LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 7 of total 7

Search options

  1. Article ; Online: Mutations in pepQ Confer Low-Level Resistance to Bedaquiline and Clofazimine in Mycobacterium tuberculosis.

    Almeida, Deepak / Ioerger, Thomas / Tyagi, Sandeep / Li, Si-Yang / Mdluli, Khisimuzi / Andries, Koen / Grosset, Jacques / Sacchettini, Jim / Nuermberger, Eric

    Antimicrobial agents and chemotherapy

    2016  Volume 60, Issue 8, Page(s) 4590–4599

    Abstract: The novel ATP synthase inhibitor bedaquiline recently received accelerated approval for treatment of multidrug-resistant tuberculosis and is currently being studied as a component of novel treatment-shortening regimens for drug-susceptible and multidrug- ... ...

    Abstract The novel ATP synthase inhibitor bedaquiline recently received accelerated approval for treatment of multidrug-resistant tuberculosis and is currently being studied as a component of novel treatment-shortening regimens for drug-susceptible and multidrug-resistant tuberculosis. In a limited number of bedaquiline-treated patients reported to date, ≥4-fold upward shifts in bedaquiline MIC during treatment have been attributed to non-target-based mutations in Rv0678 that putatively increase bedaquiline efflux through the MmpS5-MmpL5 pump. These mutations also confer low-level clofazimine resistance, presumably by a similar mechanism. Here, we describe a new non-target-based determinant of low-level bedaquiline and clofazimine cross-resistance in Mycobacterium tuberculosis: loss-of-function mutations in pepQ (Rv2535c), which corresponds to a putative Xaa-Pro aminopeptidase. pepQ mutants were selected in mice by treatment with clinically relevant doses of bedaquiline, with or without clofazimine, and were shown to have bedaquiline and clofazimine MICs 4 times higher than those for the parental H37Rv strain. Coincubation with efflux inhibitors verapamil and reserpine lowered bedaquiline MICs against both mutant and parent strains to a level below the MIC against H37Rv in the absence of efflux pump inhibitors. However, quantitative PCR (qPCR) revealed no significant differences in expression of Rv0678, mmpS5, or mmpL5 between mutant and parent strains. Complementation of a pepQ mutant with the wild-type gene restored susceptibility, indicating that loss of PepQ function is sufficient for reduced susceptibility both in vitro and in mice. Although the mechanism by which mutations in pepQ confer bedaquiline and clofazimine cross-resistance remains unclear, these results may have clinical implications and warrant further evaluation of clinical isolates with reduced susceptibility to either drug for mutations in this gene.
    MeSH term(s) Animals ; Antitubercular Agents/therapeutic use ; Clofazimine/therapeutic use ; Diarylquinolines/therapeutic use ; Female ; Mice ; Mice, Inbred BALB C ; Microbial Sensitivity Tests ; Mutation/genetics ; Mycobacterium tuberculosis/drug effects ; Mycobacterium tuberculosis/genetics ; Tuberculosis, Multidrug-Resistant/drug therapy ; Tuberculosis, Multidrug-Resistant/metabolism
    Chemical Substances Antitubercular Agents ; Diarylquinolines ; bedaquiline (78846I289Y) ; Clofazimine (D959AE5USF)
    Language English
    Publishing date 2016-07-22
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 217602-6
    ISSN 1098-6596 ; 0066-4804
    ISSN (online) 1098-6596
    ISSN 0066-4804
    DOI 10.1128/AAC.00753-16
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: GWAS for quantitative resistance phenotypes in Mycobacterium tuberculosis reveals resistance genes and regulatory regions.

    Farhat, Maha R / Freschi, Luca / Calderon, Roger / Ioerger, Thomas / Snyder, Matthew / Meehan, Conor J / de Jong, Bouke / Rigouts, Leen / Sloutsky, Alex / Kaur, Devinder / Sunyaev, Shamil / van Soolingen, Dick / Shendure, Jay / Sacchettini, Jim / Murray, Megan

    Nature communications

    2019  Volume 10, Issue 1, Page(s) 2128

    Abstract: Drug resistance diagnostics that rely on the detection of resistance-related mutations could expedite patient care and TB eradication. We perform minimum inhibitory concentration testing for 12 anti-TB drugs together with Illumina whole-genome sequencing ...

    Abstract Drug resistance diagnostics that rely on the detection of resistance-related mutations could expedite patient care and TB eradication. We perform minimum inhibitory concentration testing for 12 anti-TB drugs together with Illumina whole-genome sequencing on 1452 clinical Mycobacterium tuberculosis (MTB) isolates. We evaluate genome-wide associations between mutations in MTB genes or non-coding regions and resistance, followed by validation in an independent data set of 792 patient isolates. We confirm associations at 13 non-canonical loci, with two involving non-coding regions. Promoter mutations are measured to have smaller average effects on resistance than gene body mutations. We estimate the heritability of the resistance phenotype to 11 anti-TB drugs and identify a lower than expected contribution from known resistance genes. This study highlights the complexity of the genomic mechanisms associated with the MTB resistance phenotype, including the relatively large number of potentially causal loci, and emphasizes the contribution of the non-coding portion of the genome.
    MeSH term(s) Antitubercular Agents/pharmacology ; DNA Mutational Analysis ; Drug Resistance, Multiple, Bacterial/genetics ; Genetic Loci/genetics ; Genome, Bacterial/genetics ; Genome-Wide Association Study ; Humans ; Microbial Sensitivity Tests ; Mutation ; Mycobacterium tuberculosis/drug effects ; Mycobacterium tuberculosis/genetics ; Mycobacterium tuberculosis/isolation & purification ; Promoter Regions, Genetic/genetics ; Sputum/microbiology ; Tuberculosis, Multidrug-Resistant/drug therapy ; Tuberculosis, Multidrug-Resistant/microbiology ; Whole Genome Sequencing
    Chemical Substances Antitubercular Agents
    Language English
    Publishing date 2019-05-13
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-019-10110-6
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: A Novel 6-Benzyl Ether Benzoxaborole Is Active against Mycobacterium tuberculosis

    Patel, Nipul / O'Malley, Theresa / Zhang, Yong-Kang / Xia, Yi / Sunde, Bjorn / Flint, Lindsay / Korkegian, Aaron / Ioerger, Thomas R / Sacchettini, Jim / Alley, M R K / Parish, Tanya

    Antimicrobial agents and chemotherapy

    2017  Volume 61, Issue 9

    Abstract: We identified a novel 6-benzyl ether benzoxaborole with potent activity ... ...

    Abstract We identified a novel 6-benzyl ether benzoxaborole with potent activity against
    MeSH term(s) Antitubercular Agents/adverse effects ; Antitubercular Agents/pharmacology ; Cell Line, Tumor ; Drug Resistance, Bacterial/genetics ; Hep G2 Cells ; Humans ; Microbial Sensitivity Tests ; Mycobacterium tuberculosis/drug effects ; Mycobacterium tuberculosis/genetics ; Mycobacterium tuberculosis/growth & development ; Tuberculosis, Multidrug-Resistant/drug therapy ; Tuberculosis, Multidrug-Resistant/microbiology ; Tuberculosis, Pulmonary/drug therapy ; Tuberculosis, Pulmonary/microbiology
    Chemical Substances Antitubercular Agents
    Language English
    Publishing date 2017-08-24
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 217602-6
    ISSN 1098-6596 ; 0066-4804
    ISSN (online) 1098-6596
    ISSN 0066-4804
    DOI 10.1128/AAC.01205-17
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: The 7-phenyl benzoxaborole series is active against Mycobacterium tuberculosis.

    Korkegian, Aaron / O'Malley, Theresa / Xia, Yi / Zhou, Yasheen / Carter, David S / Sunde, Bjorn / Flint, Lindsay / Thompson, Dean / Ioerger, Thomas R / Sacchettini, Jim / Alley, M R K / Parish, Tanya

    Tuberculosis (Edinburgh, Scotland)

    2017  Volume 108, Page(s) 96–98

    Abstract: We identified a series of novel 7-phenyl benzoxaborole compounds with activity against Mycobacterium tuberculosis. Compounds had a range of activity with inhibitory concentrations ( ... ...

    Abstract We identified a series of novel 7-phenyl benzoxaborole compounds with activity against Mycobacterium tuberculosis. Compounds had a range of activity with inhibitory concentrations (IC
    MeSH term(s) Bacterial Proteins/antagonists & inhibitors ; Bacterial Proteins/genetics ; Bacterial Proteins/metabolism ; Boron Compounds/chemistry ; Boron Compounds/pharmacology ; Boron Compounds/toxicity ; Bridged Bicyclo Compounds, Heterocyclic/chemistry ; Bridged Bicyclo Compounds, Heterocyclic/pharmacology ; Bridged Bicyclo Compounds, Heterocyclic/toxicity ; Dose-Response Relationship, Drug ; Drug Resistance, Bacterial ; Humans ; Microbial Sensitivity Tests ; Mutation ; Mycobacterium tuberculosis/drug effects ; Mycobacterium tuberculosis/enzymology ; Mycobacterium tuberculosis/genetics ; NADH Dehydrogenase/antagonists & inhibitors ; NADH Dehydrogenase/genetics ; NADH Dehydrogenase/metabolism ; THP-1 Cells
    Chemical Substances Bacterial Proteins ; Boron Compounds ; Bridged Bicyclo Compounds, Heterocyclic ; NADH Dehydrogenase (EC 1.6.99.3)
    Language English
    Publishing date 2017-11-07
    Publishing country Scotland
    Document type Comparative Study ; Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2046804-0
    ISSN 1873-281X ; 1472-9792
    ISSN (online) 1873-281X
    ISSN 1472-9792
    DOI 10.1016/j.tube.2017.11.003
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Discovery of a cofactor-independent inhibitor of

    Xia, Yi / Zhou, Yasheen / Carter, David S / McNeil, Matthew B / Choi, Wai / Halladay, Jason / Berry, Pamela W / Mao, Weimin / Hernandez, Vincent / O'Malley, Theresa / Korkegian, Aaron / Sunde, Bjorn / Flint, Lindsay / Woolhiser, Lisa K / Scherman, Michael S / Gruppo, Veronica / Hastings, Courtney / Robertson, Gregory T / Ioerger, Thomas R /
    Sacchettini, Jim / Tonge, Peter J / Lenaerts, Anne J / Parish, Tanya / Alley, Mrk

    Life science alliance

    2018  Volume 1, Issue 3, Page(s) e201800025

    Abstract: New antitubercular agents are needed to combat the spread of multidrug- and extensively drug-resistant strains ... ...

    Abstract New antitubercular agents are needed to combat the spread of multidrug- and extensively drug-resistant strains of
    Language English
    Publishing date 2018-06-01
    Publishing country United States
    Document type Journal Article
    ISSN 2575-1077
    ISSN (online) 2575-1077
    DOI 10.26508/lsa.201800025
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: 2-Mercapto-Quinazolinones as Inhibitors of Type II NADH Dehydrogenase and Mycobacterium tuberculosis: Structure-Activity Relationships, Mechanism of Action and Absorption, Distribution, Metabolism, and Excretion Characterization.

    Murugesan, Dinakaran / Ray, Peter C / Bayliss, Tracy / Prosser, Gareth A / Harrison, Justin R / Green, Kirsteen / Soares de Melo, Candice / Feng, Tzu-Shean / Street, Leslie J / Chibale, Kelly / Warner, Digby F / Mizrahi, Valerie / Epemolu, Ola / Scullion, Paul / Ellis, Lucy / Riley, Jennifer / Shishikura, Yoko / Ferguson, Liam / Osuna-Cabello, Maria /
    Read, Kevin D / Green, Simon R / Lamprecht, Dirk A / Finin, Peter M / Steyn, Adrie J C / Ioerger, Thomas R / Sacchettini, Jim / Rhee, Kyu Y / Arora, Kriti / Barry, Clifton E / Wyatt, Paul G / Boshoff, Helena I M

    ACS infectious diseases

    2018  Volume 4, Issue 6, Page(s) 954–969

    Abstract: Mycobacterium tuberculosis ( MTb) possesses two nonproton pumping type II NADH dehydrogenase (NDH-2) enzymes which are predicted to be jointly essential for respiratory metabolism. Furthermore, the structure of a closely related bacterial NDH-2 has been ... ...

    Abstract Mycobacterium tuberculosis ( MTb) possesses two nonproton pumping type II NADH dehydrogenase (NDH-2) enzymes which are predicted to be jointly essential for respiratory metabolism. Furthermore, the structure of a closely related bacterial NDH-2 has been reported recently, allowing for the structure-based design of small-molecule inhibitors. Herein, we disclose MTb whole-cell structure-activity relationships (SARs) for a series of 2-mercapto-quinazolinones which target the ndh encoded NDH-2 with nanomolar potencies. The compounds were inactivated by glutathione-dependent adduct formation as well as quinazolinone oxidation in microsomes. Pharmacokinetic studies demonstrated modest bioavailability and compound exposures. Resistance to the compounds in MTb was conferred by promoter mutations in the alternative nonessential NDH-2 encoded by ndhA in MTb. Bioenergetic analyses revealed a decrease in oxygen consumption rates in response to inhibitor in cells in which membrane potential was uncoupled from ATP production, while inverted membrane vesicles showed mercapto-quinazolinone-dependent inhibition of ATP production when NADH was the electron donor to the respiratory chain. Enzyme kinetic studies further demonstrated noncompetitive inhibition, suggesting binding of this scaffold to an allosteric site. In summary, while the initial MTb SAR showed limited improvement in potency, these results, combined with structural information on the bacterial protein, will aid in the future discovery of new and improved NDH-2 inhibitors.
    MeSH term(s) Molecular Structure ; Mycobacterium tuberculosis/enzymology ; NADH Dehydrogenase/antagonists & inhibitors ; NADH Dehydrogenase/chemistry ; Quinazolinones/chemical synthesis ; Quinazolinones/chemistry ; Quinazolinones/pharmacology ; Structure-Activity Relationship
    Chemical Substances Quinazolinones ; NADH dehydrogenase II (EC 1.6.99.-) ; NADH Dehydrogenase (EC 1.6.99.3)
    Language English
    Publishing date 2018-03-26
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ISSN 2373-8227
    ISSN (online) 2373-8227
    DOI 10.1021/acsinfecdis.7b00275
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: Essential but Not Vulnerable: Indazole Sulfonamides Targeting Inosine Monophosphate Dehydrogenase as Potential Leads against Mycobacterium tuberculosis.

    Park, Yumi / Pacitto, Angela / Bayliss, Tracy / Cleghorn, Laura A T / Wang, Zhe / Hartman, Travis / Arora, Kriti / Ioerger, Thomas R / Sacchettini, Jim / Rizzi, Menico / Donini, Stefano / Blundell, Tom L / Ascher, David B / Rhee, Kyu / Breda, Ardala / Zhou, Nian / Dartois, Veronique / Jonnala, Surendranadha Reddy / Via, Laura E /
    Mizrahi, Valerie / Epemolu, Ola / Stojanovski, Laste / Simeons, Fred / Osuna-Cabello, Maria / Ellis, Lucy / MacKenzie, Claire J / Smith, Alasdair R C / Davis, Susan H / Murugesan, Dinakaran / Buchanan, Kirsteen I / Turner, Penelope A / Huggett, Margaret / Zuccotto, Fabio / Rebollo-Lopez, Maria Jose / Lafuente-Monasterio, Maria Jose / Sanz, Olalla / Diaz, Gracia Santos / Lelièvre, Joël / Ballell, Lluis / Selenski, Carolyn / Axtman, Matthew / Ghidelli-Disse, Sonja / Pflaumer, Hannah / Bösche, Markus / Drewes, Gerard / Freiberg, Gail M / Kurnick, Matthew D / Srikumaran, Myron / Kempf, Dale J / Green, Simon R / Ray, Peter C / Read, Kevin / Wyatt, Paul / Barry, Clifton E / Boshoff, Helena I

    ACS infectious diseases

    2016  Volume 3, Issue 1, Page(s) 18–33

    Abstract: A potent, noncytotoxic indazole sulfonamide was identified by high-throughput screening of >100,000 synthetic compounds for activity against Mycobacterium tuberculosis (Mtb). This noncytotoxic compound did not directly inhibit cell wall biogenesis but ... ...

    Abstract A potent, noncytotoxic indazole sulfonamide was identified by high-throughput screening of >100,000 synthetic compounds for activity against Mycobacterium tuberculosis (Mtb). This noncytotoxic compound did not directly inhibit cell wall biogenesis but triggered a slow lysis of Mtb cells as measured by release of intracellular green fluorescent protein (GFP). Isolation of resistant mutants followed by whole-genome sequencing showed an unusual gene amplification of a 40 gene region spanning from Rv3371 to Rv3411c and in one case a potential promoter mutation upstream of guaB2 (Rv3411c) encoding inosine monophosphate dehydrogenase (IMPDH). Subsequent biochemical validation confirmed direct inhibition of IMPDH by an uncompetitive mode of inhibition, and growth inhibition could be rescued by supplementation with guanine, a bypass mechanism for the IMPDH pathway. Beads containing immobilized indazole sulfonamides specifically interacted with IMPDH in cell lysates. X-ray crystallography of the IMPDH-IMP-inhibitor complex revealed that the primary interactions of these compounds with IMPDH were direct pi-pi interactions with the IMP substrate. Advanced lead compounds in this series with acceptable pharmacokinetic properties failed to show efficacy in acute or chronic murine models of tuberculosis (TB). Time-kill experiments in vitro suggest that sustained exposure to drug concentrations above the minimum inhibitory concentration (MIC) for 24 h were required for a cidal effect, levels that have been difficult to achieve in vivo. Direct measurement of guanine levels in resected lung tissue from tuberculosis-infected animals and patients revealed 0.5-2 mM concentrations in caseum and normal lung tissue. The high lesional levels of guanine and the slow lytic, growth-rate-dependent effect of IMPDH inhibition pose challenges to developing drugs against this target for use in treating TB.
    MeSH term(s) Animals ; Antitubercular Agents/pharmacology ; Drug Design ; Drug Discovery ; Drug Resistance, Bacterial ; Gene Expression Regulation, Bacterial/drug effects ; Gene Expression Regulation, Enzymologic/drug effects ; Humans ; IMP Dehydrogenase/antagonists & inhibitors ; Mice ; Mice, Inbred C57BL ; Molecular Structure ; Mutation ; Mycobacterium tuberculosis/drug effects ; Mycobacterium tuberculosis/enzymology ; Protein Conformation ; Rabbits ; Structure-Activity Relationship ; Sulfonamides/chemistry ; Sulfonamides/pharmacokinetics ; Sulfonamides/pharmacology ; Tuberculosis/drug therapy
    Chemical Substances Antitubercular Agents ; Sulfonamides ; IMP Dehydrogenase (EC 1.1.1.205)
    Language English
    Publishing date 2016-10-17
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Intramural ; Research Support, Non-U.S. Gov't
    ISSN 2373-8227
    ISSN (online) 2373-8227
    DOI 10.1021/acsinfecdis.6b00103
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top