keyword
MENU ▼
Read by QxMD icon Read
search

MTB

keyword
https://www.readbyqxmd.com/read/27920294/effects-of-increasing-the-affinity-of-card-for-rna-polymerase-on-mycobacterium-tuberculosis-growth-rrna-transcription-and-virulence
#1
Ashley L Garner, Jayan Rammohan, Jeremy P Huynh, Lucas M Onder, James Chen, Brian Bae, Drake Jensen, Leslie A Weiss, Ana Ruiz Manzano, Seth A Darst, Elizabeth A Campbell, Bryce E Nickels, Eric A Galburt, Christina L Stallings
: CarD is an essential RNA polymerase (RNAP) interacting protein in Mycobacterium tuberculosis (Mtb) that stimulates formation of RNAP-promoter open complexes. CarD plays a complex role in Mtb growth and virulence that is not fully understood. Therefore, to gain further insight into the role of CarD in Mtb growth and virulence we determined the effect of increasing the affinity of CarD for RNAP. Using site-directed mutagenesis guided by crystal structures of CarD bound to RNAP, we identified amino acid substitutions that increase the affinity of CarD for RNAP...
December 5, 2016: Journal of Bacteriology
https://www.readbyqxmd.com/read/27919693/performance-evaluation-of-xpert-mtb-rif-in-a-moderate-tuberculosis-incidence-compared-with-taqman-mtb-and-trcrapid-m-tb
#2
Kazunari Tsuyuguchi, Hideaki Nagai, Kenji Ogawa, Tomoshige Matsumoto, Kozo Morimoto, Akiko Takaki, Satoshi Mitarai
Xpert MTB/RIF is an automated nucleic acid amplification test (NAT) that can detect the presence of Mycobacterium tuberculosis complex (MTC) in clinical specimens as well as rifampicin (RIF) resistance resulting from rpoB mutation. Despite its high sensitivity and specificity for diagnosing tuberculosis (TB) with or without RIF resistance, the clinical performance of the test is variable. In this study, we evaluated the performance of Xpert MTB/RIF in a setting of moderate TB burden and high medical resources...
December 2, 2016: Journal of Infection and Chemotherapy: Official Journal of the Japan Society of Chemotherapy
https://www.readbyqxmd.com/read/27918526/mycobacterium-tuberculosis-esxh-inhibits-escrt-dependent-cd4-t-cell-activation
#3
Cynthia Portal-Celhay, JoAnn M Tufariello, Smita Srivastava, Aleena Zahra, Thais Klevorn, Patricia S Grace, Alka Mehra, Heidi S Park, Joel D Ernst, William R Jacobs, Jennifer A Philips
Mycobacterium tuberculosis (Mtb) establishes a persistent infection, despite inducing antigen-specific T-cell responses. Although T cells arrive at the site of infection, they do not provide sterilizing immunity. The molecular basis of how Mtb impairs T-cell function is not clear. Mtb has been reported to block major histocompatibility complex class II (MHC-II) antigen presentation; however, no bacterial effector or host-cell target mediating this effect has been identified. We recently found that Mtb EsxH, which is secreted by the Esx-3 type VII secretion system, directly inhibits the endosomal sorting complex required for transport (ESCRT) machinery...
December 5, 2016: Nature Microbiology
https://www.readbyqxmd.com/read/27917375/recombinant-lipoprotein-rv1016c-derived-from-mycobacterium-tuberculosis-is-a-tlr-2-ligand-that-induces-macrophages-apoptosis-and-inhibits-mhc-ii-antigen-processing
#4
Haibo Su, Shenglin Zhu, Lin Zhu, Wei Huang, Honghai Wang, Zhi Zhang, Ying Xu
TLR2-dependent cellular signaling in Mycobacterium tuberculosis-infected macrophages causes apoptosis and inhibits class II major histocompatibility complex (MHC-II) molecules antigen processing, leading to evasion of surveillance. Mycobacterium tuberculosis (MTB) lipoproteins are an important class of Toll-like receptor (TLR) ligand, and identified as specific components that mediate these effects. In this study, we identified and characterized MTB lipoprotein Rv1016c (lpqT) as a cell wall associated-protein that was exposed on the cell surface and enhanced the survival of recombinants M...
2016: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/27915106/insights-gained-from-ancient-biomolecules-into-past-and-present-tuberculosis-a-personal-perspective
#5
REVIEW
Helen D Donoghue
Ancient and historical tuberculosis (TB) can be recognized by its typical paleopathology in human remains. Using paleomicrobiology, it is possible to detect many more individuals infected with TB but with no visible lesions. Due to advances in molecular analysis over the past two decades, it is clear that TB was widespread in humans from the Neolithic period until the present day. Past human populations were associated with different lineages of the Mycobacterium tuberculosis (MTB) complex, thereby elucidating early human migrations...
November 30, 2016: International Journal of Infectious Diseases: IJID
https://www.readbyqxmd.com/read/27914363/new-insights-into-the-sar-and-drug-combination-synergy-of-2-quinolin-4-yloxy-acetamides-against-mycobacterium-tuberculosis
#6
Bruno Couto Giacobbo, Kenia Pissinate, Valnês Rodrigues-Junior, Anne Drumond Villela, Estêvão Silveira Grams, Bruno Lopes Abbadi, Fernanda Teixeira Subtil, Nathalia Sperotto, Rogério Valim Trindade, Davi Fernando Back, Maria Martha Campos, Luiz Augusto Basso, Pablo Machado, Diógenes Santiago Santos
2-(Quinolin-4-yloxy)acetamides have been described as potent and selective in vitro inhibitors of Mycobacterium tuberculosis (Mtb) growth. Herein, a new series of optimized compounds were found to demonstrate highly potent antitubercular activity, with minimum inhibitory concentration (MIC) values against drug-susceptible and drug-resistant Mycobacterium tuberculosis strains in the submicromolar range. Furthermore, the most active compounds had no apparent toxicity to mammalian cells, and they showed intracellular activities similar to those of isoniazid and rifampin in a macrophage model of Mtb infection...
November 23, 2016: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/27913043/evaluation-of-the-genexpert-mtb-rif-assay-on-extrapulmonary-and-respiratory-samples-other-than%C3%A2-sputum-a-low-burden-country-experience
#7
Sushil Pandey, Jacob Congdon, Bradley McInnes, Alina Pop, Christopher Coulter
The aim of this study was to assess the performance of the GeneXpert MTB/RIF assay on extrapulmonary (EP) and respiratory (non-sputum) clinical samples of patients suspected of having tuberculosis (TB) from Queensland, Australia. A total of 269 EP and respiratory (non-sputum) clinical samples collected from Qld patients who were suspected of having TB were subjected to the GeneXpert MTB/RIF analysis, Ziehl-Neelsen (ZN) staining, Mycobacterium tuberculosis (MTB) culture and drug susceptibility testing. Phenotypic and genotypic data were compared...
November 29, 2016: Pathology
https://www.readbyqxmd.com/read/27902881/the-chimeric-nature-of-the-genomes-of-marine-magnetotactic-coccoid-ovoid-bacteria-defines-a-novel-group-of-proteobacteria
#8
Boyang Ji, Sheng-Da Zhang, Wei-Jia Zhang, Zoe Rouy, François Alberto, Claire-Lise Santini, Sophie Mangenot, Séverine Gagnot, Nadège Philippe, Nathalie Pradel, Lichen Zhang, Sébastien Tempel, Ying Li, Claudine Médigue, Bernard Henrissat, Pedro M Coutinho, Valérie Barbe, Emmanuel Talla, Long-Fei Wu
Magnetotactic bacteria (MTB) are a group of phylogenetically and physiologically diverse Gram-negative bacteria that synthesize intracellular magnetic crystals named magnetosomes. MTB are affiliated with three classes of Proteobacteria phylum, Nitrospirae phylum, Omnitrophica phylum and probably with the candidate phylum Latescibacteria. The evolutionary origin and physiological diversity of MTB compared to other bacterial taxonomic groups remain to be illustrated. Here, we analyzed the genome of the marine magneto-ovoid strain MO-1 and found that it is closely related to Magnetococcus marinus MC-1...
November 30, 2016: Environmental Microbiology
https://www.readbyqxmd.com/read/27902737/a-comparison-of-the-sensititre-mycotb-plate-the-bactec-mgit-960-and-a-microarray-based-molecular-assay-for-the-detection-of-drug-resistance-in-clinical-mycobacterium-tuberculosis-isolates-in-moscow-russia
#9
Elena Y Nosova, Danila V Zimenkov, Anastasia A Khakhalina, Alexandra I Isakova, Ludmila Y Krylova, Marina V Makarova, Ksenia Y Galkina, Maria A Krasnova, Svetlana G Safonova, Vitaly I Litvinov, Dmitry A Gryadunov, Elena M Bogorodskaya
BACKGROUND: The goal of this study was to compare the consistency of three assays for the determination of the drug resistance of Mycobacterium tuberculosis (MTB) strains with various resistance profiles isolated from the Moscow region. METHODS: A total of 144 MTB clinical isolates with a strong bias toward drug resistance were examined using Bactec MGIT 960, Sensititre MycoTB, and a microarray-based molecular assay TB-TEST to detect substitutions in the rpoB, katG, inhA, ahpC, gyrA, gyrB, rrs, eis, and embB genes that are associated with resistance to rifampin, isoniazid, fluoroquinolones, second-line injectable drugs and ethambutol...
2016: PloS One
https://www.readbyqxmd.com/read/27898665/extending-contact-tracing-into-the-community-within-a-50-metre-radius-of-an-index-tuberculosis-patient-using-xpert-mtb-rif-in-urban-pakistan-did-it-increase-case-detection
#10
Razia Fatima, Ejaz Qadeer, Aashifa Yaqoob, Mahboob Ul Haq, Suman S Majumdar, Hemant D Shewade, Robert Stevens, Jacob Creswell, Nasir Mahmood, Ajay M V Kumar
BACKGROUND: Currently, only 62% of incident tuberculosis (TB) cases are reported to the national programme in Pakistan. Several innovative interventions are being recommended to detect the remaining 'missed' TB cases. One such intervention involved expanding contact investigation to the community using the Xpert MTB/RIF test. METHODS: This was a before and after intervention study involving retrospective record review. Passive case finding and household contact investigation was routinely done in the pre-intervention period July 2011-June 2013...
2016: PloS One
https://www.readbyqxmd.com/read/27897233/changes-in-the-membrane-associated-proteins-of-exosomes-released-from-human-macrophages-after-mycobacterium-tuberculosis-infection
#11
Gustavo Diaz, Lisa M Wolfe, Nicole A Kruh-Garcia, Karen M Dobos
Tuberculosis (TB) is the deadliest infectious disease worldwide. One obstacle hindering the elimination of TB is our lack of understanding of host-pathogen interactions. Exosomes, naturally loaded with microbial molecules, are circulating markers of TB. Changes in the host protein composition of exosomes from Mycobacterium tuberculosis (Mtb)-infected cells have not been described, can contribute to our understanding of the disease process, and serve as a direct source of biomarkers or as capture targets to enrich for exosomes containing microbial molecules...
November 29, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27895008/de-novo-emergence-of-genetically-resistant-mutants-of-mycobacterium-tuberculosis-from-the-persistence-phase-cells-formed-against-antituberculosis-drugs-in-vitro
#12
Jees Sebastian, Sharmada Swaminath, Rashmi Ravindran Nair, Kishor Jakkala, Atul Pradhan, Parthasarathi Ajitkumar
Bacterial persisters are a subpopulation of cells that can tolerate lethal concentrations of antibiotics. However, the possibility of the emergence of genetically resistant mutants from antibiotic persister cell population, upon continued exposure to lethal concentrations of antibiotics, remained unexplored. In the present study, we found that Mycobacterium tuberculosis (Mtb) cells exposed continuously to lethal concentrations of rifampicin (RIF) or moxifloxacin (MXF) for prolonged durations showed killing, RIF/MXF persistence, and regrowth phases...
November 28, 2016: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/27893795/virulence-of-mycobacterium-tuberculosis-after-acquisition-of-isoniazid-resistance-individual-nature-of-katg-mutants-and-the-possible-role-of-ahpc
#13
Luisa Maria Nieto R, Carolina Mehaffy, Elizabeth Creissen, JoLynn Troudt, Amber Troy, Helle Bielefeldt-Ohmann, Marcos Burgos, Angelo Izzo, Karen M Dobos
In the last decade, there were 10 million new tuberculosis cases per year globally. Around 9.5% of these cases were caused by isoniazid resistant (INHr) Mycobacterium tuberculosis (Mtb) strains. Although isoniazid resistance in Mtb is multigenic, mutations in the catalase-peroxidase (katG) gene predominate among the INHr strains. The effect of these drug-resistance-conferring mutations on Mtb fitness and virulence is variable. Here, we assessed differences in bacterial growth, immune response and pathology induced by Mtb strains harboring mutations at the N-terminus of the katG gene...
2016: PloS One
https://www.readbyqxmd.com/read/27892960/new-genome-wide-algorithm-identifies-novel-in-vivo-expressed-mycobacterium-tuberculosis-antigens-inducing-human-t-cell-responses-with-classical-and-unconventional-cytokine-profiles
#14
Mariateresa Coppola, Krista E van Meijgaarden, Kees L M C Franken, Susanna Commandeur, Gregory Dolganov, Igor Kramnik, Gary K Schoolnik, Inaki Comas, Ole Lund, Corine Prins, Susan J F van den Eeden, Gro E Korsvold, Fredrik Oftung, Annemieke Geluk, Tom H M Ottenhoff
New strategies are needed to develop better tools to control TB, including identification of novel antigens for vaccination. Such Mtb antigens must be expressed during Mtb infection in the major target organ, the lung, and must be capable of eliciting human immune responses. Using genome-wide transcriptomics of Mtb infected lungs we developed data sets and methods to identify IVE-TB (in-vivo expressed Mtb) antigens expressed in the lung. Quantitative expression analysis of 2,068 Mtb genes from the predicted first operons identified the most upregulated IVE-TB genes during in-vivo pulmonary infection...
November 28, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27891500/interspecies-communication-between-pathogens-and-immune-cells-via-bacterial-membrane-vesicles
#15
Katerina S Jurkoshek, Ying Wang, Jaffre J Athman, Marian R Barton, Pamela A Wearsch
The production of extracellular vesicles is a universal mechanism for intercellular communication that is conserved across kingdoms. Prokaryotes secrete 50-250 nm membrane vesicles (MVs) in a manner that is regulated by environmental stress and is thought to promote survival. Since many types of host-derived stress are encountered during infection, this implies an important role for MV secretion in bacterial pathogenesis. Accordingly, MVs produced by gram-positive and gram-negative pathogens contain toxins, virulence factors, and other molecules that promote survival in the host...
2016: Frontiers in Cell and Developmental Biology
https://www.readbyqxmd.com/read/27891336/mycobacterium-tuberculosis-beijing-genotype-in-western-iran-distribution-and-drug-resistance
#16
Parviz Mohajeri, Sakineh Moradi, Sara Atashi, Abbas Farahani
INTRODUCTION: Mycobacterium tuberculosis Beijing genotype is gaining importance all over the world because this genotype is highly prevalent in several areas and is also frequently associated with drug resistance. AIM: To identify and determine the frequency of Beijing genotype and mix infection with Beijing and non-Beijing in west of Iran and analyse the association between Beijing genotype and drug resistance. MATERIALS AND METHODS: This cross-sectional study was conducted on 146 Tuberculosis (TB) samples collected at the TB reference laboratory in Kermanshah west of Iran from January 2014 to February 2015, Mycobacterium tuberculosis isolates from sputum samples, detected by microcopy, biochemical tests and solid culture were included and then the confirmed samples with Cepheid Xpert MTB/RIF assay were subjected to drug susceptibility tests for rifampicin, isoniazid, ethambutol using proportional method...
October 2016: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/27890820/recent-developments-in-natural-product-based-drug-discovery-for-tuberculosis
#17
REVIEW
Maryline Dong, Bernhard Pfeiffer, Karl-Heinz Altmann
Natural products (NPs) have been at the origin of several established drugs against tuberculosis (TB). Although the current clinical TB pipeline does not feature any candidates derived from new NP scaffolds, numerous novel NP or NP analogs have been discovered in the recent past with promising activity against Mycobacterium tuberculosis (Mtb) This includes newly discovered structures as well as known NP classes that had not been previously recognized to be active against Mtb. These compounds could help to replenish the dry clinical TB pipeline and, thus, contribute to improvements in the treatment of a devastating disease...
November 24, 2016: Drug Discovery Today
https://www.readbyqxmd.com/read/27890360/anti-tubercular-peptides-a-quest-of-future-therapeutic-weapon-to-combat-tuberculosis
#18
REVIEW
Ameer Khusro, Chirom Aarti, Paul Agastian
Tuberculosis (TB) is a symbolic menace to mankind, infecting almost one third of the world's populace and causing over a million mortalities annually. Mycobacterium tuberculosis (Mtb) is the key pathogen of TB that invades and replicates inside the host's macrophage. With the emerging dilemma of multi-drug resistant tuberculosis (MDR-TB) and extensively-drug resistant tuberculosis (XDR-TB), the exigency for developing new TB drugs is an obligation now for worldwide researchers. Among the propitious antimycobacterial agents examined in last few decades, anti-tubercular peptides have been substantiated to be persuasive with multiple advantages such as low immunogenicity, selective affinity to bacterial negatively charged cell envelopes and most importantly divergent mechanisms of action...
November 2016: Asian Pacific Journal of Tropical Medicine
https://www.readbyqxmd.com/read/27889398/recognition-of-mycobacterial-lipids-by-immune-receptors
#19
REVIEW
Eri Ishikawa, Daiki Mori, Sho Yamasaki
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), infects one-third of the world's population and causes 1.5 million deaths each year. The cell envelopes of mycobacteria comprise a wealth of unique glycolipids, including trehalose-6,6'-dimycolate (TDM), lipoarabinomannan (LAM), lipomannan (LM), and phosphatidylinositol (PI) mannosides (PIMs). These lipids are important modulators of the host immune responses during infection and in some cases have been used as adjuvants [e.g., complete Freund's adjuvant (CFA)]...
November 23, 2016: Trends in Immunology
https://www.readbyqxmd.com/read/27883091/mycobacterium-tuberculosis-triggered-hippo-pathway-orchestrates-cxcl1-2-expression-to-modulate-host-immune-responses
#20
Monoranjan Boro, Vikas Singh, Kithiganahalli Narayanaswamy Balaji
Mycobacterium tuberculosis (Mtb) pathogenesis encompasses a plethora of finely regulated alterations within the host which eventually coin the outcome of infection. Chemokines are important components in directing immune cell recruitment to the site of infection, and shaping the disease progression. Here, we demonstrate that Hippo (mammalian sterile 20-like 1 and 2 kinases, MST1/2, in mammals), is activated during mycobacterial infection in a toll-like receptor (TLR) 2-interleukin receptor-1 associated kinases (IRAK1/4)-dependent manner...
November 24, 2016: Scientific Reports
keyword
keyword
66766
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"