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the interaction of mycobacterial protein rv2966c with host chromatin is mediated through non-cpg methylation and histone h3/h4 binding.to effectively modulate the gene expression within an infected mammalian cell, the pathogen mycobacterium tuberculosis would need to bring about epigenetic modifications at appropriate genomic loci. working on this hypothesis, we show in this study that the mycobacterial protein rv2966c is a 5-methylcytosine-specific dna methyltransferase that is secreted out from the mycobacterium and gets localized to the nucleus in addition to the cytoplasm inside the host cell. importantly, rv2966c binds to ...201525824946
sensing of mycobacterium tuberculosis and consequences to both host and bacillus.mycobacterium tuberculosis (mtb), the primary causative agent of human tuberculosis, has killed more people than any other bacterial pathogen in human history and remains one of the most important transmissible diseases worldwide. because of the long-standing interaction of mtb with humans, it is no surprise that human mucosal and innate immune cells have evolved multiple mechanisms to detect mtb during initial contact. to that end, the cell surface of human cells is decorated with numerous patt ...201525703561
phosphoproteomics analysis of a clinical mycobacterium tuberculosis beijing isolate: expanding the mycobacterial phosphoproteome catalog.reversible protein phosphorylation, regulated by protein kinases and phosphatases, mediates a switch between protein activity and cellular pathways that contribute to a large number of cellular processes. the mycobacterium tuberculosis genome encodes 11 serine/threonine kinases (stpks) which show close homology to eukaryotic kinases. this study aimed to elucidate the phosphoproteomic landscape of a clinical isolate of m. tuberculosis. we performed a high throughput mass spectrometric analysis of ...201525713560
characterization of a new m13 metallopeptidase from deep-sea shewanella sp. e525-6 and mechanistic insight into its catalysis.bacterial extracellular peptidases are important for bacterial nutrition and organic nitrogen degradation in the ocean. while many peptidases of the m13 family from terrestrial animals and bacteria are studied, there has been no report on m13 peptidases from marine bacteria. here, we characterized an m13 peptidase, peps, from the deep-sea sedimentary strain shewanella sp. e525-6, and investigated its substrate specificity and catalytic mechanism. the gene peps cloned from strain e525-6 contains ...201526779153
thiol-based redox switches in prokaryotes.bacteria encounter reactive oxygen species (ros) as a consequence of the aerobic life or as an oxidative burst of activated neutrophils during infections. in addition, bacteria are exposed to other redox-active compounds, including hypochloric acid (hocl) and reactive electrophilic species (res) such as quinones and aldehydes. these reactive species often target the thiol groups of cysteines in proteins and lead to thiol-disulfide switches in redox-sensing regulators to activate specific detoxif ...201525720121
differential repair of etheno-dna adducts by bacterial and human alkb proteins.alkb proteins are evolutionary conserved fe(ii)/2-oxoglutarate-dependent dioxygenases, which remove alkyl and highly promutagenic etheno(ɛ)-dna adducts, but their substrate specificity has not been fully determined. we developed a novel assay for the repair of ɛ-adducts by alkb enzymes using oligodeoxynucleotides with a single lesion and specific dna glycosylases and ap-endonuclease for identification of the repair products. we compared the repair of three ɛ-adducts, 1,n(6)-ethenoadenine (ɛa), 3 ...201525797601
molecular and functional characterization of recd, a novel member of the sf1 family of helicases, from mycobacterium tuberculosis.the annotated whole-genome sequence of mycobacterium tuberculosis revealed the presence of a putative recd gene; however, the biochemical characteristics of its encoded protein product (mtrecd) remain largely unknown. here, we show that mtrecd exists in solution as a stable homodimer. protein-dna binding assays revealed that mtrecd binds efficiently to single-stranded dna and linear duplexes containing 5' overhangs relative to the 3' overhangs but not to blunt-ended duplex. furthermore, mtrecd b ...201525802334
targeting the trehalose utilization pathways of mycobacterium tuberculosis.tuberculosis (tb) is an epidemic disease and the growing burden of multidrug-resistant (mdr) tb world wide underlines the need to discover new drugs to treat the disease. mycobacterium tuberculosis (mtb) is the etiological agent of most cases of tb. mtb is difficult to treat, in part, due to the presence of a sturdy hydrophobic barrier that prevents penetration of drugs through the cell wall. mtb can also survive in a non-replicative state for long periods of time avoiding the action of common a ...201526941930
benzoic acid-inducible gene expression in mycobacteria.conditional expression is a powerful tool to investigate the role of bacterial genes. here, we adapt the pseudomonas putida-derived positively regulated xyls/pm expression system to control inducible gene expression in mycobacterium smegmatis and mycobacterium tuberculosis, the causative agent of human tuberculosis. by making simple changes to a gram-negative broad-host-range xyls/pm-regulated gene expression vector, we prove that it is possible to adapt this well-studied expression system to no ...201526348349
regulation mechanism of the ald gene encoding alanine dehydrogenase in mycobacterium smegmatis and mycobacterium tuberculosis by the lrp/asnc family regulator aldr.in the presence of alanine, aldr, which belongs to the lrp/asnc family of transcriptional regulators and regulates ald encoding alanine dehydrogenase in mycobacterium smegmatis, changes its quaternary structure from a homodimer to an octamer with an open-ring conformation. four aldr-binding sites (o2, o1, o4, and o3) with a consensus sequence of ga/t-n2-nww/wwn-n2-a/tc were identified upstream of the m. smegmatis ald gene by means of dnase i footprinting analysis. o2, o1, and o4 are required for ...201526195594
lansoprazole is an antituberculous prodrug targeting cytochrome bc1.better antibiotics capable of killing multi-drug-resistant mycobacterium tuberculosis are urgently needed. despite extensive drug discovery efforts, only a few promising candidates are on the horizon and alternative screening protocols are required. here, by testing a panel of fda-approved drugs in a host cell-based assay, we show that the blockbuster drug lansoprazole (prevacid), a gastric proton-pump inhibitor, has intracellular activity against m. tuberculosis. ex vivo pharmacokinetics and ta ...201526158909
a macrophage subversion factor is shared by intracellular and extracellular pathogens.pathogenic bacteria have developed strategies to adapt to host environment and resist host immune response. several intracellular bacterial pathogens, including salmonella enterica and mycobacterium tuberculosis, share the horizontally-acquired mgtc virulence factor that is important for multiplication inside macrophages. mgtc is also found in pathogenic pseudomonas species. here we investigate for the first time the role of mgtc in the virulence of an extracellular pathogen, pseudomonas aerugin ...201526080006
tetrahydroisoquinolines affect the whole-cell phenotype of mycobacterium tuberculosis by inhibiting the atp-dependent mure ligase.(s)-leucoxine, isolated from the colombian lauraceae tree rhodostemonodaphne crenaticupula madriñan, was found to inhibit the growth of mycobacterium tuberculosis h37rv. a biomimetic approach for the chemical synthesis of a wide array of 1-substituted tetrahydroisoquinolines was undertaken with the aim of elucidating a common pharmacophore for these compounds with novel mode(s) of anti-tb action.201525656411
inherited and acquired immunodeficiencies underlying tuberculosis in childhood.tuberculosis (tb), caused by mycobacterium tuberculosis (m.tb) and a few related mycobacteria, is a devastating disease, killing more than a million individuals per year worldwide. however, its pathogenesis remains largely elusive, as only a small proportion of infected individuals develop clinical disease either during primary infection or during reactivation from latency or secondary infection. subacute, hematogenous, and extrapulmonary disease tends to be more frequent in infants, children, a ...201525703555
a new screen for tuberculosis drug candidates utilizing a luciferase-expressing recombinant mycobacterium bovis bacillus calmette-guéren.tuberculosis (tb) is a serious infectious disease caused by a bacterial pathogen. mortality from tuberculosis was estimated at 1.5 million deaths worldwide in 2013. development of new tb drugs is needed to not only to shorten the medication period but also to treat multi-drug resistant and extensively drug-resistant tb. mycobacterium tuberculosis (mtb) grows slowly and only multiplies once or twice per day. therefore, conventional drug screening takes more than 3 weeks. additionally, a biosafety ...201526571296
ismapper: identifying transposase insertion sites in bacterial genomes from short read sequence data.insertion sequences (is) are small transposable elements, commonly found in bacterial genomes. identifying the location of is in bacterial genomes can be useful for a variety of purposes including epidemiological tracking and predicting antibiotic resistance. however is are commonly present in multiple copies in a single genome, which complicates genome assembly and the identification of is insertion sites. here we present ismapper, a mapping-based tool for identification of the site and orienta ...201526336060
downregulation of host tryptophan-aspartate containing coat (taco) gene restricts the entry and survival of leishmania donovani in human macrophage model.leishmania are obligate intracellular protozoan parasites of mammalian hosts. promastigotes of leishmania are internalized by macrophages and transformed into amastigotes in phagosomes, and replicate in phagolysosomes. phagosomal maturation arrest is known to play a crucial role in the survival of pathogenic leishmania within activated macrophages. recently, tryptophan-aspartate containing coat (taco) gene has been recognized as playing a central role in the survival of mycobacterium tuberculosi ...201526528242
investigation of toll-like receptor-2 (2258g/a) and interferon gamma (+874t/a) gene polymorphisms among infertile women with female genital tuberculosis.toll-like receptor 2 (tlr2) and interferon-gamma (ifn-γ) coordinate with a diverse array of cellular programs through the transcriptional regulation of immunologically relevant genes and play an important role in immune system, reproductive physiology and basic pathology. alterations in the functions of tlr2 2258g (guanine)/ a, ifn-γ (+874t/a) and signalling molecules that result from polymorphisms are often associated with susceptibility or resistance, which may, in turn, establish the innate h ...201526114934
molecular analysis of codon 548 in the rpob gene involved in mycobacterium tuberculosis resistance to rifampin.most mycobacterium tuberculosis rifampin-resistant strains have been associated with mutations in an 81-bp rifampin resistance-determining region (rrdr) in the gene rpob. however, if this region alone were targeted, rifampin-resistant strains with mutations outside the rrdr would not be detected. in this study, among 51 rifampin-resistant clinical isolates analyzed by sequencing 1,681-bp-long dna fragments containing the rrdr, 47 isolates contained mutations within the rrdr, three isolates conta ...201525534743
mntr(rv2788): a transcriptional regulator that controls manganese homeostasis in mycobacterium tuberculosis.the pathogenic mycobacterium mycobacterium tuberculosis encodes two members of the dtxr/mntr family of metalloregulators, ider and sirr. ider represses gene expression in response to ferrous iron, and we here demonstrate that sirr (rv2788), although also annotated as an iron-dependent repressor, functions instead as a manganese-dependent transcriptional repressor and is therefore renamed mntr. mntr regulates transporters that promote manganese import and genes that respond to metal ion deficienc ...201526337157
the cytochrome bd-type quinol oxidase is important for survival of mycobacterium smegmatis under peroxide and antibiotic-induced stress.targeting respiration and atp synthesis has received strong interest as a new strategy for combatting drug-resistant mycobacterium tuberculosis. mycobacteria employ a respiratory chain terminating with two branches. one of the branches includes a cytochrome bc1 complex and an aa3-type cytochrome c oxidase while the other branch terminates with a cytochrome bd-type quinol oxidase. in this communication we show that genetic inactivation of cytochrome bd, but not of cytochrome bc1, enhances the sus ...201526015371
structure of ribosomal silencing factor bound to mycobacterium tuberculosis ribosome.the ribosomal silencing factor rsfs slows cell growth by inhibiting protein synthesis during periods of diminished nutrient availability. the crystal structure of mycobacterium tuberculosis (mtb) rsfs, together with the cryo-electron microscopy (em) structure of the large subunit 50s of mtb ribosome, reveals how inhibition of protein synthesis by rsfs occurs. rsfs binds to the 50s at l14, which, when occupied, blocks the association of the small subunit 30s. although mtb rsfs is a dimer in solut ...201526299947
thiophenecarboxamide derivatives activated by etha kill mycobacterium tuberculosis by inhibiting the ctp synthetase pyrg.to combat the emergence of drug-resistant strains of mycobacterium tuberculosis, new antitubercular agents and novel drug targets are needed. phenotypic screening of a library of 594 hit compounds uncovered two leads that were active against m. tuberculosis in its replicating, non-replicating, and intracellular states: compounds 7947882 (5-methyl-n-(4-nitrophenyl)thiophene-2-carboxamide) and 7904688 (3-phenyl-n-[(4-piperidin-1-ylphenyl)carbamothioyl]propanamide). mutants resistant to both compou ...201526097035
implication from the predicted docked interaction of sigma h and exploration of its interaction with rna polymerase in mycobacterium tuberculosis.m. tuberculosis is adapted to remain active in the extreme environmental condition due to the presence of atypical sigma factors commonly called extra cytoplasmic function (ecf) sigma factors. among the 13 sigma factors of m. tuberculosis, 10 are regarded as the ecf sigma factor that exerts their attributes in various stress response. therefore it is of interest to describe the structural prediction of one of the ecf sigma factors, sigma h (sigh), involved in oxidative and heat stress having int ...201526229290
zinc regulates a switch between primary and alternative s18 ribosomal proteins in mycobacterium tuberculosis.the mycobacterium tuberculosis genome encodes five putative 'alternative' ribosomal proteins whose expression is repressed at high zn(2+) concentration. each alternative protein has a primary homologue that is predicted to bind zn(2+). we hypothesized that zinc triggers a switch between these paired homologous proteins and therefore chose one of these pairs, s18-1/s18-2, to study mechanisms of the predicted competition for their incorporation into ribosomes. our data show that zn(2+)-depletion c ...201525858183
isolation and characterization of a hybrid respiratory supercomplex consisting of mycobacterium tuberculosis cytochrome bcc and mycobacterium smegmatis cytochrome aa3.recently, energy production pathways have been shown to be viable antitubercular drug targets to combat multidrug-resistant tuberculosis and eliminate pathogen in the dormant state. one family of drugs currently under development, the imidazo[1,2-a]pyridine derivatives, is believed to target the pathogen's homolog of the mitochondrial bc1 complex. this complex, denoted cytochrome bcc, is highly divergent from mitochondrial complex iii both in subunit structure and inhibitor sensitivity, making i ...201525861988
a functional role of rv1738 in mycobacterium tuberculosis persistence suggested by racemic protein crystallography.protein 3d structure can be a powerful predictor of function, but it often faces a critical roadblock at the crystallization step. rv1738, a protein from mycobacterium tuberculosis that is strongly implicated in the onset of nonreplicating persistence, and thereby latent tuberculosis, resisted extensive attempts at crystallization. chemical synthesis of the l- and d-enantiomeric forms of rv1738 enabled facile crystallization of the d/l-racemic mixture. the structure was solved by an ab initio ap ...201525831534
structural and functional studies of phosphoenolpyruvate carboxykinase from mycobacterium tuberculosis.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, anabolis ...201525798914
phylogenetic analysis of vitamin b12-related metabolism in mycobacterium tuberculosis.comparison of genome sequences from clinical isolates of mycobacterium tuberculosis with phylogenetically-related pathogens mycobacterium marinum, mycobacterium kansasii, and mycobacterium leprae reveals diversity amongst genes associated with vitamin b12-related metabolism. diversity is generated by gene deletion events, differential acquisition of genes by horizontal transfer, and single nucleotide polymorphisms (snps) with predicted impact on protein function and transcriptional regulation. d ...201525988174
association between intrinsic disorder and serine/threonine phosphorylation in mycobacterium tuberculosis.serine/threonine phosphorylation is an important mechanism that is involved in the regulation of protein function. in eukaryotes, phosphorylation occurs predominantly in intrinsically disordered regions of proteins. though serine/threonine phosphorylation and protein disorder are much less prevalent in prokaryotes, some bacteria have high levels of serine/threonine phosphorylation and disorder, including the medically important m. tuberculosis. here i show that serine/threonine phosphorylation s ...201525648268
mouse models of human tb pathology: roles in the analysis of necrosis and the development of host-directed therapies.a key aspect of tb pathogenesis that maintains mycobacterium tuberculosis in the human population is the ability to cause necrosis in pulmonary lesions. as co-evolution shaped m . tuberculosis (m.tb) and human responses, the complete tb disease profile and lesion manifestation are not fully reproduced by any animal model. however, animal models are absolutely critical to understand how infection with virulent m.tb generates outcomes necessary for the pathogen transmission and evolutionary succes ...201526542392
correlates of vaccine-induced protection against mycobacterium tuberculosis revealed in comparative analyses of lymphocyte populations.a critical hindrance to the development of a novel vaccine against mycobacterium tuberculosis is a lack of understanding of protective correlates of immunity and of host factors involved in a successful adaptive immune response. studies from our group and others have used a mouse-based in vitro model system to assess correlates of protection. here, using this coculture system and a panel of whole-cell vaccines with varied efficacy, we developed a comprehensive approach to understand correlates o ...201526269537
essential roles of methionine and s-adenosylmethionine in the autarkic lifestyle of mycobacterium tuberculosis.multidrug resistance, strong side effects, and compliance problems in tb chemotherapy mandate new ways to kill mycobacterium tuberculosis (mtb). here we show that deletion of the gene encoding homoserine transacetylase (meta) inactivates methionine and s-adenosylmethionine (sam) biosynthesis in mtb and renders this pathogen exquisitely sensitive to killing in immunocompetent or immunocompromised mice, leading to rapid clearance from host tissues. mtb δmeta is unable to proliferate in primary hum ...201526221021
rational modulation of the induced-fit conformational change for slow-onset inhibition in mycobacterium tuberculosis inha.slow-onset enzyme inhibitors are the subject of considerable interest as an approach to increasing the potency of pharmaceutical compounds by extending the residence time of the inhibitor on the target (the lifetime of the drug-receptor complex). however, rational modulation of residence time presents significant challenges because it requires additional mechanistic insight, such as the nature of the transition state for postbinding isomerization. our previous work, based on x-ray crystallograph ...201526147157
radiolabelling and positron emission tomography of pt70, a time-dependent inhibitor of inha, the mycobacterium tuberculosis enoyl-acp reductase.pt70 is a diaryl ether inhibitor of inha, the enoyl-acp reductase in the mycobacterium tuberculosis fatty acid biosynthesis pathway. it has a residence time of 24 min on the target, and also shows antibacterial activity in a mouse model of tuberculosis infection. due to the interest in studying target tissue pharmacokinetics of pt70, we developed a method to radiolabel pt70 with carbon-11 and have studied its pharmacokinetics in mice and baboons using positron emission tomography.201526227776
uncovering major genomic features of essential genes in bacteria and a methanogenic archaea.identification of essential genes is critical to understanding the physiology of a species, proposing novel drug targets and uncovering minimal gene sets required for life. although essential gene sets of several organisms have been determined using large-scale mutagenesis techniques, systematic studies addressing their conservation, genomic context and functions remain scant. here we integrate 17 essential gene sets from genome-wide in vitro screenings and three gene collections required for gr ...201526084810
the role of mucosal associated invariant t cells in antimicrobial immunity.mucosal associated invariant t (mait) cells are an innate-like t cell subset prevalent in humans and distributed throughout the blood and mucosal sites. human mait cells are defined by the expression of the semi-invariant tcrα chain trav1-2/traj12/20/33 and are restricted by the non-polymorphic major histocompatibility complex (mhc) class i-like molecule, mhc-related protein 1, mr1. mait cells are activated by small organic molecules, derived from the riboflavin biosynthesis pathway of bacteria ...201526217338
mr1-restricted mucosal-associated invariant t cells and their activation during infectious diseases.mr1-restricted mucosal-associated invariant t (mait) cells recognize vitamin b metabolites, which are generated by a broad range of bacteria, from escherichia coli to mycobacterium tuberculosis and bcg. mait cells have been described as innate sensors of infection as they accumulate early in infected tissues. mait cells maintain an activated phenotype throughout the course of infections, secrete inflammatory cytokines, and have the potential to directly kill infected cells, playing an important ...201526136743
identification of novel mycobacterium tuberculosis cd4 t-cell antigens via high throughput proteome screening.elicitation of cd4 ifn-gamma t cell responses to mycobacterium tuberculosis (mtb) is a rational vaccine strategy to prevent clinical tuberculosis. diagnosis of mtb infection is based on t-cell immune memory to mtb antigens. the mtb proteome contains over four thousand open reading frames (orfs). we conducted a pilot antigen identification study using 164 mtb proteins and mtb-specific t-cells expanded in vitro from 12 persons with latent mtb infection. enrichment of mtb-reactive t-cells from pbmc ...201525857935
mr1-restricted mucosal associated invariant t (mait) cells in the immune response to mycobacterium tuberculosis.the intracellular pathogen mycobacterium tuberculosis (mtb) and its human host have long co-evolved. although the host cellular immune response is critical to the control of the bacterium information on the specific contribution of different immune cell subsets in humans is incomplete. mucosal associated invariant t (mait) cells are a prevalent and unique t-cell population in humans with the capacity to detect intracellular infection with bacteria including mtb. mait cells detect bacterially der ...201525703558
compounds targeting disulfide bond forming enzyme dsbb of gram-negative bacteria.in bacteria, disulfide bonds confer stability on many proteins exported to the cell envelope or beyond. these proteins include numerous bacterial virulence factors, and thus bacterial enzymes that promote disulfide bond formation represent targets for compounds inhibiting bacterial virulence. here, we describe a new target- and cell-based screening methodology for identifying compounds that inhibit the disulfide bond-forming enzymes escherichia coli dsbb (ecdsbb) or mycobacterium tuberculosis vk ...201525686372
cytosolic access of mycobacterium tuberculosis: critical impact of phagosomal acidification control and demonstration of occurrence in vivo.mycobacterium tuberculosis (mtb) uses efficient strategies to evade the eradication by professional phagocytes, involving--as recently confirmed--escape from phagosomal confinement. while mtb determinants, such as the esx-1 type vii secretion system, that contribute to this phenomenon are known, the host cell factors governing this important biological process are yet unexplored. using a newly developed flow-cytometric approach for mtb, we show that macrophages expressing the phagosomal bivalent ...201525658322
bioinformatic and mass spectrometry identification of anaplasma phagocytophilum proteins translocated into host cell nuclei.obligate intracellular bacteria have an arsenal of proteins that alter host cells to establish and maintain a hospitable environment for replication. anaplasma phagocytophilum secrets ankyrin a (anka), via a type iv secretion system, which translocates to the nucleus of its host cell, human neutrophils. a. phagocytophilum-infected neutrophils have dramatically altered phenotypes in part explained by anka-induced transcriptional alterations. however, it is unlikely that anka is the sole effector ...201525705208
ecto-5'-nucleotidase (cd73) deficiency in mycobacterium tuberculosis-infected mice enhances neutrophil recruitment.the immune system needs safeguards that prevent collateral tissue damage mediated by the immune system while enabling an effective response against a pathogen. the purinergic pathway is one such mechanism and finely modulates inflammation by sensing nucleotides in the environment. extracellular atp is considered to be a danger signal leading to a proinflammatory response, whereas adenosine is immunosuppressive. cd73, also called ecto-5'-nucleotidase, occupies a strategic position in this pathway ...201526150535
phosphorylation of mycobacterium tuberculosis parb participates in regulating the parabs chromosome segregation system.here, we present for the first time that mycobacterium tuberculosis parb is phosphorylated by several mycobacterial ser/thr protein kinases in vitro. parb and para are the key components of bacterial chromosome segregation apparatus. parb is a cytosolic conserved protein that binds specifically to centromere-like dna pars sequences and interacts with para, a weak atpase required for its proper localization. mass spectrometry identified the presence of ten phosphate groups, thus indicating that p ...201525807382
chromosome organization and replisome dynamics in mycobacterium smegmatis.subcellular organization of the bacterial nucleoid and spatiotemporal dynamics of dna replication and segregation have been studied intensively, but the functional link between these processes remains poorly understood. here we use quantitative time-lapse fluorescence microscopy for single-cell analysis of chromosome organization and dna replisome dynamics in mycobacterium smegmatis. we report that dna replication takes place near midcell, where, following assembly of the replisome on the replic ...201525691587
rapid, semiquantitative assay to discriminate among compounds with activity against replicating or nonreplicating mycobacterium tuberculosis.the search for drugs that can kill replicating and nonreplicating mycobacterium tuberculosis faces practical bottlenecks. measurement of cfu and discrimination of bacteriostatic from bactericidal activity are costly in compounds, supplies, labor, and time. testing compounds against m. tuberculosis under conditions that prevent the replication of m. tuberculosis often involves a second phase of the test in which conditions are altered to permit the replication of bacteria that survived the first ...201526239979
gene loss dominates as a source of genetic variation within clonal pathogenic bacterial species.some of the most dangerous pathogens such as mycobacterium tuberculosis and yersinia pestis evolve clonally. this means that little or no recombination occurs between strains belonging to these species. paradoxically, although different members of these species show extreme sequence similarity of orthologous genes, some show considerable intraspecies phenotypic variation, the source of which remains elusive. to examine the possible sources of phenotypic variation within clonal pathogenic bacteri ...201526163675
molecular basis for the inhibition of β-hydroxyacyl-acp dehydratase hadab complex from mycobacterium tuberculosis by flavonoid inhibitors.dehydration is one of the key steps in the biosynthesis of mycolic acids and is vital to the growth of mycobacterium tuberculosis (mtb). consequently, stalling dehydration cures tuberculosis (tb). clinically used anti-tb drugs like thiacetazone (tac) and isoxyl (iso) as well as flavonoids inhibit the enzyme activity of the β-hydroxyacyl-acp dehydratase hadab complex. how this inhibition is exerted, has remained an enigma for years. here, we describe the first crystal structures of the mtbhadab c ...201526081470
peroxidase activity and involvement in the oxidative stress response of roseobacter denitrificans truncated hemoglobin.roseobacter denitrificans is a member of the widespread marine roseobacter genus. we report the first characterization of a truncated hemoglobin from r. denitrificans (rd. trhb) that was purified in the heme-bound form from heterologous expression of the protein in escherichia coli. rd. trhb exhibits predominantly alpha-helical secondary structure and absorbs light at 412, 538 and 572 nm. the phylogenetic classification suggests that rd. trhb falls into group ii trhbs, whereas sequence alignment ...201525658318
iron acquisition mechanisms: promising target against mycobacterium tuberculosis.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 i ...201526464608
prospects in mycobacterium bovis bacille calmette et guérin (bcg) vaccine diversity and delivery: why does bcg fail to protect against tuberculosis?mycobacterium tuberculosis (m.tb) infection leads to active tuberculosis (tb), a disease that kills one human every 18s. current therapies available to combat tb include chemotherapy and the preventative vaccine mycobacterium bovis bacille calmette et guérin (bcg). increased reporting of drug resistant m.tb strains worldwide indicates that drug development cannot be the primary mechanism for eradication. bcg vaccination has been used globally for protection against childhood and disseminated tb, ...201526319069
mycobacterium tuberculosis folate metabolism and the mechanistic basis for para-aminosalicylic acid susceptibility and resistance.para-aminosalicylic acid (pas) entered clinical use in 1946 as the second exclusive drug for the treatment of tuberculosis (tb). while pas was initially a first-line tb drug, the introduction of more potent antitubercular agents relegated pas to the second-line tier of agents used for the treatment of drug-resistant mycobacterium tuberculosis infections. despite the long history of pas usage, an understanding of the molecular and biochemical mechanisms governing the susceptibility and resistance ...201526033719
role of group 1 cd1-restricted t cells in infectious disease.the evolutionarily conserved cd1 family of antigen-presenting molecules presents lipid antigens rather than peptide antigens to t cells. cd1 molecules, unlike classical mhc molecules, display limited polymorphism, making cd1-restricted lipid antigens attractive vaccine targets that could be recognized in a genetically diverse human population. group 1 cd1 (cd1a, cd1b, and cd1c)-restricted t cells have been implicated to play critical roles in a variety of autoimmune and infectious diseases. in t ...201526175733
b cells and antibodies in the defense against mycobacterium tuberculosis infection.better understanding of the immunological components and their interactions necessary to prevent or control mycobacterium tuberculosis (mtb) infection in humans is critical for tuberculosis (tb) vaccine development strategies. although the contributory role of humoral immunity in the protection against mtb infection and disease is less defined than the role of t cells, it has been well-established for many other intracellular pathogens. here we update and discuss the increasing evidence and the ...201525703559
card stabilizes mycobacterial open complexes via a two-tiered kinetic mechanism.card is an essential and global transcriptional regulator in mycobacteria. while its biological role is unclear, card functions by interacting directly with rna polymerase (rnap) holoenzyme promoter complexes. here, using a fluorescent reporter of open complex, we quantitate rpo formation in real time and show that mycobacterium tuberculosis card has a dramatic effect on the energetics of rnap bound complexes on the m. tuberculosis rrnap3 ribosomal rna promoter. the data reveal that mycobacteriu ...201525697505
current and past strategies for bacterial culture in clinical microbiology.a pure bacterial culture remains essential for the study of its virulence, its antibiotic susceptibility, and its genome sequence in order to facilitate the understanding and treatment of caused diseases. the first culture conditions empirically varied incubation time, nutrients, atmosphere, and temperature; culture was then gradually abandoned in favor of molecular methods. the rebirth of culture in clinical microbiology was prompted by microbiologists specializing in intracellular bacteria. th ...201525567228
rabbit models for studying human infectious diseases.using an appropriate animal model is crucial for mimicking human disease conditions, and various facets including genetics, anatomy, and pathophysiology should be considered before selecting a model. rabbits (oryctolagus cuniculus) are well known for their wide use in production of antibodies, eye research, atherosclerosis and other cardiovascular diseases. however, a systematic description of the rabbit as primary experimental models for the study of various human infectious diseases is unavail ...201526678367
m. tuberculosis t cell epitope analysis reveals paucity of antigenic variation and identifies rare variable tb antigens.pathogens that evade adaptive immunity typically exhibit antigenic variation. by contrast, it appears that although the chronic human tuberculosis (tb)-causing pathogen mycobacterium tuberculosis needs to counter host t cell responses, its t cell epitopes are hyperconserved. here we present an extensive analysis of the t cell epitopes of m. tuberculosis. we combined population genomics with experimental immunology to determine the number and identity of t cell epitope sequence variants in 216 ph ...201526607161
development of a new real-time pcr system for simultaneous detection of bacteria and fungi in pathological samples.a novel system for simultaneous detection of pathogenic bacteria and fungi in pathological samples was developed using a real-time polymerase chain reaction (pcr) system. this system, designated the "multi-microbial real-time pcr", has the potential to simultaneously detect 68 bacterial and 9 fungal species in a 96-well plate format. all probe-primer sets were designed to produce amplicons smaller than 210 bp using formalin-fixed paraffin-embedded samples as input. the specificity and sensitivit ...201526823918
card uses a minor groove wedge mechanism to stabilize the rna polymerase open promoter complex.a key point to regulate gene expression is at transcription initiation, and activators play a major role. card, an essential activator in mycobacterium tuberculosis, is found in many bacteria, including thermus species, but absent in escherichia coli. to delineate the molecular mechanism of card, we determined crystal structures of thermus transcription initiation complexes containing card. the structures show card interacts with the unique dna topology presented by the upstream double-stranded/ ...201526349034
screening ancient tuberculosis with qpcr: challenges and opportunities.the field of ancient dna (adna) has rapidly accelerated in recent years as a result of new methods in next-generation sequencing, library preparation and targeted enrichment. such research is restricted, however, by the highly variable dna preservation within different tissues, especially when isolating ancient pathogens from human remains. identifying positive candidate samples via quantitative pcr (qpcr) for downstream procedures can reduce reagent costs, increase capture efficiency and maximi ...201525487341
mycobacterium tuberculosis tlya protein negatively regulates t helper (th) 1 and th17 differentiation and promotes tuberculosis pathogenesis.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 ...201525847237
trnas taking charge.most bacterial toxins derived from chromosomally encoded toxin-antitoxin (ta) systems that have been studied to date appear to protect cells from relatively short pulses of stress by triggering a reversible state of growth arrest. in contrast to many bacterial toxins that are produced as defense mechanisms and secreted from their hosts, ta toxins exert their protective effect from within the cell that produces them. ta toxin-mediated growth arrest is most frequently achieved through their abilit ...201526657107
growth-regulating mycobacterium tuberculosis vapc-mt4 toxin is an isoacceptor-specific trnase.toxin-antitoxin (ta) systems are implicated in the downregulation of bacterial cell growth associated with stress survival and latent tuberculosis infection, yet the activities and intracellular targets of these ta toxins are largely uncharacterized. here, we use a specialized rna-seq approach to identify targets of a mycobacterium tuberculosis vapc ta toxin, vapc-mt4 (also known as vapc4), which have eluded detection using conventional approaches. distinct from the one other characterized vapc ...201526158745
detection of mycobacteria, mycobacterium avium subspecies, and mycobacterium tuberculosis complex by a novel tetraplex real-time pcr assay.mycobacterium tuberculosis complex, mycobacterium avium, and many other nontuberculous mycobacteria are worldwide distributed microorganisms of major medical and veterinary importance. considering the growing epidemiologic significance of wildlife-livestock-human interrelation, developing rapid detection tools of high specificity and sensitivity is vital to assess their presence and accelerate the process of diagnosing mycobacteriosis. here we describe the development and evaluation of a novel t ...201525588660
lack of association between il-10 gene promoter polymorphisms and susceptible to tuberculosis in thai patients.cytokines play a major role in defense against mycobacterium tuberculosis infection. polymorphisms in the genes encoding various cytokines have been associated with tuberculosis susceptibility. polymorphisms of the regulatoy cytokine gene, the interleukin (il)-10 is associated with the risk of tuberculosis (tb) in different populations. however il-10 gene polymorphism and susceptibility to tb in thai is still unknown.201527276844
a feasibility study of the xpert mtb/rif test at the peripheral level laboratory in china.to evaluate the performance of xpert mtb/rif (mtb/rif) in the county-level tuberculosis (tb) laboratory in china.201525447720
synergistic effect of muramyl dipeptide with heat shock protein 70 from mycobacterium tuberculosis on immune activation.heat shock protein 70 from mycobacterium tuberculosis (mtb hsp70) has been known to modulate immune response including dendritic cell activation. muramyl dipeptide (mdp) is an immunoreactive derivative of peptidoglycan from all gram-negative and gram-positive bacteria and recognized to be responsible for function of freund's complete adjuvant. in this study, we evaluated effect of mdp on in vitro activation of bone marrow derived dendritic cells (bmdcs) and in vivo production of cytokines and ch ...201525446399
evaluation of three rapid assays for mycobacterium tuberculosis complex detection in a comprehensive hospital from west china.to assess the capacity of rapid and accurate confirmation of the mycobacterium tuberculosis complex (mtbc) in a chinese clinical laboratory.201525444951
status of vitamin d, antimicrobial peptide cathelicidin and t helper-associated cytokines in patients with diabetes mellitus and pulmonary tuberculosis.pulmonary tuberculosis (ptb) is a high burden infectious disease in china. the immune function is damaged in patients with diabetes mellitus (dm) who are easy to infect with mycobacterium tuberculosis (mtb). the growth of mtb has been shown to be restrained following the administration of vitamin d and antimicrobial peptide cathelicidin (ll-37); however, the effect in patients with dm and ptb remains unclear. vitamin d can regulate the immune system through vitamin d receptors expressed in t hel ...201525452769
adjunctive biomarkers for improving diagnosis of tuberculosis and monitoring therapeutic effects.to identify host biomarkers associated with latent tuberculosis infection (ltbi), active tuberculosis (tb), and nontuberculous mycobacteria (ntm) diseases to improve diagnosis and effective anti-tb treatment.201525452040
complete annotated genome sequence of mycobacterium tuberculosis (zopf) lehmann and neumann (atcc35812) (kurono).we report the completely annotated genome sequence of mycobacterium tuberculosis (zopf) lehmann and neumann (atcc35812) (kurono), which is a used for virulence and/or immunization studies. the complete genome sequence of m. tuberculosis kurono was determined with a length of 4,415,078 bp and a g+c content of 65.60%. the chromosome was shown to contain a total of 4,340 protein-coding genes, 53 trna genes, one transfer messenger rna for all amino acids, and 1 rrn operon. lineage analysis based on ...201525458614
the present and future of tuberculosis vaccinations.the clinical, social, and economic burden of tuberculosis (tb) remains high worldwide, thereby highlighting the importance of tb prevention. the bacilli calmette-guérin (bcg) vaccine that is currently available can protect younger children but is less effective in adults, the major source of tb transmission. in addition, the emergence of drug-resistant mycobacterium tuberculosis (mtb) strains and the high prevalence of hiv infection have significantly complicated tb prognosis and treatment. toge ...201525458613
molecular characterisation of extensively drug-resistant mycobacterium tuberculosis isolates in china.the emergence of extensively drug-resistant tuberculosis (xdr-tb) in china is a great threat to tb control. to determine the molecular characterisation of xdr-tb isolates from china and the correlations between specific drug resistance-associated mutations and different genotype strains, 58 xdr-tb isolates were sequenced in eight drug loci, including katg, inha, oxyr-ahpc intergenic region, rpob, eis, rrs, gyra and gyrb, and were genotyped using spoligotyping and analysis of the noise transfer f ...201525465521
synthesis, molecular docking and anti-mycobacterial evaluation of new imidazo[1,2-a]pyridine-2-carboxamide derivatives.new anti-tubercular agents, imidazo[1,2-a]pyridine-2-carboxamide derivatives (5a-q) have been designed and synthesized. the structural considerations of the designed molecules were further supported by the docking study with a long-chain enoyl-acyl carrier protein reductase (inha). the chemical structures of the new compounds were characterized by ir, (1)h nmr, (13)c nmr, hrms and elemental analysis. in addition, single crystal x-ray diffraction has also been recorded for compound 5f. compounds ...201525462270
antimycobacterial activity of natural products and synthetic agents: pyrrolodiquinolines and vermelhotin as anti-tubercular leads against clinical multidrug resistant isolates of mycobacterium tuberculosis.various classes of natural products and synthetic compounds were tested against reference strains and clinical multidrug resistant isolates of mycobacterium tuberculosis. vermelhotin (19), a natural tetramic acid from fungi, was the most active toward clinical mdr tb isolates (mic 1.5-12.5 μg/ml). synthetic compounds (i.e. benzoxazocines, coumarins, chromenes, and pyrrolodiquinoline derivatives) were prepared by green chemistry approaches. under microwave irradiation, a one-pot synthesis of pyrr ...201525462220
diversity and disease pathogenesis in mycobacterium tuberculosis.the increasing availability of whole-genome sequence (wgs) data for mycobacterium tuberculosis, the bacterium that causes tuberculosis (tb), suggests that circulating genotypes have been molded by three dominant evolutionary forces: long-term persistence within the human population, which requires a core programme of infection, disease, and transmission; selective pressure on specific genomic loci, which provides evidence of lineage-specific adaptation to host populations; and drug exposure, whi ...201525468790
phenotypic characterization of a novel double knockout pkni/dacb2 from mycobacterium tuberculosis.serine/threonine protein kinases play a major role in peptidoglycan biosynthesis in mycobacterium tuberculosis. to explore the mechanism in detail, in the present study, we have constructed a double knockout (dko) strain lacking pkni and dacb2 in m. tuberculosis. initially, we analyzed the colony morphology and found that the dko strain showed smoother colony morphology on solid agar and irregular shape in transmission electron microscopy. in addition, the dko strain exhibits defective biofilm a ...201525467937
enriching the annotation of mycobacterium tuberculosis h37rv proteome using remote homology detection approaches: insights into structure and function.the availability of the genome sequence of mycobacterium tuberculosis h37rv has encouraged determination of large numbers of protein structures and detailed definition of the biological information encoded therein; yet, the functions of many proteins in m. tuberculosis remain unknown. the emergence of multidrug resistant strains makes it a priority to exploit recent advances in homology recognition and structure prediction to re-analyse its gene products. here we report the structural and functi ...201525467293
analysis of a draft genome sequence of kitasatospora cheerisanensis kctc 2395 producing bafilomycin antibiotics.kitasatospora cheerisanensis kctc 2395, producing bafilomycin antibiotics belonging to plecomacrolide group, was isolated from a soil sample at mt. jiri, korea. the draft genome sequence contains 8.04 mb with 73.6% g+c content and 7,810 open reading frames. all the genes for aerial mycelium and spore formations were confirmed in this draft genome. in phylogenetic analysis of mure proteins (udp-n-acetylmuramyl-(l)-alanyl-(d)-glutamate:dap ligase) in a conserved dcw (division of cell wall) locus, ...201525471184
bacillus calmette-guérin (bcg) vaccine adverse events in victoria, australia: analysis of reports to an enhanced passive surveillance system.bacillus calmette-guérin (bcg) vaccine is used worldwide, with high efficacy against childhood mycobacterium tuberculosis (tb) meningitis and miliary tb. bcg vaccine is considered safe, with serious systematic adverse events following immunization (aefi) of immunocompetent recipients being rare, although adverse event rates vary between differing bcg strains. in victoria, australia, aefi are reported to saefvic (surveillance of adverse events following vaccination in the community), an enhanced ...201525475539
human b cells produce chemokine cxcl10 in the presence of mycobacterium tuberculosis specific t cells.the role of b cells in human host response to mycobacterium tuberculosis (mtb) infection is still controversial, but recent evidence suggest that b cell follicle like structures within the lung may influence host responses through regulation of the local cytokine environment. a candidate for such regulation could be the chemokine cxcl10. cxcl10 is mainly produced by human monocytes, but a few reports have also found cxcl10 production by human b cells. the objective of this study was to investiga ...201525476870
early lesions following aerosol challenge of rhesus macaques (macaca mulatta) with mycobacterium tuberculosis (erdman strain).three rhesus macaques (macaca mulatta) were challenged with mycobacterium tuberculosis (mtb), erdman strain, as part of studies to investigate lesion development at early time points in tuberculosis (tb) and to assess computed tomography (ct) as a method of monitoring disease progression in vivo. animals were challenged with either a high, mid or low dose of aerosolized mtb. the low-dose animal was killed humanely at 24 days post challenge (dpc) and the remaining animals at 25 dpc. abnormalities ...201525481611
hspx knock-out in mycobacterium tuberculosis leads to shorter antibiotic treatment and lower relapse rate in a mouse model--a potential novel therapeutic target.effective global tuberculosis control is hindered by the need for prolonged chemotherapy which leads to poor patient compliance. therefore novel drug targets that shorten the duration of chemotherapy and reduce disease relapse rates are highly desirable. we have previously shown that hspx, an alpha-crystallin-like protein, is associated with growth suppression of mycobacterium tuberculosis in mouse models. we determined to evaluate hspx as a novel target for controlling m. tuberculosis growth in ...201525481272
pyridoxal-phosphate dependent mycobacterial cysteine synthases: structure, mechanism and potential as drug targets.the alarming increase of drug resistance in mycobacterium tuberculosis strains poses a severe threat to human health. chemotherapy is particularly challenging because m. tuberculosis can persist in the lungs of infected individuals; estimates of the who indicate that about 1/3 of the world population is infected with latent tuberculosis providing a large reservoir for relapse and subsequent spread of the disease. persistent m. tuberculosis shows considerable tolerance towards conventional antibi ...201525484279
freund's adjuvant, nod2 and mycobacteria.mycobacterium tuberculosis contributed to the discovery of delayed-type hypersensitivity and cell-mediated immunity. however, the biochemical basis for the immunogenicity of the mycobacterial cell wall has until recently remained unknown.201525483349
effective expansion of forkhead box p3⁺ regulatory t cells via early secreted antigenic target 6 and antigen 85 complex b from mycobacterium tuberculosis.the expansion of cd4+ cd25+ forkhead box (fox)p3+ regulatory t (treg) cells has been observed in patients with mycobacterium (m.) tuberculosis; however, the mechanism of expansion remains to be elucidated. the aim of the present study was to examine the role of the early secreted antigenic target 6(esat‑6) and antigen 85 complex b (ag85b) from m. tuberculosis on treg cell expansion. to investigate the sensitivity of peripheral blood cultures to the m. tuberculosis esat‑6 and ag85b antigens, the ...201525483347
appearances are deceptive: staphylococcus superinfection of clavicular tuberculous osteomyelitis.a man, aged 25 years, presented with pain, swelling, and drainage from the right clavicular area. he had a past history of abscess at the sternoclavicular joint. the cultures from the drainage site grew methicillin-sensitive staphylococcus aureus, and he was placed on appropriate antibiotics. as s. aureus infection of the clavicle is often secondary in nature, particularly in adults, a thorough workup was done to identify the underlying cause. quantiferon gold, done as a part of the workup, came ...201525487239
genotyping and molecular characteristics of multidrug-resistant mycobacterium tuberculosis isolates from china.the aim of this study was to explore the population structure of multidrug-resistant (mdr) tuberculosis strains and distribution of resistance-associated nucleotide alteration among the different genotype mdr strains in china.201525485999
mycobacterial envelope lipids fingerprint from direct maldi-tof ms analysis of intact bacilli.mycobacterium tuberculosis (mtb) lipids including glycolipids and lipoglycans play a crucial role in the modulation of the host immune response by targeting the innate receptors c-type lectins, tlrs and the cd1 proteins of class 1. glycolipids have been shown to be biomarkers of m. tuberculosis strains and also of opportunistic mycobacteria called non-tuberculous mycobacteria. most of the structural and functional work of the mtb lipids has been done using lipids arising from m. tuberculosis cel ...201525488848
quantiferon tb-gold conversion can predict active tuberculosis development in elderly nursing home residents.the study was carried out on elderly nursing home residents in taiwan. we assessed whether the serial quantiferon-tb gold (qft-g) assay and serial tuberculin skin test (tst) were reliable tools to predict or exclude the development of active tuberculosis (tb).201525495670
combinatorial active-site variants confer sustained clavulanate resistance in blac β-lactamase from mycobacterium tuberculosis.bacterial resistance to β-lactam antibiotics is a global issue threatening the success of infectious disease treatments worldwide. mycobacterium tuberculosis has been particularly resilient to β-lactam treatment, primarily due to the chromosomally encoded blac β-lactamase, a broad-spectrum hydrolase that renders ineffective the vast majority of relevant β-lactam compounds currently in use. recent laboratory and clinical studies have nevertheless shown that specific β-lactam-blac inhibitor combin ...201525492589
added value of whole-genome sequencing for management of highly drug-resistant tb.phenotypic drug susceptibility testing (dst) for mycobacterium tuberculosis takes several weeks to complete and second-line dst is often poorly reproducible, potentially leading to compromised clinical decisions. following a fatal case of xdr tb, we investigated the potential benefit of using whole-genome sequencing to generate an in silico drug susceptibility profile.201525492392
[proposal of a five miru-vntr panel to screen clinical isolates of mycobacterium tuberculosis in mexico].tuberculosis is a public health problem across mexico. this paper aims to select a panel, with a minimum number of repetitive elements (miru-vntr) for genotypic characterization of mycobacterium tuberculosis (m. tuberculosis) clinical isolates.201525500299
z-100, extracted from mycobacterium tuberculosis strain aoyama b, promotes tnf-α production via nucleotide-binding oligomerization domain containing 2 (nod2)-dependent nf-κb activation in raw264.7 cells.macrophages are a major component of the innate immune system, and the cytokines they secrete are involved in antitumor responses. z-100 is obtained from hot-water extract of human-type mycobacterium tuberculosis strain aoyama b and activates the innate immune response. however, while z-100 is known to modulate macrophage activity, the mechanism behind this modulation is not fully understood. we evaluated the effects of z-100 on the murine macrophage cell line raw264.7. tumor necrosis factor-alp ...201525499802
mycobacterium tuberculosis 19-kda lipoprotein induces toll-like receptor 2-dependent peroxisome proliferator-activated receptor γ expression and promotes inflammatory responses in human macrophages.mycobacterium tuberculosis (m.tb) enhances its survival in macrophages by suppressing immune responses, in part through its complex cell wall structures. m.tb 19‑kda lipoprotein (p19), a component of the complex cell wall structures of m.tb, is a toll‑like receptor (tlr) agonist, and may induce immune responses through tlr2. furthermore, the activation of peroxisome proliferator‑activated receptor γ (pparγ) is also involved in m.tb‑induced immune responses in macrophages. in the present study, s ...201525504154
evaluation of point mutation detection in mycobacterium tuberculosis with isoniazid resistance using real-time pcr and taqman probe assay.rapid methods for diagnosis of mycobacterium tuberculosis (mtb) drug resistance and choosing appropriate antibiotic treatment are pivotal. thirty isoniazid (inh)-resistant and 30 inh-susceptible mtb isolates were evaluated using minimum inhibitory concentration (mic) method followed by multiplex real-time pcr (rt-pcr). amplification refractory mutation system (arms) for detection of mutation in 315 codon of katg gene and single-nucleotide polymorphism (snp) for detection of mutation in -15 (c>t) ...201525503088
computational modeling predicts il-10 control of lesion sterilization by balancing early host immunity-mediated antimicrobial responses with caseation during mycobacterium tuberculosis infection.although almost a third of the world's population is infected with the bacterial pathogen mycobacterium tuberculosis, our understanding of the functions of many immune factors involved in fighting infection is limited. determining the role of the immunosuppressive cytokine il-10 at the level of the granuloma has proven difficult because of lesional heterogeneity and the limitations of animal models. in this study, we take an in silico approach and, through a series of virtual experiments, we pre ...201525512604
potentiation of antigen-specific antibody production by peptides derived from ag85b of mycobacterium tuberculosis.to generate high-titer monoclonal antibodies, strong immuno-stimulation must be used for eliciting an intense cellular immune response. here, we report that antigen-specific antibody production was potentiated by peptide-25 derived from ag85b of mycobacterium tuberculosis, and that the production of antigen-specific igg1 in particular was markedly potentiated; specifically, this occurred because the use of peptide-25 resulted in an increase in the number of antigen-specific antibody-producing ce ...201525514091
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