software. Results: Genotyping of the studied isolates in comparison with the molecular weight marker revealed two common types; pulsotype A with 71 isolates and one multidrug resistant mycobacterium (MDR) case, and pulsotype B including 29 isolates and three MDR cases. No correlation between the antibiotypes and pulsotypes was observed. Conclusions: Molecular epidemiology studies of infectious diseases have been useful when bacterial isolates have been clustered in a period of time and in different geographical regions with variable antibiotic resistance patterns. In spite of high geographical differences and different antibiotic resistant patterns, low genetic diversity among the studied TB isolates may refer to the low rate of mutations in XbaI restriction sites in the mycobacterial genome. We also identified three MDR isolates in low-incidence pulsotype B, which could be disseminated and is highly

  1. Revisiting the essentiality of glutamate racemase in Mycobacterium tuberculosis.

    PubMed

    Morayya, Sapna; Awasthy, Disha; Yadav, Reena; Ambady, Anisha; Sharma, Umender

    2015-01-25

    Glutamate racemase (MurI) converts l-glutamate into d-glutamate which is an essential component of peptidoglycan in bacteria. The gene encoding glutamate racemase, murI has been shown to be essential for the growth of a number of bacterial species including Escherichia coli. However, in some Gram-positive species d-amino acid transaminase (Dat) can also convert l-glutamate into d-glutamate thus rendering MurI non-essential for growth. In a recent study the murI gene of Mycobacterium tuberculosis was shown to be non-essential. As d-glutamate is an essential component of peptidoglycan of M. tuberculosis, either Dat or MurI has to be essential for its survival. Since, a Dat encoding gene has not been reported in M. tuberculosis genome sequence, the reported non-essentiality of murI was unexplainable. In order to resolve this dilemma we tried to knockout murI in the presence of single and two copies of murI, in wild type and merodiploid strains respectively. It was found that murI could not be inactivated in the wild type background indicating that it could be an essential gene. Also, inactivation of murI could not be achieved in the presence of externally supplied d-glutamate in 7H9 medium suggesting that M. tuberculosis is unable to take up d-glutamate under the conditions tested. However we could generate murI knockout strains at high frequency when two copies of the gene were present indicating that at least one murI gene is required for cellular viability. The essential nature of MurI in M. tuberculosis H37Rv suggests that it could be a potential drug target. PMID:25447907

  2. Activity of 5-chloro-pyrazinamide in mice infected with Mycobacterium tuberculosis or Mycobacterium bovis

    PubMed Central

    Ahmad, Zahoor; Tyagi, Sandeep; Minkowski, Austin; Almeida, Deepak; Nuermberger, Eric L.; Peck, Kaitlin M.; Welch, John T.; Baughn, Anthony D.; Jacobs, Williams R.; Grosset, Jacques H.

    2012-01-01

    Background & objectives: Pyrazinamide is an essential component of first line anti-tuberculosis regimen as well as most of the second line regimens. This drug has a unique sterilizing activity against Mycobacterium tuberculosis. Its unique role in tuberculosis treatment has lead to the search and development of its structural analogues. One such analogue is 5-chloro-pyrazinamide (5-Cl-PZA) that has been tested under in vitro conditions against M. tuberculosis. The present study was designed with an aim to assess the activity of 5-Cl-PZA, alone and in combination with first-line drugs, against murine tuberculosis. Methods: The minimum inhibitory concentration (MIC) of 5-Cl-PZA in Middlebrook 7H9 broth (neutral pH) and the inhibitory titre of serum from mice that received a 300 mg/kg oral dose of 5-Cl-PZA 30 min before cardiac puncture were determined. To test the tolerability of orally administered 5-Cl-PZA, uninfected mice received doses up to 300 mg/kg for 2 wk. Four weeks after low-dose aerosol infection either with M. tuberculosis or M. bovis, mice were treated 5 days/wk with 5-Cl-PZA, at doses ranging from 37.5 to 150 mg/kg, either alone or in combination with isoniazid and rifampicin. Antimicrobial activity was assessed by colony-forming unit counts in lungs after 4 and 8 wk of treatment. Results: The MIC of 5-Cl-PZA against M. tuberculosis was between 12.5 and 25 μg/ml and the serum inhibitory titre was 1:4. Under the same experimental conditions, the MIC of pyrazinamide was >100 μg/ml and mouse serum had no inhibitory activity after a 300 mg/kg dose; 5-Cl-PZA was well tolerated in uninfected and infected mice up to 300 and 150 mg/kg, respectively. While PZA alone and in combination exhibited its usual antimicrobial activity in mice infected with M. tuberculosis and no activity in mice infected with M. bovis, 5-Cl-PZA exhibited antimicrobial activity neither in mice infected with M. tuberculosis nor in mice infected with M. bovis. Interpretation

  3. Personal respiratory protection against Mycobacterium tuberculosis.

    PubMed

    Fennelly, K P

    1997-03-01

    Although there are no data demonstrating the effectiveness of personal respiratory protection in the prevention of occupational tuberculosis, there are sound theoretical bases supporting the use of respirators to reduce the risk of inhalational exposure. The major factor that limits the effectiveness of most respirators is the leakage between the face and the mask. There are data suggesting that traditional fit testing of respirators does not adequately predict the degree of protection in actual use, and more research is needed in that area. There is a large range of infectiousness of aerosols of TB, and classes of respirators vary greatly in the degree of protection they offer. I have argued that respirator selection should be based on anticipated exposures. High-risk exposures to TB are often associated with cough-inducing procedures or with aerosolization of infected tissues during autopsies. In my opinion, the most reasonable type of respirator for such high-risk situations in health care settings is a PAPR hood. The concentration of infectious aerosols in well-ventilated respiratory isolation rooms is likely to be very low, and the new N95 respirators offer a reasonable balance of comfort, cost, practicality, and protection. Preliminary data from mathematical modeling studies suggest there may be little additional benefit from more sophisticated personal respiratory protection in such settings. Additional research is needed to more accurately assess exposures to TB, to determine the size and aerodynamic behavior of TB generated by infectious patients, and to more accurately define the role and effectiveness of personal respiratory protection against TB. PMID:9098607

  4. Immunogenicity and cross-reactivity against Mycobacterium tuberculosis of proteoliposomes derived from Mycobacterium bovis BCG.

    PubMed

    Reyes, Fátima; Tirado, Yanely; Puig, Alina; Borrero, Reinier; Reyes, Giselle; Fernández, Sonsire; Pérez, José Luis; Kadir, Ramlah; Zayas, Caridad; Norazmi, Mohd Nor; Sarmiento, María E; Acosta, Armando

    2013-01-01

    The only currently available vaccine against tuberculosis (TB) is Mycobacterium bovis Bacille Calmette-Guerin (BCG), which has inconsistent efficacy to protect against the disease in adults. M. tuberculosis (MTB) cell wall components have been implicated in the pathogenicity of TB and therefore have been a prime target for the identification and characterization of cell wall proteins with potential application in vaccine development. In this regard, proteoliposomes (PLs) derived from mycobacteria containing lipids and cell wall proteins could be potential vaccine candidates against TB. In the present study PLs derived from BCG were prepared. These homogeneous population of spherical microparticles was then immunized into Balb/c mice. Sera of immunized animals showed high IgG response and strong cross-reactivity against different MTB antigens.These results showed that BCG PLs could be potential vaccine candidates against TB. PMID:23458692

  5. Rapid susceptibility testing of Mycobacterium avium complex and Mycobacterium tuberculosis isolated from AIDS patients

    NASA Technical Reports Server (NTRS)

    Dhople, Arvind M.

    1994-01-01

    In ominous projections issued by both U.S. Public Health Service and the World Health Organization, the epidemic of HIV infection will continue to rise more rapidly worldwide than predicted earlier. The AIDS patients are susceptible to diseases called opportunistic infections of which tuberculosis and Mycobacterium avium complex (MAC) infection are most common. This has created an urgent need to uncover new drugs for the treatment of these infections. In the seventies, NASA scientists at Goddard Space Flight Center, Greenbelt, MD, had adopted a biochemical indicator, adenosine triphosphate (ATP), to detect presence of life in extraterrestrial space. We proposed to develop ATP assay technique to determine sensitivity of antibacterial compounds against MAC and M. tuberculosis.

  6. Pulmonary Tuberculosis Caused by Mycobacterium bovis in China

    PubMed Central

    Jiang, Guanglu; Wang, Guirong; Chen, Suting; Yu, Xia; Wang, Xiaobo; Zhao, Liping; Ma, Yifeng; Dong, Lingling; Huang, Hairong

    2015-01-01

    The epidemiology of Mycobacterium bovis infection in humans in China is unknown. In this study, pulmonary tuberculosis caused by M. bovis in China was studied. A total of 4069 clinical strains isolated from sputa during the 2007–2009 nationwide surveillance of drug-resistant tuberculosis in China were analyzed. M. bovis was identified by para-nitrobenzoic acid and thiophen-2-carboxylic acid hydrazide growth tests, spoligotyping and multiplex PCR amplification. In addition, a total of 1828 clinical specimens were recruited from Beijing Chest Hospital (Beijing, China) for Löwenstein-Jensen (LJ) culture, both on standard LJ medium and LJ medium containing 4.5 mg/ml(W/V) sodium pyruvate, the latter being the preferred medium for M. bovis growth. The isolates which demonstrated more vigorous on pyruvate containing medium than on standard LJ medium were then identified by multiplex PCR amplification. Only 1 isolate from the nationwide surveillance was confirmed as M. bovis-BCG. The isolate belonged to a predominant spoligotype SB0120 (ST482). In addition, no M. bovis isolate was acquired by the continuous screening step in Beijing Chest Hospital. M. bovis has a negligible contribution to pulmonary tuberculosis in China, so neither laboratory identification nor clinical treatment of M. bovis infection need be considered in routine work. PMID:25736338

  7. Genotyping of ancient Mycobacterium tuberculosis strains reveals historic genetic diversity

    PubMed Central

    Müller, Romy; Roberts, Charlotte A.; Brown, Terence A.

    2014-01-01

    The evolutionary history of the Mycobacterium tuberculosis complex (MTBC) has previously been studied by analysis of sequence diversity in extant strains, but not addressed by direct examination of strain genotypes in archaeological remains. Here, we use ancient DNA sequencing to type 11 single nucleotide polymorphisms and two large sequence polymorphisms in the MTBC strains present in 10 archaeological samples from skeletons from Britain and Europe dating to the second–nineteenth centuries AD. The results enable us to assign the strains to groupings and lineages recognized in the extant MTBC. We show that at least during the eighteenth–nineteenth centuries AD, strains of M. tuberculosis belonging to different genetic groups were present in Britain at the same time, possibly even at a single location, and we present evidence for a mixed infection in at least one individual. Our study shows that ancient DNA typing applied to multiple samples can provide sufficiently detailed information to contribute to both archaeological and evolutionary knowledge of the history of tuberculosis. PMID:24573854

  8. A New Approach for Pyrazinamide Susceptibility Testing in Mycobacterium tuberculosis

    PubMed Central

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

    2012-01-01

    Background: 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. Objective: To evaluate the rate of POA extrusion from Mycobacterium tuberculosis as a parameter to detect PZA resistance. Methods: 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. Result: POA efflux rate predicted PZA resistance with 70.83%–92.85% sensitivity and 100% specificity compared with BACTEC 460. Conclusion: 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. PMID:22372927

  9. Direct inhibitors of InhA active against Mycobacterium tuberculosis

    PubMed Central

    Manjunatha, Ujjini H.; Rao, Srinivasa P. S.; Kondreddi, Ravinder Reddy; Noble, Christian G.; Camacho, Luis R.; Tan, Bee H.; Ng, Seow H.; Ng, Pearly Shuyi; Ma, N. L.; Lakshminarayana, Suresh B.; Herve, Maxime; Barnes, S. Whitney; Yu, Weixuan; Kuhen, Kelli; Blasco, Francesca; Beer, David; Walker, John R.; Tonge, Peter J.; Glynne, Richard; Smith, Paul W.; Diagana, Thierry T.

    2015-01-01

    New chemotherapeutic agents are urgently required to combat the global spread of multi-drug resistant tuberculosis (MDR-TB). The mycobacterial enoyl reductase, InhA, is one of the few clinically-validated targets in tuberculosis drug discovery. Here, we report the identification of a new class of direct InhA inhibitors, the 4-hydroxy-2-pyridones, using phenotypic high-throughput whole-cell screening. This class of orally-active compounds showed potent bactericidal activity against common isoniazid-resistant TB clinical isolates. Biophysical studies revealed that 4-hydroxy-2-pyridones bound specifically to InhA in an NADH-dependent manner and blocked the enoyl-substrate binding pocket. The lead compound NITD-916 directly blocked InhA in a dose-dependent manner and showed in vivo efficacy in acute and established mouse models of infection by Mycobacterium tuberculosis. Collectively, our structural and biochemical data open up new avenues for rational structure-guided optimization of the 4-hydroxy-2-pyridone class of compounds for the treatment of MDR-TB. PMID:25568071

  10. EFFECT OF PYRAZINAMIDASE ACTIVITY ON PYRAZINAMIDE RESISTANCE IN MYCOBACTERIUM TUBERCULOSIS

    PubMed Central

    Sheen, Patricia; Ferrer, Patricia; Gilman, Robert H.; López-Llano, Jon; Fuentes, Patricia; Valencia, Eddy; Zimic, Mirko J.

    2009-01-01

    Resistance of Mycobacterium tuberculosis to pyrazinamide is associated with mutations in the pncA gene, which codes for pyrazinamidase. The association between the enzymatic activity of mutated pyrazinamidases and the level of pyrazinamide resistance remains poorly understood. Twelve M. tuberculosis clinical isolates resistant to pyrazinamide were selected based on Wayne activity and localization of pyrazinamidase mutation. Recombinant pyrazinamidases were expressed and tested for their kinetic parameters (activity, kcat, Km, and efficiency). Pyrazinamide resistance level was measured by Bactec-460TB and 7H9 culture. The linear correlation between the resistance level and the kinetic parameters of the corresponding mutated pyrazinamidase was calculated. The enzymatic activity and efficiency of the mutated pyrazinamidases varied with the site of mutation and ranged widely from low to high levels close to the corresponding of the wild-type enzyme. The level of resistance was significantly associated with pyrazinamidase activity and efficiency, but only 27.3% of its statistical variability was explained. Although pyrazinamidase mutations are indeed associated with resistance, the loss of pyrazinamidase activity and efficiency as assessed in the recombinant mutated enzymes is not sufficient to explain a high variability of the level of pyrazinamide resistance, suggesting that complementary mechanisms for pyrazinamide resistance in M. tuberculosis with mutations in pncA are more important than currently thought. PMID:19249243

  11. Proteomic analysis of ofloxacin-mono resistant Mycobacterium tuberculosis isolates.

    PubMed

    Lata, Manju; Sharma, Divakar; Deo, Nirmala; Tiwari, Pramod Kumar; Bisht, Deepa; Venkatesan, Krishnamurthy

    2015-09-01

    Drug resistance particularly, multi drug resistance tuberculosis (MDR-TB) has emerged as a major problem in the chemotherapy of tuberculosis. Ofloxacin (OFX) has been used as second-line drug against MDR-TB. The principal target of the OFX is DNA gyrase encoded by gyrA and gyrB genes. Many explanations have been proposed for drug resistance to OFX but still some mechanisms are unknown. As proteins manifest most of the biological processes, these are attractive targets for developing drugs and diagnostics/therapeutics. We examined the OFX resistant Mycobacterium tuberculosis isolates by proteomic approach (2DE-MALDI-TOF-MS) and bioinformatic tools under OFX induced conditions. Our study showed fourteen proteins (Rv0685, Rv0363c, Rv2744c, Rv3803c, Rv2534c, Rv2140c, Rv1475c, Rv0440, Rv2245, Rv1436, Rv3551, Rv0148, Rv2882c and Rv0733) with increased intensities in OFX resistant and OFX induced as compared to susceptible isolates. Bioinformatic analysis of hypothetical proteins (Rv2744c, Rv2140c, Rv3551 and Rv0148) revealed the presence of conserved motifs and domains. Molecular docking showed proper interaction of OFX with residues of conserved motifs. These proteins might be involved in the OFX modulation/neutralization and act as novel resistance mechanisms as well as potential for diagnostics and drug targets against OFX resistance. This article is part of a Special Issue entitled: Proteomics in India. PMID:26238929

  12. Copper resistance is essential for virulence of Mycobacterium tuberculosis.

    PubMed

    Wolschendorf, Frank; Ackart, David; Shrestha, Tej B; Hascall-Dove, Laurel; Nolan, Scott; Lamichhane, Gyanu; Wang, Ying; Bossmann, Stefan H; Basaraba, Randall J; Niederweis, Michael

    2011-01-25

    Copper (Cu) is essential for many biological processes, but is toxic when present in excessive amounts. In this study, we provide evidence that Cu plays a crucial role in controlling tuberculosis. A Mycobacterium tuberculosis (Mtb) mutant lacking the outer membrane channel protein Rv1698 accumulated 100-fold more Cu and was more susceptible to Cu toxicity than WT Mtb. Similar phenotypes were observed for a M. smegmatis mutant lacking the homolog Ms3747, demonstrating that these mycobacterial copper transport proteins B (MctB) are essential for Cu resistance and maintenance of low intracellular Cu levels. Guinea pigs responded to infection with Mtb by increasing the Cu concentration in lung lesions. Loss of MctB resulted in a 1,000- and 100-fold reduced bacterial burden in lungs and lymph nodes, respectively, in guinea pigs infected with Mtb. In mice, the persistence defect of the Mtb mctB mutant was exacerbated by the addition of Cu to the diet. These experiments provide evidence that Cu is used by the mammalian host to control Mtb infection and that Cu resistance mechanisms are crucial for Mtb virulence. Importantly, Mtb is much more susceptible to Cu than other bacteria and is killed in vitro by Cu concentrations lower than those found in phagosomes of macrophages. Hence, this study reveals an Achilles heel of Mtb that might be a promising target for tuberculosis chemotherapy. PMID:21205886

  13. Isolation and restriction site maps of the genes encoding five Mycobacterium tuberculosis proteins.

    PubMed

    Shinnick, T M; Krat, C; Schadow, S

    1987-07-01

    A series of recombinant phage expressing five Mycobacterium tuberculosis antigens were isolated. Restriction maps for these antigens were deduced, and the size of the expressed proteins was determined. PMID:3036711

  14. Isolation and restriction site maps of the genes encoding five Mycobacterium tuberculosis proteins.

    PubMed Central

    Shinnick, T M; Krat, C; Schadow, S

    1987-01-01

    A series of recombinant phage expressing five Mycobacterium tuberculosis antigens were isolated. Restriction maps for these antigens were deduced, and the size of the expressed proteins was determined. Images PMID:3036711

  15. Racial differences in susceptibility to infection by Mycobacterium tuberculosis.

    PubMed

    Stead, W W; Senner, J W; Reddick, W T; Lofgren, J P

    1990-02-15

    The prevalence of tuberculosis among blacks is known to be about twice that among whites. When we looked at infection rates among the initially tuberculin-negative residents of 165 racially integrated nursing homes in Arkansas, we were stimulated to investigate whether this difference could be due in part to racial differences in susceptibility to Mycobacterium tuberculosis infection. A new infection was defined by an increase of greater than or equal to 12 mm of induration after a tuberculin skin test (5 tuberculin units) administered at least 60 days after a negative two-step test. On repeat skin testing of the 25,398 initially tuberculin-negative nursing home residents, we found that 13.8 percent of the blacks and only 7.2 percent of the whites had evidence of a new infection (relative risk, 1.9; 95 percent confidence interval, 1.7 to 2.1). Blacks were infected more frequently, regardless of the race of the source patient. In homes with a single source patient who was white, 17.4 percent of the black and 11.7 percent of the white residents became infected (relative risk, 1.5; 95 percent confidence interval, 1.2 to 1.9); in homes with a single source patient who was black, 12.4 percent of the black and 7.7 percent of the white residents became infected (relative risk, 1.6; 95 percent confidence interval, 1.2 to 2.1). However, there was no racial difference in the percentage of residents who had recently converted to positive status who, in the absence of preventive therapy, were later found to have clinical tuberculosis (blacks, 11.5 percent; whites, 10.6 percent). Data from three outbreaks of tuberculosis in two prisons also showed that blacks have about twice the relative risk of whites of becoming infected with M. tuberculosis. We conclude that blacks are more readily infected by M. tuberculosis than are whites. The data also suggest that susceptibility to M. tuberculosis infection varies independently of the factors governing the progression to clinical

  16. Multiple small RNAs identified in Mycobacterium bovis BCG are also expressed in Mycobacterium tuberculosis and Mycobacterium smegmatis

    PubMed Central

    DiChiara, Jeanne M.; Contreras-Martinez, Lydia M.; Livny, Jonathan; Smith, Dorie; McDonough, Kathleen A.; Belfort, Marlene

    2010-01-01

    Tuberculosis (TB) is a major global health problem, infecting millions of people each year. The causative agent of TB, Mycobacterium tuberculosis, is one of the world’s most ancient and successful pathogens. However, until recently, no work on small regulatory RNAs had been performed in this organism. Regulatory RNAs are found in all three domains of life, and have already been shown to regulate virulence in well-known pathogens, such as Staphylococcus aureus and Vibrio cholera. Here we report the discovery of 34 novel small RNAs (sRNAs) in the TB-complex M. bovis BCG, using a combination of experimental and computational approaches. Putative homologues of many of these sRNAs were also identified in M. tuberculosis and/or M. smegmatis. Those sRNAs that are also expressed in the non-pathogenic M. smegmatis could be functioning to regulate conserved cellular functions. In contrast, those sRNAs identified specifically in M. tuberculosis could be functioning in mediation of virulence, thus rendering them potential targets for novel antimycobacterials. Various features and regulatory aspects of some of these sRNAs are discussed. PMID:20181675

  17. Mycobacterium tuberculosis PPE protein Rv0256c induces strong B cell response in tuberculosis patients.

    PubMed

    Abraham, Philip Raj; Latha, Gaddam Suman; Valluri, Vijaya Lakshmi; Mukhopadhyay, Sangita

    2014-03-01

    Tuberculosis (TB) is one of the most important diseases of humans and major public health problem worldwide. Early and accurate diagnosis of TB is necessary for the treatment, prevention, and control of TB. Therefore, it is important to identify suitable antigens that can differentiate active tuberculosis patients from BCG-vaccinated individuals. In the present study, we have used Rv0256c (PPE2) protein of Mycobacterium tuberculosis to screen the sera of infected patients belonging to different clinical TB presentations, and BCG-vaccinated clinically healthy individuals by enzyme immunoassay. Our results demonstrated that Rv0256c displayed stronger and specific immunoreactivity against the sera obtained from clinically active tuberculosis patients compared to PPD and ESAT-6 and could differentiate the TB-patients from the BCG-vaccinated controls. Importantly, Rv0256c was also found to detect even the extrapulmonary and smear-negative pulmonary cases which often are tedious and difficult to detect using conventional diagnostic methods. This study suggests that Rv0256c can be used as a potential marker for the serodiagnosis of tuberculosis patients. PMID:23827809

  18. Systems-Based Approaches to Probing Metabolic Variation within the Mycobacterium tuberculosis Complex

    PubMed Central

    Lofthouse, Emma K.; Wheeler, Paul R.; Beste, Dany J. V.; Khatri, Bhagwati L.; Wu, Huihai; Mendum, Tom A.; Kierzek, Andrzej M.; McFadden, Johnjoe

    2013-01-01

    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. PMID:24098743

  19. Comparative analyses of transport proteins encoded within the genomes of Mycobacterium tuberculosis and Mycobacterium leprae

    PubMed Central

    Youm, Jiwon; Saier, Milton H.

    2012-01-01

    The co-emergence of multidrug resistant pathogenic bacterial strains and the HIV pandemic has made tuberculosis a leading public health threat. The causative agent is Mycobacterium tuberculosis (Mtu), a facultative intracellular parasite. Mycobacterium leprae (Mle), a related organism that causes leprosy, is an obligate intracellular parasite. Given that different transporters are required for bacterial growth and persistence under a variety of growth conditions, we conducted comparative analyses of transport proteins encoded within the genomes of these two organisms. A minimal set of genes required for intracellular and extracellular life were identified. Drug efflux systems utilizing primary active transport mechanisms have been preferentially retained in Mle and still others preferentially lost. Transporters associated with environmental adaptation found in Mtu were mostly lost in Mle. These findings provide starting points for experimental studies that may elucidate the dependencies of pathogenesis on transport for these two pathogenic mycobacteria. They also lead to suggestions regarding transporters that function in intra- versus extra-cellular growth. PMID:22179038

  20. Rv2358 and FurB: Two Transcriptional Regulators from Mycobacterium tuberculosis Which Respond to Zinc

    PubMed Central

    Canneva, Fabio; Branzoni, Manuela; Riccardi, Giovanna; Provvedi, Roberta; Milano, Anna

    2005-01-01

    In a previous work, we demonstrated that the Mycobacterium tuberculosis Rv2358-furB operon is induced by zinc. In this study, the orthologous genes from Mycobacterium smegmatis mc2155 were inactivated and mutants analyzed. Rv2358 protein was purified and found to bind upstream of the Rv2358 gene. Binding was inhibited by Zn2+ ions. PMID:16077132

  1. Immunogenic potential of latency associated antigens against Mycobacterium tuberculosis.

    PubMed

    Singh, Swati; Saraav, Iti; Sharma, Sadhna

    2014-02-01

    Tuberculosis remains a great health threat to the world among infectious diseases particularly with the advent of human immunodeficiency virus and emergence of drug resistant strains. In the light of the inconsistent efficacy imparted by the only currently available pre-exposure vaccine bacillus Calmette-Guerin BCG, the development of an improved TB vaccine is a very high international research priority. Vaccine candidates currently in clinical trials are also pre-exposure vaccines that aim to prevent active tuberculosis during an individual's lifetime. According to World Health Organization approximately a third of the world's population is latently infected with Mycobacterium tuberculosis. Dormancy or latency of Mycobacteria is associated with the formation of granuloma with poorly perfused interior leading to expression of genes which help them survive in this hostile environment. A group of about 50 genes belonging to the DosR regulon also known as latency antigens are expressed by Mycobacteria when they are persisting in the immuno-competent host. An understanding of the immunological effects produced by products of these latency induced genes may help in making a more potent vaccine. Incorporation of latency antigens into improved (live or subunit) vaccines may enhance the impact of these vaccines in which BCG priming can be followed by multisubunit protein boosting. These vaccines could act as post exposure vaccines for containment and prevention of latent TB activation. This heterologous boosting of BCG-primed immunity will be able to stimulate the known immune correlates of protective immunity against M. tuberculosis i.e. TH1 cells (CD4(+) and CD8(+) T cells) mediated immune responses with cytokines such as IFN-γ and TNF-α⋅ In our review we have analysed and compared the immunogenic potential of various latency-associated antigens of the DosR regulon in line with the current strategy of developing a recombinant post exposure booster vaccine. PMID

  2. Potent Inhibitors of a Shikimate Pathway Enzyme from Mycobacterium tuberculosis

    PubMed Central

    Reichau, Sebastian; Jiao, Wanting; Walker, Scott R.; Hutton, Richard D.; Baker, Edward N.; Parker, Emily J.

    2011-01-01

    Tuberculosis remains a serious global health threat, with the emergence of multidrug-resistant strains highlighting the urgent need for novel antituberculosis drugs. The enzyme 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAH7PS) catalyzes the first step of the shikimate pathway for the biosynthesis of aromatic compounds. This pathway has been shown to be essential in Mycobacterium tuberculosis, the pathogen responsible for tuberculosis. DAH7PS catalyzes a condensation reaction between P-enolpyruvate and erythrose 4-phosphate to give 3-deoxy-d-arabino-heptulosonate 7-phosphate. The enzyme reaction mechanism is proposed to include a tetrahedral intermediate, which is formed by attack of an active site water on the central carbon of P-enolpyruvate during the course of the reaction. Molecular modeling of this intermediate into the active site reported in this study shows a configurational preference consistent with water attack from the re face of P-enolpyruvate. Based on this model, we designed and synthesized an inhibitor of DAH7PS that mimics this reaction intermediate. Both enantiomers of this intermediate mimic were potent inhibitors of M. tuberculosis DAH7PS, with inhibitory constants in the nanomolar range. The crystal structure of the DAH7PS-inhibitor complex was solved to 2.35 Å. Both the position of the inhibitor and the conformational changes of active site residues observed in this structure correspond closely to the predictions from the intermediate modeling. This structure also identifies a water molecule that is located in the appropriate position to attack the re face of P-enolpyruvate during the course of the reaction, allowing the catalytic mechanism for this enzyme to be clearly defined. PMID:21454647

  3. Molecular diagnosis of fluoroquinolone resistance in Mycobacterium tuberculosis.

    PubMed

    Bernard, Christine; Veziris, Nicolas; Brossier, Florence; Sougakoff, Wladimir; Jarlier, Vincent; Robert, Jérôme; Aubry, Alexandra

    2015-03-01

    As a consequence of the use of fluoroquinolones (FQ), resistance to FQ has emerged, leading to cases of nearly untreatable and extensively drug-resistant tuberculosis. Mutations in DNA gyrase represent the main mechanism of FQ resistance. A full understanding of the pattern of mutations found in FQ-resistant (FQ(r)) clinical isolates, and of their proportions, is crucial for improving molecular methods for the detection of FQ resistance in Mycobacterium tuberculosis. In this study, we reviewed the detection of FQ resistance in isolates addressed to the French National Reference Center for Mycobacteria from 2007 to 2012, with the aim of evaluating the performance of PCR sequencing in a real-life context. gyrA and gyrB sequencing, performed prospectively on M. tuberculosis clinical isolates, was compared for FQ susceptibility to 2 mg/liter ofloxacin by the reference proportion method. A total of 605 isolates, of which 50% were multidrug resistant, were analyzed. The increase in FQ(r) strains among multidrug-resistant (MDR) strains during the time of the study was alarming (8% to 30%). The majority (78%) of the isolates with gyrA mutations were FQ(r), whereas only 36% of those with gyrB mutations were FQ(r). Only 12% of the FQ(r) isolates had a single mutation in gyrB. Combined gyrA and gyrB sequencing led to >93% sensitivity for detecting resistance. The analysis of the four false-positive and the five false-negative results of gyrA and gyrB sequencing illustrated the actual limitations of the reference proportion method. Our data emphasize the need for combined gyrA and gyrB sequencing in the investigation of FQ susceptibility in M. tuberculosis and challenge the validity of the current phenotype-based approach as the diagnostic gold standard for determining FQ resistance. PMID:25534742

  4. Rapid Diagnosis of Tuberculosis by Real-Time High-Resolution Imaging of Mycobacterium tuberculosis Colonies.

    PubMed

    Ghodbane, Ramzi; Asmar, Shady; Betzner, Marlena; Linet, Marie; Pierquin, Joseph; Raoult, Didier; Drancourt, Michel

    2015-08-01

    Culture remains the cornerstone of diagnosis for pulmonary tuberculosis, but the fastidiousness of Mycobacterium tuberculosis may delay culture-based diagnosis for weeks. We evaluated the performance of real-time high-resolution imaging for the rapid detection of M. tuberculosis colonies growing on a solid medium. A total of 50 clinical specimens, including 42 sputum specimens, 4 stool specimens, 2 bronchoalveolar lavage fluid specimens, and 2 bronchial aspirate fluid specimens were prospectively inoculated into (i) a commercially available Middlebrook broth and evaluated for mycobacterial growth indirectly detected by measuring oxygen consumption (standard protocol) and (ii) a home-made solid medium incubated in an incubator featuring real-time high-resolution imaging of colonies (real-time protocol). Isolates were identified by Ziehl-Neelsen staining and matrix-assisted laser desorption ionization-time of flight mass spectrometry. Use of the standard protocol yielded 14/50 (28%) M. tuberculosis isolates, which is not significantly different from the 13/50 (26%) M. tuberculosis isolates found using the real-time protocol (P = 1.00 by Fisher's exact test), and the contamination rate of 1/50 (2%) was not significantly different from the contamination rate of 2/50 (4%) using the real-time protocol (P = 1.00). The real-time imaging protocol showed a 4.4-fold reduction in time to detection, 82 ± 54 h versus 360 ± 142 h (P < 0.05). These preliminary data give the proof of concept that real-time high-resolution imaging of M. tuberculosis colonies is a new technology that shortens the time to growth detection and the laboratory diagnosis of pulmonary tuberculosis. PMID:26085608

  5. Rapid Diagnosis of Tuberculosis by Real-Time High-Resolution Imaging of Mycobacterium tuberculosis Colonies

    PubMed Central

    Ghodbane, Ramzi; Asmar, Shady; Betzner, Marlena; Linet, Marie; Pierquin, Joseph; Raoult, Didier

    2015-01-01

    Culture remains the cornerstone of diagnosis for pulmonary tuberculosis, but the fastidiousness of Mycobacterium tuberculosis may delay culture-based diagnosis for weeks. We evaluated the performance of real-time high-resolution imaging for the rapid detection of M. tuberculosis colonies growing on a solid medium. A total of 50 clinical specimens, including 42 sputum specimens, 4 stool specimens, 2 bronchoalveolar lavage fluid specimens, and 2 bronchial aspirate fluid specimens were prospectively inoculated into (i) a commercially available Middlebrook broth and evaluated for mycobacterial growth indirectly detected by measuring oxygen consumption (standard protocol) and (ii) a home-made solid medium incubated in an incubator featuring real-time high-resolution imaging of colonies (real-time protocol). Isolates were identified by Ziehl-Neelsen staining and matrix-assisted laser desorption ionization–time of flight mass spectrometry. Use of the standard protocol yielded 14/50 (28%) M. tuberculosis isolates, which is not significantly different from the 13/50 (26%) M. tuberculosis isolates found using the real-time protocol (P = 1.00 by Fisher's exact test), and the contamination rate of 1/50 (2%) was not significantly different from the contamination rate of 2/50 (4%) using the real-time protocol (P = 1.00). The real-time imaging protocol showed a 4.4-fold reduction in time to detection, 82 ± 54 h versus 360 ± 142 h (P < 0.05). These preliminary data give the proof of concept that real-time high-resolution imaging of M. tuberculosis colonies is a new technology that shortens the time to growth detection and the laboratory diagnosis of pulmonary tuberculosis. PMID:26085608

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

    NASA Astrophysics Data System (ADS)

    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.

  7. An Elucidation of Neutrophil Functions against Mycobacterium tuberculosis Infection

    PubMed Central

    Morris, Devin; Nguyen, Thien; Kim, John; Kassissa, Christine; Khurasany, Melissa; Luong, Jennifer; Kasko, Sarah; Pandya, Shalin; Chu, Michael; Chi, Po-Ting; Lagman, Minette; Venketaraman, Vishwanath

    2013-01-01

    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. PMID:24312131

  8. Turning the respiratory flexibility of Mycobacterium tuberculosis against itself.

    PubMed

    Lamprecht, Dirk A; Finin, Peter M; Rahman, Md Aejazur; Cumming, Bridgette M; Russell, Shannon L; Jonnala, Surendranadha R; Adamson, John H; Steyn, Adrie J C

    2016-01-01

    The Mycobacterium tuberculosis (Mtb) electron transport chain (ETC) has received significant attention as a drug target, however its vulnerability may be affected by its flexibility in response to disruption. Here we determine the effect of the ETC inhibitors bedaquiline, Q203 and clofazimine on the Mtb ETC, and the value of the ETC as a drug target, by measuring Mtb's respiration using extracellular flux technology. We find that Mtb's ETC rapidly reroutes around inhibition by these drugs and increases total respiration to maintain ATP levels. Rerouting is possible because Mtb rapidly switches between terminal oxidases, and, unlike eukaryotes, is not susceptible to back pressure. Increased ETC activity potentiates clofazimine's production of reactive oxygen species, causing rapid killing in vitro and in a macrophage model. Our results indicate that combination therapy targeting the ETC can be exploited to enhance killing of Mtb. PMID:27506290

  9. Cell-autonomous effector mechanisms against mycobacterium tuberculosis.

    PubMed

    MacMicking, John D

    2014-10-01

    Few pathogens run the gauntlet of sterilizing immunity like Mycobacterium tuberculosis (Mtb). This organism infects mononuclear phagocytes and is also ingested by neutrophils, both of which possess an arsenal of cell-intrinsic effector mechanisms capable of eliminating it. Here Mtb encounters acid, oxidants, nitrosylating agents, and redox congeners, often exuberantly delivered under low oxygen tension. Further pressure is applied by withholding divalent Fe²⁺, Mn²⁺, Cu²⁺, and Zn²⁺, as well as by metabolic privation in the form of carbon needed for anaplerosis and aromatic amino acids for growth. Finally, host E3 ligases ubiquinate, cationic peptides disrupt, and lysosomal enzymes digest Mtb as part of the autophagic response to this particular pathogen. It is a testament to the evolutionary fitness of Mtb that sterilization is rarely complete, although sufficient to ensure most people infected with this airborne bacterium remain disease-free. PMID:25081628

  10. The DNA-binding network of Mycobacterium tuberculosis

    PubMed Central

    Minch, Kyle J.; Rustad, Tige R.; Peterson, Eliza J. R.; Winkler, Jessica; Reiss, David J.; Ma, Shuyi; Hickey, Mark; Brabant, William; Morrison, Bob; Turkarslan, Serdar; Mawhinney, Chris; Galagan, James E.; Price, Nathan D.; Baliga, Nitin S.; Sherman, David R.

    2015-01-01

    Mycobacterium tuberculosis (MTB) infects 30% of all humans and kills someone every 20–30 s. Here we report genome-wide binding for ~80% of all predicted MTB transcription factors (TFs), and assayed global expression following induction of each TF. The MTB DNA-binding network consists of ~16,000 binding events from 154 TFs. We identify >50 TF-DNA consensus motifs and >1,150 promoter-binding events directly associated with proximal gene regulation. An additional ~4,200 binding events are in promoter windows and represent strong candidates for direct transcriptional regulation under appropriate environmental conditions. However, we also identify >10,000 ‘dormant’ DNA-binding events that cannot be linked directly with proximal transcriptional control, suggesting that widespread DNA binding may be a common feature that should be considered when developing global models of coordinated gene expression. PMID:25581030

  11. Turning the respiratory flexibility of Mycobacterium tuberculosis against itself

    PubMed Central

    Lamprecht, Dirk A.; Finin, Peter M.; Rahman, Md. Aejazur; Cumming, Bridgette M.; Russell, Shannon L.; Jonnala, Surendranadha R.; Adamson, John H.; Steyn, Adrie J. C.

    2016-01-01

    The Mycobacterium tuberculosis (Mtb) electron transport chain (ETC) has received significant attention as a drug target, however its vulnerability may be affected by its flexibility in response to disruption. Here we determine the effect of the ETC inhibitors bedaquiline, Q203 and clofazimine on the Mtb ETC, and the value of the ETC as a drug target, by measuring Mtb's respiration using extracellular flux technology. We find that Mtb's ETC rapidly reroutes around inhibition by these drugs and increases total respiration to maintain ATP levels. Rerouting is possible because Mtb rapidly switches between terminal oxidases, and, unlike eukaryotes, is not susceptible to back pressure. Increased ETC activity potentiates clofazimine's production of reactive oxygen species, causing rapid killing in vitro and in a macrophage model. Our results indicate that combination therapy targeting the ETC can be exploited to enhance killing of Mtb. PMID:27506290

  12. Cell-Autonomous Effector Mechanisms against Mycobacterium tuberculosis

    PubMed Central

    MacMicking, John D.

    2014-01-01

    Few pathogens run the gauntlet of sterilizing immunity like Mycobacterium tuberculosis (Mtb). This organism infects mononuclear phagocytes and is also ingested by neutrophils, both of which possess an arsenal of cell-intrinsic effector mechanisms capable of eliminating it. Here Mtb encounters acid, oxidants, nitrosylating agents, and redox congeners, often exuberantly delivered under low oxygen tension. Further pressure is applied by withholding divalent Fe2+, Mn2+, Cu2+, and Zn2+, as well as by metabolic privation in the form of carbon needed for anaplerosis and aromatic amino acids for growth. Finally, host E3 ligases ubiquinate, cationic peptides disrupt, and lysosomal enzymes digest Mtb as part of the autophagic response to this particular pathogen. It is a testament to the evolutionary fitness of Mtb that sterilization is rarely complete, although sufficient to ensure most people infected with this airborne bacterium remain disease-free. PMID:25081628

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

    PubMed Central

    Coll, Francesc; McNerney, Ruth; Guerra-Assunção, José Afonso; Glynn, Judith R.; Perdigão, João; Viveiros, Miguel; Portugal, Isabel; Pain, Arnab; Martin, Nigel; Clark, Taane G.

    2014-01-01

    Strain-specific genomic diversity in the Mycobacterium tuberculosis complex (MTBC) is an important factor in pathogenesis that may affect virulence, transmissibility, host response and emergence of drug resistance. Several systems have been proposed 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. PMID:25176035

  14. CCL2 Responses to Mycobacterium tuberculosis Are Associated with Disease Severity in Tuberculosis

    PubMed Central

    Hasan, Zahra; Cliff, Jacqueline M.; Dockrell, Hazel M.; Jamil, Bushra; Irfan, Muhammad; Ashraf, Mussarat; Hussain, Rabia

    2009-01-01

    Background Leucocyte activating chemokines such as CCL2, CCL3, and CXCL8 together with proinflammatory IFNγ, TNFα 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, IFNγ, IL10 and CCL3, and mRNA expression of CCL2, TNFα, 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 IFNγ was greater in L-ETB than PTB (p = 0.04), while BCG-induced IFNγ was greater in L-ETB as compared with D-ETB patients (p = 0.036). TNFα 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 TNFα 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. PMID

  15. Clinical Impact of Mycobacterium tuberculosis W-Beijing Genotype Strain Infection on Aged Patients in Taiwan▿

    PubMed Central

    Feng, Jia-Yih; Su, Wei-Juin; Tsai, Cheng-Chien; Chang, Shi-Chuan

    2008-01-01

    The impact of W-Beijing genotype Mycobacterium tuberculosis on treatment outcome was evaluated in 249 newly diagnosed tuberculosis patients. No significant difference in the treatment outcome was found between the W-Beijing and non-W-Beijing groups. However, a poor outcome was more common in the elderly patients (≥65 years) infected with the W-Beijing strain. PMID:18596137

  16. Draft Genome Sequence of Mycobacterium tuberculosis KT-0133, Isolated in South Korea.

    PubMed

    Kwon, Taesoo; Han, Seung Jung; Yoo, Won Gi; Yun, Mi-Ran; Lee, Sanghyun; Lee, Jong Seok; Kim, Dae-Won

    2016-01-01

    Here, we present the draft genome sequence of Mycobacterium tuberculosis KT-0133, which belongs to the Korean-Beijing family. This sequence will provide a new perspective on the evolution and accommodation of M. tuberculosis KT-0133 in human hosts. PMID:26868407

  17. Emergence of potential superbug mycobacterium tuberculosis, lessons from new delhi mutant-1 bacterial strains.

    PubMed

    Nazir, Taha; Abraham, Suraj; Islam, Azharul

    2012-01-01

    Recent reports have shown that certain bacterial strains attain the New Delhi Metallo-beta-lactamase-1 (NDM-1) enzyme and become resistant to a broad range of antibiotics. Similarly, more dangerous "superbugs" of multi-drug resistant (MDR) and extensive drug resistant (XDR) Mycobacterium tuberculosis strains are gradually emerging through rapid genetic mutation caused by prescription non-compliance or unsupervised indiscriminate use of anti-tubercular drugs or other antibiotics. Mycobacterium tuberculosis cases have been reported in highly susceptible population groups including the aboriginal communities of US and Canada. In Canada alone, the total number of reported tuberculosis cases has decreased over the past decade. However, there is a steady increase in HIV cases in certain communities including the aboriginal communities. Reintroduction of MDR/XDR strains of tuberculosis is possible in these susceptible communities, which in turn may pose serious public health situation. MDR/XDR strains of tuberculosis are virtually untreatable using current anti-tubercular medication protocols. Thus, MDR/XDR tuberculosis presents a grave global public health threat. The unpredictable genetic mechanism involved in generating MDR/XDR resistant strains of Mycobacterium tuberculosis may pose greater challenges in developing appropriate treatment strategies. In this article, we briefly review potential genetic mechanism of emerging NDM-1 bacterial strains and draw a rationale parallel to the underlying genetic mechanism of MDR/XDR Mycobacterium tuberculosis strain development. PMID:23267308

  18. Rapid genotypic detection of rifampin- and isoniazid-resistant Mycobacterium tuberculosis directly in clinical specimens.

    PubMed

    Bang, Didi; Bengård Andersen, Ase; Thomsen, Vibeke Østergaard

    2006-07-01

    A multiplex PCR DNA strip assay (Genotype MTBDR) designed to detect rifampin (rpoB) and high-level isoniazid (katG) resistance mutations in Mycobacterium tuberculosis isolates was optimized for clinical specimens. Successful genotypic results were achieved with 36 of 38 (95%) smear-positive respiratory specimens, allowing rapid therapeutic adjustments in transmittable drug-resistant tuberculosis. PMID:16825393

  19. A cooperative oxygen-binding hemoglobin from Mycobacterium tuberculosis

    PubMed Central

    Couture, Manon; Yeh, Syun-Ru; Wittenberg, Beatrice A.; Wittenberg, Jonathan B.; Ouellet, Yannick; Rousseau, Denis L.; Guertin, Michel

    1999-01-01

    Two putative hemoglobin genes, glbN and glbO, were recently discovered in the complete genome sequence of Mycobacterium tuberculosis H37Rv. Here, we show that the glbN gene encodes a dimeric hemoglobin (HbN) that binds oxygen cooperatively with very high affinity (P50 = 0.013 mmHg at 20°C) because of a fast combination (25 μM−1⋅s−1) and a slow dissociation (0.2 s−1) rate. Resonance Raman spectroscopy and ligand association/dissociation kinetic measurements, along with mutagenesis studies, reveal that the stabilization of the bound oxygen is achieved through a tyrosine at the B10 position in the distal pocket of the heme with a conformation that is unique among the globins. Physiological studies performed with Mycobacterium bovis bacillus Calmette–Guérin demonstrate that the expression of HbN is greatly enhanced during the stationary phase in aerobic cultures but not under conditions of limited oxygen availability. The results suggest that, physiologically, the primary role of HbN may be to protect the bacilli against reactive nitrogen species produced by the host macrophage. PMID:10500158

  20. Response of inbred mice to aerosol challenge with Mycobacterium tuberculosis.

    PubMed

    Musa, S A; Kim, Y; Hashim, R; Wang, G Z; Dimmer, C; Smith, D W

    1987-08-01

    An autosomal dominant gene (Bcg), which maps to mouse chromosome 1, has been shown to confer on mice resistance to attenuated Mycobacterium bovis BCG Montreal, Salmonella typhimurium, and Leishmania donovani. Most animal models used for the study of the Bcg gene have involved intravenous injection of a large number of microorganisms (greater than 10(4) CFU). The present study examines the effect of the Bcg gene on the resistance of inbred mice to challenge via the respiratory route with 5 to 10 CFU of virulent Mycobacterium tuberculosis. The number of tubercle bacilli recovered from the lung lobes indicates that the growth kinetics of the microorganism did not differ between BCG-resistant and BCG-susceptible strains of mice. The number of tubercle bacilli recovered from the spleen was also similar among strains. Although there were reproducible differences in the time of first recovery of bacilli from the spleen, these differences appeared to be unrelated to the expression of the Bcg gene. When mice were challenged with purified protein derivative, all strains responded similarly as observed by measurements of footpad swelling. PMID:3112014

  1. [Tuberculosis cutis luposa gigantea with Mycobacterium bovis detection].

    PubMed

    Bonnekoh, B; Schütt-Gerowitt, H; Thiele, B; Mahrle, G

    1990-10-01

    In an 80-year-old woman, retired farmworker, we observed lupus vulgaris extending over more than half of her leg. The extreme size of the affected area made us talk of a giant form in this case. Bacteriological investigation revealed Mycobacterium bovis. The minimal amount of tuberculin required to induce a positive intradermal reaction was 10 IU (GT Behring). Another case with similar dimensions (reported by Christiansen in 1967) had been caused by Mycobacterium avium and developed over a period of at least 5 years. The vast cutaneous affection of our patient, in contrast, had developed within only one year, starting from a brownish macula of the size of a palm on her upper leg. This macula - presumably the manifestation of quiescent lupus vulgaris - had not changed for more than 40 years. This late exacerbation of post-primary tuberculosis might have been favored by the patient's reduced immunologic resistance on account of her advanced age. In addition, local cofactors - namely ankylosis of her knee and contact eczematous dermatitis - have to be considered. In accordance with the resistogram, the disease responded to monotherapy with isoniazide. PMID:2291294

  2. Antigenic characterization of dimorphic surface protein in Mycobacterium tuberculosis.

    PubMed

    Matsuba, Takashi; Siddiqi, Umme Ruman; Hattori, Toshio; Nakajima, Chie; Fujii, Jun; Suzuki, Yasuhiko

    2016-05-01

    The Mycobacterium tuberculosis Rv0679c protein is a surface protein that contributes to host cell invasion. We previously showed that a single nucleotide transition of the Rv0679c gene leads to a single amino acid substitution from asparagine to lysine at codon 142 in the Beijing genotype family. In this study, we examined the immunological effect of this substitution. Several recombinant proteins were expressed in Escherichia coli and Mycobacterium smegmatis and characterized with antisera and two monoclonal antibodies named 5D4-C2 and 8G10-H2. A significant reduction of antibody binding was detected by enzyme-linked immunosorbent assay (ELISA) and western blot analysis in the Lys142-type protein. This reduction of 8G10-H2 binding was more significant, with the disappearance of a signal in the proteins expressed by recombinant mycobacteria in western blot analysis. In addition, epitope mapping analysis of the recombinant proteins showed a linear epitope by 5D4-C2 and a discontinuous epitope by 8G10-H2. The antibody recognizing the conformational epitope detected only mycobacterial Asn142-type recombinant protein. Our results suggest that a single amino acid substitution of Rv0679c has potency for antigenic change in Beijing genotype strains. PMID:27190237

  3. Characterization of Mycobacterium tuberculosis EsxA Membrane Insertion

    PubMed Central

    Ma, Yue; Keil, Verena; Sun, Jianjun

    2015-01-01

    EsxA (ESAT-6), an important virulence factor of Mycobacterium tuberculosis, plays an essential role in phagosome rupture and bacterial cytosolic translocation within host macrophages. Our previous study showed that EsxA exhibits a unique membrane-interacting activity that is not found in its ortholog from nonpathogenic Mycobacterium smegmatis. However, the molecular mechanism of EsxA membrane insertion remains unknown. In this study, we generated truncated EsxA proteins with deletions of the N- and/or C-terminal flexible arm. Using a fluorescence-based liposome leakage assay, we found that both the N- and C-terminal arms were required for membrane disruption. Moreover, we found that, upon acidification, EsxA converted into a more organized structure with increased α-helical content, which was evidenced by CD analysis and intrinsic tryptophan fluorescence. Finally, using an environmentally sensitive fluorescent dye, we obtained direct evidence that the central helix-turn-helix motif of EsxA inserted into the membranes and formed a membrane-spanning pore. A model of EsxA membrane insertion is proposed and discussed. PMID:25645924

  4. STAT3 Represses Nitric Oxide Synthesis in Human Macrophages upon Mycobacterium tuberculosis Infection

    PubMed Central

    Queval, Christophe J.; Song, Ok-Ryul; Deboosère, Nathalie; Delorme, Vincent; Debrie, Anne-Sophie; Iantomasi, Raffaella; Veyron-Churlet, Romain; Jouny, Samuel; Redhage, Keely; Deloison, Gaspard; Baulard, Alain; Chamaillard, Mathias; Locht, Camille; Brodin, Priscille

    2016-01-01

    Mycobacterium tuberculosis is a successful intracellular pathogen. Numerous host innate immune responses signaling pathways are induced upon mycobacterium invasion, however their impact on M. tuberculosis replication is not fully understood. Here we reinvestigate the role of STAT3 specifically inside human macrophages shortly after M. tuberculosis uptake. We first show that STAT3 activation is mediated by IL-10 and occurs in M. tuberculosis infected cells as well as in bystander non-colonized cells. STAT3 activation results in the inhibition of IL-6, TNF-α, IFN-γ and MIP-1β. We further demonstrate that STAT3 represses iNOS expression and NO synthesis. Accordingly, the inhibition of STAT3 is detrimental for M. tuberculosis intracellular replication. Our study thus points out STAT3 as a key host factor for M. tuberculosis intracellular establishment in the early stages of macrophage infection. PMID:27384401

  5. Genetic diversity of Mycobacterium tuberculosis isolated from tuberculosis patients in the Serengeti ecosystem in Tanzania

    PubMed Central

    Mbugi, Erasto V.; Katale, Bugwesa Z.; Siame, Keith K.; Keyyu, Julius D.; Kendall, Sharon L.; Dockrell, Hazel M.; Streicher, Elizabeth M.; Michel, Anita L.; Rweyemamu, Mark M.; Warren, Robin M.; Matee, Mecky I.; van Helden, Paul D.

    2015-01-01

    Summary This study was part of a larger cross-sectional survey that was evaluating tuberculosis (TB) infection in humans, livestock and wildlife in the Serengeti ecosystem in Tanzania. The study aimed at evaluating the genetic diversity of Mycobacterium tuberculosis isolates from TB patients attending health facilities in the Serengeti ecosystem. DNA was extracted from 214 sputum cultures obtained from consecutively enrolled newly diagnosed untreated TB patients aged ≥18 years. Spacer oligonucleotide typing (spoligotyping) and Mycobacterium Interspersed Repetitive Units and Variable Number Tandem Repeat (MIRU-VNTR) were used to genotype M. tuberculosis to establish the circulating lineages. Of the214 M. tuberculosis isolates genotyped, 55 (25.7%) belonged to the Central Asian (CAS) family, 52 (24.3%) were T family (an ill-defined family), 38 (17.8%) belonged to the Latin American Mediterranean (LAM) family, 25 (11.7%) to the East-African Indian (EAI) family, 25 (11.7%) comprised of different unassigned (‘Serengeti’) strain families, while 8 (3.7%) belonged to the Beijing family. A minority group that included Haarlem, X, U and S altogether accounted for 11 (5.2%) of all genotypes. MIRU-VNTR typing produced diverse patterns within and between families indicative of unlinked transmission chains. We conclude that, in the Serengeti ecosystem only a few successful families predominate namely CAS, T, LAM and EAI families. Other types found in lower prevalence are Beijing, Haarlem, X, S and MANU. The Haarlem, EAI_Somalia, LAM3 and S/convergent and X2 subfamilies found in this study were not reported in previous studies in Tanzania. PMID:25522841

  6. The mtp40 gene is not present in all strains of Mycobacterium tuberculosis.

    PubMed Central

    Weil, A; Plikaytis, B B; Butler, W R; Woodley, C L; Shinnick, T M

    1996-01-01

    A multiple PCR-based assay that targets IS6110 and the mtp40 gene was evaluated for the rapid differentiation of Mycobacterium bovis and M. tuberculosis, two of the causative agents of tuberculosis. The IS6110 target is present in both species, whereas the mtp40 gene was thought to be specific for M.tuberculosis (P.Del Portillo, L.A. Murillo, and M.E. Patarroyo, J. Clin. Microbiol. 29:2163-2168, 1991). However, the mtp-40 gene is not present in all M. tuberculosis strains and, hence, is not useful for differentiating M.tuberculosis and M.bovis. PMID:8862608

  7. Transcriptional Adaptation of Drug-tolerant Mycobacterium tuberculosis During Treatment of Human Tuberculosis

    PubMed Central

    Walter, Nicholas D.; Dolganov, Gregory M.; Garcia, Benjamin J.; Worodria, William; Andama, Alfred; Musisi, Emmanuel; Ayakaka, Irene; Van, Tran T.; Voskuil, Martin I.; de Jong, Bouke C.; Davidson, Rebecca M.; Fingerlin, Tasha E.; Kechris, Katerina; Palmer, Claire; Nahid, Payam; Daley, Charles L.; Geraci, Mark; Huang, Laurence; Cattamanchi, Adithya; Strong, Michael; Schoolnik, Gary K.; Davis, John Lucian

    2015-01-01

    Background. Treatment initiation rapidly kills most drug-susceptible Mycobacterium tuberculosis, but a bacterial subpopulation tolerates prolonged drug exposure. We evaluated drug-tolerant bacilli in human sputum by comparing messenger RNA (mRNA) expression of drug-tolerant bacilli that survive the early bactericidal phase with treatment-naive bacilli. Methods. M. tuberculosis gene expression was quantified via reverse-transcription polymerase chain reaction in serial sputa from 17 Ugandans treated for drug-susceptible pulmonary tuberculosis. Results. Within 4 days, bacterial mRNA abundance declined >98%, indicating rapid killing. Thereafter, the rate of decline slowed >94%, indicating drug tolerance. After 14 days, 16S ribosomal RNA transcripts/genome declined 96%, indicating slow growth. Drug-tolerant bacilli displayed marked downregulation of genes associated with growth, metabolism, and lipid synthesis and upregulation in stress responses and key regulatory categories—including stress-associated sigma factors, transcription factors, and toxin-antitoxin genes. Drug efflux pumps were upregulated. The isoniazid stress signature was induced by initial drug exposure, then disappeared after 4 days. Conclusions. Transcriptional patterns suggest that drug-tolerant bacilli in sputum are in a slow-growing, metabolically and synthetically downregulated state. Absence of the isoniazid stress signature in drug-tolerant bacilli indicates that physiological state influences drug responsiveness in vivo. These results identify novel drug targets that should aid in development of novel shorter tuberculosis treatment regimens. PMID:25762787

  8. SInCRe—structural interactome computational resource for Mycobacterium tuberculosis

    PubMed Central

    Metri, Rahul; Hariharaputran, Sridhar; Ramakrishnan, Gayatri; Anand, Praveen; Raghavender, Upadhyayula S.; Ochoa-Montaño, Bernardo; Higueruelo, Alicia P.; Sowdhamini, Ramanathan; Chandra, Nagasuma R.; Blundell, Tom L.; Srinivasan, Narayanaswamy

    2015-01-01

    We have developed an integrated database for Mycobacterium tuberculosis H37Rv (Mtb) that collates information on protein sequences, domain assignments, functional annotation and 3D structural information along with protein–protein and protein–small molecule interactions. SInCRe (Structural Interactome Computational Resource) is developed out of CamBan (Cambridge and Bangalore) collaboration. The motivation for development of this database is to provide an integrated platform to allow easily access and interpretation of data and results obtained by all the groups in CamBan in the field of Mtb informatics. In-house algorithms and databases developed independently by various academic groups in CamBan are used to generate Mtb-specific datasets and are integrated in this database to provide a structural dimension to studies on tuberculosis. The SInCRe database readily provides information on identification of functional domains, genome-scale modelling of structures of Mtb proteins and characterization of the small-molecule binding sites within Mtb. The resource also provides structure-based function annotation, information on small-molecule binders including FDA (Food and Drug Administration)-approved drugs, protein–protein interactions (PPIs) and natural compounds that bind to pathogen proteins potentially and result in weakening or elimination of host–pathogen protein–protein interactions. Together they provide prerequisites for identification of off-target binding. Database URL: http://proline.biochem.iisc.ernet.in/sincre PMID:26130660

  9. SInCRe-structural interactome computational resource for Mycobacterium tuberculosis.

    PubMed

    Metri, Rahul; Hariharaputran, Sridhar; Ramakrishnan, Gayatri; Anand, Praveen; Raghavender, Upadhyayula S; Ochoa-Montaño, Bernardo; Higueruelo, Alicia P; Sowdhamini, Ramanathan; Chandra, Nagasuma R; Blundell, Tom L; Srinivasan, Narayanaswamy

    2015-01-01

    We have developed an integrated database for Mycobacterium tuberculosis H37Rv (Mtb) that collates information on protein sequences, domain assignments, functional annotation and 3D structural information along with protein-protein and protein-small molecule interactions. SInCRe (Structural Interactome Computational Resource) is developed out of CamBan (Cambridge and Bangalore) collaboration. The motivation for development of this database is to provide an integrated platform to allow easily access and interpretation of data and results obtained by all the groups in CamBan in the field of Mtb informatics. In-house algorithms and databases developed independently by various academic groups in CamBan are used to generate Mtb-specific datasets and are integrated in this database to provide a structural dimension to studies on tuberculosis. The SInCRe database readily provides information on identification of functional domains, genome-scale modelling of structures of Mtb proteins and characterization of the small-molecule binding sites within Mtb. The resource also provides structure-based function annotation, information on small-molecule binders including FDA (Food and Drug Administration)-approved drugs, protein-protein interactions (PPIs) and natural compounds that bind to pathogen proteins potentially and result in weakening or elimination of host-pathogen protein-protein interactions. Together they provide prerequisites for identification of off-target binding. PMID:26130660

  10. The mechanism of redox sensing in Mycobacterium tuberculosis.

    PubMed

    Bhat, Shabir Ahmad; Singh, Nisha; Trivedi, Abhishek; Kansal, Pallavi; Gupta, Pawan; Kumar, Ashwani

    2012-10-15

    Tuberculosis epidemics have defied constraint despite the availability of effective treatment for the past half-century. Mycobacterium tuberculosis, the causative agent of TB, is continually exposed to a number of redox stressors during its pathogenic cycle. The mechanisms used by Mtb to sense redox stress and to maintain redox homeostasis are central to the success of Mtb as a pathogen. Careful analysis of the Mtb genome has revealed that Mtb lacks classical redox sensors such as FNR, FixL, and OxyR. Recent studies, however, have established that Mtb is equipped with various sophisticated redox sensors that can detect diverse types of redox stress, including hypoxia, nitric oxide, carbon monoxide, and the intracellular redox environment. Some of these sensors, such as heme-based DosS and DosT, are unique to mycobacteria, whereas others, such as the WhiB proteins and anti-σ factor RsrA, are unique to actinobacteria. This article provides a comprehensive review of the literature on these redox-sensory modules in the context of TB pathogenesis. PMID:22921590

  11. Amperometric immunosensor for rapid detection of Mycobacterium tuberculosis

    NASA Astrophysics Data System (ADS)

    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.

  12. Tuberculosis Caused by Mycobacterium africanum, United States, 2004–2013

    PubMed Central

    Bloss, Emily; Heilig, Charles M.; Click, Eleanor S.

    2016-01-01

    Mycobacterium africanum is endemic to West Africa and causes tuberculosis (TB). We reviewed reported cases of TB in the United States during 2004–2013 that had lineage assigned by genotype (spoligotype and mycobacterial interspersed repetitive unit variable number tandem repeats). M. africanum caused 315 (0.4%) of 73,290 TB cases with lineage assigned by genotype. TB caused by M. africanum was associated more with persons from West Africa (adjusted odds ratio [aOR] 253.8, 95% CI 59.9–1,076.1) and US-born black persons (aOR 5.7, 95% CI 1.2–25.9) than with US-born white persons. TB caused by M. africanum did not show differences in clinical characteristics when compared with TB caused by M. tuberculosis. Clustered cases defined as >2 cases in a county with identical 24-locus mycobacterial interspersed repetitive unit genotypes, were less likely for M. africanum (aOR 0.1, 95% CI 0.1–0.4), which suggests that M. africanum is not commonly transmitted in the United States. PMID:26886258

  13. The Mycobacterium tuberculosis Drugome and Its Polypharmacological Implications

    PubMed Central

    Kinnings, Sarah L.; Xie, Li; Fung, Kingston H.; Jackson, Richard M.; Xie, Lei; Bourne, Philip E.

    2010-01-01

    We report a computational approach that integrates structural bioinformatics, molecular modelling and systems biology to construct a drug-target network on a structural proteome-wide scale. The approach has been applied to the genome of Mycobacterium tuberculosis (M.tb), the causative agent of one of today's most widely spread infectious diseases. The resulting drug-target interaction network for all structurally characterized approved drugs bound to putative M.tb receptors, we refer to as the ‘TB-drugome’. The TB-drugome reveals that approximately one-third of the drugs examined have the potential to be repositioned to treat tuberculosis and that many currently unexploited M.tb receptors may be chemically druggable and could serve as novel anti-tubercular targets. Furthermore, a detailed analysis of the TB-drugome has shed new light on the controversial issues surrounding drug-target networks [1]–[3]. Indeed, our results support the idea that drug-target networks are inherently modular, and further that any observed randomness is mainly caused by biased target coverage. The TB-drugome (http://funsite.sdsc.edu/drugome/TB) has the potential to be a valuable resource in the development of safe and efficient anti-tubercular drugs. More generally the methodology may be applied to other pathogens of interest with results improving as more of their structural proteomes are determined through the continued efforts of structural biology/genomics. PMID:21079673

  14. Meropenem inhibits D,D-carboxypeptidase activity in Mycobacterium tuberculosis.

    PubMed

    Kumar, Pradeep; Arora, Kriti; Lloyd, John R; Lee, Ill Y; Nair, Vinod; Fischer, Elizabeth; Boshoff, Helena I M; Barry, Clifton E

    2012-10-01

    Carbapenems such as meropenem are being investigated for their potential therapeutic utility against highly drug-resistant tuberculosis. These β-lactams target the transpeptidases that introduce interpeptide cross-links into bacterial peptidoglycan thereby controlling rigidity of the bacterial envelope. Treatment of Mycobacterium tuberculosis (Mtb) with the β-lactamase inhibitor clavulanate together with meropenem resulted in rapid, polar, cell lysis releasing cytoplasmic contents. In Mtb it has been previously demonstrated that 3-3 cross-linkages [involving two diaminopimelate (DAP) molecules] predominate over 4-3 cross-linkages (involving one DAP and one D-alanine) in stationary-phase cells. We purified and analysed peptidoglycan from Mtb and found that 3-3 cross-linkages predominate throughout all growth phases and the ratio of 4-3/3-3 linkages does not vary significantly under any growth condition. Meropenem treatment was accompanied by a dramatic accumulation of unlinked pentapeptide stems with no change in the tetrapeptide pools, suggesting that meropenem inhibits both a D,D-carboxypeptidase and an L,D-transpeptidase. We purified a candidate D,D-carboxypeptidase DacB2 and showed that meropenem indeed directly inhibits this enzyme by forming a stable adduct at the enzyme active site. These results suggest that the rapid lysis of meropenem-treated cells is the result of synergistically inhibiting the transpeptidases that introduce 3,3-cross-links while simultaneously limiting the pool of available substrates available for cross-linking. PMID:22906310

  15. Synthesis and evaluation of new 2-aminothiophenes against Mycobacterium tuberculosis.

    PubMed

    Thanna, Sandeep; Knudson, Susan E; Grzegorzewicz, Anna; Kapil, Sunayana; Goins, Christopher M; Ronning, Donald R; Jackson, Mary; Slayden, Richard A; Sucheck, Steven J

    2016-07-01

    Tuberculosis (TB) and its drug resistant forms kills more people than any other infectious disease. This fact emphasizes the need to identify new drugs to treat TB. 2-Aminothiophenes (2AT) have been reported to inhibit Pks13, a validated anti-TB drug target. We synthesized a library of 42 2AT compounds. Among these, compound 33 showed remarkable potency against Mycobacterium tuberculosis (Mtb) H37RV (MIC = 0.23 μM) and showed an impressive potency (MIC = 0.20-0.44 μM) against Mtb strains resistant to isoniazid, rifampicin and fluoroquinolones. The site of action for the compound 33 is presumed to be Pks13 or an earlier enzyme in the mycolic acid biosynthetic pathway. This inference is based on structural similarity of the compound 33 with known Pks13 inhibitors, which is corroborated by mycolic acid biosynthesis studies showing that the compound strongly inhibits the biosynthesis of all forms of mycolic acid in Mtb. In summary, these studies suggest 33 represents a promising anti-TB lead that exhibits activity well below toxicity to human monocytic cells. PMID:27251120

  16. Spoligotyping for molecular epidemiology of the Mycobacterium tuberculosis complex.

    PubMed

    Driscoll, Jeffrey R

    2009-01-01

    Spacer oligonucleotide typing, or spoligotyping, is a rapid, polymerase chain reaction (PCR)-based method for genotyping strains of the Mycobacterium tuberculosis complex (MTB). Spoligotyping data can be represented in absolute terms (digitally), and the results can be readily shared among laboratories, thereby enabling the creation of large international databases. Since the spoligotype assay was standardized more than 10 yr ago, tens of thousands of isolates have been analyzed, giving a global picture of MTB strain diversity. The method is highly reproducible and has been developed into a high-throughput assay for large molecular epidemiology projects. In the United States, spoligotyping is employed on nearly all newly identified culture-positive cases of tuberculosis as part of a national genotyping program. The strengths of this method include its low cost, its digital data results, the good correlation of its results with other genetics markers, its fair level of overall differentiation of strains, its high-throughput capacity, and its ability to provide species information. However, the method's weaknesses include the inability of spoligotyping to differentiate well within large strain families such as the Beijing family, the potential for convergent evolution of patterns, the limited success in improving the assay through expansion, and the difficulty in obtaining the specialized membranes and instrumentation. PMID:19521871

  17. Cloning, expression and characterization of Mycobacterium tuberculosis sirR.

    PubMed

    Namwat, Wises; Somnate, Baramee; Maleehual, Dutsadee; Chareonsudjai, Sorujsiri; Lulitanond, Viraphong; Faksri, Kiatichai

    2014-05-01

    Identification of new drug targets is important for the improvement of chemotherapy for tuberculosis treatment. Metal-associated gene products are candidates for novel drug development. A Mycobacterium tuberculosis (MTB) sirR-encoded protein has been proposed, but the function of MTB SirR has not yet been elucidated. Bioinformatics analysis revealed that MTB SirR contains iron binding domains with 34%-59% similarity to previously described metal-dependent gene regulators and that the gene lies in Rv2787-sirR operon. RT-PCR revealed that the Rv2787-sirR operon is transcribed a single bicistronic mRNA. Heterologous expression, purification and characterization of recombinant MTB His-tagged SirR demonstrated a 25 kDa protein (by SDS-PAGE and immunoblotting) that exists as a dimer (native PAGE). Based on electrophoretic mobility shift assay, MTB SirR bound a cis element located at -85 bp upstream of its operon. As Rv2787-sirR operon is unique only to MTB (and M. bovis), further studies on its regulation and other functions of the encoded proteins should provide leads towards the discovery of novel anti-TB drugs. PMID:24974654

  18. 2-Phenylindole and Arylsulphonamide: Novel Scaffolds Bactericidal against Mycobacterium tuberculosis

    PubMed Central

    2014-01-01

    A cellular activity-based screen on Mycobacterium tuberculosis (Mtb) H37Rv using a focused library from the AstraZeneca corporate collection led to the identification of 2-phenylindoles and arylsulphonamides, novel antimycobacterial scaffolds. Both the series were bactericidal in vitro and in an intracellular macrophage infection model, active against drug sensitive and drug resistant Mtb clinical isolates, and specific to mycobacteria. The scaffolds showed promising structure–activity relationships; compounds with submicromolar cellular potency were identified during the hit to lead exploration. Furthermore, compounds from both scaffolds were tested for inhibition of known target enzymes or pathways of antimycobacterial drugs including InhA, RNA polymerase, DprE1, topoisomerases, protein synthesis, and oxidative-phosphorylation. Compounds did not inhibit any of the targets suggesting the potential of a possible novel mode of action(s). Hence, both scaffolds provide the opportunity to be developed further as leads and tool compounds to uncover novel mechanisms for tuberculosis drug discovery. PMID:25221657

  19. Succinate dehydrogenase is the regulator of respiration in Mycobacterium tuberculosis.

    PubMed

    Hartman, Travis; Weinrick, Brian; Vilchèze, Catherine; Berney, Michael; Tufariello, Joanne; Cook, Gregory M; Jacobs, William R

    2014-11-01

    In chronic infection, Mycobacterium tuberculosis bacilli are thought to enter a metabolic program that provides sufficient energy for maintenance of the protonmotive force, but is insufficient to meet the demands of cellular growth. We sought to understand this metabolic downshift genetically by targeting succinate dehydrogenase, the enzyme which couples the growth processes controlled by the TCA cycle with the energy production resulting from the electron transport chain. M. tuberculosis contains two operons which are predicted to encode succinate dehydrogenase enzymes (sdh-1 and sdh-2); we found that deletion of Sdh1 contributes to an inability to survive long term stationary phase. Stable isotope labeling and mass spectrometry revealed that Sdh1 functions as a succinate dehydrogenase during aerobic growth, and that Sdh2 is dispensable for this catalysis, but partially overlapping activities ensure that the loss of one enzyme can incompletely compensate for loss of the other. Deletion of Sdh1 disturbs the rate of respiration via the mycobacterial electron transport chain, resulting in an increased proportion of reduced electron carrier (menaquinol) which leads to increased oxygen consumption. The loss of respiratory control leads to an inability to recover from stationary phase. We propose a model in which succinate dehydrogenase is a governor of cellular respiration in the adaptation to low oxygen environments. PMID:25412183

  20. Clinical value of whole-genome sequencing of Mycobacterium tuberculosis.

    PubMed

    Takiff, Howard E; Feo, Oscar

    2015-09-01

    Whole-genome sequencing (WGS) is now common as a result of new technologies that can rapidly sequence a complete bacterial genome for US$500 or less. Many studies have addressed questions about tuberculosis with WGS, and knowing the sequence of the entire genome, rather than only a few fragments, has greatly increased the precision of molecular epidemiology and contact tracing. Additionally, topics such as the mutation rate, drug resistance, the target of new drugs, and the phylogeny and evolution of the Mycobacterium tuberculosis complex bacteria have been elucidated by WGS. Nonetheless, WGS has not explained differences in transmissibility between strains, or why some strains are more virulent than others or more prone to development of multidrug resistance. With advances in technology, WGS of clinical specimens could become routine in high-income countries; however, its relevance will probably depend on easy to use software to efficiently process the sequences produced and accessible genomic databases that can be mined in future studies. PMID:26277037

  1. Sulfolipid-1 biosynthesis restricts Mycobacterium tuberculosis growth in human macrophages.

    PubMed

    Gilmore, Sarah A; Schelle, Michael W; Holsclaw, Cynthia M; Leigh, Clifton D; Jain, Madhulika; Cox, Jeffery S; Leary, Julie A; Bertozzi, Carolyn R

    2012-05-18

    Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, is a highly evolved human pathogen characterized by its formidable cell wall. Many unique lipids and glycolipids from the Mtb cell wall are thought to be virulence factors that mediate host-pathogen interactions. An intriguing example is Sulfolipid-1 (SL-1), a sulfated glycolipid that has been implicated in Mtb pathogenesis, although no direct role for SL-1 in virulence has been established. Previously, we described the biochemical activity of the sulfotransferase Stf0 that initiates SL-1 biosynthesis. Here we show that a stf0-deletion mutant exhibits augmented survival in human but not murine macrophages, suggesting that SL-1 negatively regulates the intracellular growth of Mtb in a species-specific manner. Furthermore, we demonstrate that SL-1 plays a role in mediating the susceptibility of Mtb to a human cationic antimicrobial peptide in vitro, despite being dispensable for maintaining overall cell envelope integrity. Thus, we hypothesize that the species-specific phenotype of the stf0 mutant is reflective of differences in antimycobacterial effector mechanisms of macrophages. PMID:22360425

  2. Genetic markers, genotyping methods & next generation sequencing in Mycobacterium tuberculosis

    PubMed Central

    Desikan, Srinidhi; Narayanan, Sujatha

    2015-01-01

    Molecular epidemiology (ME) is one of the main areas in tuberculosis research which is widely used to study the transmission epidemics and outbreaks of tubercle bacilli. It exploits the presence of various polymorphisms in the genome of the bacteria that can be widely used as genetic markers. Many DNA typing methods apply these genetic markers to differentiate various strains and to study the evolutionary relationships between them. The three widely used genotyping tools to differentiate Mycobacterium tuberculosis strains are IS6110 restriction fragment length polymorphism (RFLP), spacer oligotyping (Spoligotyping), and mycobacterial interspersed repeat units - variable number of tandem repeats (MIRU-VNTR). A new prospect towards ME was introduced with the development of whole genome sequencing (WGS) and the next generation sequencing (NGS) methods, where the entire genome is sequenced that not only helps in pointing out minute differences between the various sequences but also saves time and the cost. NGS is also found to be useful in identifying single nucleotide polymorphisms (SNPs), comparative genomics and also various aspects about transmission dynamics. These techniques enable the identification of mycobacterial strains and also facilitate the study of their phylogenetic and evolutionary traits. PMID:26205019

  3. Bioluminescence for Assessing Drug Potency against Nonreplicating Mycobacterium tuberculosis

    PubMed Central

    Vocat, Anthony; Hartkoorn, Ruben C.; Lechartier, Benoit; Zhang, Ming; Dhar, Neeraj

    2015-01-01

    Targeting dormant Mycobacterium tuberculosis represents a challenge to antituberculosis drug discovery programs. We previously reported and validated the use of the streptomycin (STR)-dependent M. tuberculosis 18b strain as a tool for assessing drug potency against nonreplicating bacteria both in vitro and in vivo. In this study, we generated a luminescent 18b strain, named 18b-Lux, by transforming the bacteria with a vector expressing the luxCDABE operon from Photorhabdus luminescens. Luciferase expression was demonstrated under replicating conditions, and, more importantly, luminescence levels significantly above background were detected following STR removal. The sensitivity of STR-starved 18b-Lux to approved and candidate antituberculosis therapeutic agents was evaluated by means of a luciferase assay in a 96-well format. Results mirrored the data obtained with the standard resazurin reduction microplate assay, and the luminescence readout allowed time course assessments of drug efficacy in vitro. Specifically, we proved that bedaquiline, the rifamycins, and sutezolid displayed time-dependent activity against dormant bacteria, while pyrazinamide and SQ109 showed bactericidal effects at the highest concentrations tested. Overall, we established the optimal conditions for an inexpensive, simple, and very sensitive assay with great potential for future applications. PMID:25896710

  4. Challenging Mycobacterium tuberculosis dormancy mechanisms and their immunodiagnostic potential.

    PubMed

    Chaves, Alexandre Silva; Rodrigues, Michele Fernandes; Mattos, Ana Márcia Menezes; Teixeira, Henrique Couto

    2015-01-01

    Mycobacterium tuberculosis is the etiologic agent of tuberculosis, one of the world's greatest cause of morbidity and mortality due to infectious disease. Many evolutionary mechanisms have contributed to its high level of adaptation as a host pathogen. Prior to become dormant, a group of about 50 genes related to metabolic changes are transcribed by the DosR regulon, one of the most complex and important systems of host-pathogen interaction. This genetic mechanism allows the mycobacteria to persist during long time periods, establishing the so-called latent infection. Even in the presence of a competent immune response, the host cannot eliminate the pathogen, only managing to keep it surrounded by an unfavorable microenvironment for its growth. However, conditions such as immunosuppression may reestablish optimal conditions for bacterial growth, culminating in the onset of active disease. The interactions between the pathogen and its host are still not completely elucidated. Nonetheless, many studies are being carried out in order to clarify this complex relationship, thus creating new possibilities for patient approach and laboratory screening. PMID:26358744

  5. Biochemical Characterization of Uracil Phosphoribosyltransferase from Mycobacterium tuberculosis

    PubMed Central

    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

  6. Bioluminescence for assessing drug potency against nonreplicating Mycobacterium tuberculosis.

    PubMed

    Vocat, Anthony; Hartkoorn, Ruben C; Lechartier, Benoit; Zhang, Ming; Dhar, Neeraj; Cole, Stewart T; Sala, Claudia

    2015-07-01

    Targeting dormant Mycobacterium tuberculosis represents a challenge to antituberculosis drug discovery programs. We previously reported and validated the use of the streptomycin (STR)-dependent M. tuberculosis 18b strain as a tool for assessing drug potency against nonreplicating bacteria both in vitro and in vivo. In this study, we generated a luminescent 18b strain, named 18b-Lux, by transforming the bacteria with a vector expressing the luxCDABE operon from Photorhabdus luminescens. Luciferase expression was demonstrated under replicating conditions, and, more importantly, luminescence levels significantly above background were detected following STR removal. The sensitivity of STR-starved 18b-Lux to approved and candidate antituberculosis therapeutic agents was evaluated by means of a luciferase assay in a 96-well format. Results mirrored the data obtained with the standard resazurin reduction microplate assay, and the luminescence readout allowed time course assessments of drug efficacy in vitro. Specifically, we proved that bedaquiline, the rifamycins, and sutezolid displayed time-dependent activity against dormant bacteria, while pyrazinamide and SQ109 showed bactericidal effects at the highest concentrations tested. Overall, we established the optimal conditions for an inexpensive, simple, and very sensitive assay with great potential for future applications. PMID:25896710

  7. Evaluation of an Immunochromatographic Assay Kit for Rapid Identification of Mycobacterium tuberculosis Complex in Clinical Isolates▿

    PubMed Central

    Park, Mi Young; Kim, Young Jin; Hwang, Sang Hyun; Kim, Hyoung Hoi; Lee, Eun Yup; Jeong, Seok Hoon; Chang, Chulhun L.

    2009-01-01

    We evaluated a new immunochromatographic assay (ICA) using mouse monoclonal anti-MPT64 antibody for rapid discrimination between Mycobacterium tuberculosis and nontuberculous mycobacteria in clinical isolates. A study with mycobacteria and other organisms showed excellent sensitivity (≅99%) and specificity (100%) and an appropriate detection limit (105 CFU/ml) when tested with M. tuberculosis H37Rv. This ICA can simplify the identification of M. tuberculosis in clinical laboratories. PMID:19052177

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

    PubMed Central

    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

  9. Mycobacterium africanum—Review of an Important Cause of Human Tuberculosis in West Africa

    PubMed Central

    de Jong, Bouke C.; Antonio, Martin; Gagneux, Sebastien

    2010-01-01

    Mycobacterium africanum consists of two phylogenetically distinct lineages within the Mycobacterium tuberculosis complex, known as M. africanum West African 1 and M. africanum West African 2. These lineages are restricted to West Africa, where they cause up to half of human pulmonary tuberculosis. In this review we discuss the definition of M. africanum, describe the prevalence and restricted geographical distribution of M. africanum West African 1 and 2, review the occurrence of M. africanum in animals, and summarize the phenotypic differences described thus far between M. africanum and M. tuberculosis sensu stricto. PMID:20927191

  10. Immunogenicity and protective efficacy of novel Mycobacterium tuberculosis antigens.

    PubMed

    Derrick, Steven C; Yabe, Idalia M; Yang, Amy; Kolibab, Kristopher; Hollingsworth, Brynn; Kurtz, Sherry L; Morris, Sheldon

    2013-09-23

    With tuberculosis continuing to be a major cause of global morbidity and mortality, a new vaccine is urgently needed. Tuberculosis subunit vaccines have been shown to induce robust immune responses in humans and are a potentially safer alternative to BCG for use in HIV-endemic areas. In this study, we investigated the protective efficacy of 16 different novel Mycobacterium tuberculosis antigens using an aerogenic mouse model of pulmonary tuberculosis. These antigens were tested as subunit vaccines formulated in dimethyl dioctadecyl ammonium bromide (DDA) - D(+) with trehalose 6,6 dibenenate (TDB) (DDA/TDB) adjuvant administered alone as monovalent vaccines or in combination. Six of these antigens (Rv1626, Rv1735, Rv1789, Rv2032, Rv2220, and Rv3478) were shown to consistently and significantly reduce bacterial burdens in the lungs of mice relative to nonvaccinated controls. Three of these six (Rv1789, Rv2220, and Rv3478) induced levels of protective immunity that were essentially equivalent to protection induced by the highly immunogenic antigen 85B (>0.5 log₁₀CFU reduction in the lungs relative to naïve mice). Importantly, when these three antigens were combined, protection essentially equivalent to that mediated by BCG was observed. When either Rv1626 or Rv2032 were combined with the highly protective E6-85 fusion protein (antigen 85B fused to ESAT-6), the protection observed was equivalent to BCG-induced protection at one and three months post-aerosol infection and was significantly greater than the protection observed when E6-85 was administered alone at 3 months post-infection. Using multiparameter flow cytometry, monofunctional IFNγ CD4T cells and different multifunctional CD4T cell subsets capable of secreting multiple cytokines (IFNγ, TNFα and/or IL-2) were shown to be induced by the three most protective antigens with splenocyte CD4T cell frequencies significantly greater than observed in naïve controls. The identification of these highly

  11. Construction, molecular modeling, and simulation of Mycobacterium tuberculosis cell walls.

    PubMed

    Hong, Xuan; Hopfinger, A J

    2004-01-01

    The mycobacterial cell wall is extraordinarily thick and tight consisting mainly of (1). long chain fatty acids, the mycolic acids, and (2). a unique polysaccharide, arabinogalactan (AG). These two chemical constituents are covalently linked through ester bonds. Minnikin (The Biology of the Mycobacteria; Academic: London, 1982) proposed that the mycobacterial cell wall is composed of an asymmetric lipid bilayer. The inner leaflet of the cell wall contains mycolic acids covalently linked to AG. This inner leaflet is believed to have the lowest permeability to organic compounds of the overall cell wall. Conformational search and molecular dynamics simulation were used to explore the conformational profile of AG and the conformations and structural organization of the mycolic acid-AG complex, and overall, an inner leaflet molecular model of the cell wall was constructed. The terminal arabinose residues of AG that serve as linkers between AG and mycolic acids were found to exist in four major chemical configurations. The mycolate hydrocarbon chains were determined to be tightly packed and perpendicular to the "plane" formed by the oxygen atoms of the 5-hydroxyl groups of the terminal arabinose residues. For Mycobacterium tuberculosis, the average packing distance between mycolic acids is estimated to be approximately 7.3 A. Thus, Minnikin's model is supported by this computational study. Overall, this modeling and simulation approach provides a way to probe the mechanism of low permeability of the cell wall and the intrinsic drug resistance of M. tuberculosis. In addition, monolayer models were built for both dipalmitoylphosphatidylethanolamine and dimyristoylphosphatidylcholine, two common phospholipids in bacterial and animal membranes, respectively. Structural comparisons of these cell wall phospholipid membrane models were made to the M. tuberculosis cell wall model. PMID:15132700

  12. Structural and functional studies of phosphoenolpyruvate carboxykinase from Mycobacterium tuberculosis.

    PubMed

    Machová, Iva; Snášel, Jan; Dostál, Jiří; Brynda, Jiří; Fanfrlík, Jindřich; Singh, Mahavir; Tarábek, Ján; Vaněk, Ondřej; Bednárová, Lucie; Pichová, Iva

    2015-01-01

    Tuberculosis, the second leading infectious disease killer after HIV, remains a top public health priority. The causative agent of tuberculosis, Mycobacterium tuberculosis (Mtb), which can cause both acute and clinically latent infections, reprograms metabolism in response to the host niche. Phosphoenolpyruvate carboxykinase (Pck) is the enzyme at the center of the phosphoenolpyruvate-pyruvate-oxaloacetate node, which is involved in regulating the carbon flow distribution to catabolism, anabolism, or respiration in different states of Mtb infection. Under standard growth conditions, Mtb Pck is associated with gluconeogenesis and catalyzes the metal-dependent formation of phosphoenolpyruvate. In non-replicating Mtb, Pck can catalyze anaplerotic biosynthesis of oxaloacetate. Here, we present insights into the regulation of Mtb Pck activity by divalent cations. Through analysis of the X-ray structure of Pck-GDP and Pck-GDP-Mn2+ complexes, mutational analysis of the GDP binding site, and quantum mechanical (QM)-based analysis, we explored the structural determinants of efficient Mtb Pck catalysis. We demonstrate that Mtb Pck requires presence of Mn2+ and Mg2+ cations for efficient catalysis of gluconeogenic and anaplerotic reactions. The anaplerotic reaction, which preferably functions in reducing conditions that are characteristic for slowed or stopped Mtb replication, is also effectively activated by Fe2+ in the presence of Mn2+ or Mg2+ cations. In contrast, simultaneous presence of Fe2+ and Mn2+ or Mg2+ inhibits the gluconeogenic reaction. These results suggest that inorganic ions can contribute to regulation of central carbon metabolism by influencing the activity of Pck. Furthermore, the X-ray structure determination, biochemical characterization, and QM analysis of Pck mutants confirmed the important role of the Phe triad for proper binding of the GDP-Mn2+ complex in the nucleotide binding site and efficient catalysis of the anaplerotic reaction. PMID:25798914

  13. Portrait of a Pathogen: The Mycobacterium tuberculosis Proteome In Vivo

    PubMed Central

    Kruh, Nicole A.; Troudt, Jolynn; Izzo, Angelo; Prenni, Jessica; Dobos, Karen M.

    2010-01-01

    Background Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is a facultative intracellular pathogen that can persist within the host. The bacteria are thought to be in a state of reduced replication and metabolism as part of the chronic lung infection. Many in vitro studies have dissected the hypothesized environment within the infected lung, defining the bacterial response to pH, starvation and hypoxia. While these experiments have afforded great insight, the picture remains incomplete. The only way to study the combined effects of these environmental factors and the mycobacterial response is to study the bacterial response in vivo. Methodology/Principal Findings We used the guinea pig model of tuberculosis to examine the bacterial proteome during the early and chronic stages of disease. Lungs were harvested thirty and ninety days after aerosol challenge with Mtb, and analyzed by liquid chromatography-mass spectrometry. To date, in vivo proteomics of the tubercle bacillus has not been described and this work has generated the first large-scale shotgun proteomic data set, comprising over 500 unique protein identifications. Cell wall and cell wall processes, and intermediary metabolism and respiration were the two major functional classes of proteins represented in the infected lung. These classes of proteins displayed the greatest heterogeneity indicating important biological processes for establishment of a productive bacterial infection and its persistence. Proteins necessary for adaptation throughout infection, such as nitrate/nitrite reduction were found at both time points. The PE-PPE protein class, while not well characterized, represented the third most abundant category and showed the most consistent expression during the infection. Conclusions/Significance Cumulatively, the results of this work may provide the basis for rational drug design – identifying numerous Mtb proteins, from essential kinases to products involved in

  14. Micrococcin P1 - A bactericidal thiopeptide active against Mycobacterium tuberculosis.

    PubMed

    Degiacomi, Giulia; Personne, Yoann; Mondésert, Guillaume; Ge, Xueliang; Mandava, Chandra Sekhar; Hartkoorn, Ruben C; Boldrin, Francesca; Goel, Pavitra; Peisker, Kristin; Benjak, Andrej; Barrio, Maria Belén; Ventura, Marcello; Brown, Amanda C; Leblanc, Véronique; Bauer, Armin; Sanyal, Suparna; Cole, Stewart T; Lagrange, Sophie; Parish, Tanya; Manganelli, Riccardo

    2016-09-01

    The lack of proper treatment for serious infectious diseases due to the emergence of multidrug resistance reinforces the need for the discovery of novel antibiotics. This is particularly true for tuberculosis (TB) for which 3.7% of new cases and 20% of previously treated cases are estimated to be caused by multi-drug resistant strains. In addition, in the case of TB, which claimed 1.5 million lives in 2014, the treatment of the least complicated, drug sensitive cases is lengthy and disagreeable. Therefore, new drugs with novel targets are urgently needed to control resistant Mycobacterium tuberculosis strains. In this manuscript we report the characterization of the thiopeptide micrococcin P1 as an anti-tubercular agent. Our biochemical experiments show that this antibiotic inhibits the elongation step of protein synthesis in mycobacteria. We have further identified micrococcin resistant mutations in the ribosomal protein L11 (RplK); the mutations were located in the proline loop at the N-terminus. Reintroduction of the mutations into a clean genetic background, confirmed that they conferred resistance, while introduction of the wild type RplK allele into resistant strains re-established sensitivity. We also identified a mutation in the 23S rRNA gene. These data, in good agreement with previous structural studies suggest that also in M. tuberculosis micrococcin P1 functions by binding to the cleft between the 23S rRNA and the L11 protein loop, thus interfering with the binding of elongation factors Tu and G (EF-Tu and EF-G) and inhibiting protein translocation. PMID:27553416

  15. Structural and Functional Studies of Phosphoenolpyruvate Carboxykinase from Mycobacterium tuberculosis

    PubMed Central

    Machová, Iva; Snášel, Jan; Dostál, Jiří; Brynda, Jiří; Fanfrlík, Jindřich; Singh, Mahavir; Tarábek, Ján; Vaněk, Ondřej; Bednárová, Lucie; Pichová, Iva

    2015-01-01

    Tuberculosis, the second leading infectious disease killer after HIV, remains a top public health priority. The causative agent of tuberculosis, Mycobacterium tuberculosis (Mtb), which can cause both acute and clinically latent infections, reprograms metabolism in response to the host niche. Phosphoenolpyruvate carboxykinase (Pck) is the enzyme at the center of the phosphoenolpyruvate-pyruvate-oxaloacetate node, which is involved in regulating the carbon flow distribution to catabolism, anabolism, or respiration in different states of Mtb infection. Under standard growth conditions, Mtb Pck is associated with gluconeogenesis and catalyzes the metal-dependent formation of phosphoenolpyruvate. In non-replicating Mtb, Pck can catalyze anaplerotic biosynthesis of oxaloacetate. Here, we present insights into the regulation of Mtb Pck activity by divalent cations. Through analysis of the X-ray structure of Pck-GDP and Pck-GDP-Mn2+ complexes, mutational analysis of the GDP binding site, and quantum mechanical (QM)-based analysis, we explored the structural determinants of efficient Mtb Pck catalysis. We demonstrate that Mtb Pck requires presence of Mn2+ and Mg2+ cations for efficient catalysis of gluconeogenic and anaplerotic reactions. The anaplerotic reaction, which preferably functions in reducing conditions that are characteristic for slowed or stopped Mtb replication, is also effectively activated by Fe2+ in the presence of Mn2+ or Mg2+ cations. In contrast, simultaneous presence of Fe2+ and Mn2+ or Mg2+ inhibits the gluconeogenic reaction. These results suggest that inorganic ions can contribute to regulation of central carbon metabolism by influencing the activity of Pck. Furthermore, the X-ray structure determination, biochemical characterization, and QM analysis of Pck mutants confirmed the important role of the Phe triad for proper binding of the GDP-Mn2+ complex in the nucleotide binding site and efficient catalysis of the anaplerotic reaction. PMID:25798914

  16. Diagnostic value of antibody responses to multiple antigens from Mycobacterium tuberculosis in active and latent tuberculosis.

    PubMed

    Senoputra, Muhammad Andrian; Shiratori, Beata; Hasibuan, Fakhrial Mirwan; Koesoemadinata, Raspati Cundarani; Apriani, Lika; Ashino, Yugo; Ono, Kenji; Oda, Tetsuya; Matsumoto, Makoto; Suzuki, Yasuhiko; Alisjahbana, Bachti; Hattori, Toshio

    2015-11-01

    We investigated the antibody responses to 10 prospective Mycobacterium tuberculosis (MTB) antigens and evaluated their ability to discriminate between latent (LTBI) and active pulmonary tuberculosis (TB). Our results indicate that plasma levels of anti-α-crystallin (ACR), antilipoarabinomannan, anti-trehalose 6,6'-dimycolate, and anti-tubercular-glycolipid antigen antibodies were higher in patients with active TB, compared to those in the LTBI and control subjects. No differences in the antibodies were observed between the control and LTBI subjects. Antibodies against the glycolipid antigens could not distinguish between Mycobacterium avium complex (MAC)-negative TB patients and MAC-infected LTBI individuals. The most useful serological marker was antibodies to ACR, with MAC-negative TB patients having higher titers than those observed in MAC-positive LTBI and control subjects. Our data indicate that antibody to ACR is a promising target for the serological diagnosis of patients with active TB patients. When dealing with antiglycolipid antibodies, MAC coinfection should always be considered in serological studies. PMID:26307672

  17. Isolation of Mycobacterium kumamotonense from a patient with pulmonary infection and latent tuberculosis.

    PubMed

    Kontos, Fanourios; Mavromanolakis, Dimitrios Nikitas; Zande, Marina Chari; Gitti, Zoe Georgios

    2016-01-01

    Mycobacterium kumamotonense is a novel, slow-growing non-chromogenic nontuberculous mycobacterium, which belongs to Mycobacterium terrae complex. We report, for the first time in Greece, the isolation of M. kumamotonense from an immunocompetent patient with pulmonary infection and latent tuberculosis. M. kumamotonense was identified by sequencing analysis of 16S rDNA and 65-kDa heat shock protein genes while by commercial molecular assays it was misidentified as Mycobacterium celatum. Antibiotic susceptibility testing was performed by the reference broth microdilution method. The strain was susceptible to amikacin, clarithromycin, rifampin, ciprofloxacin, moxifloxacin, rifabutin, ethambutol and linezolid. PMID:27080783

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

    PubMed

    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

  19. Identification of gene targets against dormant phase Mycobacterium tuberculosis infections

    PubMed Central

    Murphy, Dennis J; Brown, James R

    2007-01-01

    Background Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), infects approximately 2 billion people worldwide and is the leading cause of mortality due to infectious disease. Current TB therapy involves a regimen of four antibiotics taken over a six month period. Patient compliance, cost of drugs and increasing incidence of drug resistant M. tuberculosis strains have added urgency to the development of novel TB therapies. Eradication of TB is affected by the ability of the bacterium to survive up to decades in a dormant state primarily in hypoxic granulomas in the lung and to cause recurrent infections. Methods The availability of M. tuberculosis genome-wide DNA microarrays has lead to the publication of several gene expression studies under simulated dormancy conditions. However, no single model best replicates the conditions of human pathogenicity. In order to identify novel TB drug targets, we performed a meta-analysis of multiple published datasets from gene expression DNA microarray experiments that modeled infection leading to and including the dormant state, along with data from genome-wide insertional mutagenesis that examined gene essentiality. Results Based on the analysis of these data sets following normalization, several genome wide trends were identified and used to guide the selection of targets for therapeutic development. The trends included the significant up-regulation of genes controlled by devR, down-regulation of protein and ATP synthesis, and the adaptation of two-carbon metabolism to the hypoxic and nutrient limited environment of the granuloma. Promising targets for drug discovery were several regulatory elements (devR/devS, relA, mprAB), enzymes involved in redox balance and respiration, sulfur transport and fixation, pantothenate, isoprene, and NAD biosynthesis. The advantages and liabilities of each target are discussed in the context of enzymology, bacterial pathways, target tractability, and drug development

  20. Hemophagocytic lymphohistiocytosis: An unusual complication in disseminated Mycobacterium tuberculosis

    PubMed Central

    Padhi, Somanath; Ravichandran, Kandasamy; Sahoo, Jayaprakash; Varghese, Renu G’Boy; Basheer, Aneesh

    2015-01-01

    Background: Hemophagocytic lymphohistiocytosis (HLH) is an uncommon, potentially fatal, hyperinflammatory syndrome that may rarely complicate the clinical course of disseminated Mycobacterium tuberculosis (MTB). The clinical course of tuberculosis-associated HLH (TB-HLH) has been reported to be unpredictable. Materials and Methods: Here we describe the clinicopathological features, laboratory parameters, management, and outcome data of a patient who satisfied the 2004 diagnostic criteria for HLH secondary to disseminated MTB; we also do a systematic review of the international literature on TB-HLH. The literature review (January 1975–March 2014) found that HLH complicated the clinical course of 63 tuberculosis patients (41 males, 22 females, mean age = 45 ± 23.5 years) with a high mortality rate of 49% (31/63 died). The mean serum ferritin level (n = 44/63) was 5963 ng/mL (range 500–38,539 ng/mL); and a higher proportion (54.2%) of patients had pancytopenia at presentation. On univariate analysis (n = 53/63), age >30 years [hazard ratio (HR): 2.79, 95% confidence interval (CI):1.03–7.56, P = 0.03], presence of comorbidities (HR 4.59, CI: 1.08–19.52, P = 0.04), marked hemophagocytosis in bone marrow (HR: 2.65, CI: 1.16–6.05, P = 0.02), and nonusage/delayed usage of antitubercular therapy (ATT) (HR: 3.44, CI: 1.51–7.87, P = 0.003) were associated with decreased survival, though none of these parameters attained statistical significance (P > 0.05) in multivariate analysis. Usage of corticosteroids and/or immunomodulator drugs (HR 1.00, CI: 0.66–3.22, P = 0.35) did not alter the outcome in these patients. Conclusion: HLH should be considered as a differential diagnosis in patients with tuberculosis who present with cytopenias, organomegaly, and coagulopathy. Strong clinical suspicion and early usage of ATT might be useful in reducing the morbidity and mortality. The utility of immunosuppressive/immunomodulator therapy lacks general concensus among

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

    PubMed

    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. PMID:25951404

  2. Cloning and sequence analysis of a class A beta-lactamase from Mycobacterium tuberculosis H37Ra.

    PubMed Central

    Hackbarth, C J; Unsal, I; Chambers, H F

    1997-01-01

    A cosmid library from Mycobacterium tuberculosis H37Ra was introduced into Mycobacterium smegmatis, and eight recombinant clones with increased resistance to cefoxitin were identified. Isoelectric focusing detected an M. tuberculosis-derived beta-lactamase in one of these recombinant clones. A sequence analysis identified it as a class A beta-lactamase whose expression correlated with the increased resistance phenotype. PMID:9145897

  3. Mycobacterium bovis infection of cattle and white-tailed deer: Translational research of relevance to human tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tuberculosis (TB) is a premier example of a disease complex with pathogens primarily affecting humans (i.e., Mycobacterium tuberculosis) or livestock and wildlife (i.e., Mycobacterium bovis) and with a long history of inclusive collaborations between physicians and veterinarians. Advances with the s...

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

    PubMed Central

    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

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

    PubMed

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

    2015-12-01

    Latent tuberculosis infection (LTBI) is characterised by the presence of immune responses to previously acquired Mycobacterium tuberculosis infection without clinical evidence of active tuberculosis (TB). Here we report evidence-based guidelines from the World Health Organization for a public health approach to the management of LTBI in high risk individuals in countries with high or middle upper income and TB incidence of <100 per 100 000 per year. The guidelines strongly recommend systematic testing and treatment of LTBI in people living with HIV, adult and child contacts of pulmonary TB cases, patients initiating anti-tumour necrosis factor treatment, patients receiving dialysis, patients preparing for organ or haematological transplantation, and patients with silicosis. In prisoners, healthcare workers, immigrants from high TB burden countries, homeless persons and illicit drug users, systematic testing and treatment of LTBI is conditionally recommended, according to TB epidemiology and resource availability. Either commercial interferon-gamma release assays or Mantoux tuberculin skin testing could be used to test for LTBI. Chest radiography should be performed before LTBI treatment to rule out active TB disease. Recommended treatment regimens for LTBI include: 6 or 9 month isoniazid; 12 week rifapentine plus isoniazid; 3-4 month isoniazid plus rifampicin; or 3-4 month rifampicin alone. PMID:26405286

  6. Molecular diversity of Mycobacterium tuberculosis isolates from patients with pulmonary tuberculosis in Mozambique

    PubMed Central

    2010-01-01

    Background Mozambique is one of the countries with the highest burden of tuberculosis (TB) in Sub-Saharan Africa, and information on the predominant genotypes of Mycobacterium tuberculosis circulating in the country are important to better understand the epidemic. This study determined the predominant strain lineages that cause TB in Mozambique. Results A total of 445 M. tuberculosis isolates from seven different provinces of Mozambique were characterized by spoligotyping and resulting profiles were compared with the international spoligotyping database SITVIT2. The four most predominant lineages observed were: the Latin-American Mediterranean (LAM, n = 165 or 37%); the East African-Indian (EAI, n = 132 or 29.7%); an evolutionary recent but yet ill-defined T clade, (n = 52 or 11.6%); and the globally-emerging Beijing clone, (n = 31 or 7%). A high spoligotype diversity was found for the EAI, LAM and T lineages. Conclusions The TB epidemic in Mozambique is caused by a wide diversity of spoligotypes with predominance of LAM, EAI, T and Beijing lineages. PMID:20663126

  7. Genotype heterogeneity of Mycobacterium tuberculosis within geospatial hotspots suggests foci of imported infection in Sydney, Australia.

    PubMed

    Gurjav, Ulziijargal; Jelfs, Peter; Hill-Cawthorne, Grant A; Marais, Ben J; Sintchenko, Vitali

    2016-06-01

    In recent years the State of New South Wales (NSW), Australia, has maintained a low tuberculosis incidence rate with little evidence of local transmission. Nearly 90% of notified tuberculosis cases occurred in people born in tuberculosis-endemic countries. We analyzed geographic, epidemiological and genotypic data of all culture-confirmed tuberculosis cases to identify the bacterial and demographic determinants of tuberculosis hotspot areas in NSW. Standard 24-loci mycobacterium interspersed repetitive unit-variable number tandem repeat (MIRU-24) typing was performed on all isolates recovered between 2009 and 2013. In total 1692/1841 (91.9%) cases with confirmed Mycobacterium tuberculosis infection had complete MIRU-24 and demographic data and were included in the study. Despite some year-to-year variability, spatio-temporal analysis identified four tuberculosis hotspots. The incidence rate and the relative risk of tuberculosis in these hotspots were 2- to 10-fold and 4- to 8-fold higher than the state average, respectively. MIRU-24 profiles of M. tuberculosis isolates associated with these hotspots revealed high levels of heterogeneity. This suggests that these spatio-temporal hotspots, within this low incidence setting, can represent areas of predominantly imported infection rather than clusters of cases due to local transmission. These findings provide important epidemiological insight and demonstrate the value of combining tuberculosis genotyping and spatiotemporal data to guide better-targeted public health interventions. PMID:26187743

  8. Mycobacterium tuberculosis Zinc Metalloprotease-1 Assists Mycobacterial Dissemination in Zebrafish.

    PubMed

    Vemula, Mani H; Medisetti, Raghavender; Ganji, Rakesh; Jakkala, Kiran; Sankati, Swetha; Chatti, Kiranam; Banerjee, Sharmistha

    2016-01-01

    Zinc metalloprotease-1 (Zmp1) from Mycobacterium tuberculosis (M.tb), the tuberculosis (TB) causing bacillus, is a virulence factor involved in inflammasome inactivation and phagosome maturation arrest. We earlier reported that Zmp1 was secreted under granuloma-like stress conditions, induced Th2 cytokine microenvironment and was highly immunogenic in TB patients as evident from high anti-Zmp1 antibody titers in their sera. In this study, we deciphered a new physiological role of Zmp1 in mycobacterial dissemination. Exogenous treatment of THP-1 cells with 500 nM and 1 μM of recombinant Zmp1 (rZmp1) resulted in necrotic cell death. Apart from inducing secretion of necrotic cytokines, TNFα, IL-6, and IL-1β, it also induced the release of chemotactic chemokines, MCP-1, MIP-1β, and IL-8, suggesting its likely function in cell migration and mycobacterial dissemination. This was confirmed by Gap closure and Boyden chamber assays, where Zmp1 treated CHO or THP-1 cells showed ∼2 fold increased cell migration compared to the untreated cells. Additionally, Zebrafish-M. marinum based host-pathogen model was used to study mycobacterial dissemination in vivo. Td-Tomato labeled M. marinum (TdM. marinum) when injected with rZmp1 showed increased dissemination to tail region from the site of injection as compared to the untreated control fish in a dose-dependent manner. Summing up these observations along with the earlier reports, we propose that Zmp1, a multi-faceted protein, when released by mycobacteria in granuloma, may lead to necrotic cell damage and release of chemotactic chemokines by surrounding infected macrophages, attracting new immune cells, which in turn may lead to fresh cellular infections, thus assisting mycobacterial dissemination. PMID:27621726

  9. TuberQ: a Mycobacterium tuberculosis protein druggability database

    PubMed Central

    Radusky, Leandro; Lanzarotti, Esteban; Luque, Javier; Barril, Xavier; Marti, Marcelo A.; Turjanski, Adrián G.

    2014-01-01

    In 2012 an estimated 8.6 million people developed tuberculosis (TB) and 1.3 million died from the disease [including 320 000 deaths among human immunodeficiency virus (HIV)-positive people]. There is an urgent need for new anti-TB drugs owing to the following: the fact that current treatments have severe side effects, the increasing emergence of multidrug-resistant strains of Mycobacterium tuberculosis (Mtb), the negative drug–drug interactions with certain HIV (or other disease) treatments and the ineffectiveness against dormant Mtb. In this context we present here the TuberQ database, a novel resource for all researchers working in the field of drug development in TB. The main feature of TuberQ is to provide a druggability analysis of Mtb proteins in a consistent and effective manner, contributing to a better selection of potential drug targets for screening campaigns and the analysis of targets for structure-based drug design projects. The structural druggability analysis is combined with features related to the characteristics of putative inhibitor binding pockets and with functional and biological data of proteins. The structural analysis is performed on all available unique Mtb structures and high-quality structural homology-based models. This information is shown in an interactive manner, depicting the protein structure, the pockets and the associated characteristics for each protein. TuberQ also provides information about gene essentiality information, as determined from whole cell–based knockout experiments, and expression information obtained from microarray experiments done in different stress-related conditions. We hope that TuberQ will be a powerful tool for researchers working in TB and eventually will lead to the identification of novel putative targets and progresses in therapeutic activities. Database URL: http://tuberq.proteinq.com.ar/ PMID:24816183

  10. Pyrazinamide resistance in Mycobacterium tuberculosis: Review and update.

    PubMed

    Njire, Moses; Tan, Yaoju; Mugweru, Julius; Wang, Changwei; Guo, Jintao; Yew, WingWai; Tan, Shouyong; Zhang, Tianyu

    2016-03-01

    The global control and management of tuberculosis (TB) is faced with the formidable challenge of worsening scenarios of drug-resistant disease. Pyrazinamide (PZA) is an indispensable first-line drug used for the treatment of TB. It plays a key role in reducing TB relapse rates, shortening the course of the disease treatment from 9-12 months to 6 months, and the treatment of patients infected with bacillary strains that are resistant to at least isoniazid and rifampicin. Additionally, it is the only first-line anti-TB drug most likely to be maintained in all new regimens, which are aimed at reducing the treatment period of susceptible, multi-drug resistant and extensively drug-resistant TB. It has a preferential sterilizing activity against non-replicating persister bacilli with low metabolism at acid pH in vitro or in vivo during active inflammation where other drugs may not act so well. PZA seem to have a non-specific cellular target and instead, exerts its anti-mycobacterial effect by disrupting the membrane energetics, the trans-translation process, acidification of the cytoplasm and perhaps coenzyme A synthesis, which is required for survival of Mycobacterium tuberculosis (MTB) persisters. Indeed, the emergence of MTB strains resistant to PZA represents an important clinical and public health problem. The essential role of PZA in TB treatment underlines the need for accurate and rapid detection of its resistance. This article presents an updated review of the molecular mechanisms of drug action and resistance in MTB against PZA, commenting on the several research gaps and proposed drug targets for PZA. PMID:26521205