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Garg N, Luzzatto-Knaan T, Melnik AV, Caraballo-Rodríguez AM, Floros DJ, Petras D, Gregor R, Dorrestein PC, Phelan VV. Natural products as mediators of disease. Nat Prod Rep 2017; 34:194-219. [PMID: 27874907 PMCID: PMC5299058 DOI: 10.1039/c6np00063k] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Covering: up to 2016Humans are walking microbial ecosystems, each harboring a complex microbiome with the genetic potential to produce a vast array of natural products. Recent sequencing data suggest that our microbial inhabitants are critical for maintaining overall health. Shifts in microbial communities have been correlated to a number of diseases including infections, inflammation, cancer, and neurological disorders. Some of these clinically and diagnostically relevant phenotypes are a result of the presence of small molecules, yet we know remarkably little about their contributions to the health of individuals. Here, we review microbe-derived natural products as mediators of human disease.
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Affiliation(s)
- Neha Garg
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Tal Luzzatto-Knaan
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Alexey V. Melnik
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | | | - Dimitrios J. Floros
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093
| | - Daniel Petras
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Rachel Gregor
- Department of Chemistry and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
| | - Pieter C. Dorrestein
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Vanessa V. Phelan
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, The University of Colorado Anschutz Medical Campus, Aurora, CO 80045
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Stringent Response Factors PPX1 and PPK2 Play an Important Role in Mycobacterium tuberculosis Metabolism, Biofilm Formation, and Sensitivity to Isoniazid In Vivo. Antimicrob Agents Chemother 2016; 60:6460-6470. [PMID: 27527086 DOI: 10.1128/aac.01139-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/09/2016] [Indexed: 01/30/2023] Open
Abstract
Mycobacterium tuberculosis remains a global health threat largely due to the lengthy duration of curative antibiotic treatment, contributing to medical nonadherence and the emergence of drug resistance. This prolonged therapy is likely due to the presence of M. tuberculosis persisters, which exhibit antibiotic tolerance. Inorganic polyphosphate [poly(P)] is a key regulatory molecule in the M. tuberculosis stringent response mediating antibiotic tolerance. The polyphosphate kinase PPK1 is responsible for poly(P) synthesis in M. tuberculosis, while the exopolyphosphatases PPX1 and PPX2 and the GTP synthase PPK2 are responsible for poly(P) hydrolysis. In the present study, we show by liquid chromatography-tandem mass spectrometry that poly(P)-accumulating M. tuberculosis mutant strains deficient in ppx1 or ppk2 had significantly lower intracellular levels of glycerol-3-phosphate (G3P) and 1-deoxy-xylulose-5-phosphate. Real-time PCR revealed decreased expression of genes in the G3P synthesis pathway in each mutant. The ppx1-deficient mutant also showed a significant accumulation of metabolites in the tricarboxylic acid cycle, as well as altered arginine and NADH metabolism. Each poly(P)-accumulating strain showed defective biofilm formation, while deficiency of ppk2 was associated with increased sensitivity to plumbagin and meropenem and deficiency of ppx1 led to enhanced susceptibility to clofazimine. A DNA vaccine expressing ppx1 and ppk2, together with two other members of the M. tuberculosis stringent response, M. tuberculosis rel and sigE, did not show protective activity against aerosol challenge with M. tuberculosis, but vaccine-induced immunity enhanced the killing activity of isoniazid in a murine model of chronic tuberculosis. In summary, poly(P)-regulating factors of the M. tuberculosis stringent response play an important role in M. tuberculosis metabolism, biofilm formation, and antibiotic sensitivity in vivo.
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Ben-Kahla I, Al-Hajoj S. Drug-resistant tuberculosis viewed from bacterial and host genomes. Int J Antimicrob Agents 2016; 48:353-60. [PMID: 27566907 DOI: 10.1016/j.ijantimicag.2016.07.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 06/26/2016] [Accepted: 07/15/2016] [Indexed: 12/14/2022]
Abstract
The outcome of infection with Mycobacterium tuberculosis (MTB) is largely influenced by the host-pathogen interaction in which both the human host and the MTB genetic backgrounds play an important role. Whether this interaction also influences the selection and expansion of drug-resistant MTB strains is the primary focus of this review. We first outline the main and recent findings regarding MTB determinants implicated in the development of drug resistance. Second, we examine data regarding human genetic factors that may play a role in TB drug resistance. We highlight interesting openings for TB research and therapy.
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Affiliation(s)
- Imen Ben-Kahla
- Mycobacteriology Section, Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Sahal Al-Hajoj
- Mycobacteriology Section, Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
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54
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Li Q, Zhou M, Fan X, Yan J, Li W, Xie J. Mycobacteriophage SWU1 gp39 can potentiate multiple antibiotics against Mycobacterium via altering the cell wall permeability. Sci Rep 2016. [PMID: 27350398 DOI: 10.1038/srep28701srep28701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023] Open
Abstract
M. tuberculosis is intrinsically tolerant to many antibiotics largely due to the imperviousness of its unusual mycolic acid-containing cell wall to most antimicrobials. The emergence and increasingly widespread of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) revitalized keen interest in phage-inspired therapy. SWU1gp39 is a novel gene from mycobacteriophage SWU1 with unknown function. SWU1gp39 expressed in M. smegmatis conferred the host cell increased susceptibility to multiple antibiotics, including isoniazid, erythromycin, norfloxacin, ampicillin, ciprofloxacin, ofloxacin, rifampicin and vancomycin, and multiple environment stresses such as H2O2, heat shock, low pH and SDS. By using EtBr/Nile red uptake assays, WT-pAL-gp39 strain showed higher cell wall permeability than control strain WT-pAL. Moreover, the WT-pAL-gp39 strain produced more reactive oxygen species and reduced NAD(+)/NADH ratio. RNA-Seq transcriptomes of the WT-pAL-gp39 and WT-pAL revealed that the transcription of 867 genes was differentially regulated, including genes associated with lipid metabolism. Taken together, our results implicated that SWU1gp39, a novel gene from mycobacteriophage, disrupted the lipid metabolism of host and increased cell wall permeability, ultimately potentiated the efficacy of multiple antibiotics and stresses against mycobacteria.
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Affiliation(s)
- Qiming Li
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Mingliang Zhou
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Xiangyu Fan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China
- School of Biological Science and Technology, University of Jinan, Shandong 250022, China
| | - Jianlong Yan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Weimin Li
- National Tuberculosis Clinical Lab of China, Beijing Key laboratory on Drug-resistant Tuberculosis Research, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China
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55
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Li Q, Zhou M, Fan X, Yan J, Li W, Xie J. Mycobacteriophage SWU1 gp39 can potentiate multiple antibiotics against Mycobacterium via altering the cell wall permeability. Sci Rep 2016; 6:28701. [PMID: 27350398 PMCID: PMC4923848 DOI: 10.1038/srep28701] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/08/2016] [Indexed: 12/14/2022] Open
Abstract
M. tuberculosis is intrinsically tolerant to many antibiotics largely due to the imperviousness of its unusual mycolic acid-containing cell wall to most antimicrobials. The emergence and increasingly widespread of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) revitalized keen interest in phage-inspired therapy. SWU1gp39 is a novel gene from mycobacteriophage SWU1 with unknown function. SWU1gp39 expressed in M. smegmatis conferred the host cell increased susceptibility to multiple antibiotics, including isoniazid, erythromycin, norfloxacin, ampicillin, ciprofloxacin, ofloxacin, rifampicin and vancomycin, and multiple environment stresses such as H2O2, heat shock, low pH and SDS. By using EtBr/Nile red uptake assays, WT-pAL-gp39 strain showed higher cell wall permeability than control strain WT-pAL. Moreover, the WT-pAL-gp39 strain produced more reactive oxygen species and reduced NAD(+)/NADH ratio. RNA-Seq transcriptomes of the WT-pAL-gp39 and WT-pAL revealed that the transcription of 867 genes was differentially regulated, including genes associated with lipid metabolism. Taken together, our results implicated that SWU1gp39, a novel gene from mycobacteriophage, disrupted the lipid metabolism of host and increased cell wall permeability, ultimately potentiated the efficacy of multiple antibiotics and stresses against mycobacteria.
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Affiliation(s)
- Qiming Li
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Mingliang Zhou
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Xiangyu Fan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China
- School of Biological Science and Technology, University of Jinan, Shandong 250022, China
| | - Jianlong Yan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Weimin Li
- National Tuberculosis Clinical Lab of China, Beijing Key laboratory on Drug-resistant Tuberculosis Research, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China
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56
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Mycobacteriophage putative GTPase-activating protein can potentiate antibiotics. Appl Microbiol Biotechnol 2016; 100:8169-77. [PMID: 27345061 DOI: 10.1007/s00253-016-7681-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/09/2016] [Accepted: 06/13/2016] [Indexed: 02/07/2023]
Abstract
The soaring incidences of infection by antimicrobial resistant (AR) pathogens and shortage of effective antibiotics with new mechanisms of action have renewed interest in phage therapy. This scenario is exemplified by resistant tuberculosis (TB), caused by resistant Mycobacterium tuberculosis. Mycobacteriophage SWU1 A321_gp67 encodes a putative GTPase-activating protein. Mycobacterium smegmatis with gp67 overexpression showed changed colony formation and biofilm morphology and supports the efficacy of streptomycin and capreomycin against Mycobacterium. gp67 down-regulated the transcription of genes involved in cell wall and biofilm development. To our knowledge, this is the first report to show that phage protein in addition to lysin or recombination components can synergize with existing antibiotics. Phage components might represent a promising new clue for better antibiotic potentiators.
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57
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Lahiri N, Shah RR, Layre E, Young D, Ford C, Murray MB, Fortune SM, Moody DB. Rifampin Resistance Mutations Are Associated with Broad Chemical Remodeling of Mycobacterium tuberculosis. J Biol Chem 2016; 291:14248-14256. [PMID: 27226566 DOI: 10.1074/jbc.m116.716704] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Indexed: 11/06/2022] Open
Abstract
Global control of tuberculosis has become increasingly complicated with the emergence of multidrug-resistant strains of Mycobacterium tuberculosis First-line treatments are anchored by two antibiotics, rifampin and isoniazid. Most rifampin resistance occurs through the acquisition of missense mutations in the rifampin resistance-determining region, an 81-base pair region encoding the rifampin binding site on the β subunit of RNA polymerase (rpoB). Although these mutations confer a survival advantage in the presence of rifampin, they may alter the normal process of transcription, thereby imposing significant fitness costs. Because the downstream biochemical consequences of the rpoB mutations are unknown, we used an organism-wide screen to identify the number and types of lipids changed after rpoB mutation. A new mass spectrometry-based profiling platform systematically compared ∼10,000 cell wall lipids in a panel of rifampin-resistant mutants within two genetically distinct strains, CDC1551and W-Beijing. This unbiased lipidomic survey detected quantitative alterations (>2-fold, p < 0.05) in more than 100 lipids in each mutant. By focusing on molecular events that change among most mutants and in both genetic backgrounds, we found that rifampin resistance mutations lead to altered concentrations of mycobactin siderophores and acylated sulfoglycolipids. These findings validate a new organism-wide lipidomic analysis platform for drug-resistant mycobacteria and provide direct evidence for characteristic remodeling of cell wall lipids in rifampin-resistant strains of M. tuberculosis The specific links between rifampin resistance and named lipid factors provide diagnostic and therapeutic targets that may be exploited to address the problem of drug resistance.
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Affiliation(s)
- Nivedita Lahiri
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115
| | - Rupal R Shah
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Emilie Layre
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115
| | - David Young
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115
| | - Chris Ford
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Megan B Murray
- Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Sarah M Fortune
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
| | - D Branch Moody
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115.
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58
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Thiol reductive stress induces cellulose-anchored biofilm formation in Mycobacterium tuberculosis. Nat Commun 2016; 7:11392. [PMID: 27109928 PMCID: PMC4848537 DOI: 10.1038/ncomms11392] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 03/21/2016] [Indexed: 12/30/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) forms biofilms harbouring antibiotic-tolerant bacilli in vitro, but the factors that induce biofilm formation and the nature of the extracellular material that holds the cells together are poorly understood. Here we show that intracellular thiol reductive stress (TRS) induces formation of Mtb biofilms in vitro, which harbour drug-tolerant but metabolically active bacteria with unchanged levels of ATP/ADP, NAD(+)/NADH and NADP(+)/NADPH. The development of these biofilms requires DNA, RNA and protein synthesis. Transcriptional analysis suggests that Mtb modulates only ∼7% of its genes for survival in biofilms. In addition to proteins, lipids and DNA, the extracellular material in these biofilms is primarily composed of polysaccharides, with cellulose being a key component. Our results contribute to a better understanding of the mechanisms underlying Mtb biofilm formation, although the clinical relevance of Mtb biofilms in human tuberculosis remains unclear.
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59
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Abstract
Bacteria have a natural propensity to grow as sessile, matrix-encapsulated, multicellular communities called biofilms. Formation of biofilms proceeds through genetically programmed, distinct developmental stages signaled by intricate networks of communication among the constituent population and their environment. Growing in the complex and heterogeneous microenvironments of biofilms, the resident bacteria acquire unique phenotypes that are generally not associated with their planktonic counterparts. Most notable among these is an extraordinary level of tolerance to a variety of environmental stresses, including antibiotics. Although mycobacteria have long been observed to spontaneously form complex multicellular structures in vitro, it has only recently become apparent that these structures are not only formed through dedicated genetic pathways but are also tolerant to antibiotics. In this article, we review the recent advances in the understanding of mycobacterial biofilms in vitro. We further consider the possible linkage between biofilm-like lifestyles and characteristic persistence of mycobacterial infections against host-defense mechanisms as well as antibiotics.
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60
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Mohandas P, Budell WC, Mueller E, Au A, Bythrow GV, Quadri LEN. Pleiotropic consequences of gene knockouts in the phthiocerol dimycocerosate and phenolic glycolipid biosynthetic gene cluster of the opportunistic human pathogen Mycobacterium marinum. FEMS Microbiol Lett 2016; 363:fnw016. [PMID: 26818253 DOI: 10.1093/femsle/fnw016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2016] [Indexed: 11/14/2022] Open
Abstract
Phthiocerol dimycocerosates (PDIMs) and phenolic glycolipids (PGLs) contribute to the pathogenicity of several mycobacteria. Biosynthesis of these virulence factors requires polyketide synthases and other enzymes that represent potential targets for the development of adjuvant antivirulence drugs. We used six isogenic Mycobacterium marinum mutants, each with a different gene knockout in the PDIM/PGL biosynthetic pathway, to probe the pleiotropy of mutations leading to PDIM(-) PGL(-), PDIM(+) PGL(-) or PDIM(-) PGL(+) phenotypes. We evaluated the M. marinum mutants for changes in antibiotic susceptibility, cell envelope permeability, biofilm formation, surface properties, sliding motility and virulence in an amoeba model. The analysis also permitted us to begin exploring the hypothesis that different gene knockouts rendering the same PDIM and/or PGL deficiency phenotypes lead to M. marinum mutants with equivalent pleiotropic profiles. Overall, the results of our study revealed a complex picture of pleiotropic patterns emerging from different gene knockouts, uncovered unexpected phenotypic inequalities between mutants, and provided new insight into the phenotypic consequences of gene knockouts in the PDIM/PGL biosynthetic pathway.
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Affiliation(s)
- Poornima Mohandas
- Biology Department, Brooklyn College, City University of New York, Brooklyn, NY 11210, USA Biology Program, Graduate Center, City University of New York, NY 10016, USA
| | - William C Budell
- Biology Department, Brooklyn College, City University of New York, Brooklyn, NY 11210, USA Biology Program, Graduate Center, City University of New York, NY 10016, USA
| | - Emily Mueller
- Biology Department, Brooklyn College, City University of New York, Brooklyn, NY 11210, USA
| | - Andrew Au
- Biology Department, Brooklyn College, City University of New York, Brooklyn, NY 11210, USA
| | - Glennon V Bythrow
- Biology Department, Brooklyn College, City University of New York, Brooklyn, NY 11210, USA Biology Program, Graduate Center, City University of New York, NY 10016, USA
| | - Luis E N Quadri
- Biology Department, Brooklyn College, City University of New York, Brooklyn, NY 11210, USA Biology Program, Graduate Center, City University of New York, NY 10016, USA
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61
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Affiliation(s)
- Diala Faddoul
- Descanso Pediatrics, Huntington Medical Foundation, 1346 Foothill Boulevard Suite 201, La Canada, CA 91011, USA.
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62
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Flores-Valdez MA, de Jesús Aceves-Sánchez M, Pedroza-Roldán C, Vega-Domínguez PJ, Prado-Montes de Oca E, Bravo-Madrigal J, Laval F, Daffé M, Koestler B, Waters CM. The cyclic di-GMP phosphodiesterase geneRv1357c/BCG1419caffects BCG Pellicle production andIn Vivomaintenance. IUBMB Life 2015; 67:129-38. [DOI: 10.1002/iub.1353] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 01/13/2015] [Indexed: 11/12/2022]
Affiliation(s)
- Mario Alberto Flores-Valdez
- Biotecnología Médica y Farmacéutica; Centro de Investigación y Asistencia en Tecnología y diseño del Estado de Jalisco, A.C; Guadalajara Jalisco México
| | - Michel de Jesús Aceves-Sánchez
- Biotecnología Médica y Farmacéutica; Centro de Investigación y Asistencia en Tecnología y diseño del Estado de Jalisco, A.C; Guadalajara Jalisco México
| | - César Pedroza-Roldán
- Biotecnología Médica y Farmacéutica; Centro de Investigación y Asistencia en Tecnología y diseño del Estado de Jalisco, A.C; Guadalajara Jalisco México
| | - Perla Jazmín Vega-Domínguez
- Biotecnología Médica y Farmacéutica; Centro de Investigación y Asistencia en Tecnología y diseño del Estado de Jalisco, A.C; Guadalajara Jalisco México
| | - Ernesto Prado-Montes de Oca
- Biotecnología Médica y Farmacéutica; Centro de Investigación y Asistencia en Tecnología y diseño del Estado de Jalisco, A.C; Guadalajara Jalisco México
| | - Jorge Bravo-Madrigal
- Biotecnología Médica y Farmacéutica; Centro de Investigación y Asistencia en Tecnología y diseño del Estado de Jalisco, A.C; Guadalajara Jalisco México
| | - Françoise Laval
- Département Mécanismes Moléculaires des Infections Mycobactériennes; Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale; Toulouse France
| | - Mamadou Daffé
- Département Mécanismes Moléculaires des Infections Mycobactériennes; Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale; Toulouse France
| | - Ben Koestler
- Department of Microbiology and Molecular Genetics; 5180 Biomedical Physical Sciences, Michigan State University; East Lansing MI USA
| | - Christopher M. Waters
- Department of Microbiology and Molecular Genetics; 5180 Biomedical Physical Sciences, Michigan State University; East Lansing MI USA
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63
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Deficiency of the novel exopolyphosphatase Rv1026/PPX2 leads to metabolic downshift and altered cell wall permeability in Mycobacterium tuberculosis. mBio 2015; 6:e02428. [PMID: 25784702 PMCID: PMC4453511 DOI: 10.1128/mbio.02428-14] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mycobacterium tuberculosis can persist for decades in the human host. Stringent response pathways involving inorganic polyphosphate [poly(P)], which is synthesized and hydrolyzed by polyphosphate kinase (PPK) and exopolyphosphatase (PPX), respectively, are believed to play a key regulatory role in bacterial persistence. We show here that M. tuberculosis poly(P) accumulation is temporally linked to bacillary growth restriction. We also identify M. tuberculosis Rv1026 as a novel exopolyphosphatase with hydrolytic activity against long-chain poly(P). Using a tetracycline-inducible expression system to knock down expression of Rv1026 (ppx2), we found that M. tuberculosis poly(P) accumulation leads to slowed growth and reduced susceptibility to isoniazid, increased resistance to heat and acid pH, and enhanced intracellular survival during macrophage infection. By transmission electron microscopy, the ppx2 knockdown strain exhibited increased cell wall thickness, which was associated with reduced cell wall permeability to hydrophilic drugs rather than induction of drug efflux pumps or altered biofilm formation relative to the empty vector control. Transcriptomic and metabolomic analysis revealed a metabolic downshift of the ppx2 knockdown characterized by reduced transcription and translation and a downshift of glycerol-3-phosphate levels. In summary, poly(P) plays an important role in M. tuberculosis growth restriction and metabolic downshift and contributes to antibiotic tolerance through altered cell wall permeability. The stringent response, involving the regulatory molecules inorganic polyphosphate [poly(P)] and (p)ppGpp, is believed to mediate Mycobacterium tuberculosis persistence. In this study, we identified a novel enzyme (Rv1026, PPX2) responsible for hydrolyzing long-chain poly(P). A genetically engineered M. tuberculosis strain deficient in the ppx2 gene showed increased poly(P) levels, which were associated with early bacterial growth arrest and reduced susceptibility to the first-line drug isoniazid, as well as increased bacterial survival during exposure to stress conditions and within macrophages. Relative to the control strain, the mutant showed increased thickness of the cell wall and reduced drug permeability. Global gene expression and metabolite analysis revealed reduced expression of the transcriptional and translational machinery and a shift in carbon source utilization. In summary, regulation of the poly(P) balance is critical for persister formation in M. tuberculosis.
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64
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Abstract
Our understanding of the biological principles of mycobacterial tolerance to antibiotics is crucial for developing shorter anti-tuberculosis regimens. Various in vitro approaches have been developed to identify the conditions that promote mycobacterial persistence against antibiotics. In our laboratories, we have developed a detergent-free in vitro growth model, in which mycobacteria spontaneously grow at the air-medium interface as self-organized multicellular structures, called biofilms. Mycobacterial biofilms harbor a subpopulation of drug tolerant persisters at a greater frequency than their planktonic counterpart. Importantly, development of these structures is genetically programmed, and defective biofilms of isogenic mutants harbor fewer persisters. Thus, genetic analysis of mycobacterial biofilms in vitro could potentially be a powerful tool to unravel the biology of drug tolerance in mycobacteria. In this chapter we describe a method for screening biofilm-defective mutants of mycobacteria in a 96-well format, which readily yields a clonally pure mutant for further studies.
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Affiliation(s)
- Anil K Ojha
- Division of Genetics, Wadsworth CenterNew York State Department of Health, 150 New Scotland Avenue, Albany, NY, 12208, USA,
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65
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Sharma IM, Petchiappan A, Chatterji D. Quorum sensing and biofilm formation in mycobacteria: Role of c-di-GMP and methods to study this second messenger. IUBMB Life 2014; 66:823-34. [DOI: 10.1002/iub.1339] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Accepted: 12/04/2014] [Indexed: 12/18/2022]
Affiliation(s)
- Indra Mani Sharma
- Molecular Biophysics Unit; Indian Institute of Science; Bangalore Karnataka India
| | - Anushya Petchiappan
- Molecular Biophysics Unit; Indian Institute of Science; Bangalore Karnataka India
| | - Dipankar Chatterji
- Molecular Biophysics Unit; Indian Institute of Science; Bangalore Karnataka India
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66
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Effects of clofazimine on planktonic and biofilm growth of Mycobacterium tuberculosis and Mycobacterium smegmatis. J Glob Antimicrob Resist 2014; 3:13-18. [PMID: 27873644 DOI: 10.1016/j.jgar.2014.12.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/12/2014] [Accepted: 12/05/2014] [Indexed: 11/23/2022] Open
Abstract
Mycobacteria form lipid-rich biofilms that restrict the efficacy of antimicrobial chemotherapy, possibly necessitating the use of lipophilic antibiotics. In the current study, the activity of one such agent, clofazimine, against Mycobacterium tuberculosis and Mycobacterium smegmatis planktonic cells and biofilms was investigated. Minimum inhibitory concentrations (MICs) of clofazimine were determined for planktonic cultures, whilst minimum bactericidal concentrations (MBCs) were determined for planktonic, biofilm-producing and biofilm-encased organisms using standard bacteriological procedures. The effects of clofazimine on biofilm formation and the stability of pre-formed biofilm were measured using a crystal violet-based spectrophotometric procedure. In the case of M. smegmatis, clofazimine was found to be active against planktonic phase (MICs and MBCs of 2.5mg/L and >20mg/L, respectively) and biofilm-producing organisms (MBC of 2.5mg/L); clofazimine demonstrated greater activity against M. tuberculosis, corresponding values of 0.06, 5 and 0.3mg/L. Although clofazimine inhibited biofilm production both by M. tuberculosis and M. smegmatis (P<0.05 at ≥0.07mg/L and ≥0.3mg/L, respectively) and appeared to reduce the pre-formed M. tuberculosis biofilm, addition of antimicrobial agent to pre-existing biofilm matrices failed to kill biofilm-encased organisms. In conclusion, clofazimine is more effective against M. tuberculosis than against M. smegmatis, exhibiting bactericidal activity both for actively growing and slowly replicating bacilli but not for non-replicating organisms of both species.
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67
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Hosseini H, Fooladi AAI, Arjomandzadegan M, Emami N, Bornasi H. Genetics study and transmission electron microscopy of pili in susceptible and resistant clinical isolates of Mycobacterium tuberculosis. ASIAN PAC J TROP MED 2014; 7S1:S199-203. [PMID: 25312121 DOI: 10.1016/s1995-7645(14)60232-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 06/06/2014] [Accepted: 06/26/2014] [Indexed: 10/24/2022] Open
Abstract
OBJECTIVE To study genetic bases and morphology of pili in Mycobacterium tuberculosis (M. tuberculosis). METHODS PCR and sequencing were used to investigate two related pili, Mtp and Flp genes in clinical isolates of M. tuberculosis. The primers were designed and PCR program were set for whole genes amplification. PCR products of the two genes from all isolates were sequenced by an applied biosystems apparatus and the results were analysed by online software. In the other hands, harvested cells from fresh cultures of isolates were undergoing specific sample preparation for sectional and negative staining for transmission electron microscopy. RESULTS Electrophoresis revealed two specific bonds of 361 bp for Mtp and 150 bp for Flp genes and confirmed primer and PCR conditions designing. There were not any mutations in sequencing results of Mtp and Flp in comparison with reference sequence. Transmission electron microscopy examination revealed two distinct types of pili in the isolates as a bundle-forming pilus and rope-like pilus. From total investigated cells, 10% harbored pili in their structure. CONCLUSIONS Two genes of pili in all clinical isolates of M. tuberculosis were conserved and two morphological types of pili were detected. We proposed that by targeting pili proteins by a suitable inhibitor, it could affect the pathogenesis especially in resistant forms.
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Affiliation(s)
- Hossein Hosseini
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Abbas Ali Imani Fooladi
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Mohammad Arjomandzadegan
- Tuberculosis and Pediatric Infectious Resaerch Center, Arak University of Medical Sciences, Arak, Iran.
| | - Navid Emami
- Tuberculosis and Pediatric Infectious Resaerch Center, Arak University of Medical Sciences, Arak, Iran
| | - Hamid Bornasi
- Tuberculosis and Pediatric Infectious Resaerch Center, Arak University of Medical Sciences, Arak, Iran
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68
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Mycobacterium tuberculosis strains lacking surface lipid phthiocerol dimycocerosate are susceptible to killing by an early innate host response. Infect Immun 2014; 82:5214-22. [PMID: 25287926 DOI: 10.1128/iai.01340-13] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The innate immune response plays an important but unknown role in host defense against Mycobacterium tuberculosis. To define the function of innate immunity during tuberculosis, we evaluated M. tuberculosis replication dynamics during murine infection. Our data show that the early pulmonary innate immune response limits M. tuberculosis replication in a MyD88-dependent manner. Strikingly, we found that little M. tuberculosis cell death occurs during the first 2 weeks of infection. In contrast, M. tuberculosis cells deficient in the surface lipid phthiocerol dimycocerosate (PDIM) exhibited significant death rates, and consequently, total bacterial numbers were reduced. Host restriction of PDIM-deficient M. tuberculosis was not alleviated by the absence of interferon gamma (IFN-γ), inducible nitric oxide synthase (iNOS), or the phagocyte oxidase subunit p47. Taken together, these data indicate that PDIM protects M. tuberculosis from an early innate host response that is independent of IFN-γ, reactive nitrogen intermediates, and reactive oxygen species. By employing a pathogen replication tracking tool to evaluate M. tuberculosis replication and death during infection, we identify both host and pathogen factors affecting the outcome of infection.
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69
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Vázquez CL, Lerner TR, Kasmapour B, Pei G, Gronow A, Bianco MV, Blanco FC, Bleck CKE, Geffers R, Bigi F, Abraham WR, Gutierrez MG. Experimental selection of long-term intracellular mycobacteria. Cell Microbiol 2014; 16:1425-40. [PMID: 24779357 PMCID: PMC4283733 DOI: 10.1111/cmi.12303] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Revised: 04/09/2014] [Accepted: 04/13/2014] [Indexed: 11/30/2022]
Abstract
Some intracellular bacteria are known to cause long-term infections that last decades without compromising the viability of the host. Although of critical importance, the adaptations that intracellular bacteria undergo during this long process of residence in a host cell environment remain obscure. Here, we report a novel experimental approach to study the adaptations of mycobacteria imposed by a long-term intracellular lifestyle. Selected Mycobacterium bovis BCG through continuous culture in macrophages underwent an adaptation process leading to impaired phenolic glycolipids (PGL) synthesis, improved usage of glucose as a carbon source and accumulation of neutral lipids. These changes correlated with increased survival of mycobacteria in macrophages and mice during re-infection and also with the specific expression of stress- and survival-related genes. Our findings identify bacterial traits implicated in the establishment of long-term cellular infections and represent a tool for understanding the physiological states and the environment that bacteria face living in fluctuating intracellular environments.
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Affiliation(s)
- Cristina L Vázquez
- Research Group Phagosome Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
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70
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Qvist T, Pressler T, Høiby N, Katzenstein TL. Shifting paradigms of nontuberculous mycobacteria in cystic fibrosis. Respir Res 2014; 15:41. [PMID: 24725650 PMCID: PMC3986433 DOI: 10.1186/1465-9921-15-41] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 04/04/2014] [Indexed: 01/27/2023] Open
Abstract
Important paradigms of pulmonary disease with nontuberculous mycobacteria (NTM) are currently shifting based on an increasing attention within the field of cystic fibrosis (CF). These shifts are likely to benefit the management of all patients with pulmonary NTM, regardless of underlying pathology. Currently several key areas are being revised: The first outbreak of human NTM transmission has been proven and new evidence of biofilm growth in vivo has been demonstrated. A better understanding of the clinical impact of NTM infection has led to increased diagnostic vigilance and new recommendations for lung transplantation are under way. While recent changes have reinvigorated the interest in NTM disease, the challenge remains, whether such advances can be successfully translated into improved management and care.
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Affiliation(s)
- Tavs Qvist
- Department of Infectious Diseases, Cystic Fibrosis Center Copenhagen, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
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71
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Ackart DF, Hascall-Dove L, Caceres SM, Kirk NM, Podell BK, Melander C, Orme IM, Leid JG, Nick JA, Basaraba RJ. Expression of antimicrobial drug tolerance by attached communities of Mycobacterium tuberculosis. Pathog Dis 2014; 70:359-69. [PMID: 24478060 PMCID: PMC4361083 DOI: 10.1111/2049-632x.12144] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/15/2014] [Accepted: 01/16/2014] [Indexed: 11/28/2022] Open
Abstract
There is an urgent need to improve methods used to screen antituberculosis drugs. An in vitro assay was developed to test drug treatment strategies that specifically target drug-tolerant Mycobacterium tuberculosis. The H37Rv strain of M. tuberculosis survived antimicrobial treatment as attached microbial communities when maintained in tissue culture media (RPMI-1640) with or without lysed human peripheral blood leukocytes. When cultured planktonically in the presence of Tween-80, bacilli failed to form microbial communities or reach logarithmic phase growth yet remained highly susceptible to antimicrobial drugs. In the absence of Tween, bacilli tolerated drug therapy by forming complex microbial communities attached to untreated well surfaces or to the extracellular matrix derived from lysed human leukocytes. Treatment of microbial communities with DNase I or Tween effectively dispersed bacilli and restored drug susceptibility. These data demonstrate that in vitro expression of drug tolerance by M. tuberculosis is linked to the establishment of attached microbial communities and that dispersion of bacilli targeting the extracellular matrix including DNA restores drug susceptibility. Modifications of this in vitro assay may prove beneficial in a high-throughput platform to screen new antituberculosis drugs especially those that target drug-tolerant bacilli.
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Affiliation(s)
- David F. Ackart
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
| | - Laurel Hascall-Dove
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
| | - Silvia M. Caceres
- Department of Medicine, National Jewish Health, Denver, CO, United States of America
| | - Natalie M. Kirk
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
| | - Brendan K. Podell
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
| | - Christian Melander
- Department of Chemistry, North Carolina State University, Raleigh, NC, United States of America
| | - Ian M. Orme
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
| | - Jeff G. Leid
- Medical Products Division, W.L. Gore and Associates, Flagstaff, AZ, United States of America
| | - Jerry A. Nick
- Department of Medicine, National Jewish Health, Denver, CO, United States of America
| | - Randall J. Basaraba
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
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72
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Quadri LEN. Biosynthesis of mycobacterial lipids by polyketide synthases and beyond. Crit Rev Biochem Mol Biol 2014; 49:179-211. [DOI: 10.3109/10409238.2014.896859] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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73
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Ackart DF, Lindsey EA, Podell BK, Melander RJ, Basaraba RJ, Melander C. Reversal of Mycobacterium tuberculosis phenotypic drug resistance by 2-aminoimidazole-based small molecules. Pathog Dis 2014; 70:370-8. [PMID: 24478046 DOI: 10.1111/2049-632x.12143] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 01/17/2014] [Accepted: 01/20/2014] [Indexed: 12/21/2022] Open
Abstract
The expression of phenotypic drug resistance or drug tolerance serves as a strategy for Mycobacterium tuberculosis to survive in vivo antimicrobial drug treatment; however, the mechanisms are poorly understood. Progress toward a more in depth understanding of in vivo drug tolerance and the discovery of new therapeutic strategies designed specifically to treat drug-tolerant M. tuberculosis are hampered by the lack of appropriate in vitro assays. A library of 2-aminoimidazole-based small molecules combined with the antituberculosis drug isoniazid was screened against M. tuberculosis expressing in vitro drug tolerance as microbial communities attached to an extracellular matrix derived from lysed leukocytes. Based on the ability of nine of ten 2-aminoimidazole compounds to inhibit Mycobacterium smegmatis biofilm formation and three of ten molecules capable of dispersing established biofilms, two active candidates and one inactive control were tested against drug-tolerant M. tuberculosis. The two active compounds restored isoniazid susceptibility as well as reduced the in vitro minimum inhibitory concentrations of isoniazid in a dose-dependent manner. The dispersion of drug-tolerant M. tuberculosis with 2-aminoimidazole-based small molecules as an adjunct to antimicrobial treatment has the potential to be an effective antituberculosis treatment strategy designed specifically to eradicate drug-tolerant M. tuberculosis.
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Affiliation(s)
- David F Ackart
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA
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74
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Orme IM. A new unifying theory of the pathogenesis of tuberculosis. Tuberculosis (Edinb) 2013; 94:8-14. [PMID: 24157189 DOI: 10.1016/j.tube.2013.07.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 07/24/2013] [Accepted: 07/29/2013] [Indexed: 10/26/2022]
Abstract
It is set in stone that Mycobacterium tuberculosis is a facultative intracellular bacterial parasite. This axiom drives our knowledge of the host response, the way we design vaccines against the organism by generating protective T cells, and to a lesser extent, the way we try to target anti-microbial drugs. The purpose of this article is to commit total heresy. I believe that M. tuberculosis can equally well be regarded as an extracellular pathogen and may in fact spend a large percentage of its human lung "life-cycle" in this environment. It is of course intracellular as well, but this may well be little more than a brief interlude after infection of a new host during which the bacterium must replicate to increase its chances of transmission and physiologically adapt prior to moving back to an extracellular phase. As a result, by focusing almost completely on just the intracellular phase, we may be making serious strategic errors in the way we try to intervene in this pathogenic process. It is my opinion that when a TB bacillus enters the lungs and starts to reside inside an alveolar macrophage, its central driving force is to switch on a process leading to lung necrosis, since it is only by this process that the local lung tissue can be destroyed and the bacillus can be exhaled and transmitted. I present here a new model of the pathogenesis of the disease that attempts to unify the pathogenic process of infection, disease, persistence [rather than latency], and reactivation.
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Affiliation(s)
- Ian M Orme
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA.
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Ramsugit S, Guma S, Pillay B, Jain P, Larsen MH, Danaviah S, Pillay M. Pili contribute to biofilm formation in vitro in Mycobacterium tuberculosis. Antonie Van Leeuwenhoek 2013; 104:725-35. [DOI: 10.1007/s10482-013-9981-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 07/20/2013] [Indexed: 11/24/2022]
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Pacheco SA, Hsu FF, Powers KM, Purdy GE. MmpL11 protein transports mycolic acid-containing lipids to the mycobacterial cell wall and contributes to biofilm formation in Mycobacterium smegmatis. J Biol Chem 2013; 288:24213-22. [PMID: 23836904 DOI: 10.1074/jbc.m113.473371] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A growing body of evidence indicates that MmpL (mycobacterial membrane protein large) transporters are dedicated to cell wall biosynthesis and transport mycobacterial lipids. How MmpL transporters function and the identities of their substrates have not been fully elucidated. We report the characterization of Mycobacterium smegmatis MmpL11. We showed previously that M. smegmatis lacking MmpL11 has reduced membrane permeability that results in resistance to host antimicrobial peptides. We report herein the further characterization of the M. smegmatis mmpL11 mutant and identification of the MmpL11 substrates. We found that biofilm formation by the M. smegmatis mmpL11 mutant was distinct from that by wild-type M. smegmatis. Analysis of cell wall lipids revealed that the mmpL11 mutant failed to export the mycolic acid-containing lipids monomeromycolyl diacylglycerol and mycolate ester wax to the bacterial surface. In addition, analysis of total lipids indicated that the mycolic acid-containing precursor molecule mycolyl phospholipid accumulated in the mmpL11 mutant compared with wild-type mycobacteria. MmpL11 is encoded at a chromosomal locus that is conserved across pathogenic and nonpathogenic mycobacteria. Phenotypes of the M. smegmatis mmpL11 mutant are complemented by the expression of M. smegmatis or M. tuberculosis MmpL11, suggesting that MmpL11 plays a conserved role in mycobacterial cell wall biogenesis.
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Affiliation(s)
- Sophia A Pacheco
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon 97239, USA
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77
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Islam MS, Richards JP, Ojha AK. Targeting drug tolerance in mycobacteria: a perspective from mycobacterial biofilms. Expert Rev Anti Infect Ther 2013; 10:1055-66. [PMID: 23106280 DOI: 10.1586/eri.12.88] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Multidrug chemotherapy for 6-9-months is one of the primary treatments in effective control of tuberculosis, although the mechanisms underlying the persistence of its etiological agent, Mycobacterium tuberculosis, against antibiotics remain unclear. Ever-mounting evidence indicates that the survival of many environmental and pathogenic microbial species against antibiotics is influenced by their ability to grow as surface-associated multicellular communities called biofilms. In recent years, several mycobacterial species, including M. tuberculosis, have been found to form drug-tolerant biofilms in vitro through genetically controlled mechanisms. In this review, the authors discuss the relevance of the in vitro mycobacterial biofilms in understanding the antibiotic recalcitrance of tuberculosis infections.
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Affiliation(s)
- Mohammad S Islam
- Department of Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
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78
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Peyyala R, Ebersole JL. Multispecies biofilms and host responses: "discriminating the trees from the forest". Cytokine 2012; 61:15-25. [PMID: 23141757 DOI: 10.1016/j.cyto.2012.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 09/28/2012] [Accepted: 10/04/2012] [Indexed: 02/07/2023]
Abstract
Periodontal diseases reflect a tissue destructive process of the hard and soft tissues of the periodontium that are initiated by the accumulation of multispecies bacterial biofilms in the subgingival sulcus. This accumulation, in both quantity and quality of bacteria, results in a chronic immunoinflammatory response of the host to control this noxious challenge, leading to collateral damage of the tissues. As knowledge of the characteristics of the host-bacterial interactions in the oral cavity has expanded, new knowledge has become available on the complexity of the microbial challenge and the repertoire of host responses to this challenge. Recent results from the Human Microbiome Project continue to extend the array of taxa, genera, and species of bacteria that inhabit the multiple niches in the oral cavity; however, there is rather sparse information regarding variations in how host cells discriminate commensal from pathogenic species, as well as how the host response is affected by the three-dimensional architecture and interbacterial interactions that occur in the oral biofilms. This review provides some insights into these processes by including existing literature on the biology of nonoral bacterial biofilms, and the more recent literature just beginning to document how the oral cavity responds to multispecies biofilms.
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Affiliation(s)
- R Peyyala
- Center for Oral Health Research, College of Dentistry, University of Kentucky, Lexington, KY 40536, United States
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Esteban J, García-Pedrazuela M, Muñoz-Egea MC, Alcaide F. Current treatment of nontuberculous mycobacteriosis: an update. Expert Opin Pharmacother 2012; 13:967-86. [DOI: 10.1517/14656566.2012.677824] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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