| identification of novel inhibitors of m. tuberculosis growth using whole cell based high-throughput screening. | despite the urgent need for new antitubercular drugs, few are on the horizon. to combat the problem of emerging drug resistance, structurally unique chemical entities that inhibit new targets will be required. here we describe our investigations using whole cell screening of a diverse collection of small molecules as a methodology for identifying novel inhibitors that target new pathways for mycobacterium tuberculosis drug discovery. we find that conducting primary screens using model mycobacter ... | 2012 | 22577943 |
| antimycobacterial activities of novel 5-(1h-1,2,3-triazolyl)methyl oxazolidinones. | the antibacterial activities of a series of triazolyl oxazolidinones against mycobacterium tuberculosis strain in vitro and in vivo in a mice model are presented. most active compounds were noncytotoxic against vero cells with acceptable selectivity indexes (si) as measures of compound tolerability. structure activity relationships (sars) revealed that analogs with alkylcarbonyl (ic(90): < 0.2 to 0.422 μg/ml) and arylcarbonyl (ic(90): < 0.2 to 2.103 μg/ml) groups at the piperazine 4n-position-di ... | 2012 | 22577542 |
| evaluation of the nitrate reductase assay for the rapid detection of resistance to first-line medications in mycobacterium tuberculosis strains isolated from patients in a general hospital. | we compared the nitrate reductase assay with the proportion method, which is considered the gold standard, in 57 mycobacterium tuberculosis strains isolated from patients treated at the federal university of minas gerais hospital das clínicas, located in the city of belo horizonte, brazil. for rifampin and isoniazid, the sensitivity, specificity, and accuracy of the nitrate reductase assay were all 100%, whereas they were 100%, 88.9%, and 66.7%, respectively, for streptomycin and 98.0%, 100%, an ... | 2015 | 22576429 |
| methylthioxylose--a jewel in the mycobacterial crown? | ten years ago an unusual sugar was discovered in a cell wall polysaccharide of mycobacterium tuberculosis. structural elucidation revealed the presence of the first thiosugar in a bacterial polysaccharide. synthetic studies have helped to define its relative and absolute configuration as α-d-methylthioxylofuranosyl. while its biosynthetic origins remain the subject of speculation, work has begun to define its possible biological roles. | 2012 | 22575989 |
| a solvent free, four-component synthesis and 1,3-dipolar cycloaddition of 4(h)-pyrans with nitrile oxides: synthesis and discovery of antimycobacterial activity of enantiomerically pure 1,2,4-oxadiazoles. | four-component reactions of (r)-1-(1-phenylethyl)tetrahydro-4(1h)-pyridinone, aromatic aldehydes and malononitrile in a 1:2:1 molar ratio in the presence of solid sodium ethoxide under solvent free conditions afforded an inseparable mixture of two diastereomeric 4(h)-pyrans in near quantitative yields. these compounds upon 1,3-dipolar cycloaddition with nitrile oxides furnished two enantiomerically pure 1,2,4-oxadiazoles in moderate yields, which were screened for in vitro activity against mycob ... | 2012 | 22575534 |
| molecular typing of mycobacterium tuberculosis isolated from adult patients with tubercular spondylitis. | tuberculosis (tb) is endemic in taiwan and usually affects the lung, spinal tb accounting for 1-3% of all tb infections. the manifestations of spinal tb are different from those of pulmonary tb. the purpose of this study was to define the epidemiological molecular types of mycobacterial strains causing spinal tb. | 2013 | 22575429 |
| potential use of nitrate reductase as a biomarker for the identification of active and dormant inhibitors of mycobacterium tuberculosis in a thp1 infection model. | the development of a macrophage-based, antitubercular high-throughput screening system could expedite discovery programs for identifying novel inhibitors. in this study, the kinetics of nitrate reduction (nr) by mycobacterium tuberculosis during growth in thp1 macrophages was found to be almost parallel to viable bacilli count. nr in the culture medium containing 50 mm of nitrate was found to be optimum on the fifth day after infection with m. tuberculosis. the signal-to-noise (s/n) ratio and z- ... | 2012 | 22573731 |
| synthesis and antimycobacterial activity of prodrugs of sulfur dioxide (so2). | here, we synthesized and studied a library of 2,4-dinitrophenylsulfonamides that closely resembled n-benzyl-2,4-dinitrophenylsulfonamide (1), a thiol-activated prodrug of sulfur dioxide (so(2)) which has shown high potency as a mycobacterium tuberculosis (mtb) inhibitory agent. the ability of these compounds to generate so(2) in the presence of a thiol was evaluated. a good correlation between pk(ah) of the corresponding amine and reactivity with thiols to generate so(2) was found suggesting tha ... | 2012 | 22572576 |
| immunogenicity and protective efficacy of a novel recombinant bcg strain overexpressing antigens ag85a and ag85b. | recombinant bacillus calmette-guérin (rbcg) strain is the promising vaccine candidate for tuberculosis (tb) prevention, which aims at providing more enduring and enhanced protection than the parental bcg vaccine. in this study, three rbcg strains overexpressing immunodominant antigens ag85b (rbcg::85b), ag85a (rbcg::85a), or both (rbcg::ab) of mycobacterium tuberculosis were constructed, respectively. rbcg strains showed higher level of overexpression of ag85a and/or ag85b proteins than bcg cont ... | 2012 | 22570667 |
| 3d-qsar studies on fluroquinolones derivatives as inhibitors for tuberculosis. | a quantitative structure activity relationship (qsar) study was performed on the fluroquinolones known to have anti-tuberculosis activity. the 3d-qsar models were generated using stepwise variable selection of the four methods - multiple regression (mr), partial least square regression (plsr), principal component regression (pcr) and artificial neural networks (knn-mfa). the statistical result showed a significant correlation coefficient q(2) (90%) for mr model and an external test set of (pred_ ... | 2012 | 22570519 |
| multidrug-resistant tuberculosis in port-au-prince, haiti. | to determine the prevalence of multidrug-resistant tuberculosis (mdr-tb) among patients with new smear-positive pulmonary tb in port-au-prince, haiti. | 2012 | 22569696 |
| performance of an interferon-gamma release assay to diagnose latent tuberculosis infection during pregnancy. | to evaluate an interferon (ifn)-gamma release assay in diagnosing latent tuberculosis infection in pregnant adolescents and women at risk for exposure to mycobacterium tuberculosis. | 2012 | 22569120 |
| implication of the rd(rio) mycobacterium tuberculosis sublineage in multidrug resistant tuberculosis in portugal. | multidrug and extensively drug resistant mycobacterium tuberculosis are a threat to tuberculosis control programs. genotyping methods, such as spoligotyping and miru-vntr typing (mycobacterial interspersed repetitive units), are useful in monitoring potentially epidemic strains and estimating strain phylogenetic lineages and/or genotypic families. m. tuberculosis latin american mediterranean (lam) family is a major worldwide contributor to tuberculosis (tb). lam specific molecular markers, ag85c ... | 2012 | 22569099 |
| effect of antimicrobial peptides on atpase activity and proton pumping in plasma membrane vesicles obtained from mycobacteria. | the potential usefulness of antimicrobial peptides (amps) as antimycobacterial compounds has not been extensively explored. although a myriad of studies on amps from different sources have been done, some of its mechanisms of action are still unknown. maganins are of particular interest since they do not lyse non-dividing mammalian cells. in this work, amps with well-recognized activity against bacteria were synthesized, characterized, purified and their antimycobacterial activity and influence ... | 2012 | 22569076 |
| pediatric tuberculosis: new guidelines and recommendations. | to discuss the recommendations pertaining to infants, children, and adolescents in new and updated tuberculosis (tb) guidelines that have been published since 2010 - with emphasis on those from supranational organizations. | 2012 | 22568943 |
| [mycobacterium tuberculosis mutants with multidrug resistance: history of origin, genetic and molecular mechanisms of resistance, and emerging challenges]. | the review summarizes the data on the mycobacterium tuberculosis mutations that lead to multidrug resistance (mdr) to various antibiotics. mdr strains arose over the past 30 years as a variety of antituberculosis drugs were introduced in medicine, and they largely discount the results of chemotherapy for tuberculosis. the most dangerous of them are strains with extensive drug resistance (xdr), which are resistant to four or five different drugs on average. the molecular mechanisms that make a st ... | 2012 | 22567849 |
| pulmonary disease due to mycobacterium tuberculosis in a horse: zoonotic concerns and limitations of antemortem testing. | a case of pulmonary tuberculosis caused by mycobacterium tuberculosis was diagnosed in a horse. clinical evaluation performed prior to euthanasia did not suggest tuberculosis, but postmortem examination provided pathological and bacteriological evidence of mycobacteriosis. in the lungs, multiple tuberculoid granulomas communicating with the bronchiolar lumen, pleural effusion, and a granulomatous lymphadenitis involving mediastinal and tracheobronchial lymph nodes were found. serologic response ... | 2012 | 22567544 |
| the use of interferon gamma release assays in the diagnosis of active tuberculosis. | interferon gamma release assays (igras) are in vitro immunologic diagnostic tests used to identify mycobacterium tuberculosis infection. they cannot differentiate between latent and active infections. the cutoff suggested by the manufacturer is 0.35 iu/ml for latent tuberculosis. as igra tests were recently approved for the differential diagnosis of active tuberculosis, we assessed the diagnostic accuracy of the latest generation igra for detection of active tuberculosis in a low-incidence area ... | 2012 | 22567275 |
| maintenance of sensitivity of the t-spot.tb assay after overnight storage of blood samples, dar es salaam, tanzania. | background. t-spot.tb is an interferon gamma release assay for detecting mycobacterium tuberculosis infection. the requirement to process within 8 hours is constraining, deters use, and leads to invalid results. addition of t cell xtend reagent may allow delayed processing, but has not been extensively field tested. design. consecutive afb smear positive adult tuberculosis patients were prospectively recruited in dar es salaam, tanzania. patients provided a medical history, 1-3 sputum samples fo ... | 2012 | 22567274 |
| escape from the phagosome: the explanation for mhc-i processing of mycobacterial antigens? | mycobacterium tuberculosis (mtb) is thought to live in an altered phagosomal environment. in this setting, the mechanisms by which mycobacterial antigens access the major histocompatibility class i (mhc-i) processing machinery remain incompletely understood. there is evidence that mtb antigens can be processed in both endocytic and cytosolic environments, with different mechanisms being proposed for how mtb antigens can access the cytosol. recently, electron microscopy was used to demonstrate th ... | 2012 | 22566923 |
| tuberculous brain abscess and subdural empyema in an immunocompetent child: significance of afb staining in aspirated pus. | tuberculous brain abscess and subdural empyema are extremely rare manifestations of central nervous system tuberculosis. here, we report a case of an 11-year-old immunocompetent child who developed temporal lobe abscess and subdural empyema following chronic otitis media. a right temporal craniotomy was performed and the abscess was excised. the ziehl nielsen staining of the aspirated pus from the temporal lobe abscess yielded acid fast bacilli. prompt administration of antituberculous treatment ... | 2012 | 22566728 |
| dynamic roles of type i and type ii ifns in early infection with mycobacterium tuberculosis. | although the protective role of type ii ifn, or ifn-γ, against mycobacterium tuberculosis has been established, the effects of type i ifns are still unclear. one potential confounding factor is the overlap of function between the two signaling pathways. we used mice carrying null mutations in the type i ifnr, type ii ifnr, or both and compared their immune responses to those of wild-type mice following aerosol infection with m. tuberculosis. we discovered that, in the absence of a response to if ... | 2012 | 22566567 |
| population pharmacokinetics and pharmacodynamics of ofloxacin in south african patients with multidrug-resistant tuberculosis. | despite the important role of fluoroquinolones and the predominant use of ofloxacin for treating multidrug-resistant tuberculosis in south africa, there are limited data on ofloxacin pharmacokinetics in patients with multidrug-resistant tuberculosis, no ofloxacin pharmacokinetic data from south african patients, and no direct assessment of the relationship between ofloxacin pharmacokinetics and the mic of ofloxacin of patient isolates. our objectives are to describe ofloxacin pharmacokinetics in ... | 2012 | 22564839 |
| patients exposed to mycobacterium tuberculosis infection with a prominent ige response. | even though it has been reported that chronic immune activation associated with intestinal helminthic infections results in a predominant ige response, specific ige antibodies that are also interleukin 4 (il-4) dependent have been reported in tuberculosis patients; however, this fact has not been widely reported. this study was aimed at investigating the levels of circulating ige in warao (an indigenous population) of the orinoco river delta, an area isolated from contact with the tubercle bacil ... | 2012 | 22564424 |
| evaluation of nutrient agar for the culture of mycobacterium tuberculosis using the microcolony detection method. | we evaluated nutrient agar using the microcolony detection method for the recovery of mycobacterium tuberculosis on 37 acid-fast bacilli (afb) positive sputum specimens, and compared it with conventional löwenstein-jensen (lj) medium. nutrient agar detected 35 isolates compared to 34 on lj medium. the mean time to detection of mycobacteria on nutrient agar and lj medium was respectively 9.6 and 21.4 days. the contamination rate on nutrient agar and lj medium was respectively 5.4% and 2.7%. nutri ... | 2012 | 22564319 |
| appropriate devr (dosr)-mediated signaling determines transcriptional response, hypoxic viability and virulence of mycobacterium tuberculosis. | the devr(dosr) regulon is implicated in hypoxic adaptation and virulence of mycobacterium tuberculosis. the present study was designed to decipher the impact of perturbation in devr-mediated signaling on these properties. | 2012 | 22563409 |
| [molecular analysis of strains from tuberculosis patients in polish prisons in 2004-2008. initial analysis of the project]. | correctional facilities are recognised breeding ground for infectious diseases. as the world health organization reported the incidence of infectious diseases in prison's population is 10-100 times higher than in general population. the incidence of tuberculosis among correctional inmates in poland in 2008 was 270/100000, that is around 10 times higher than among non-prisoners. | 2012 | 22562272 |
| conformational changes upon ligand binding in the essential class ii fumarase rv1098c from mycobacterium tuberculosis. | rv1098c, an essential gene in mycobacterium tuberculosis, codes for a class ii fumarase. we describe here the crystal structure of rv1098c in complex with l-malate, fumarate or the competitive inhibitor meso-tartrate. the models reveal that substrate binding promotes the closure of the active site through conformational changes involving the catalytic ss-loop and the c-terminal domain, which likely represents a general feature of this enzyme superfamily. analysis of ligand-enzyme interactions as ... | 2012 | 22561013 |
| the mycobacterium tuberculosis very-long-chain fatty acyl-coa synthetase: structural basis for housing lipid substrates longer than the enzyme. | the mycobacterium tuberculosis acid-induced operon myma encodes the fatty acyl-coa synthetase fadd13 and is essential for virulence and intracellular growth of the pathogen. fatty acyl-coa synthetases activate lipids before entering into the metabolic pathways and are also involved in transmembrane lipid transport. unlike soluble fatty acyl-coa synthetases, but like the mammalian integral-membrane very-long-chain acyl-coa synthetases, fadd13 accepts lipid substrates up to the maximum length test ... | 2012 | 22560731 |
| molecular characterization of fluoroquinolone-resistant mycobacterium tuberculosis clinical isolates from shanghai, china. | china is one of the countries with the highest prevalence of fluoroquinolone-resistant (fq(r)) mycobacterium tuberculosis. nevertheless, knowledge on the molecular characterization of the fq(r)m. tuberculosis strains of this region remains very limited. this study was performed to investigate the frequencies and types of mutations present in fq(r)m. tuberculosis clinical isolates collected in shanghai, china. a total of 206 fq(r)m. tuberculosis strains and 21 ofloxacin-sensitive (fq(s)) m. tuber ... | 2012 | 22560167 |
| in vitro effects of citrus oils against mycobacterium tuberculosis and non-tuberculous mycobacteria of clinical importance. | we evaluated the in vitro activity of citrus oils against mycobacterium tuberculosis and other non-tuberculous mycobacterium species. citrus essential oils were tested against a variety of mycobacterium species and strains using the bactec radiometric growth system. cold pressed terpeneless valencia oil (cpt) was further tested using the wayne model of in vitro latency. exposure of m. tuberculosis and m. bovis bcg to 0.025 % cold pressed terpeneless valencia orange oil (cpt) resulted in a 3-log ... | 2012 | 22560037 |
| characterization of a novel arsr-like regulator encoded by rv2034 in mycobacterium tuberculosis. | the genome of mycobacterium tuberculosis, the causative agent of tuberculosis, encodes a large number of putative transcriptional regulators. however, the identity and target genes of only a few of them have been clearly identified to date. in a recent study, the arsr family regulator rv2034 was characterized as a novel positive regulator of phop. in the current study, we characterized the auto-repressive capabilities of rv2034 and identified several residues in the protein critical for its dna ... | 2012 | 22558408 |
| mycobacterium tuberculosis growth following aerobic expression of the dosr regulon. | the mycobacterium tuberculosis regulator dosr is induced by multiple stimuli including hypoxia, nitric oxide and redox stress. overlap of these stimuli with conditions thought to promote latency in infected patients fuels a model in which dosr regulon expression is correlated with bacteriostasis in vitro and a proxy for latency in vivo. here, we find that inducing the dosr regulon to wildtype levels in aerobic, replicating m. tuberculosis does not alter bacterial growth kinetics. we conclude tha ... | 2012 | 22558276 |
| monthly follow-ups of interferon-γ release assays among health-care workers in contact with patients with tb. | interferon-γ (ifn-γ) release assays (igras), which can overcome several limitations of the tuberculin skin test in detecting latent tb infection, were introduced recently in routine clinical practice. however, igras are highly dynamic tests, and the t-cell responses tend to fluctuate over time. we wanted to evaluate the conversion and reversion rates of monthly igras over 1 year among health-care workers (hcws) in contact with patients with tb in south korea, a country with an intermediate tb bu ... | 2012 | 22556318 |
| synthesis and in vitro antibacterial activity of novel 3-azabicyclo[3.3.0]octanyl oxazolidinones. | we synthesized a series of oxazolidinone-type antibacterials in which morpholine c-ring of linezolid has been modified by substituted 3-azabicyclo[3.3.0]octanyl rings. acetamide or 1,2,3-triazole heterocycle was used as c-5 side chain of oxazolidinone. the resulting series of compounds was then screened in vitro against panel of susceptible and resistant gram-positive, gram-negative bacteria, and mycobacterium tuberculosis (mtb). several analogs in this series exhibited potent in vitro antibacte ... | 2012 | 22553981 |
| association between the cd209 promoter -336a/g polymorphism and susceptibility to tuberculosis: a meta-analysis. | dendritic cell-specific intracellular adhesion molecule-3 grabbing nonintegrin (dc-sign), encoded by the cd209 gene, is a major mycobacterium tuberculosis receptor on human dendritic cells. the potentially functional -336a/g polymorphism in the cd209 promoter region has been associated with susceptibility to tuberculosis (tb), but the results have been inconclusive. we performed a meta-analysis to clarify the relationship between the cd209-336a/g variant and the risk of tb. | 2012 | 22553928 |
| molecular characterization of multidrug- and extensively drug-resistant mycobacterium tuberculosis strains in jiangxi, china. | in this study, a total of 77 multidrug-resistant and extensively drug-resistant (mdr and xdr, respectively) isolates of mycobacterium tuberculosis were characterized among samples from patients living in jiangxi province, china. the following two approaches were used: (i) genotyping all drug-resistant isolates by the 15-locus miru-vntr (mycobacterial interspersed repetitive-unit-variable-number tandem-repeat) method and identifying the beijing family genotype using the rd105 deletion targeted mu ... | 2012 | 22553245 |
| seektb, a two-stage multiplex real-time-pcr-based method for differentiation of the mycobacterium tuberculosis complex. | tuberculosis (tb) in humans is caused by members of the mycobacterium tuberculosis complex (mtc). the accurate identification of the mtc member causing human infection is important because the treatment of tb caused by some mtc members requires an alteration of the standard drug regimen, it can inform whether transmission is human to human or zoonotic, and it enables accurate epidemiology studies that help improve tb control. in this study, an internally controlled two-stage multiplex real-time ... | 2012 | 22553241 |
| rapid spoligotyping of mycobacterium tuberculosis complex bacteria by use of a microarray system with automatic data processing and assignment. | membrane-based spoligotyping has been converted to dna microarray format to qualify it for high-throughput testing. we have shown the assay's validity and suitability for direct typing from tissue and detecting new spoligotypes. advantages of the microarray methodology include rapidity, ease of operation, automatic data processing, and affordability. | 2012 | 22553239 |
| can a simple flotation method lower the limit of detection of mycobacterium tuberculosis in extrapulmonary samples analyzed by the genexpert mtb/rif assay? | the rapid and accurate diagnosis of tuberculosis (tb) in children and extrapulmonary tb in adults continues to be a challenge. in this study, we determined the lower limit of detection (lod) of the genexpert mtb/rif assay with nonrespiratory specimens and investigated the utility of flotation procedures for concentrating the bacilli. clinical specimens (9 cerebrospinal fluid [csf], 13 gastric aspirate, 8 tissue, and 17 stool) were spiked with single-celled mycobacterium tuberculosis, and the lod ... | 2012 | 22553234 |
| previous use of quinolones: a surrogate marker for first line anti-tuberculosis drugs resistance in hiv-infected patients? | drug resistant mycobacterium tuberculosis causes much higher rates of treatment toxicity, failure or relapse, and mortality. we determined the drug resistant profile of mycobacterium tuberculosis strains isolated from a population of hiv-infected patients in southern brazil and studied the potential factors associated with resistance. | 2017 | 22552455 |
| characterization of gyra and gyrb mutations and fluoroquinolone resistance in mycobacterium tuberculosis clinical isolates from hubei province, china. | the study aimed to investigate gyra and gyrb mutations in mycobacterium tuberculosis (mtb) clinical strains from 93 patients with pulmonary tuberculosis in hubei province, china, and analyze the association between mutation patterns of the genes and ofloxacin resistance level. | 2017 | 22552454 |
| t-bet acts as a powerful adjuvant in ag85b dna‑based vaccination against tuberculosis. | owing to the limitations of traditional bacillus calmette-guerin vaccines and the low efficacy of dna vaccines expressing single antigens of mycobacterium tuberculosis, there is a pressing requirement for adjuvants capable of strengthing the immunogenicity and effectiveness of these vaccines against tuberculosis (tb). t-bet (tbx21) is a transcription factor, which controls the optimal development of type-1 immune responses responsible for the potent protection of vaccines against tb. however, li ... | 2012 | 22552442 |
| [sternoclavicular joint tuberculosis]. | a 24-year old woman presented with an abscess localized at the median side of the right clavicle. there were no clinical signs of tuberculosis and radiological evaluation was normal. pcr-assay on tuberculosis following aspiration of the pus collection was positive for mycobacterium tuberculosis. she responded well on regular anti-tuberculosis treatment. | 2012 | 22551751 |
| tuberculous meningitis in a lung transplanted patient. | a 57-year-old female lung transplant recipient developed tuberculosis after quadruple maintenance immunosuppression for acute cellular rejection with respiratory compromise. deteriorating neurological status led to cerebral imaging and lumbar puncture, which showed mycobacterium tuberculosis. tuberculous meningitis with elevated intracranial pressure was treated for 2 weeks on a neurosurgical ward, and intensive care therapy was necessary for another 2 weeks. complete neurological recovery was a ... | 2012 | 22548838 |
| mouse model for efficacy testing of antituberculosis agents via intrapulmonary delivery. | here we describe an experimental murine model that allows for aerosolized antituberculosis drug efficacy testing. intrapulmonary aerosol delivery of isoniazid, capreomycin, and amikacin to mice with pulmonary infection of mycobacterium tuberculosis demonstrated efficacy in reducing pulmonary bacterial loads similar to that seen by standard drug delivery methods, even when lower concentrations of drugs and fewer doses were used in the aerosolized drug regimens. interestingly, intrapulmonary deliv ... | 2012 | 22547626 |
| rifapentine is not more active than rifampin against chronic tuberculosis in guinea pigs. | rifamycins are key sterilizing drugs in the current treatment of active tuberculosis (tb). daily dosing of rifapentine (p), a potent rifamycin with high intracellular accumulation, in place of rifampin (r) in the standard antitubercular regimen significantly shortens the duration of treatment needed to prevent relapse in a murine model of active tb. we undertook the current study to compare directly the activities of human-equivalent doses of p and r in a guinea pig model of chronic tb, in which ... | 2012 | 22547623 |
| bronchiolitis obliterans organizing pneumonia (boop) after renal transplantation. | a 42-year-old renal transplant recipient was admitted with fever, anorexia, malaise, nonproductive cough, and dyspnea of 1-week duration. multiple cultures of blood, sputum, and urine were negative. the possibility of bronchiolitis obliterans with organizing pneumonia (boop) was considered when pulmonary infiltrate did not respond to conventional antibiotic therapy. high-resolution computed tomography of the chest revealed patchy air-space consolidation and ground-glass opacities, predominantly ... | 2013 | 22547135 |
| tuberculosis in saudi arabia: prevalence and antimicrobial resistance. | tuberculosis is a serious contagious disease caused by mycobacterium tuberculosis and is endemic in many countries. over the past two decades, there has been an increase in the number of multidrug-resistant tb and extensively drug-resistant tb cases around the world. as in many countries, tb is common in saudi arabia. the disease is particularly relevant in the kingdom because of its population dynamics including a large number of resident expatriates mainly from tb endemic regions and the influ ... | 2012 | 22546717 |
| infection of human thp-1 cells with dormant mycobacterium tuberculosis. | dormant, non-replicating mycobacterium tuberculosis h37rv strain cultured in hypoxic conditions was used to infect thp-1 cells. cfus counting, kinyoun staining and electron microscopy showed that dormant bacilli infected thp-1 cells at a rate similar to replicating m. tuberculosis, but failed to grow during the first 6 days of infection. the absence of growth was specific to the intracellular compartment, as demonstrated by efficient growth in liquid medium. quantification of β-actin mrna recove ... | 2012 | 22546526 |
| distinct effector memory cd4+ t cell signatures in latent mycobacterium tuberculosis infection, bcg vaccination and clinically resolved tuberculosis. | two billion people worldwide are estimated to be latently infected with mycobacterium tuberculosis (mtb) and are at risk for developing active tuberculosis since mtb can reactivate to cause tb disease in immune-compromised hosts. individuals with latent mtb infection (ltbi) and bcg-vaccinated individuals who are uninfected with mtb, harbor antigen-specific memory cd4(+) t cells. however, the differences between long-lived memory cd4(+) t cells induced by latent mtb infection (ltbi) versus bcg va ... | 2012 | 22545156 |
| mycobacterium tuberculosis modulates macrophage lipid-sensing nuclear receptors pparγ and tr4 for survival. | mycobacterium tuberculosis-macrophage interactions are key to pathogenesis and clearance of these bacteria. although interactions between m. tuberculosis-associated lipids and tlrs, non-tlrs, and opsonic receptors have been investigated, interactions of these lipids and infected macrophage lipid repertoire with lipid-sensing nuclear receptors expressed in macrophages have not been addressed. in this study, we report that m. tuberculosis-macrophage lipids can interact with host peroxisome prolife ... | 2012 | 22544925 |
| the dormancy regulator dosr controls ribosome stability in hypoxic mycobacteria. | it is thought that during latent infection, mycobacterium tuberculosis bacilli are retained within granulomas in a low-oxygen environment. the dormancy survival (dos) regulon, regulated by the response regulator dosr, appears to be essential for hypoxic survival in m. tuberculosis, but it is not known how the regulon promotes survival. here we report that mycobacteria, in contrast to enteric bacteria, do not form higher-order structures (e.g. ribosomal dimers) upon entry into stasis. instead, ri ... | 2012 | 22544737 |
| a novel assay detecting recall response to mycobacterium tuberculosis: comparison with existing assays. | a strategy to reduce the burden of active tb is isoniazid preventive therapy for latent tb infection (ltbi). however, current assays used to diagnose ltbi all have limitations. in these proof of concept studies, we compared the agreement of a novel flow cytometry assay detecting cd25/cd134 co-expression with quantiferon-tb gold in-tube (qfn-git) and tuberculin skin test (tst) in the detection of recall immune response to tb. the cd25/cd134 assay, qfn-git and tst were performed on 74 participants ... | 2012 | 22542644 |
| enhanced cellular immune response elicited by a dna vaccine fused with ub against mycobacterium tuberculosis. | this study evaluated the immune response elicited by a ub-fused ag85a dna vaccine against mycobacterium tuberculosis. balb/c mice were vaccinated with plasmid dna encoding ag85a protein, ub-fused ag85a dna vaccine (ubgr-ag85a) and negative dna vaccines, respectively. ag85a dna vaccine immunization induced a th(l)-polarized immune response. the production of th(l)-type cytokine (ifn-γ) and proliferative t cell responses was enhanced significantly in mice immunized with ubgr-ag85a fusion dna vacci ... | 2012 | 22540309 |
| direct molecular detection of mycobacterium tuberculosis complex from clinical samples - an adjunct to cultural method of laboratory diagnosis of tuberculosis. | tuberculosis, a communicable disease with significant morbidity and mortality, is the leading cause of death in the world from bacterial infectious disease. because of its public health importance, there is need for rapid and definitive method of detecting the causative organism. several approaches have been attempted, but the molecular methods, especially polymerase chain reaction assays are the most promising for rapid detection of mycobacterium tuberculosis complex from clinical samples. | 2011 | 22540099 |
| mycobacteria-infected bystander macrophages trigger maturation of dendritic cells and enhance their ability to mediate hiv transinfection. | synergistic interplay between mycobacterium tuberculosis (mtb) and hiv in coinfected individuals leads to the acceleration of both tuberculosis and hiv disease. mtb, as well as hiv, may modulate the function of many immune cells, including dcs. to dissect the bystander impact of mφs infected with mtb on dc functionality, we here investigated changes in dc phenotype, cytokine profiles, and hiv-1 transinfecting ability. an in vitro system was used in which human monocyte-derived dcs were exposed t ... | 2012 | 22539293 |
| deletion of manc in corynebacterium glutamicum results in a phospho-myo-inositol mannoside- and lipoglycan-deficient mutant. | mannose is an important constituent of the immunomodulatory glycoconjugates of the mycobacterial cell wall: lipoarabinomannan (lam), lipomannan (lm) and the related phospho-myo-inositol mannosides (pims). in mycobacterium tuberculosis and the related bacillus corynebacterium glutamicum, mannose is either imported from the medium or derived from glycolysis, and is subsequently converted into the nucleotide-based sugar donor guanosine diphosphomannose (gdp-mannose). this can be utilized by the gly ... | 2012 | 22539165 |
| janus-faced liposomes enhance antimicrobial innate immune response in mycobacterium tuberculosis infection. | we have generated unique asymmetric liposomes with phosphatidylserine (ps) distributed at the outer membrane surface to resemble apoptotic bodies and phosphatidic acid (pa) at the inner layer as a strategy to enhance innate antimycobacterial activity in phagocytes while limiting the inflammatory response. results show that these apoptotic body-like liposomes carrying pa (abl/pa) (i) are more efficiently internalized by human macrophages than by nonprofessional phagocytes, (ii) induce cytosolic c ... | 2012 | 22538807 |
| protein-protein interactions between histidine kinases and response regulators of mycobacterium tuberculosis h37rv. | using yeast two-hybrid assay, we investigated protein-protein interactions between all orthologous histidine kinase (hk)/response regulator (rr) pairs of m. tuberculosis h37rv and identified potential protein-protein interactions between a noncognate hk/rr pair, dost/narl. the protein interaction between dost and narl was verified by phosphotransfer reaction from dost to narl. furthermore, we found that the dost and doss hks, which share considerable sequence similarities to each other and form ... | 2012 | 22538656 |
| computational structural analysis of proteins of mycobacterium tuberculosis and a resource for identifying off-targets. | advancement in technology has helped to solve structures of several proteins including m. tuberculosis (mtb) proteins. identifying similarity between protein structures could not only yield valuable clues to their function, but can also be employed for motif finding, protein docking and off-target identification. the current study has undertaken analysis of structures of all mtb gene products with available structures was analyzed. majority of the mtb proteins belonged to the α/β class. 23 diffe ... | 2012 | 22538508 |
| [tuberculosis]. | tuberculosis is still one of the most important infectious disease worldwide. in germany the tuberculosis incidence has been declining for decades to currently about 4500 new cases per year. a new challenge poses the rising number tuberculosis cases with drug resistant strains of mycobacterium tuberculosis. substantiell progress has been achieved in the diagnosis of tuberculosis with new molecular techniques that can lead to a much faster and more reliable identification of cases with acid-fast ... | 2012 | 22538419 |
| concomitant drug- and infection-induced antineutrophil cytoplasmic autoantibody (anca)-associated vasculitis with multispecific anca. | to report the first case of concomitant drug- and infection-induced antineutrophil cytoplasmic antibodies (anca)-associated vasculitis (aav) in a patient treated with propylthiouracil (ptu) and suffering from tuberculosis. | 2012 | 22538212 |
| utility of polymerase chain reaction in diagnosis of tuberculosis in our setup: a ten years experience. | to evaluate the yield of polymerase chain reaction (pcr) for detection of mycobacterium tuberculosis from different clinical specimens. | 2012 | 22538034 |
| in vitro and in vivo identification of a novel cytotoxic t lymphocyte epitope from rv3425 of mycobacterium tuberculosis. | the identification of novel cytotoxic t lymphocyte (ctl) epitopes is important to analysis of the involvement of cd8(+) t cells in mycobacterium tuberculosis infection as well as to the development of peptide vaccines. in this study, a novel ctl epitope from region of difference 11 encoded antigen rv3425 was identified. epitopes were predicted by the reversal immunology approach. rv3425-p118 (liasnvagv) was identified as having relatively strong binding affinity and stability towards the hla-a*0 ... | 2012 | 22537173 |
| point-of-care detection of lipoarabinomannan (lam) in urine for diagnosis of hiv-associated tuberculosis: a state of the art review. | detection of mycobacterium tuberculosis antigens in urine is attractive as a potential means of diagnosing tuberculosis (tb) regardless of the anatomical site of disease. the most promising candidate antigen is the cell wall lipopolysaccharide antigen lipoarabinomannan (lam), which has been used to develop commercially available enzyme-linked immunosorbent assays. although highly variable diagnostic accuracy has been observed in different clinical populations, it is now clear that this assay has ... | 2012 | 22536883 |
| use of interferon-gamma release assays in a health care worker screening program: experience from a tertiary care centre in the united states. | interferon-gamma release assays including the quantiferon-tb gold in-tube test (qft-git [cellestis ltd, australia]) may be used in place of the tuberculin skin test (tst) in surveillance programs for mycobacterium tuberculosis infection control. however, data on performance and practicality of the qft-git in such programs for health care workers (hcws) are limited. | 2016 | 22536576 |
| mycoketide: a cd1c-presented antigen with important implications in mycobacterial infection. | mycobacterium tuberculosis and related mycobacteria species are unique in that the acid-fast bacilli possess a highly lipid-rich cell wall that not simply confers resistance to treatment with acid alcohol, but also controls their survival and virulence. it has recently been established that a fraction of the cell wall lipid components of mycobacteria can function as antigens targeted by the acquired immunity of the host. human group 1 cd1 molecules (cd1a, cd1b, and cd1c) bind a pool of lipid ant ... | 2012 | 22536277 |
| human tuberculous meningitis caused by mycobacterium caprae. | tuberculous meningitis (tm) causes substantial morbidity and mortality in humans. human tm has been known to be induced by bacteria from the mycobacterium tuberculosis complex (mtbc), such as m. tuberculosis and m. bovis. | 2012 | 22536183 |
| rapid, high-throughput detection of rifampin resistance and heteroresistance in mycobacterium tuberculosis by use of sloppy molecular beacon melting temperature coding. | rifampin resistance in mycobacterium tuberculosis is largely determined by mutations in an 80-bp rifampin resistance determining region (rrdr) of the rpob gene. we developed a rapid single-well pcr assay to identify rrdr mutations. the assay uses sloppy molecular beacons to probe an asymmetric pcr of the m. tuberculosis rrdr by melting temperature (t(m)) analysis. a three-point t(m) code is generated which distinguishes wild-type from mutant rrdr dna sequences in approximately 2 h. the assay was ... | 2012 | 22535987 |
| complete annotated genome sequence of mycobacterium tuberculosis erdman. | we report the completely annotated genome sequence of mycobacterium tuberculosis erdman (tmc 107; atcc 35801), which is a well-known laboratory strain of m. tuberculosis. | 2012 | 22535945 |
| [dna mutations associated to rifampicin or isoniazid resistance in m. tuberculosis clinical isolates from sonora, mexico]. | to perform the analysis of specific regions of the major genes associated with resistance to isoniazid or rifampin. | 2013 | 22535176 |
| synthesis of potent inhibitors of β-ketoacyl-acyl carrier protein synthase iii as potential antimicrobial agents. | mycobacterium tuberculosis fabh, an essential enzyme in the mycolic acid biosynthetic pathway, is an attractive target for novel anti-tubercolosis agents. structure-based design and synthesis of 1-(4-carboxybutyl)-4-(4-(substituted benzyloxy)phenyl)-1h-pyrrole-2-carboxylic acid derivatives 7a-h, a subset of eight potential fabh inhibitors, is described in this paper. the vilsmeier-haack reaction was employed as a key step. the structures of all the newly synthesized compounds were identified by ... | 2012 | 22534662 |
| isolation of a distinct mycobacterium tuberculosis mannose-capped lipoarabinomannan isoform responsible for recognition by cd1b-restricted t cells. | mannose-capped lipoarabinomannan (manlam) is a complex lipoglycan abundantly present in the mycobacterium tuberculosis cell envelope. many biological properties have been ascribed to manlam, from directly interacting with the host and participating in the intracellular survival of m. tuberculosis, to triggering innate and adaptive immune responses, including the activation of cd1b-restricted t cells. due to its structural complexity, manlam is considered a heterogeneous population of molecules w ... | 2012 | 22534567 |
| characterization of ffh of mycobacterium tuberculosis and its interaction with 4.5s rna. | signal recognition particle (srp) mediates targeting of proteins to appropriate cellular compartments, which is an important process in all living organisms. in prokaryotes, srp consists of ffh, a protein, and 4.5s rna that recognizes signal peptide emerging from ribosomes. the srp (ffh) of one the most successful intracellular pathogen, mycobacterium tuberculosis, has been investigated with respect to biochemical properties. in the present study, ffh of m. tuberculosis was overexpressed and was ... | 2012 | 22534010 |
| resuscitation-promoting factors (rpf): in search of inhibitors. | resuscitation promoting factors (rpf) are a family of proteins secreted by actively growing actinobacteria, including mycobacterium tuberculosis. experimental evidence suggests that rpfs play a distinct role in bacterial resuscitation and re-growth as well as reactivation of chronic tuberculosis in mice. the striking similarity of the rpfs structure to cell wall hydrolysing enzymes has provided a basis for the development of novel low molecular weight inhibitors of rpfs activity. in particular, ... | 2012 | 22533619 |
| impact of structural domains of the heparin binding hemagglutinin of mycobacterium tuberculosis on function. | among the few well characterized virulence factors of mycobacterium tuberculosis (mtb) is the heparinbinding hemagglutinin (hbha). hbha is a 21-kda protein that localizes to the mycobacterial surface where it can interact with host components. interaction with epithelial cells and components of the extracellular matrix is mediated by the methylated lysine-rich c-terminal domain of the protein. the n-terminal end of hbha contains a coiled coil motif which is involved in protein oligomerization an ... | 2012 | 22533618 |
| nod2 enhances the innate response of alveolar macrophages to mycobacterium tuberculosis in humans. | a role for the nucleotide-binding oligomerization domain 2 (nod2) receptor in pulmonary innate immune responses has recently been explored. in the present study, we investigated the role that nod2 plays in human alveolar macrophage innate responses and determined its involvement in the response to infection with virulent mycobacterium tuberculosis. our results showed that nod2 was expressed in human alveolar macrophages, and significant amounts of il-1β, il-6, and tnf-α were produced upon ligand ... | 2012 | 22531915 |
| cba/j mice generate protective immunity to soluble ag85 but fail to respond efficiently to ag85 during natural mycobacterium tuberculosis infection. | in cba/j mice, susceptibility to mycobacterium tuberculosis (m.tb) is associated with low interferon-gamma (ifn-γ) responses to antigens (antigen 85 (ag85) and early secreted antigenic target-6 (esat-6)) that have been defined as immunodominant. here, we asked whether the failure of cba/j mice to recognize ag85 is a consequence of m.tb infection or whether cba/j mice have a general defect in generating specific t-cell responses to this protein antigen. we compared cba/j mice during primary m.tb ... | 2012 | 22531914 |
| using tuberculin skin test as an entry point to screen for latent and active tuberculosis in thai people living with hiv. | tuberculin skin test (tst) identifies patients highly likely to benefit from isoniazid preventive therapy and tuberculosis (tb) prevalence may differ by tst status. we evaluated latent and active tb screening and diagnosis strategies among people living with hiv (plhiv) incorporating tst as the initial screening step. | 2012 | 22531757 |
| surgical treatment to increase the success rate of multidrug-resistant tuberculosis. | mycobacterium tuberculosis infects more than one-third of the world's population and causes an estimated 2-3 million deaths annually. the medical treatment of multidrug-resistant tuberculosis (mdr-tb) can cure 50-75% of cases. the median prevalence of new mdr-tb cases is 1.1%, while that of previously treated cases is 7%. | 2012 | 22531273 |
| swab culture monitoring of automated endoscope reprocessors after high-level disinfection. | to conduct a bacterial culture study for monitoring decontamination of automated endoscope reprocessors (aers) after high-level disinfection (hld). | 2012 | 22529696 |
| similarity in the isolation rate of mycobacterium tuberculosis for new and treated cases of tuberculosis in sputum specimens preserved under cetylpyridinium chloride. | | 2012 | 22529637 |
| global analysis of the regulon of the transcriptional repressor lexa, a key component of sos response in mycobacterium tuberculosis. | the dna damage response is crucial for bacterial survival. the transcriptional repressor lexa is a key component of the sos response, the main mechanism for the regulation of dna repair genes in many bacteria. in contrast, in mycobacteria gene induction by dna damage is carried out by two mechanisms; a relatively small number of genes are thought to be regulated by lexa, and a larger number by an alternate, independent mechanism. in this study we have used chip-seq analysis to identify 25 in viv ... | 2012 | 22528497 |
| zoonotic transmission of tuberculosis between pastoralists and their livestock in south-east ethiopia. | despite huge global efforts in tuberculosis (tb) control, pastoral areas remain under-investigated. during two years sputum and fine needle aspirate (fna) specimens were collected from 260 ethiopian pastoralists of oromia and somali regional states with suspected pulmonary tb and from 32 cases with suspected tb lymphadenitis. in parallel, 207 suspected tuberculous lesions were collected from cattle, camels and goats at abattoirs. all specimens were processed and cultured for mycobacteria; sample ... | 2012 | 22526748 |
| gyra/b fluoroquinolone resistance allele profiles amongst mycobacterium tuberculosis isolates from mainland china. | fluoroquinolones are important second-line drugs for the treatment of tuberculosis. a comprehensive profile of resistance mutation patterns of dna gyrase, the major target of fluoroquinolones, is crucial for molecular diagnosis of drug resistance and improvement of treatment efficacy. to investigate the mutation types of the genes encoding the a and b subunits of dna gyrase (gyra and gyrb, respectively) in ofloxacin- and levofloxacin-resistant mycobacterium tuberculosis strains prevalent in main ... | 2012 | 22526012 |
| structure of phosphoserine aminotransferase from mycobacterium tuberculosis. | mycobacterium tuberculosis (mtb), the causative agent of tb, remains a serious world health problem owing to limitations of the available drugs and the emergence of resistant strains. in this context, key biosynthetic enzymes from mtb are attractive targets for the development of new therapeutic drugs. here, the 1.5 å resolution crystal structure of mtb phosphoserine aminotransferase (mtbpsat) in complex with its cofactor, pyridoxal 5'-phosphate (plp), is reported. mtbpsat is an essential enzyme ... | 2012 | 22525753 |
| peripheral t cell cytokine responses for diagnosis of active tuberculosis. | a test for diagnosis of active tuberculosis (tb) from peripheral blood could tremendously improve clinical management of patients. | 2012 | 22523581 |
| evaluation of real-time polymerase chain reaction for detection of the 16s ribosomal rna gene of mycobacterium tuberculosis and the diagnosis of cervical tuberculous lymphadenitis in a country with a high tuberculosis incidence. | tuberculous lymphadenitis (tbl) is the most common form of extrapulmonary tuberculosis. currently, the standard diagnostic test for tbl is culture, which takes more than several weeks to yield results. we studied a real-time polymerase chain reaction (pcr) for rapid detection of mycobacterium tuberculosis in cervical lymph node specimens obtained from patients in a country where the tuberculosis incidence is high. | 2012 | 22523265 |
| deciphering the proteome of the in vivo diagnostic reagent "purified protein derivative" from mycobacterium tuberculosis. | purified protein derivative (ppd) has served as a safe and effective diagnostic reagent for 60 years and is the only broadly available material to diagnose latent tuberculosis infections. this reagent is also used as a standard control for a number of in vitro immunological assays. nevertheless, the molecular composition and specific products that contribute to the extraordinary immunological reactivity of ppd are poorly defined. here, a proteomic approach was applied to elucidate the gene produ ... | 2012 | 22522804 |
| [recommendations from the spanish society of paediatric infectious diseases on the diagnosis and treatment of non-tuberculous mycobacterial cervical lymphadenitis]. | non-tuberculous mycobacteria (ntm) have been increasingly isolated over the last 20 years in spain. however, as ntm disease is not a notifiable condition, there is no national registry, thus the true prevalence and incidence of these infections in children are difficult to estimate. cervical adenitis is the most common clinical manifestation of ntm infection in immunocompetent children. the clinical course can be sub-acute or chronic, and is often associated with fluctuation, fistulisation, and ... | 2012 | 22522153 |
| screening a library of 1600 adamantyl ureas for anti-mycobacterium tuberculosis activity in vitro and for better physical chemical properties for bioavailability. | adamantyl ureas were previously identified as a group of compounds active against mycobacterium tuberculosis in culture with minimum inhibitor concentrations (mics) below 0.1 μg/ml. these compounds have been shown to target mmpl3, a protein involved in secretion of trehalose mono-mycolate. they also inhibit both human soluble epoxide hydrolase (hseh) and m. tuberculosis epoxide hydrolases. however, active compounds to date have high clogp's and are poorly soluble, leading to low bioavailability ... | 2012 | 22522007 |
| polymorphisms in sp110 are not associated with pulmonary tuberculosis in indonesians. | despite being high transmissible, mycobacterium tuberculosis (m. tuberculosis) infection causes active disease in only 5-10% of disease-susceptible individuals. this has instigated interest in studying potentially underlying genetic host factors and mechanisms in tuberculosis (tb). the recent identification of the intracellular pathogen resistance 1 (ipr1) gene, which plays a major role in controlling m. tuberculosis susceptibility and infection severity in mice (pan et al., 2005), has prompted ... | 2012 | 22522001 |
| low rates of synonymous mutations in sequences of mycobacterium tuberculosis gyra and katg genes. | partial sequences of katg and gyra genes have been obtained from multi and extensively drug-resistant (mdr and xdr) clinical isolates of mycobacterium tuberculosis. nonsynonymous (dn) and synonymous (ds) distances between those sequences have been calculated by kumar method. results revealed that dn is significantly higher than ds between some pairs of partial gyra sequences. we found out that dn is higher than ds in many other partial and complete sequences of katg and gyra coding regions depos ... | 2012 | 22521568 |
| sensitivity of quantiferon-tb gold in-tube for diagnosis of recent versus remote m. tuberculosis infection. | the sensitivity of quantiferon-tb gold in-tube was measured in 104 subjects with recent (≤2 years) and remote mycobacterium tuberculosis infection using tuberculin skin test conversion as the reference standard. the sensitivity was not significantly different between the 2 groups (33% versus 20%, p = 0.3). this finding suggests interferon-γ release assays may not be more sensitive for diagnosis of recent than remote infection. longitudinal studies are needed to validate this finding. | 2012 | 22521052 |
| strong immunogenicity and cross-reactivity of mycobacterium tuberculosis esx-5 type vii secretion: encoded pe-ppe proteins predicts vaccine potential. | the genome of mycobacterium tuberculosis (mtb) encodes five type vii secretion systems, esx-1 to esx-5, most of which are associated with genes encoding pe/ppe proteins, named after their n-terminal pro-glu (pe) or pro-pro-glu (ppe) motifs. here, we describe the strong t cell immunogenicity of the esx-5-encoded pe/ppe proteins, which share a large panel of cross-reactive cd4(+) epitopes with substantial numbers of their esx-5-nonassociated pe/ppe homologs. the immunogenicity of these numerous pe ... | 2012 | 22520463 |
| involvement of the autophagy pathway in trafficking of mycobacterium tuberculosis bacilli through cultured human type ii epithelial cells. | interactions between mycobacterium tuberculosis bacilli and alveolar macrophages have been extensively characterized, while similar analyses in epithelial cells have not been performed. in this study, we microscopically examined endosomal trafficking of m. tuberculosis strain erdman in a549 cells, a human type ii pneumocyte cell line. immuno-electron microscopic (iem) analyses indicate that m. tuberculosis bacilli are internalized to a compartment labelled first with rab5 and then with rab7 smal ... | 2012 | 22519722 |
| rapid detection of rpob gene mutations conferring rifampin resistance in mycobacterium tuberculosis. | multidrug-resistant mycobacterium tuberculosis strains are widespread and present a challenge to effective treatment of this infection. the need for a low-cost and rapid detection method for clinically relevant mutations in mycobacterium tuberculosis that confer multidrug resistance is urgent, particularly for developing countries. we report here a novel test that detects the majority of clinically relevant mutations in the beta subunit of the rna polymerase (rpob) gene that confer resistance to ... | 2012 | 22518852 |
| outbreak of transient conversions of the quantiferon-tb gold in-tube test in laboratory health care worker screenings. | gamma interferon release assays were recently introduced in health care worker (hcws) screenings for tuberculosis surveillance. in longitudinal surveys, conversions and reversions are seen, and yet whether these changes are unspecific or are an expression of new infections and microbial clearance remains unclear. in order to further elucidate these changes, we analyzed an outbreak of 15 transient conversions in 53 hcws who operate in the same laboratory and handle specimens potentially containin ... | 2012 | 22518010 |
| non-acid-fastness in mycobacterium tuberculosis δkasb mutant correlates with the cell envelope electron density. | the acid-fastness is the most important and the most specific characteristics in mycobacteria, the mechanism of which is not clear but may be attributed to the lipid rich cell wall of this bacterium. while the exact component(s) responsible for this staining method remained unidentified, a mycobacterium tuberculosis mutant, attenuated strain that produced shorter mycolic acids with defects in trans-cyclopropanation was shown to be acid fast negative. in this study, we examined the ultrastructure ... | 2012 | 22516756 |