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van der Niet S, Green KD, Schimmel IM, de Bakker J, Lodder B, Reits EA, Garneau-Tsodikova S, van der Wel NN. Zafirlukast induces DNA condensation and has bactericidal effect on replicating Mycobacterium abscessus. Antimicrob Agents Chemother 2024; 68:e0002924. [PMID: 38990015 PMCID: PMC11304721 DOI: 10.1128/aac.00029-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 06/09/2024] [Indexed: 07/12/2024] Open
Abstract
Mycobacterium abscessus infections are emerging in cystic fibrosis patients, and treatment success rate in these patients is only 33% due to extreme antibiotic resistance. Thus, new treatment options are essential. An interesting target could be Lsr2, a nucleoid-associated protein involved in mycobacterial virulence. Zafirlukast is a Food and Drug Administration (FDA)-approved drug against asthma that was shown to bind Lsr2. In this study, zafirlukast treatment is shown to reduce M. abscessus growth, with a minimal inhibitory concentration of 16 µM and a bactericidal concentration of 64 µM in replicating bacteria only. As an initial response, DNA condensation, a known stress response of mycobacteria, occurs after 1 h of treatment with zafirlukast. During continued zafirlukast treatment, the morphology of the bacteria alters and the structural integrity of the bacteria is lost. After 4 days of treatment, reduced viability is measured in different culture media, and growth of M. abscessus is reduced in a dose-dependent manner. Using transmission electron microscopy, we demonstrated that the hydrophobic multilayered cell wall and periplasm are disorganized and ribosomes are reduced in size and relocalized. In summary, our data demonstrate that zafirlukast alters the morphology of M. abscessus and is bactericidal at 64 µM. The bactericidal concentration of zafirlukast is relatively high, and it is only effective on replicating bacteria but as zafirlukast is an FDA-approved drug, and currently used as an anti-asthma treatment, it could be an interesting drug to further study in in vivo experiments to determine whether it could be used as an antibiotic for M. abscessus infections.
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Affiliation(s)
- Sanne van der Niet
- Electron Microscopy Centre Amsterdam, Amsterdam University Medical Centre, Amsterdam, the Netherlands
| | - Keith D. Green
- College of Pharmacy, University of Kentucky, Lexington, Kentucky, USA
| | - Irene M. Schimmel
- Electron Microscopy Centre Amsterdam, Amsterdam University Medical Centre, Amsterdam, the Netherlands
| | - Jordy de Bakker
- Electron Microscopy Centre Amsterdam, Amsterdam University Medical Centre, Amsterdam, the Netherlands
| | - Bastiaan Lodder
- Electron Microscopy Centre Amsterdam, Amsterdam University Medical Centre, Amsterdam, the Netherlands
| | - Eric A. Reits
- Electron Microscopy Centre Amsterdam, Amsterdam University Medical Centre, Amsterdam, the Netherlands
| | | | - Nicole N. van der Wel
- Electron Microscopy Centre Amsterdam, Amsterdam University Medical Centre, Amsterdam, the Netherlands
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2
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Wuo MG, Dulberger CL, Warner TC, Brown RA, Sturm A, Ultee E, Bloom-Ackermann Z, Choi C, Zhu J, Garner EC, Briegel A, Hung DT, Rubin EJ, Kiessling LL. Fluorogenic Probes of the Mycobacterial Membrane as Reporters of Antibiotic Action. J Am Chem Soc 2024; 146:17669-17678. [PMID: 38905328 DOI: 10.1021/jacs.4c00617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/23/2024]
Abstract
The genus Mycobacterium includes species such as Mycobacterium tuberculosis, which can cause deadly human diseases. These bacteria have a protective cell envelope that can be remodeled to facilitate their survival in challenging conditions. Understanding how such conditions affect membrane remodeling can facilitate antibiotic discovery and treatment. To this end, we describe an optimized fluorogenic probe, N-QTF, that reports on mycolyltransferase activity, which is vital for cell division and remodeling. N-QTF is a glycolipid probe that can reveal dynamic changes in the mycobacterial cell envelope in both fast- and slow-growing mycobacterial species. Using this probe to monitor the consequences of antibiotic treatment uncovered distinct cellular phenotypes. Even antibiotics that do not directly inhibit cell envelope biosynthesis cause conspicuous phenotypes. For instance, mycobacteria exposed to the RNA polymerase inhibitor rifampicin release fluorescent extracellular vesicles (EVs). While all mycobacteria release EVs, fluorescent EVs were detected only in the presence of RIF, indicating that exposure to the drug alters EV content. Macrophages exposed to the EVs derived from RIF-treated cells released lower levels of cytokines, suggesting the EVs moderate immune responses. These data suggest that antibiotics can alter EV content to impact immunity. Our ability to see such changes in EV constituents directly results from exploiting these chemical probes.
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Affiliation(s)
- Michael G Wuo
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue Cambridge, Cambridge, Massachusetts 02139, United States
| | - Charles L Dulberger
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 677 Huntington Ave, Boston, Massachusetts 02115, United States
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford St, Cambridge, Massachusetts 02138, United States
| | - Theodore C Warner
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue Cambridge, Cambridge, Massachusetts 02139, United States
| | - Robert A Brown
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Alexander Sturm
- Broad Institute of MIT and Harvard, 415 Main St, Cambridge, Massachusetts 02142, United States
| | - Eveline Ultee
- Institute of Biology, Leiden University, Rapenburg 70, 2311 EZ Leiden, The Netherlands
| | - Zohar Bloom-Ackermann
- Broad Institute of MIT and Harvard, 415 Main St, Cambridge, Massachusetts 02142, United States
| | - Catherine Choi
- Broad Institute of MIT and Harvard, 415 Main St, Cambridge, Massachusetts 02142, United States
| | - Junhao Zhu
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 677 Huntington Ave, Boston, Massachusetts 02115, United States
| | - Ethan C Garner
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford St, Cambridge, Massachusetts 02138, United States
| | - Ariane Briegel
- Institute of Biology, Leiden University, Rapenburg 70, 2311 EZ Leiden, The Netherlands
| | - Deborah T Hung
- Broad Institute of MIT and Harvard, 415 Main St, Cambridge, Massachusetts 02142, United States
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, 55 Fruit Street, Boston, Massachusetts 02114, United States
- Department of Genetics, Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, United States
| | - Eric J Rubin
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 677 Huntington Ave, Boston, Massachusetts 02115, United States
| | - Laura L Kiessling
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue Cambridge, Cambridge, Massachusetts 02139, United States
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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3
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Santoshi M, Tare P, Nagaraja V. Nucleoid-associated proteins of mycobacteria come with a distinctive flavor. Mol Microbiol 2024. [PMID: 38922783 DOI: 10.1111/mmi.15287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 05/31/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024]
Abstract
In every bacterium, nucleoid-associated proteins (NAPs) play crucial roles in chromosome organization, replication, repair, gene expression, and other DNA transactions. Their central role in controlling the chromatin dynamics and transcription has been well-appreciated in several well-studied organisms. Here, we review the diversity, distribution, structure, and function of NAPs from the genus Mycobacterium. We highlight the progress made in our understanding of the effects of these proteins on various processes and in responding to environmental stimuli and stress of mycobacteria in their free-living as well as during distinctive intracellular lifestyles. We project them as potential drug targets and discuss future studies to bridge the information gap with NAPs from well-studied systems.
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Affiliation(s)
- Meghna Santoshi
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
| | - Priyanka Tare
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
| | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
- Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
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4
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Sarangi A, Singh SP, Das BS, Rajput S, Fatima S, Bhattacharya D. Mycobacterial biofilms: A therapeutic target against bacterial persistence and generation of antibiotic resistance. Heliyon 2024; 10:e32003. [PMID: 38882302 PMCID: PMC11176842 DOI: 10.1016/j.heliyon.2024.e32003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 06/18/2024] Open
Abstract
Mycobacterium tuberculosis (M. tb) is the causative agent of Tuberculosis, one of the deadliest infectious diseases. According to the WHO Report 2023, in 2022, approximately 10.6 million people got infected with TB, and 1.6 million died. It has multiple antibiotics for treatment, but the major drawback of anti-tuberculosis therapy (ATT) is, its prolonged treatment duration. The major contributors to the lengthy treatment period are mycobacterial persistence and drug tolerance. Persistent M. tb is phenotypically drug tolerant and metabolically slow down which makes it difficult to be eliminated during ATT. These persisting bacteria are a huge reservoir of impending disease, waiting to get reactivated upon the onset of an immune compromising state. Directly Observed Treatment Short-course, although effective against replicating bacteria; fails to eliminate the drug-tolerant persisters making TB still the second-highest killer globally. There are different mechanisms for the development of drug-tolerant mycobacterial populations being investigated. Recently, the role of biofilms in the survival and host-evasion mechanism of persisters has come to light. Therefore, it is crucial to understand the mechanism of adaptation, survival and attainment of drug tolerance by persisting M. tb-populations, in order to design better immune responses and therapeutics for the effective elimination of these bacteria by reducing the duration of treatment and also circumvent the generation of drug-resistance to achieve the goal of global eradication of TB. This review summarizes the drug-tolerance mechanism and biofilms' role in providing a niche to dormant-M.tb. We also discuss methods of targeting biofilms to achieve sterile eradication of the mycobacteria and prevent its reactivation by achieving adequate immune responses.
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Affiliation(s)
- Ashirbad Sarangi
- Centre for Biotechnology, School of Pharmaceutical Sciences, Siksha 'O' Anusandhan (Deemed to be University), Bhubaneswar, Odisha, India
| | - Shashi Prakash Singh
- Vaccine and Gene Therapy Institute (VGTI) Oregon National Primate Research Centre (ONPRC) Oregon Health and Science University (OHSU) Beaverton, Oregon, USA
| | - Bhabani Shankar Das
- Centre for Biotechnology, School of Pharmaceutical Sciences, Siksha 'O' Anusandhan (Deemed to be University), Bhubaneswar, Odisha, India
| | - Sristi Rajput
- Departmental of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, Madhya Pradesh, India
| | - Samreen Fatima
- UMass Chan Medical School, University of Massachusetts, Worcester, MA, USA
| | - Debapriya Bhattacharya
- Centre for Biotechnology, School of Pharmaceutical Sciences, Siksha 'O' Anusandhan (Deemed to be University), Bhubaneswar, Odisha, India
- Departmental of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, Madhya Pradesh, India
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5
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Gerges E, Rodríguez-Ordoñez MDP, Durand N, Herrmann JL, Crémazy F. Lsr2, a pleiotropic regulator at the core of the infectious strategy of Mycobacterium abscessus. Microbiol Spectr 2024; 12:e0352823. [PMID: 38353553 PMCID: PMC10913753 DOI: 10.1128/spectrum.03528-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 01/22/2024] [Indexed: 03/06/2024] Open
Abstract
Mycobacterium abscessus is a non-tuberculous mycobacterium, causing lung infections in cystic fibrosis patients. During pulmonary infection, M. abscessus switches from smooth (Mabs-S) to rough (Mabs-R) morphotypes, the latter being hyper-virulent. Previously, we isolated the lsr2 gene as differentially expressed during S-to-R transition. lsr2 encodes a pleiotropic transcription factor that falls under the superfamily of nucleoid-associated proteins. Here, we used two functional genomic methods, RNA-seq and chromatin immunoprecipitation-sequencing (ChIP-seq), to elucidate the molecular role of Lsr2 in the pathobiology of M. abscessus. Transcriptomic analysis shows that Lsr2 differentially regulates gene expression across both morphotypes, most of which are involved in several key cellular processes of M. abscessus, including host adaptation and antibiotic resistance. These results were confirmed through quantitative real-time PCR, as well as by minimum inhibitory concentration tests and infection tests on macrophages in the presence of antibiotics. ChIP-seq analysis revealed that Lsr2 extensively binds the M. abscessus genome at AT-rich sequences and appears to form long domains that participate in the repression of its target genes. Unexpectedly, the genomic distribution of Lsr2 revealed no distinctions between Mabs-S and Mabs-R, implying more intricate mechanisms at play for achieving target selectivity.IMPORTANCELsr2 is a crucial transcription factor and chromosome organizer involved in intracellular growth and virulence in the smooth and rough morphotypes of Mycobacterium abscessus. Using RNA-seq and chromatin immunoprecipitation-sequencing (ChIP-seq), we investigated the molecular role of Lsr2 in gene expression regulation along with its distribution on M. abscessus genome. Our study demonstrates the pleiotropic regulatory role of Lsr2, regulating the expression of many genes coordinating essential cellular and molecular processes in both morphotypes. In addition, we have elucidated the role of Lsr2 in antibiotic resistance both in vitro and in vivo, where lsr2 mutant strains display heightened sensitivity to antibiotics. Through ChIP-seq, we reported the widespread distribution of Lsr2 on M. abscessus genome, revealing a direct repressive effect due to its extensive binding on promoters or coding sequences of its targets. This study unveils the significant regulatory role of Lsr2, intricately intertwined with its function in shaping the organization of the M. abscessus genome.
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Affiliation(s)
- Elias Gerges
- Université Paris-Saclay, UVSQ, Inserm, Infection et inflammation, Montigny-Le-Bretonneux, France
| | - María del Pilar Rodríguez-Ordoñez
- Université Paris-Saclay, Université d’Evry, Laboratoire Européen de Recherche pour la Polyarthrite rhumatoïde-Genhotel, Evry, France
| | - Nicolas Durand
- Université Paris-Saclay, UVSQ, Inserm, Infection et inflammation, Montigny-Le-Bretonneux, France
| | - Jean-Louis Herrmann
- Université Paris-Saclay, UVSQ, Inserm, Infection et inflammation, Montigny-Le-Bretonneux, France
- APHP, GHU Paris-Saclay, Hôpital Raymond Poincaré, Service de Microbiologie, Garches, France
| | - Frédéric Crémazy
- Université Paris-Saclay, UVSQ, Inserm, Infection et inflammation, Montigny-Le-Bretonneux, France
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6
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Gerges E, Herrmann JL, Crémazy F. [Lsr2: A Nucleoid Associated Protein (NAP) and a transcription factor in mycobacteria]. Med Sci (Paris) 2024; 40:154-160. [PMID: 38411423 DOI: 10.1051/medsci/2023218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024] Open
Abstract
Lsr2, a small protein mainly found in actinobacteria, plays a crucial role in the virulence and adaptation of mycobacteria to environmental conditions. As a member of the nucleoid-associated protein (NAPs) superfamily, Lsr2 influences DNA organization by facilitating the formation of chromosomal loops in vitro and, therefore, may be a major player in the three-dimensional folding of the genome. Additionally, Lsr2 also acts as a transcription factor, regulating the expression of numerous genes responsible for coordinating a myriad of cellular and molecular processes essential for the actinobacteria. Similar to the H-NS protein, its ortholog in enterobacteria, its role in transcriptional repression likely relies on oligomerization, rigidifying, and bridging of DNA, thereby disrupting RNA polymerase recruitment as well as the elongation of RNA transcripts.
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Affiliation(s)
- Elias Gerges
- Université Paris-Saclay, UVSQ, Inserm, Infection et inflammation, 78180 Montigny-Le-Bretonneux, France
| | - Jean-Louis Herrmann
- Université Paris-Saclay, UVSQ, Inserm, Infection et inflammation, 78180 Montigny-Le-Bretonneux, France
| | - Frédéric Crémazy
- Université Paris-Saclay, UVSQ, Inserm, Infection et inflammation, 78180 Montigny-Le-Bretonneux, France
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7
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Juárez-Cepeda J, Valenzuela O, Garibay-Valdez E, Velazquez C, Garibay-Escobar A. Gene expression during the development of Mycobacterium smegmatis biofilms on hydroxyapatite surfaces. Int Microbiol 2024; 27:257-263. [PMID: 37311924 DOI: 10.1007/s10123-023-00385-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/19/2023] [Accepted: 05/31/2023] [Indexed: 06/15/2023]
Abstract
Bacterial biofilms are a consortium of bacteria that are strongly bound to each other and the surface on which they developed irreversibly. Bacteria can survive adverse environmental conditions and undergo changes when transitioning from a planktonic form to community cells. The process of mycobacteria adhesion is complex, involving characteristics and properties of bacteria, surfaces, and environmental factors; therefore, the formation of different biofilms is possible. Cell wall-, lipid-, and lipid transporter-related genes (glycopeptidolipids, GroEL1, protein kinase) are important in mycobacterial biofilm development. We investigated gene expression during in vitro development of Mycobacterium smegmatis biofilms on a hydroxyapatite (HAP) surface. Biofilm formation by M. smegmatis cells was induced for 1, 2, 3, and 5 days on the HAP surface. Mycobacteria on polystyrene generated an air-liquid interface biofilm, and on the fifth day, it increased by 35% in the presence of HAP. Six genes with key roles in biofilm formation were analyzed by real-time RT‒qPCR during the biofilm formation of M. smegmatis on both abiotic surfaces. The expression of groEL1, lsr2, mmpL11, mps, pknF, and rpoZ genes during biofilm formation on the HAP surface did not exhibit significant changes compared to the polystyrene surface. These genes involved in biofilm formation are not affected by HAP.
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Affiliation(s)
- Jacqueline Juárez-Cepeda
- Departmento de Ciencias Químico Biológicas, Universidad de Sonora, Rosales y Luis Encinas S/N, 83000, Hermosillo, Sonora, México
| | - Olivia Valenzuela
- Departmento de Ciencias Químico Biológicas, Universidad de Sonora, Rosales y Luis Encinas S/N, 83000, Hermosillo, Sonora, México
| | - Estefanía Garibay-Valdez
- Centro de Investigación en Alimentación y Desarrollo, A. C. Km 0.6 Carretera a La Victoria, Hermosillo, Sonora, México
| | - Carlos Velazquez
- Departmento de Ciencias Químico Biológicas, Universidad de Sonora, Rosales y Luis Encinas S/N, 83000, Hermosillo, Sonora, México
| | - Adriana Garibay-Escobar
- Departmento de Ciencias Químico Biológicas, Universidad de Sonora, Rosales y Luis Encinas S/N, 83000, Hermosillo, Sonora, México.
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8
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Ling X, Liu X, Wang K, Guo M, Ou Y, Li D, Xiang Y, Zheng J, Hu L, Zhang H, Li W. Lsr2 acts as a cyclic di-GMP receptor that promotes keto-mycolic acid synthesis and biofilm formation in mycobacteria. Nat Commun 2024; 15:695. [PMID: 38267428 PMCID: PMC10808224 DOI: 10.1038/s41467-024-44774-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 01/03/2024] [Indexed: 01/26/2024] Open
Abstract
Cyclic di-GMP (c-di-GMP) is a second messenger that promotes biofilm formation in several bacterial species, but the mechanisms are often unclear. Here, we report that c-di-GMP promotes biofilm formation in mycobacteria in a manner dependent on the nucleoid-associated protein Lsr2. We show that c-di-GMP specifically binds to Lsr2 at a ratio of 1:1. Lsr2 upregulates the expression of HadD, a (3R)-hydroxyacyl-ACP dehydratase, thus promoting the synthesis of keto-mycolic acid and biofilm formation. Thus, Lsr2 acts as a c-di-GMP receptor that links the second messenger's function to lipid synthesis and biofilm formation in mycobacteria.
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Affiliation(s)
- Xiaocui Ling
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Xiao Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Kun Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Minhao Guo
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Yanzhe Ou
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Danting Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Yulin Xiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Jiachen Zheng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Lihua Hu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Hongyun Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Weihui Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530004, China.
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9
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Finks SS, Moudgalya P, Weihe C, Martiny JBH. The contribution of plasmids to trait diversity in a soil bacterium. ISME COMMUNICATIONS 2024; 4:ycae025. [PMID: 38584646 PMCID: PMC10999282 DOI: 10.1093/ismeco/ycae025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 02/11/2024] [Accepted: 02/12/2024] [Indexed: 04/09/2024]
Abstract
Plasmids are so closely associated with pathogens and antibiotic resistance that their potential for conferring other traits is often overlooked. Few studies consider how the full suite of traits encoded by plasmids is related to a host's environmental adaptation, particularly for Gram-positive bacteria. To investigate the role that plasmid traits might play in microbial communities from natural ecosystems, we identified plasmids carried by isolates of Curtobacterium (phylum Actinomycetota) from a variety of soil environments. We found that plasmids were common, but not ubiquitous, in the genus and varied greatly in their size and genetic diversity. There was little evidence of phylogenetic conservation among Curtobacterium plasmids even for closely related bacterial strains within the same ecotype, indicating that horizontal transmission of plasmids is common. The plasmids carried a wide diversity of traits that were not a random subset of the host chromosome. Furthermore, the composition of these plasmid traits was associated with the environmental context of the host bacterium. Together, the results indicate that plasmids contribute substantially to the microdiversity of a soil bacterium and that this diversity may play a role in niche differentiation and a bacterium's adaptation to its local environment.
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Affiliation(s)
- Sarai S Finks
- Department of Ecology and Evolutionary Biology, University of California Irvine, 321 Steinhaus Hall, Irvine, CA 92697-2525, United States
| | - Pranav Moudgalya
- Department of Ecology and Evolutionary Biology, University of California Irvine, 321 Steinhaus Hall, Irvine, CA 92697-2525, United States
| | - Claudia Weihe
- Department of Ecology and Evolutionary Biology, University of California Irvine, 321 Steinhaus Hall, Irvine, CA 92697-2525, United States
| | - Jennifer B H Martiny
- Department of Ecology and Evolutionary Biology, University of California Irvine, 321 Steinhaus Hall, Irvine, CA 92697-2525, United States
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10
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Keshavam CC, Naz S, Gupta A, Sanyal P, Kochar M, Gangwal A, Sangwan N, Kumar N, Tyagi E, Goel S, Singh NK, Sowpati DT, Khare G, Ganguli M, Raze D, Locht C, Basu-Modak S, Gupta M, Nandicoori VK, Singh Y. The heparin-binding hemagglutinin protein of Mycobacterium tuberculosis is a nucleoid-associated protein. J Biol Chem 2023; 299:105364. [PMID: 37865319 PMCID: PMC10665949 DOI: 10.1016/j.jbc.2023.105364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/05/2023] [Accepted: 10/10/2023] [Indexed: 10/23/2023] Open
Abstract
Nucleoid-associated proteins (NAPs) regulate multiple cellular processes such as gene expression, virulence, and dormancy throughout bacterial species. NAPs help in the survival and adaptation of Mycobacterium tuberculosis (Mtb) within the host. Fourteen NAPs have been identified in Escherichia coli; however, only seven NAPs are documented in Mtb. Given its complex lifestyle, it is reasonable to assume that Mtb would encode for more NAPs. Using bioinformatics tools and biochemical experiments, we have identified the heparin-binding hemagglutinin (HbhA) protein of Mtb as a novel sequence-independent DNA-binding protein which has previously been characterized as an adhesion molecule required for extrapulmonary dissemination. Deleting the carboxy-terminal domain of HbhA resulted in a complete loss of its DNA-binding activity. Atomic force microscopy showed HbhA-mediated architectural modulations in the DNA, which may play a regulatory role in transcription and genome organization. Our results showed that HbhA colocalizes with the nucleoid region of Mtb. Transcriptomics analyses of a hbhA KO strain revealed that it regulates the expression of ∼36% of total and ∼29% of essential genes. Deletion of hbhA resulted in the upregulation of ∼73% of all differentially expressed genes, belonging to multiple pathways suggesting it to be a global repressor. The results show that HbhA is a nonessential NAP regulating gene expression globally and acting as a plausible transcriptional repressor.
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Affiliation(s)
| | - Saba Naz
- Department of Zoology, University of Delhi, Delhi, India; CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Aanchal Gupta
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Priyadarshini Sanyal
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India; Academy of Scientific and Innovative Research (AcSIR), CSIR- Centre for Cellular and Molecular Biology (CSIR-CCMB) Campus, Hyderabad, India
| | - Manisha Kochar
- Department of Zoology, University of Delhi, Delhi, India; CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | | | - Nitika Sangwan
- Department of Zoology, University of Delhi, Delhi, India
| | - Nishant Kumar
- Department of Zoology, University of Delhi, Delhi, India
| | - Ekta Tyagi
- Department of Zoology, University of Delhi, Delhi, India
| | - Simran Goel
- Department of Zoology, University of Delhi, Delhi, India
| | | | | | - Garima Khare
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - Munia Ganguli
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Dominique Raze
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR9017 - CIIL - Centre for Infection and Immunity of Lille, Lille, France
| | - Camille Locht
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR9017 - CIIL - Centre for Infection and Immunity of Lille, Lille, France
| | | | - Meetu Gupta
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.
| | - Vinay Kumar Nandicoori
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India; Academy of Scientific and Innovative Research (AcSIR), CSIR- Centre for Cellular and Molecular Biology (CSIR-CCMB) Campus, Hyderabad, India; National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India.
| | - Yogendra Singh
- Department of Zoology, University of Delhi, Delhi, India; Delhi School of Public Health, Institution of Eminence, University of Delhi, Delhi, India.
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11
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Kumar P, Behera A, Tiwari P, Karthik S, Biswas M, Sonawane A, Mobin SM. Exploring the antimicrobial potential of isoniazid loaded Cu-based metal-organic frameworks as a novel strategy for effective killing of Mycobacterium tuberculosis. J Mater Chem B 2023; 11:10929-10940. [PMID: 37937634 DOI: 10.1039/d3tb02292g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
Tuberculosis (TB) remains one of the most infectious pathogens with the highest human mortality and morbidity. Biofilm formation during Mycobacterium tuberculosis (Mtb) infection is responsible for bacterial growth, communication, and, most essentially, increased resistance/tolerance to antibiotics leading to higher bacterial persistence. Thus, biofilm growth is presently considered a key virulence factor in the case of chronic disease. Metal-Organic Frameworks (MOFs) have recently emerged as a highly efficient system to improve existing antibiotics' therapeutic efficacy and reduce adverse effects. In this regard, we have synthesized Cu-MOF (IITI-3) using a solvothermal approach. IITI-3 was well characterized by various spectroscopic techniques. Herein, IITI-3 was first encapsulated with isoniazid (INH) to form INH@IITI-3 with 10 wt% loading within 1 hour. INH@IITI-3 was well characterized by PXRD, TGA, FTIR, and BET surface area analysis. Furthermore, the drug release kinetics studies of INH@IITI-3 have been performed at pH 5.8 and 7.4 to mimic the small intestine and blood pH, respectively. The results show that drug release follows first-order kinetics. Furthermore, the antimycobacterial activity of INH@IITI-3 demonstrated significant bacterial killing and altered the structural morphology of the bacteria. Moreover, INH@IITI-3 was able to inhibit the mycobacterial biofilm formation upon treatment and showed less cytotoxicity toward the murine RAW264.7 macrophages. Thus, this work significantly opens up new possibilities for the applications of INH@IITI-3 in biofilm infections in Mtb and further contributes to TB therapeutics.
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Affiliation(s)
- Pawan Kumar
- Department of Chemistry, Indian Institute of Technology, Indore, Simrol, Madhya Pradesh, India
| | - Ananyaashree Behera
- School of Biotechnology, KIIT Deemed to be University, Bhubaneswar, Odisha, India.
| | - Pranav Tiwari
- Department of Chemistry, Indian Institute of Technology, Indore, Simrol, Madhya Pradesh, India
| | - Sibi Karthik
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Madhya Pradesh, India
| | - Mainak Biswas
- School of Biotechnology, KIIT Deemed to be University, Bhubaneswar, Odisha, India.
| | - Avinash Sonawane
- School of Biotechnology, KIIT Deemed to be University, Bhubaneswar, Odisha, India.
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Madhya Pradesh, India
| | - Shaikh M Mobin
- Department of Chemistry, Indian Institute of Technology, Indore, Simrol, Madhya Pradesh, India
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Madhya Pradesh, India
- Center for Advance Electronic (CAE), Indian Institute of Technology, Indore, Simrol, Madhya Pradesh, India
- Center for Electric Vehicle and Intelligent Transport Systems, Indian Institute of Technology, Indore, Simrol, Madhya Pradesh, India
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12
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Nisbett LM, Previti ML, Seeliger JC. A Loss of Function in LprG-Rv1410c Homologues Attenuates Growth during Biofilm Formation in Mycobacterium smegmatis. Pathogens 2023; 12:1375. [PMID: 38133260 PMCID: PMC10745849 DOI: 10.3390/pathogens12121375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/11/2023] [Accepted: 11/15/2023] [Indexed: 12/23/2023] Open
Abstract
MmpL (mycobacterial membrane protein large) proteins are integral membrane proteins that have been implicated in the biosynthesis and/or transport of mycobacterial cell wall lipids. Given the cellular location of these proteins, however, it is unclear how cell wall lipids are transported beyond the inner membrane. Moreover, given that mycobacteria grow at the poles, we also do not understand how new cell wall is added in a highly localized and presumably coordinated manner. Here, we examine the relationship between two lipid transport pathways associated with the proteins MmpL11 and LprG-Rv1410c. The lipoprotein LprG has been shown to interact with proteins involved in cell wall processes including MmpL11, which is required in biofilms for the surface localization of certain lipids. Here we report that deletion of mmpL11 (MSMEG_0241) or the lprG-rv1410c operon homologues MSMEG_3070-3069 in Mycobacterium smegmatis produced similar biofilm defects that were distinct from that of the previously reported mmpL11 transposon insertion mutant. Analysis of pellicle biofilms, bacterial growth, lipid profiles, and gene expression revealed that the biofilm phenotypes could not be directly explained by changes in the synthesis or localization of biofilm-related lipids or the expression of biofilm-related genes. Instead, the shared biofilm phenotype between ΔMSMEG_3070-3069 and ΔmmpL11 may be related to their modest growth defect, while the origins of the distinct mmpL11::Tn biofilm defect remain unclear. Our findings suggest that the mechanisms that drive pellicle biofilm formation in M. smegmatis are not connected to crosstalk between the LprG-Rv1410c and MmpL11 pathways and that any functional interaction between these proteins does not relate directly to their lipid transport function.
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Affiliation(s)
- Lisa-Marie Nisbett
- Department of Pharmacological Sciences, Stony Brook University, 100 Nicolls Road, Stony Brook, NY 11794, USA
| | | | - Jessica C. Seeliger
- Department of Pharmacological Sciences, Stony Brook University, 100 Nicolls Road, Stony Brook, NY 11794, USA
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13
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Anand PK, Kaur J. Rv3539 (PPE63) of Mycobacterium Tuberculosis Promotes Survival of Mycobacterium Smegmatis in Human Macrophages Cell Line via Cell Wall Modulation of Bacteria and Altering Host's Immune Response. Curr Microbiol 2023; 80:267. [PMID: 37401981 DOI: 10.1007/s00284-023-03360-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 05/31/2023] [Indexed: 07/05/2023]
Abstract
The modulation of host's immune response plays an important role in the intracellular survival of Mycobacterium tuberculosis. The intracellular pathogen counteracts environmental stresses with help of the expression of several genes. The M. tuberculosis genome encodes several immune-modulatory proteins including PE (proline-glutamic acid)/PPE (proline-proline-glutamic acid) superfamily proteins. It is unclear how the unique PE/PPE proteins superfamily contributes to survival under different stress and pathophysiology conditions. Previously, we showed that PPE63 (Rv3539) has C-terminal esterase extension and was localized as a membrane attached and in extracellular compartment. Therefore, the probability of these proteins interacting with the host to modulate the host immune response cannot be ruled out. The physiological role of PPE63 was characterized by expressing the PPE63 in the M. smegmatis, a non-pathogenic strain intrinsically deficient of PPE63. The recombinant M. smegmatis expressing PPE63 altered the colony morphology, lipid composition, and integrity of the cell wall. It provided resistance to multiple hostile environmental stress conditions and several antibiotics. MS_Rv3539 demonstrated higher infection and intracellular survival in comparison to the MS_Vec in the PMA-differentiated THP-1 cells. The decreased intracellular level of ROS, NO, and expression of iNOS was observed in THP-1 cells upon infection with MS_Rv3539 in comparison to MS_Vec. Further, the decrease in expression of pro-inflammatory cytokines like IL-6, TNF-α, and IL-1β and enhanced anti-inflammatory cytokines like IL-10, pointed toward its role in immune modulation. Overall this study suggested the role of Rv3539 in enhanced intracellular survival of M. smegmatis via cell wall modulation and altered immune response of host.
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Affiliation(s)
- Pradeep K Anand
- Department of Biotechnology, Panjab University, BMS Block-1, South Campus, Chandigarh, 160014, India
| | - Jagdeep Kaur
- Department of Biotechnology, Panjab University, BMS Block-1, South Campus, Chandigarh, 160014, India.
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14
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Chaudhary V, Pal AK, Singla M, Ghosh A. Elucidating the role of c-di-AMP in Mycobacterium smegmatis: Phenotypic characterization and functional analysis. Heliyon 2023; 9:e15686. [PMID: 37305508 PMCID: PMC10256829 DOI: 10.1016/j.heliyon.2023.e15686] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 06/13/2023] Open
Abstract
Cyclic-di-AMP (c-di-AMP) is an important secondary messenger molecule that plays a critical role in monitoring several important cellular processes, especially in several Gram-positive bacteria. In this study, we seek to unravel the physiological significance of the molecule c-di-AMP in Mycobacterium smegmatis under different conditions, using strains with altered c-di-AMP levels: c-di-AMP null mutant (ΔdisA) and a c-di-AMP over-expression mutant (Δpde). Our thorough analysis of the mutants revealed that the intracellular concentration of c-di-AMP could determine many basic phenotypes such as colony architecture, cell shape, cell size, membrane permeability etc. Additionally, it was shown to play a significant role in multiple stress adaptation pathways in the case of different DNA and membrane stresses. Our study also revealed how the biofilm phenotypes of M. smegmatis cells are altered with high intracellular c-di-AMP concentration. Next, we checked how c-di-AMP contributes to antibiotic resistance or susceptibility characteristics of M. smegmatis, which was followed by a detailed transcriptome profile analysis to reveal key genes and pathways such as translation, arginine biosynthesis, cell wall and plasma membrane are regulated by c-di-AMP in mycobacteria.
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15
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Wang K, Cui X, Ling X, Chen J, Zheng J, Xiang Y, Li W. D-Xylose Blocks the Broad Negative Regulation of XylR on Lipid Metabolism and Affects Multiple Physiological Characteristics in Mycobacteria. Int J Mol Sci 2023; 24:ijms24087086. [PMID: 37108247 PMCID: PMC10138657 DOI: 10.3390/ijms24087086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/01/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
D-xylose is the most abundant fermentable pentose, which usually represents an architectural component of the bacterial cell wall. However, its regulatory function and the involved signaling pathway in bacteria remain largely unclear. Here, we show that D-xylose can act as a signaling molecule to regulate the lipid metabolism and affect multiple physiological characteristics in mycobacteria. D-xylose directly interacts with XylR and inhibits its DNA-binding ability, thus blocking XylR-mediated repression. The xylose inhibitor, XylR, plays a global regulatory role and affects the expression of 166 mycobacterial genes that are involved in lipid synthesis and metabolism. Furthermore, we show that the xylose-dependent gene regulation of XylR affects the multiple physiological characteristics of Mycobacterium smegmatis, including bacterial size, colony phenotype, biofilm formation, cell aggregation, and antibiotic resistance. Finally, we found that XylR inhibited the survival of Mycobacterium bovis BCG in the host. Our findings provide novel insights into the molecular mechanism of lipid metabolism regulation and its correlation with bacterial physiological phenotypes.
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Affiliation(s)
- Kun Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Xujie Cui
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Xiaocui Ling
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Jiarui Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Jiachen Zheng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Yuling Xiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Weihui Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China
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16
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Peng SH, Lee SH, Chen CC, Lin YC, Chang Y, Hsieh PH, Shih HN, Ueng SWN, Chang CH. Nontuberculous mycobacteria peri-prosthetic joint infection: An outcome analysis for two stage revision arthroplasty. J Orthop Surg (Hong Kong) 2022; 30:10225536221140610. [PMID: 36396130 DOI: 10.1177/10225536221140610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
PURPOSE Nontuberculous mycobacteria periprosthetic joint infection (NTMPJI) is a rare complication of hip or knee joint arthroplasty. The experience for outcomes of NTMPJI treatment is still limited. The objective of this study was to investigate the outcome of hip or knee nontuberculous mycobacteria periprosthetic joint infection following treatment with two-stage exchange arthroplasty. MATERIAL AND METHODS From 1995 to 2020, 12 patients with NTMPJI were treated with two-stage exchange arthroplasty at our institution. We collected and analyzed variables including demographic data, comorbidity, microbiological data, treatment outcome and antibiotic formula in bone cement. RESULTS Mycobacterium abcessus (n = 6) and Mycobacterium chelonae (n = 2) constitute the majority of the cases. Five patients had early-onset PJIs and the other seven patients were late onset. The success rate of two-stage exchange arthroplasty was 66.7% (8 of 12). Three patients experienced infection relapse, and one patient had soft tissue compromise complication. Post-operative antibiotic therapy may not improve the success rate (4 of 6 cases, 66.7%). Based on in vitro study, the most commonly used effective antibiotic in bone cement spacer for nontuberculous mycobacteria was amikacin. CONCLUSIONS nontuberculous mycobacteria is a rare cause of PJIs and should be suspected especially in relatively immunocompromised patients. Resection arthroplasty with staged reimplantation is the preferred approach. Prolonged post-operative antibiotic therapy before reimplantation may not improve the success rate. Delayed revision surgery may not be needed and can be performed once C-reactive protein level is normal after a drug holiday.
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Affiliation(s)
- Shih-Hui Peng
- Department of Orthopedic Surgery, 38014Chang Gung Memorial Hospital, Linkou, Taiwan.,College of Medicine, 38014Chang Gung University, Taoyuan, Taiwan.,Bone and Joint Research Center, 38014Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Sheng-Hsun Lee
- Department of Orthopedic Surgery, 38014Chang Gung Memorial Hospital, Linkou, Taiwan.,College of Medicine, 38014Chang Gung University, Taoyuan, Taiwan.,Bone and Joint Research Center, 38014Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Chun-Chieh Chen
- Department of Orthopedic Surgery, 38014Chang Gung Memorial Hospital, Linkou, Taiwan.,College of Medicine, 38014Chang Gung University, Taoyuan, Taiwan.,Bone and Joint Research Center, 38014Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Yu-Chih Lin
- Department of Orthopedic Surgery, 38014Chang Gung Memorial Hospital, Linkou, Taiwan.,College of Medicine, 38014Chang Gung University, Taoyuan, Taiwan.,Bone and Joint Research Center, 38014Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Yuhan Chang
- Department of Orthopedic Surgery, 38014Chang Gung Memorial Hospital, Linkou, Taiwan.,College of Medicine, 38014Chang Gung University, Taoyuan, Taiwan.,Bone and Joint Research Center, 38014Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Pang-Hsin Hsieh
- Department of Orthopedic Surgery, 38014Chang Gung Memorial Hospital, Linkou, Taiwan.,College of Medicine, 38014Chang Gung University, Taoyuan, Taiwan.,Bone and Joint Research Center, 38014Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Hsin-Nung Shih
- Department of Orthopedic Surgery, 38014Chang Gung Memorial Hospital, Linkou, Taiwan.,College of Medicine, 38014Chang Gung University, Taoyuan, Taiwan.,Bone and Joint Research Center, 38014Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Steve W N Ueng
- Department of Orthopedic Surgery, 38014Chang Gung Memorial Hospital, Linkou, Taiwan.,College of Medicine, 38014Chang Gung University, Taoyuan, Taiwan.,Bone and Joint Research Center, 38014Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Chih-Hsiang Chang
- Department of Orthopedic Surgery, 38014Chang Gung Memorial Hospital, Linkou, Taiwan.,College of Medicine, 38014Chang Gung University, Taoyuan, Taiwan.,Bone and Joint Research Center, 38014Chang Gung Memorial Hospital, Linkou, Taiwan.,Graduate Institute of Clinical Medical Sciences, College of Medicine, 38014Chang Gung University, Taoyuan, Taiwan
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17
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Boopathi S, Ramasamy S, Haridevamuthu B, Murugan R, Veerabadhran M, Jia AQ, Arockiaraj J. Intercellular communication and social behaviors in mycobacteria. Front Microbiol 2022; 13:943278. [PMID: 36177463 PMCID: PMC9514802 DOI: 10.3389/fmicb.2022.943278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
Cell-to-cell communication is a fundamental process of bacteria to exert communal behaviors. Sputum samples of patients with cystic fibrosis have often been observed with extensive mycobacterial genetic diversity. The emergence of heterogenic mycobacterial populations is observed due to subtle changes in their morphology, gene expression level, and distributive conjugal transfer (DCT). Since each subgroup of mycobacteria has different hetero-resistance, they are refractory against several antibiotics. Such genetically diverse mycobacteria have to communicate with each other to subvert the host immune system. However, it is still a mystery how such heterogeneous strains exhibit synchronous behaviors for the production of quorum sensing (QS) traits, such as biofilms, siderophores, and virulence proteins. Mycobacteria are characterized by division of labor, where distinct sub-clonal populations contribute to the production of QS traits while exchanging complimentary products at the community level. Thus, active mycobacterial cells ensure the persistence of other heterogenic clonal populations through cooperative behaviors. Additionally, mycobacteria are likely to establish communication with neighboring cells in a contact-independent manner through QS signals. Hence, this review is intended to discuss our current knowledge of mycobacterial communication. Understanding mycobacterial communication could provide a promising opportunity to develop drugs to target key pathways of mycobacteria.
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Affiliation(s)
- Seenivasan Boopathi
- Key Laboratory of Tropical Biological Resources of Ministry Education, School of Pharmaceutical Sciences, Hainan University, Haikou, China
- Department of Biotechnology, College of Science and Humanities, SRM Institute of Science and Technology, Chennai, Tamil Nadu, India
| | - Subbiah Ramasamy
- Department of Biochemistry, Cardiac Metabolic Disease Laboratory, School of Biological Sciences, Madurai Kamaraj University, Madurai, India
| | - B. Haridevamuthu
- Department of Biotechnology, College of Science and Humanities, SRM Institute of Science and Technology, Chennai, Tamil Nadu, India
| | - Raghul Murugan
- Department of Biotechnology, College of Science and Humanities, SRM Institute of Science and Technology, Chennai, Tamil Nadu, India
| | - Maruthanayagam Veerabadhran
- Biofouling and Biofilm Processes Section, Water and Steam Chemistry Division, Bhabha Atomic Research Centre Facilities, Kalpakkam, Tamil Nadu, India
| | - Ai-Qun Jia
- Key Laboratory of Tropical Biological Resources of Ministry Education, School of Pharmaceutical Sciences, Hainan University, Haikou, China
- *Correspondence: Ai-Qun Jia
| | - Jesu Arockiaraj
- Department of Biotechnology, College of Science and Humanities, SRM Institute of Science and Technology, Chennai, Tamil Nadu, India
- Jesu Arockiaraj ;
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18
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Rani A, Alam A, Ahmad F, P. M, Saurabh A, Zarin S, Mitra DK, Hasnain SE, Ehtesham NZ. Mycobacterium tuberculosis Methyltransferase Rv1515c Can Suppress Host Defense Mechanisms by Modulating Immune Functions Utilizing a Multipronged Mechanism. Front Mol Biosci 2022; 9:906387. [PMID: 35813825 PMCID: PMC9263924 DOI: 10.3389/fmolb.2022.906387] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
Mycobacterium tuberculosis (M. tb) gene Rv1515c encodes a conserved hypothetical protein exclusively present within organisms of MTB complex and absent in non-pathogenic mycobacteria. In silico analysis revealed that Rv1515c contain S-adenosylmethionine binding site and methyltransferase domain. The DNA binding and DNA methyltransferase activity of Rv1515c was confirmed in vitro. Knock-in of Rv1515c in a model mycobacteria M. smegmatis (M. s_Rv1515c) resulted in remarkable physiological and morphological changes and conferred the recombinant strain with an ability to adapt to various stress conditions, including resistance to TB drugs. M. s_Rv1515c was phagocytosed at a greater rate and displayed extended intra-macrophage survival in vitro. Recombinant M. s_Rv1515c contributed to enhanced virulence by suppressing the host defense mechanisms including RNS and ROS production, and apoptotic clearance. M. s_Rv1515c, while suppressing the phagolysosomal maturation, modulated pro-inflammatory cytokine production and also inhibited antigen presentation by downregulating the expression of MHC-I/MHC-II and co-stimulatory signals CD80 and CD86. Mice infected with M. s_Rv1515c produced more Treg cells than vector control (M. s_Vc) and exhibited reduced effector T cell responses, along-with reduced expression of macrophage activation markers in the chronic phase of infection. M. s_Rv1515c was able to survive in the major organs of mice up to 7 weeks post-infection. These results indicate a crucial role of Rv1515c in M. tb pathogenesis.
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Affiliation(s)
- Anshu Rani
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi (IIT-D), New Delhi, India
- ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - Anwar Alam
- ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - Faraz Ahmad
- ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - Manjunath P.
- ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - Abhinav Saurabh
- Department of Transplant Immunology and Immunogenetics, All India Institute of Medical Sciences, New Delhi, India
| | - Sheeba Zarin
- ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - Dipendra Kumar Mitra
- Department of Transplant Immunology and Immunogenetics, All India Institute of Medical Sciences, New Delhi, India
| | - Seyed E. Hasnain
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi (IIT-D), New Delhi, India
- Department of Life Science, School of Basic Sciences and Research, Sharda University, Greater Noida, India
- *Correspondence: Seyed E. Hasnain, , , , Nasreen Z. Ehtesham, ,
| | - Nasreen Z. Ehtesham
- ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
- *Correspondence: Seyed E. Hasnain, , , , Nasreen Z. Ehtesham, ,
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19
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Immunobiology of tubercle bacilli and prospects of immunomodulatory drugs to tackle tuberculosis (TB) and other non-tubercular mycobacterial infections. Immunobiology 2022; 227:152224. [PMID: 35533535 PMCID: PMC9068598 DOI: 10.1016/j.imbio.2022.152224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/25/2022] [Accepted: 05/03/2022] [Indexed: 01/17/2023]
Abstract
The COVID-19 pandemic has set back progress made on antimicrobial resistance (AMR). Without urgent re-focus, we risk slowing down drug discovery and providing treatment for drug resistant Mycobacterium tuberculosis. Unique in its immune evasion, dormancy and resuscitation, the causal pathogens of tuberculosis (TB) have demonstrated resistance to antibiotics with efflux pumps and the ability to form biofilms. Repurposing drugs is a prospective avenue for finding new anti-TB drugs. There are many advantages to discovering novel targets of an existing drug, as the pharmacokinetic and pharmacodynamic properties have already been established, they are cost-efficient and can be commercially accelerated for the new development. One such group of drugs are non-steroidal anti-inflammatory drugs (NSAIDs) that are originally known for their ability to supress the host proinflammatory responses. In addition to their anti-inflammatory properties, some NSAIDs have been discovered to have antimicrobial modes of action. Of particular interest is Carprofen, identified to inhibit the efflux mechanism and disrupt biofilm formation in mycobacteria. Due to the complexities of host-pathogens interactions in the lung microbiome, inflammatory responses must carefully be controlled alongside the in vivo actions of the prospective anti-infectives. This critical review explores the potential dual role of a selection of NSAIDs, as an anti-inflammatory and anti-tubercular adjunct to reverse the tide of antimicrobial resistance in existing treatments.
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20
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Ferrell KC, Johansen MD, Triccas JA, Counoupas C. Virulence Mechanisms of Mycobacterium abscessus: Current Knowledge and Implications for Vaccine Design. Front Microbiol 2022; 13:842017. [PMID: 35308378 PMCID: PMC8928063 DOI: 10.3389/fmicb.2022.842017] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/08/2022] [Indexed: 12/22/2022] Open
Abstract
Mycobacterium abscessus is a member of the non-tuberculous mycobacteria (NTM) group, responsible for chronic infections in individuals with cystic fibrosis (CF) or those otherwise immunocompromised. While viewed traditionally as an opportunistic pathogen, increasing research into M. abscessus in recent years has highlighted its continued evolution into a true pathogen. This is demonstrated through an extensive collection of virulence factors (VFs) possessed by this organism which facilitate survival within the host, particularly in the harsh environment of the CF lung. These include VFs resembling those of other Mycobacteria, and non-mycobacterial VFs, both of which make a notable contribution in shaping M. abscessus interaction with the host. Mycobacterium abscessus continued acquisition of VFs is cause for concern and highlights the need for novel vaccination strategies to combat this pathogen. An effective M. abscessus vaccine must be suitably designed for target populations (i.e., individuals with CF) and incorporate current knowledge on immune correlates of protection against M. abscessus infection. Vaccination strategies must also build upon lessons learned from ongoing efforts to develop novel vaccines for other pathogens, particularly Mycobacterium tuberculosis (M. tb); decades of research into M. tb has provided insight into unconventional and innovative vaccine approaches that may be applied to M. abscessus. Continued research into M. abscessus pathogenesis will be critical for the future development of safe and effective vaccines and therapeutics to reduce global incidence of this emerging pathogen.
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Affiliation(s)
- Kia C. Ferrell
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- Tuberculosis Research Program, Centenary Institute, Sydney, NSW, Australia
- *Correspondence: Kia C. Ferrell,
| | - Matt D. Johansen
- Centre for Inflammation, Centenary Institute, University of Technology, Sydney, NSW, Australia
- Faculty of Science, School of Life Sciences, University of Technology, Sydney, NSW, Australia
| | - James A. Triccas
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- Sydney Institute for Infectious Diseases and the Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Claudio Counoupas
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- Tuberculosis Research Program, Centenary Institute, Sydney, NSW, Australia
- Sydney Institute for Infectious Diseases and the Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
- Claudio Counoupas,
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Dokic A, Peterson E, Arrieta-Ortiz ML, Pan M, Di Maio A, Baliga N, Bhatt A. Mycobacterium abscessus biofilms produce an extracellular matrix and have a distinct mycolic acid profile. Cell Surf 2021; 7:100051. [PMID: 33912773 PMCID: PMC8066798 DOI: 10.1016/j.tcsw.2021.100051] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 02/06/2023] Open
Abstract
A non-tuberculous mycobacterium, Mycobacterium abscessus is an emerging opportunistic pathogen associated with difficult to treat pulmonary infections, particularly in patients suffering from cystic fibrosis. It is capable of forming biofilms in vitro that result in an increase of already high levels of antibiotic resistance in this bacterium. Evidence that M. abscessus forms biofilm-like microcolonies in patient lungs and on medical devices further implicated the need to investigate this biofilm in detail. Therefore, in this study we characterized the M. abscessus pellicular biofilm, formed on a liquid-air interface, by studying its molecular composition, and its transcriptional profile in comparison to planktonic cells. Using scanning electron micrographs and fluorescence microscopy, we showed that M. abscessus biofilms produce an extracellular matrix composed of lipids, proteins, carbohydrates and extracellular DNA. Transcriptomic analysis of biofilms revealed an upregulation of pathways involved in the glyoxylate shunt, redox metabolism and mycolic acid biosynthesis. Genes involved in elongation and desaturation of mycolic acids were highly upregulated in biofilms and, mirroring those findings, biochemical analysis of mycolates revealed molecular changes and an increase in mycolic acid chain length. Together these results give us an insight into the complex structure of M. abscessus biofilms, the understanding of which may be adapted for clinical use in treatment of biofilm infections, including strategies for dispersing the extracellular matrix, allowing antibiotics to gain access to bacteria within the biofilm.
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Affiliation(s)
- Anja Dokic
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | | | | | - Min Pan
- Institute for Systems Biology, Seattle, WA 98109 USA
| | - Alessandro Di Maio
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Nitin Baliga
- Institute for Systems Biology, Seattle, WA 98109 USA
| | - Apoorva Bhatt
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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22
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Elimination of PknL and MSMEG_4242 in Mycobacterium smegmatis alters the character of the outer cell envelope and selects for mutations in Lsr2. ACTA ACUST UNITED AC 2021; 7:100060. [PMID: 34485766 PMCID: PMC8408660 DOI: 10.1016/j.tcsw.2021.100060] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 11/23/2022]
Abstract
Elimination of pknL and adjacent gene MSMEG_4242 in M. smegmatis produces rough & smooth colonies. All smooth colony mutants have inactivated lsr2 genes. Inactivated lsr2 leads to high expression of MSMEG_4727 and increased synthesis of LOS. Smooth mutants don’t form biofilms, have longer bacilli and increased sliding motility. Rough strains deleted for pknL and MSMEG_4242 form biofilms but have aberrant sliding motility. We propose a phosphorylation cascade of PknB phosphorylating PknL that then phosphorylates Lsr2.
Four serine/threonine kinases are present in all mycobacteria: PknA, PknB, PknG and PknL. PknA and PknB are essential for growth and replication, PknG regulates metabolism, but little is known about PknL. Inactivation of pknL and adjacent regulator MSMEG_4242 in rough colony M. smegmatis mc2155 produced both smooth and rough colonies. Upon restreaking rough colonies, smooth colonies appeared at a frequency of ~ 1/250. Smooth mutants did not form biofilms, showed increased sliding motility and anomalous lipids on thin-layer chromatography, identified by mass spectrometry as lipooligosaccharides and perhaps also glycopeptidolipids. RNA-seq and Sanger sequencing revealed that all smooth mutants had inactivated lsr2 genes due to mutations and different IS1096 insertions. When complemented with lsr2, the colonies became rough, anomalous lipids disappeared and sliding motility decreased. Smooth mutants showed increased expression of IS1096 transposase TnpA and MSMEG_4727, which encodes a protein similar to PKS5. When MSMEG_4727 was deleted, smooth pknL/MSMEG_4242/lsr2 mutants reverted to rough, formed good biofilms, their motility decreased slightly and their anomalous lipids disappeared. Rough delpknL/del4242 mutants formed poor biofilms and showed decreased, aberrant sliding motility and both phenotypes were complemented with the two deleted genes. Inactivation of lsr2 changes colony morphology from rough to smooth, augments sliding motility and increases expression of MSMEG_4727 and other enzymes synthesizing lipooligosaccharides, apparently preventing biofilm formation. Similar morphological phase changes occur in other mycobacteria, likely reflecting environmental adaptations. PknL and MSMEG_4242 regulate lipid components of the outer cell envelope and their absence selects for lsr2 inactivation. A regulatory, phosphorylation cascade model is proposed.
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Crotta Asis A, Savoretti F, Cabruja M, Gramajo H, Gago G. Characterization of key enzymes involved in triacylglycerol biosynthesis in mycobacteria. Sci Rep 2021; 11:13257. [PMID: 34168231 PMCID: PMC8225852 DOI: 10.1038/s41598-021-92721-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 06/08/2021] [Indexed: 02/05/2023] Open
Abstract
Phosphatidic acid phosphatase (PAP) catalyzes the dephosphorylation of phosphatidic acid (PA) yielding diacylglycerol (DAG), the lipid precursor for triacylglycerol (TAG) biosynthesis. PAP activity has a key role in the regulation of PA flux towards TAG or glycerophospholipid synthesis. In this work we have characterized two Mycobacterium smegmatis genes encoding for functional PAP proteins. Disruption of both genes provoked a sharp reduction in de novo TAG biosynthesis in early growth phase cultures under stress conditions. In vivo labeling experiments demonstrated that TAG biosynthesis was restored in the ∆PAP mutant when bacteria reached exponential growth phase, with a concomitant reduction of phospholipid synthesis. In addition, comparative lipidomic analysis showed that the ∆PAP strain had increased levels of odd chain fatty acids esterified into TAGs, suggesting that the absence of PAP activity triggered other rearrangements of lipid metabolism, like phospholipid recycling, in order to maintain the wild type levels of TAG. Finally, the lipid changes observed in the ∆PAP mutant led to defective biofilm formation. Understanding the interaction between TAG synthesis and the lipid composition of mycobacterial cell envelope is a key step to better understand how lipid homeostasis is regulated during Mycobacterium tuberculosis infection.
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Affiliation(s)
- Agostina Crotta Asis
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Franco Savoretti
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Matías Cabruja
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
- Stanford University, Stanford, USA
| | - Hugo Gramajo
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
| | - Gabriela Gago
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
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Lsr2 and Its Novel Paralogue Mediate the Adjustment of Mycobacterium smegmatis to Unfavorable Environmental Conditions. mSphere 2021; 6:6/3/e00290-21. [PMID: 33980681 PMCID: PMC8125055 DOI: 10.1128/msphere.00290-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Nucleoid-associated proteins (NAPs) are the most abundant proteins involved in bacterial chromosome organization and global transcription regulation. The mycobacterial NAP family includes many diverse proteins; some are unique to actinobacteria, and many are crucial for survival under stress (e.g., HupB and Lsr2) and/or optimal growth conditions (e.g., mycobacterial integration host factor [mIHF]). Lsr2 is a nucleoid-associated protein (NAP) that has been found strictly in actinobacteria, including mycobacteria. It is a functional homolog of histone-like nucleoid-structuring protein (H-NS); it acts as a DNA-bridging protein that plays a role in chromosomal organization and transcriptional regulation. To date, the studies on Lsr2 have focused mainly on Mycobacterium tuberculosis. In this study, we analyze the role of Lsr2 as a transcription factor in Mycobacterium smegmatis, a saprophytic bacterium whose natural habitat (soil and water) substantially differs from those of the obligatory mycobacterial pathogens. Our chromatin immunoprecipitation-sequencing (ChIP-seq) data revealed that Lsr2 binds preferentially to AT-rich regions of the M. smegmatis chromosome. We found that Lsr2 acts mainly as a repressor, controlling gene expression either directly by binding promoter regions or indirectly through DNA loop formation and DNA coating. One of the Lsr2-repressed genes encodes polyketide synthase (MSMEG_4727), which is involved in the synthesis of lipooligosaccharides (LOSs). An M. smegmatis strain deprived of Lsr2 produces more LOSs, which is mirrored by changes in the smoothness of cells and their susceptibilities to antibiotics. Unlike M. tuberculosis, M. smegmatis additionally encodes a paralogue of Lsr2, MSMEG_1060, which is a novel member of the mycobacterial NAP family. The Lsr2 and MSMEG_1060 proteins exhibit different DNA binding specificities and chromosomal localizations. Our results suggest that these proteins help M. smegmatis cells cope with stress conditions, including hypoxia and exposure to antibiotics. Thus, the present work provides novel insight into the role of Lsr2 paralogues in the ability of a saprophytic mycobacterial species to adjust to environmental changes. IMPORTANCE Nucleoid-associated proteins (NAPs) are the most abundant proteins involved in bacterial chromosome organization and global transcription regulation. The mycobacterial NAP family includes many diverse proteins; some are unique to actinobacteria, and many are crucial for survival under stress (e.g., HupB and Lsr2) and/or optimal growth conditions (e.g., mycobacterial integration host factor [mIHF]). Here, we present a comprehensive study concerning two functional homologues of mycobacterial H-NS: Lsr2 and its paralogue from M. smegmatis, MSMEG_1060. We found that Lsr2 plays a role in transcriptional regulation, mainly by repressing gene expression via DNA loop formation and/or DNA-coating mechanisms. Intriguingly, the number of Lsr2-mediated genes was found to increase under hypoxia. Compared to Lsr2, MSMEG_1060 exhibits a different DNA binding specificity and chromosomal localization. Since tuberculosis remains a serious worldwide health problem, studies on stress response-mediating agents, such as Lsr2, may contribute to the development of novel antituberculosis drugs.
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25
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Niño-Padilla EI, Velazquez C, Garibay-Escobar A. Mycobacterial biofilms as players in human infections: a review. BIOFOULING 2021; 37:410-432. [PMID: 34024206 DOI: 10.1080/08927014.2021.1925886] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 04/18/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
The role of biofilms in pathogenicity and treatment strategies is often neglected in mycobacterial infections. In recent years, the emergence of nontuberculous mycobacterial infections has necessitated the development of novel prophylactic strategies and elucidation of the mechanisms underlying the establishment of chronic infections. More importantly, the question arises whether members of the Mycobacterium tuberculosis complex can form biofilms and contribute to latent tuberculosis and drug resistance because of the long-lasting and recalcitrant nature of its infections. This review discusses some of the molecular mechanisms by which biofilms could play a role in infection or pathological events in humans.
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Affiliation(s)
| | - Carlos Velazquez
- Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Hermosillo, Sonora, México
| | - Adriana Garibay-Escobar
- Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Hermosillo, Sonora, México
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26
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Lsr2, a nucleoid-associated protein influencing mycobacterial cell cycle. Sci Rep 2021; 11:2910. [PMID: 33536448 PMCID: PMC7858621 DOI: 10.1038/s41598-021-82295-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 01/04/2021] [Indexed: 01/30/2023] Open
Abstract
Nucleoid-associated proteins (NAPs) are responsible for maintaining highly organized and yet dynamic chromosome structure in bacteria. The genus Mycobacterium possesses a unique set of NAPs, including Lsr2, which is a DNA-bridging protein. Importantly, Lsr2 is essential for the M. tuberculosis during infection exhibiting pleiotropic activities including regulation of gene expression (mainly as a repressor). Here, we report that deletion of lsr2 gene profoundly impacts the cell morphology of M. smegmatis, which is a model organism for studying the cell biology of M. tuberculosis and other mycobacterial pathogens. Cells lacking Lsr2 are shorter, wider, and more rigid than the wild-type cells. Using time-lapse fluorescent microscopy, we showed that fluorescently tagged Lsr2 forms large and dynamic nucleoprotein complexes, and that the N-terminal oligomerization domain of Lsr2 is indispensable for the formation of nucleoprotein complexes in vivo. Moreover, lsr2 deletion exerts a significant effect on the replication time and replisome dynamics. Thus, we propose that the Lsr2 nucleoprotein complexes may contribute to maintaining the proper organization of the newly synthesized DNA and therefore influencing mycobacterial cell cycle.
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27
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Xu H, Su Z, Li W, Deng Y, He ZG. MmbR, a master transcription regulator that controls fatty acid β-oxidation genes in Mycolicibacterium smegmatis. Environ Microbiol 2020; 23:1096-1114. [PMID: 32985741 DOI: 10.1111/1462-2920.15249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 09/23/2020] [Indexed: 11/29/2022]
Abstract
An unusually high lipid content and a complex lipid profile are the most distinctive features of the mycobacterial cell envelope. However, our understanding of the regulatory mechanism underlying mycobacterial lipid metabolism is limited, and the major regulators responsible for lipid homeostasis remain to be characterized. Here, we identified MmbR as a novel master regulator that is essential for maintaining lipid homeostasis in Mycolicibacterium smegmatis. We found that MmbR controls fatty acid β-oxidation and modulates biofilm formation in Mycolicibacterium smegmatis. Although MmbR possesses the properties of nucleoid-associated proteins, it acts as a TetR-like transcription factor, directly regulating and intensively repressing the expression of a group of core genes involved in fatty acid β-oxidation. Furthermore, both long-chain acyl-Coenzyme A and fatty acids appear to regulate the signal molecules modulated by MmbR. The deletion of mmbR led to a significant reduction in intracellular fatty acid content and a decrease in the relative lipid composition of the biofilm. The lack of mmbR led to morphological changes in the mycobacterial colony, defects in biofilm formation and enhanced sensitivity to anti-tuberculosis drugs. Our study is the first to establish a link between the transcriptional regulation of fatty acid β-oxidation genes and lipid homeostasis in mycobacteria.
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Affiliation(s)
- Hui Xu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhi Su
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Weihui Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Yimin Deng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zheng-Guo He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
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28
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Pereira AC, Ramos B, Reis AC, Cunha MV. Non-Tuberculous Mycobacteria: Molecular and Physiological Bases of Virulence and Adaptation to Ecological Niches. Microorganisms 2020; 8:microorganisms8091380. [PMID: 32916931 PMCID: PMC7563442 DOI: 10.3390/microorganisms8091380] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/06/2020] [Accepted: 09/07/2020] [Indexed: 12/15/2022] Open
Abstract
Non-tuberculous mycobacteria (NTM) are paradigmatic colonizers of the total environment, circulating at the interfaces of the atmosphere, lithosphere, hydrosphere, biosphere, and anthroposphere. Their striking adaptive ecology on the interconnection of multiple spheres results from the combination of several biological features related to their exclusive hydrophobic and lipid-rich impermeable cell wall, transcriptional regulation signatures, biofilm phenotype, and symbiosis with protozoa. This unique blend of traits is reviewed in this work, with highlights to the prodigious plasticity and persistence hallmarks of NTM in a wide diversity of environments, from extreme natural milieus to microniches in the human body. Knowledge on the taxonomy, evolution, and functional diversity of NTM is updated, as well as the molecular and physiological bases for environmental adaptation, tolerance to xenobiotics, and infection biology in the human and non-human host. The complex interplay between individual, species-specific and ecological niche traits contributing to NTM resilience across ecosystems are also explored. This work hinges current understandings of NTM, approaching their biology and heterogeneity from several angles and reinforcing the complexity of these microorganisms often associated with a multiplicity of diseases, including pulmonary, soft-tissue, or milliary. In addition to emphasizing the cornerstones of knowledge involving these bacteria, we identify research gaps that need to be addressed, stressing out the need for decision-makers to recognize NTM infection as a public health issue that has to be tackled, especially when considering an increasingly susceptible elderly and immunocompromised population in developed countries, as well as in low- or middle-income countries, where NTM infections are still highly misdiagnosed and neglected.
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Affiliation(s)
- André C. Pereira
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal; (A.C.P.); (B.R.); (A.C.R.)
- Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Beatriz Ramos
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal; (A.C.P.); (B.R.); (A.C.R.)
- Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Ana C. Reis
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal; (A.C.P.); (B.R.); (A.C.R.)
- Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Mónica V. Cunha
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal; (A.C.P.); (B.R.); (A.C.R.)
- Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Correspondence: ; Tel.: +351-217-500-000 (ext. 22461)
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Zhao X, Duan X, Dai Y, Zhen J, Guo J, Zhang K, Wang X, Kuang Z, Wang H, Niu J, Fan L, Xie J. Mycobacterium Von Willebrand factor protein MSMEG_3641 is involved in biofilm formation and intracellular survival. Future Microbiol 2020; 15:1033-1044. [PMID: 32811177 DOI: 10.2217/fmb-2020-0064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Aim: Mycobacterium tuberculosis in vitro biofilm is associated with the virulence and persistence capability. Our aim is to delineate factors involved in biofilms development. Materials & methods: We performed transposon mutants screen and found that mutation of MSMEG_3641, a homolog of M. tuberculosis Rv1836c, can change M. smegmatis colony morphology and biofilm. Results: MSMEG_3641 contains a vWA domain that is highly conserved among Mycobacteria. The phenotypes of MSMEG_3641 mutants include disrupted biofilm, weakened migration ability and changed colony morphology. All phenotypes might be contributed to the enhanced cell wall permeability and declined cell aggregation ability. Conclusion: To our knowledge, this is the first report concerning the mycobacteria Von Willebrand factor domain function, especially in colony morphology and biofilm development.
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Affiliation(s)
- Xiaokang Zhao
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & 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, Chongqing 400715, China
| | - Xiangke Duan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & 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, Chongqing 400715, China
| | - Yongdong Dai
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & 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, Chongqing 400715, China
| | - Junfeng Zhen
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & 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, Chongqing 400715, China
| | - Jiaohan Guo
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & 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, Chongqing 400715, China
| | - Ke Zhang
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & 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, Chongqing 400715, China
| | - Xiaoyu Wang
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & 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, Chongqing 400715, China
| | - Zhongmei Kuang
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & 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, Chongqing 400715, China
| | - Hao Wang
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & 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, Chongqing 400715, China
| | - Jingjing Niu
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & 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, Chongqing 400715, China
| | - Lin Fan
- Shanghai Clinic & Research Center of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai Key Laboratory of Tuberculosis, Shanghai 200433, China
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & 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, Chongqing 400715, China
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30
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Conditional down-regulation of GreA impacts expression of rRNA and transcription factors, affecting Mycobacterium smegmatis survival. Sci Rep 2020; 10:5802. [PMID: 32242064 PMCID: PMC7118132 DOI: 10.1038/s41598-020-62703-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/24/2020] [Indexed: 12/26/2022] Open
Abstract
Gre, one of the conserved transcription factors in bacteria, modulates RNA polymerase (RNAP) activity to ensure processivity and fidelity of RNA synthesis. Gre factors regulate transcription by inducing the intrinsic-endonucleolytic activity of RNAP, allowing the enzyme to resume transcription from the paused and arrested sites. While Escherichia coli and a number of eubacteria harbor GreA and GreB, genus mycobacteria has a single Gre (GreA). To address the importance of the GreA in growth, physiology and gene expression of Mycobacterium smegmatis, we have constructed a conditional knock-down strain of GreA. The GreA depleted strain exhibited slow growth, drastic changes in cell surface phenotype, cell death, and increased susceptibility to front-line anti-tubercular drugs. Transcripts and 2D-gel electrophoresis (2D-PAGE) analysis of the GreA conditional knock-down strain showed altered expression of the genes involved in transcription regulation. Among the genes analysed, expression of RNAP subunits (β, β’ and ω), carD, hupB, lsr2, and nusA were affected to a large extent. Severe reduction in the expression of genes of rRNA operon in the knock-down strain reveal a role for GreA in regulating the core components of the translation process.
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Ali MK, Zhen G, Nzungize L, Stojkoska A, Duan X, Li C, Duan W, Xu J, Xie J. Mycobacterium tuberculosis PE31 ( Rv3477) Attenuates Host Cell Apoptosis and Promotes Recombinant M. smegmatis Intracellular Survival via Up-regulating GTPase Guanylate Binding Protein-1. Front Cell Infect Microbiol 2020; 10:40. [PMID: 32117813 PMCID: PMC7020884 DOI: 10.3389/fcimb.2020.00040] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 01/21/2020] [Indexed: 12/23/2022] Open
Abstract
The Mycobacterium (M.) tuberculosis comprising proline–glutamic acid (PE) subfamily proteins associate with virulence, pathogenesis, and host-immune modulations. While the functions of most of this family members are not yet explored. Here, we explore the functions of “PE only” subfamily member PE31 (Rv3477) in virulence and host-pathogen interactions. We have expressed the M. tuberculosis PE31 in non-pathogenic Mycobacterium smegmatis strain (Ms_PE31) and demonstrated that PE31 significantly altered the cell facet features including colony morphology and biofilm formation. PE31 expressing M. smegmatis showed more resistant to the low pH, diamide, H2O2 and surface stress. Moreover, Ms_PE31 showed higher intracellular survival in macrophage THP-1 cells. Ms_PE31 significantly down-regulated the production of IL-12p40 and IL-6, while up-regulates the production of IL-10 in macrophages. Ms_PE31 also induced the expression of guanylate-binding protein-1 (GBP-1) in macrophages. Further analysis demonstrates that Ms_PE31 inhibits the caspase-3 activation and reduces the macrophages apoptosis. Besides, the NF-κB signaling pathway involves the interplay between Ms_PE31 and macrophages. Collectively, our finding identified that PE31 act as a functionally relevant virulence factor of M. tuberculosis.
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Affiliation(s)
- Md Kaisar Ali
- 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, Institute of Modern Biopharmaceuticals, Southwest University, Chongqing, China
| | - Gong Zhen
- 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, Institute of Modern Biopharmaceuticals, Southwest University, Chongqing, China
| | - Lambert Nzungize
- 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, Institute of Modern Biopharmaceuticals, Southwest University, Chongqing, China
| | - Andrea Stojkoska
- 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, Institute of Modern Biopharmaceuticals, Southwest University, Chongqing, China
| | - Xiangke Duan
- 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, Institute of Modern Biopharmaceuticals, Southwest University, Chongqing, China
| | - Chunyan Li
- 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, Institute of Modern Biopharmaceuticals, Southwest University, Chongqing, China
| | - Wei Duan
- 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, Institute of Modern Biopharmaceuticals, Southwest University, Chongqing, China
| | - Junqi Xu
- 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, Institute of Modern Biopharmaceuticals, Southwest University, Chongqing, China
| | - Jianping Xie
- 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, Institute of Modern Biopharmaceuticals, Southwest University, Chongqing, China
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Hegde SR. Computational Identification of the Proteins Associated With Quorum Sensing and Biofilm Formation in Mycobacterium tuberculosis. Front Microbiol 2020; 10:3011. [PMID: 32038515 PMCID: PMC6988586 DOI: 10.3389/fmicb.2019.03011] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 12/16/2019] [Indexed: 12/23/2022] Open
Abstract
With prolonged therapy and increased instances of drug resistance, tuberculosis is viewed as a serious infectious disease causing high mortality. Emerging concepts in Mycobacterium tuberculosis pathogenicity include biofilm formation, which endows bacterial survival in the host for a long time. To tackle chronic tuberculosis infection, a detailed understanding of the bacterial survival mechanisms is crucial. Using comparative genomics and literature mining, 115 M. tuberculosis proteins were shortlisted for their likely association with biofilm formation or quorum sensing. These include essential genes such as secA2, lpqY-sugABC, Rv1176c, and Rv0195, many of which are also known virulence factors. Furthermore, the functional relationship among these proteins was established by considering known protein-protein interactions, regulatory interactions, and gene expression correlation data/information. Graph centrality and motif analyses predicted the importance of proteins, such as Rv0081, DevR, RegX3, Rv0097, and Rv1996 in M. tuberculosis biofilm formation. Analysis of conservation across other biofilm-forming bacteria suggests that most of these genes are conserved in mycobacteria. As the processes, such as quorum sensing, leading to biofilm formation involve diverse pathways and interactions between proteins, these system-wide studies provide a novel perspective toward understanding mycobacterial persistence.
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Affiliation(s)
- Shubhada R Hegde
- Institute of Bioinformatics and Applied Biotechnology, Bengaluru, India
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Li Y, Li W, Xie Z, Xu H, He ZG. MpbR, an essential transcriptional factor for Mycobacterium tuberculosis survival in the host, modulates PIM biosynthesis and reduces innate immune responses. J Genet Genomics 2019; 46:575-589. [DOI: 10.1016/j.jgg.2019.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 11/28/2019] [Accepted: 12/02/2019] [Indexed: 01/08/2023]
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Gupta S, Kumar A, Singh K, Kumari R, Sharma A, Singh RK, Pandey SK, Anupurba S. Rv1273c, an ABC transporter of Mycobacterium tuberculosis promotes mycobacterial intracellular survival within macrophages via modulating the host cell immune response. Int J Biol Macromol 2019; 142:320-331. [PMID: 31593717 DOI: 10.1016/j.ijbiomac.2019.09.103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 08/18/2019] [Accepted: 09/13/2019] [Indexed: 02/06/2023]
Abstract
Mycobacterium proteins, especially cell wall associated proteins, interact with host macrophage to regulate the functions and cytokine production. So, identification and characterization of such proteins is essential for understanding tuberculosis pathogenesis. The role of the ABC transporter proteins in the pathophysiology and virulence of Mycobacterium tuberculosis is not clearly understood. In the present study, Rv1273c, an ABC transporter, has been expressed in a non-pathogenic and fast growing Mycobacterium smegmatis strain to explore its role in host pathogen interactions. Over expression of Rv1273c resulted in enhanced intracellular survival in macrophage as well as modified cell wall architecture. We found altered colony morphology and cell surface properties that might be linked with remodelling of bacterial cell wall which may help in the intracellular survival of mycobacterium. However, the enhanced intracellular survival was not found to be the consequence of an increased resistance to intracellular stresses. The activation of macrophage by Rv1273c was associated with perturbed cytokine production. Pharmacological inhibition experiment and western immunoblotting suggested that this altered cytokine profile was mediated possibly by NF-kB and p38 pathway in macrophage. Overall, the present findings indicated that Rv1273c enhanced mycobacterium persistence and mediated the evasion of immune responses during infection.
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Affiliation(s)
- Smita Gupta
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Arun Kumar
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Kamal Singh
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Richa Kumari
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Ajay Sharma
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Rakesh K Singh
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Satyendra K Pandey
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Shampa Anupurba
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
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35
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Rani P, Nagaraja V. Genome-wide mapping of Topoisomerase I activity sites reveal its role in chromosome segregation. Nucleic Acids Res 2019; 47:1416-1427. [PMID: 30566665 PMCID: PMC6379724 DOI: 10.1093/nar/gky1271] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 11/30/2018] [Accepted: 12/13/2018] [Indexed: 11/13/2022] Open
Abstract
DNA Topoisomerase I (TopoI) in eubacteria is the principle DNA relaxase, belonging to Type 1A group. The enzyme from Mycobacterium smegmatis is essential for cell survival and distinct from other eubacteria in having several unusual characteristics. To understand genome-wide TopoI engagements in vivo, functional sites were mapped by employing a poisonous variant of the enzyme and a newly discovered inhibitor, both of which arrest the enzyme activity after the first transestrification reaction, thereby leading to the accumulation of protein-DNA covalent complexes. The cleavage sites are subsets of TopoI binding sites, implying that TopoI recruitment does not necessarily lead to DNA cleavage in vivo. The cleavage protection conferred by nucleoid associated proteins in vitro suggest a similar possibility in vivo. Co-localization of binding and cleavage sites of the enzyme on transcription units, implying that both TopoI recruitment and function are associated with active transcription. Attenuation of the cleavage upon Rifampicin treatment confirms the close connection between transcription and TopoI action. Notably, TopoI is inactive upstream of the Transcription start site (TSS) and activated following transcription initiation. The binding of TopoI at the Ter region, and the DNA cleavage at the Ter indicates TopoI involvement in chromosome segregation, substantiated by its catenation and decatenation activities.
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Affiliation(s)
- Phoolwanti Rani
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
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36
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Kaur J, Kaur J. Rv0518, a nutritive stress inducible GDSL lipase of Mycobacterium tuberculosis, enhanced intracellular survival of bacteria by cell wall modulation. Int J Biol Macromol 2019; 135:180-195. [DOI: 10.1016/j.ijbiomac.2019.05.121] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 05/17/2019] [Accepted: 05/20/2019] [Indexed: 10/26/2022]
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Zeng S, Constant P, Yang D, Baulard A, Lefèvre P, Daffé M, Wattiez R, Fontaine V. Cpn60.1 (GroEL1) Contributes to Mycobacterial Crabtree Effect: Implications for Biofilm Formation. Front Microbiol 2019; 10:1149. [PMID: 31244785 PMCID: PMC6579834 DOI: 10.3389/fmicb.2019.01149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 05/06/2019] [Indexed: 12/18/2022] Open
Abstract
Biofilm formation is a survival strategy for microorganisms facing a hostile environment. Under biofilm, bacteria are better protected against antibacterial drugs and the immune response, increasing treatment difficulty, as persistent populations recalcitrant to chemotherapy are promoted. Deciphering mechanisms leading to biofilms could, thus, be beneficial to obtain new antibacterial drug candidates. Here, we show that mycobacterial biofilm formation is linked to excess glycerol adaptation and the concomitant establishment of the Crabtree effect. This effect is characterized by respiratory reprogramming, ATP downregulation, and secretion of various metabolites including pyruvate, acetate, succinate, and glutamate. Interestingly, the Crabtree effect was abnormal in a mycobacterial strain deficient for Cpn60.1 (GroEL1). Indeed, this mutant strain had a compromised ability to downregulate ATP and secreted more pyruvate, acetate, succinate, and glutamate in the culture medium. Importantly, the mutant strain had higher intracellular pyruvate and produced more toxic methylglyoxal, suggesting a glycolytic stress leading to growth stasis and consequently biofilm failure. This study demonstrates, for the first time, the link between mycobacterial biofilm formation and the Crabtree effect.
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Affiliation(s)
- Sheng Zeng
- Microbiology, Bioorganic and Macromolecular Chemistry Research Unit, Faculté de Pharmacie, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Patricia Constant
- Department of Tuberculosis and Infection Biology, Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Dong Yang
- Microbiology, Bioorganic and Macromolecular Chemistry Research Unit, Faculté de Pharmacie, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Alain Baulard
- Institut Pasteur de Lille, Université de Lille, CNRS, INSERM, CHU Lille, U1019-UMR 8204, Center for Infection and Immunity of Lille, Lille, France
| | - Philippe Lefèvre
- Microbiology, Bioorganic and Macromolecular Chemistry Research Unit, Faculté de Pharmacie, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Mamadou Daffé
- Department of Tuberculosis and Infection Biology, Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Ruddy Wattiez
- Department of Proteomics and Microbiology, University of Mons, Mons, Belgium
| | - Véronique Fontaine
- Microbiology, Bioorganic and Macromolecular Chemistry Research Unit, Faculté de Pharmacie, Université Libre de Bruxelles (ULB), Brussels, Belgium
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38
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Le Moigne V, Bernut A, Cortès M, Viljoen A, Dupont C, Pawlik A, Gaillard JL, Misguich F, Crémazy F, Kremer L, Herrmann JL. Lsr2 Is an Important Determinant of Intracellular Growth and Virulence in Mycobacterium abscessus. Front Microbiol 2019; 10:905. [PMID: 31114557 PMCID: PMC6503116 DOI: 10.3389/fmicb.2019.00905] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 04/09/2019] [Indexed: 12/30/2022] Open
Abstract
Mycobacterium abscessus, a pathogen responsible for severe lung infections in cystic fibrosis patients, exhibits either smooth (S) or rough (R) morphotypes. The S-to-R transition correlates with inhibition of the synthesis and/or transport of glycopeptidolipids (GPLs) and is associated with an increase of pathogenicity in animal and human hosts. Lsr2 is a small nucleoid-associated protein highly conserved in mycobacteria, including M. abscessus, and is a functional homolog of the heat-stable nucleoid-structuring protein (H-NS). It is essential in Mycobacterium tuberculosis but not in the non-pathogenic model organism Mycobacterium smegmatis. It acts as a master transcriptional regulator of multiple genes involved in virulence and immunogenicity through binding to AT-rich genomic regions. Previous transcriptomic studies, confirmed here by quantitative PCR, showed increased expression of lsr2 (MAB_0545) in R morphotypes when compared to their S counterparts, suggesting a possible role of this protein in the virulence of the R form. This was addressed by generating lsr2 knock-out mutants in both S (Δlsr2-S) and R (Δlsr2-R) variants, demonstrating that this gene is dispensable for M. abscessus growth. We show that the wild-type S variant, Δlsr2-S and Δlsr2-R strains were more sensitive to H2O2 as compared to the wild-type R variant of M. abscessus. Importantly, virulence of the Lsr2 mutants was considerably diminished in cellular models (macrophage and amoeba) as well as in infected animals (mouse and zebrafish). Collectively, these results emphasize the importance of Lsr2 in M. abscessus virulence.
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Affiliation(s)
| | - Audrey Bernut
- UMR 9004, Centre National de la Recherche Scientifique, Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier, Montpellier, France
| | | | - Albertus Viljoen
- UMR 9004, Centre National de la Recherche Scientifique, Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier, Montpellier, France
| | - Christian Dupont
- UMR 9004, Centre National de la Recherche Scientifique, Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier, Montpellier, France
| | - Alexandre Pawlik
- Unité de Pathogénomique Mycobactérienne, Institut Pasteur, Paris, France
| | - Jean-Louis Gaillard
- 2I, UVSQ, INSERM, Université Paris-Saclay, Versailles, France.,APHP, GHU PIFO, Hôpital Raymond-Poincaré - Hôpital Ambroise-Paré, Boulogne-Billancourt, France
| | | | | | - Laurent Kremer
- UMR 9004, Centre National de la Recherche Scientifique, Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier, Montpellier, France.,INSERM, Institut de Recherche en Infectiologie de Montpellier, Montpellier, France
| | - Jean-Louis Herrmann
- 2I, UVSQ, INSERM, Université Paris-Saclay, Versailles, France.,APHP, GHU PIFO, Hôpital Raymond-Poincaré - Hôpital Ambroise-Paré, Boulogne-Billancourt, France
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39
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Chakraborty P, Kumar A. The extracellular matrix of mycobacterial biofilms: could we shorten the treatment of mycobacterial infections? MICROBIAL CELL 2019; 6:105-122. [PMID: 30740456 PMCID: PMC6364259 DOI: 10.15698/mic2019.02.667] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A number of non-tuberculous mycobacterium species are opportunistic pathogens and ubiquitously form biofilms. These infections are often recalcitrant to treatment and require therapy with multiple drugs for long duration. The biofilm resident bacteria also display phenotypic drug tolerance and thus it has been hypothesized that the drug unresponsiveness in vivo could be due to formation of biofilms inside the host. We have discussed the biofilms of several pathogenic non-tuberculous mycobacterium (NTM) species in context to the in vivo pathologies. Besides pathogenic NTMs, Mycobacterium smegmatis is often used as a model organism for understanding mycobacterial physiology and has been studied extensively for understanding the mycobacterial biofilms. A number of components of the mycobacterial cell wall such as glycopeptidolipids, short chain mycolic acids, monomeromycolyl diacylglycerol, etc. have been shown to play an important role in formation of pellicle biofilms. It shall be noted that these components impart a hydrophobic character to the mycobacterial cell surface that facilitates cell to cell interaction. However, these components are not necessarily the constituents of the extracellular matrix of mycobacterial biofilms. In the end, we have described the biofilms of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis. Three models of Mtb biofilm formation have been proposed to study the factors regulating biofilm formation, the physiology of the resident bacteria, and the nature of the biomaterial that holds these bacterial masses together. These models include pellicle biofilms formed at the liquid-air interface of cultures, leukocyte lysate-induced biofilms, and thiol reductive stressinduced biofilms. All the three models offer their own advantages in the study of Mtb biofilms. Interestingly, lipids (mainly keto-mycolic acids) are proposed to be the primary component of extracellular polymeric substance (EPS) in the pellicle biofilm, whereas the leukocyte lysate-induced and thiol reductive stress-induced biofilms possess polysaccharides as the primary component of EPS. Both models also contain extracellular DNA in the EPS. Interestingly, thiol reductive stressinduced Mtb biofilms are held together by cellulose and yet unidentified structural proteins. We believe that a better understanding of the EPS of Mtb biofilms and the physiology of the resident bacteria will facilitate the development of shorter regimen for TB treatment.
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Affiliation(s)
- Poushali Chakraborty
- Council of Scientific and Industrial Research, Institute of Microbial Technology, Chandigarh, India 160036
| | - Ashwani Kumar
- Council of Scientific and Industrial Research, Institute of Microbial Technology, Chandigarh, India 160036.,CSIR-Academy of Scientific & Innovative Research (AcSIR), Council of Scientific & Industrial Research, New Delhi-110001
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40
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Karade SS, Pandey S, Ansari A, Das S, Tripathi S, Arora A, Chopra S, Pratap JV, Dasgupta A. Rv3272 encodes a novel Family III CoA transferase that alters the cell wall lipid profile and protects mycobacteria from acidic and oxidative stress. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1867:317-330. [PMID: 30342240 DOI: 10.1016/j.bbapap.2018.10.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/01/2018] [Accepted: 10/16/2018] [Indexed: 11/26/2022]
Abstract
The availability of complete genome sequence of Mycobacterium tuberculosis has provided an important tool to understand the mycobacterial biology with respect to host-pathogen interaction, which is an unmet need of the hour owing to continuous increasing drug resistance. Hypothetical proteins are often an overlooked pool though half the genome encodes for such proteins of unknown function that could potentially play vital roles in mycobacterial biology. In this context, we report the structural and functional characterization of the hypothetical protein Rv3272. Sequence analysis classifies Rv3272 as a Family III CoA transferase with the classical two domain structure and conserved Aspartate residue (D175). The crystal structure of the wild type protein (2.2 Å) demonstrated the associated inter-locked dimer while that of the D175A mutant co-crystallized with octanoyl-CoA demonstrated relative movement between the two domains. Isothermal titration calorimetry studies indicate that Rv3272 binds to fatty acyl-CoAs of varying carbon chain lengths, with palmitoyl-CoA (C16:0) exhibiting maximum affinity. To determine the functional relevance of Rv3272 in mycobacterial biology, we ectopically expressed Rv3272 in M. smegmatis and assessed that its expression encodes significant alteration in cell surface with marked differences in triacylglycerol accumulation. Additionally, Rv3272 expression protects mycobacteria from acidic, oxidative and antibiotic stress under in vitro conditions. Taken together, these studies indicate a significant role for Rv3272 in host-pathogen interaction.
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Affiliation(s)
- Sharanbasappa Shrimant Karade
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - Shilpika Pandey
- Microbiology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - Ahmadullah Ansari
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - Swetarka Das
- Microbiology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - Sarita Tripathi
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - Ashish Arora
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - Sidharth Chopra
- Microbiology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - J Venkatesh Pratap
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India.
| | - Arunava Dasgupta
- Microbiology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India.
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41
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Nath Y, Ray SK, Buragohain AK. Essential role of the ESX-3 associated eccD3 locus in maintaining the cell wall integrity of Mycobacterium smegmatis. Int J Med Microbiol 2018; 308:784-795. [PMID: 30257807 DOI: 10.1016/j.ijmm.2018.06.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/21/2018] [Accepted: 06/24/2018] [Indexed: 11/28/2022] Open
Abstract
Mycobacterial pathogens have evolved a unique secretory apparatus called the Type VII secretion system (T7SS) which comprises of five gene clusters designated as ESX1, ESX2, ESX3, ESX4, and ESX5. Of these the ESX3 T7SS plays an important role in the regulatory uptake of iron from the environment, thereby enabling the bacteria to establish successful infection in the host. However, ESX3 secretion system is conserved among all the mycobacterial species including the fast-growing nonpathogenic species M. smegmatis. Although the function of ESX3 T7SS is known to be absolutely critical for establishing infection by M. tuberculosis, its conserved nature in all the pathogenic and nonpathogenic mycobacterial species intrigues to explore the additional functional roles in Mycobacterium species through which potent targets for drugs can be identified and developed. In the present study, we investigated the possible role of EccD3, a transmembrane protein of the ESX3 T7SS in M. smegmatis by deleting the entire eccD3 gene by efficient allelic exchange method. The preliminary investigations through the creation of knockout mutant of the eccD3 gene indicate that this secretory apparatus has an important role in maintaining the cell wall integrity which was evident from the abnormal colony morphology, lack of biofilm formation and difference in cell wall permeability.
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Affiliation(s)
- Yutika Nath
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Tezpur, Assam, 784028, India.
| | - Suvendra Kumar Ray
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Tezpur, Assam, 784028, India.
| | - Alak Kumar Buragohain
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Tezpur, Assam, 784028, India; Dibrugarh University, Dibrugarh, Assam, 786004, India.
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42
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Gómez L, Alvarez F, Betancur D, Oñate A. Brucellosis vaccines based on the open reading frames from genomic island 3 of Brucella abortus. Vaccine 2018; 36:2928-2936. [PMID: 29685597 DOI: 10.1016/j.vaccine.2018.04.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/02/2018] [Accepted: 04/04/2018] [Indexed: 01/18/2023]
Abstract
Brucella abortus is the etiological agent of brucellosis, a zoonotic disease affecting cattle and humans. This disease has been partially controlled in cattle by immunization with live attenuated B. abortus S19 and RB51 strains. However, use of these vaccine strains has been associated with safety issues in animals and humans. New vaccines have since emerged in the prevention of brucellosis, particularly DNA vaccines, which have shown effectiveness and a good safety profile. Their protection efficacy in mice is associated with the induction of Th1 type and cytotoxic T cell mediated immune response against structural antigens and virulence factors expressed during B. abortus infection. Some antigenic candidate for vaccine design against brucellosis (mainly DNA vaccines) have been obtained from genomic island 3 (GI-3) of B. abortus, which encodes several open reading frames (ORFs) involved in the intracellular survival and virulence of this pathogen. The immunogenicity and protection conferred by these DNA vaccines in a murine model is reviewed in this article, suggesting that some of them could be safe and effective vaccine candidates against to prevent B. abortus infection.
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Affiliation(s)
- Leonardo Gómez
- Laboratory of Molecular Immunology, Faculty of Biological Sciences, Department of Microbiology, University of Concepción, Concepción, Chile
| | - Francisco Alvarez
- Laboratory of Molecular Immunology, Faculty of Biological Sciences, Department of Microbiology, University of Concepción, Concepción, Chile
| | - Daniel Betancur
- Laboratory of Molecular Immunology, Faculty of Biological Sciences, Department of Microbiology, University of Concepción, Concepción, Chile
| | - Angel Oñate
- Laboratory of Molecular Immunology, Faculty of Biological Sciences, Department of Microbiology, University of Concepción, Concepción, Chile.
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43
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Characterization of a novel regulatory pathway for mannitol metabolism and its coordination with biofilm formation in Mycobacterium smegmatis. J Genet Genomics 2018; 45:477-488. [DOI: 10.1016/j.jgg.2018.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 06/26/2018] [Indexed: 01/03/2023]
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44
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Two dd-Carboxypeptidases from Mycobacterium smegmatis Affect Cell Surface Properties through Regulation of Peptidoglycan Cross-Linking and Glycopeptidolipids. J Bacteriol 2018; 200:JB.00760-17. [PMID: 29735762 DOI: 10.1128/jb.00760-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 04/25/2018] [Indexed: 11/20/2022] Open
Abstract
During the peptidoglycan (PG) maturation of mycobacteria, the glycan strands are interlinked by both 3-3 (between two meso-diaminopimelic acids [meso-DAPs]) and 4-3 cross-links (between d-Ala and meso-DAP), though there is a predominance (60 to 80%) of 3-3 cross-links. The dd-carboxypeptidases (dd-CPases) act on pentapeptides to generate tetrapeptides that are used by ld-transpeptidases as substrates to form 3-3 cross-links. Therefore, dd-CPases play a crucial role in mycobacterial PG cross-link formation. However, the physiology of dd-CPases in mycobacteria is relatively unexplored. In this study, we deleted two dd-CPase genes, msmeg_2433 and msmeg_2432, both individually and in combination, from Mycobacterium smegmatis mc2155. Though the single dd-CPase gene deletions had no significant impact on the mycobacterial physiology, many interesting functional alterations were observed in the double-deletion mutant, viz, a predominance in PG cross-link formation was shifted from 3-3 cross-links to 4-3, cell surface glycopeptidolipid (GPL) expression was reduced, and susceptibility to β-lactams and antitubercular agents was enhanced. Moreover, the survival rate of the double mutant within murine macrophages was higher than that of the parent. Interestingly, the complementation with any one of the dd-CPase genes could restore the wild-type phenotype. In a nutshell, we infer that the altered ratio of 4-3 to 3-3 PG cross-links might have influenced the expression of surface GPLs, colony morphology, biofilm formation, drug susceptibility, and subsistence of the cells within macrophages.IMPORTANCE The glycan strands in mycobacterial peptidoglycan (PG) are interlinked by both 3-3 and 4-3 cross-links. The dd-CPases generate tetrapeptides by acting on the pentapeptides, and ld-transpeptidases use tetrapeptides as substrates to form 3-3 cross-links. In this study, we showed that simultaneous deletions of two dd-CPases alter the nature of PG cross-linking from 3-3 cross-links to 4-3 cross-links. The deletions subsequently decrease the expression of glycopeptidolipids (significant surface lipid present in many nontuberculous mycobacteria, including Mycobacterium smegmatis) and affect other physiological parameters, like cell morphology, growth rate, biofilm formation, antibiotic susceptibility, and survival within murine macrophages. Thus, unraveling the physiology of dd-CPases might help us design antimycobacterial therapeutics in the future.
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The Mycobacterium tuberculosis protein Rv2387 is involved in cell wall remodeling and susceptibility to acidic conditions. Biochem Biophys Res Commun 2018; 503:625-630. [PMID: 29902462 DOI: 10.1016/j.bbrc.2018.06.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 06/11/2018] [Indexed: 11/22/2022]
Abstract
The distinctive cell walls of mycobacteria are characteristic features of these bacteria. Individual cell wall components influence diverse mycobacterial phenotypes, such as colony morphology, virulence and stress resistance. To investigate the role of the hypothetical protein Rv2387, we constructed a Mycobacterium smegmatis strain that heterologously expressed this ORF, and we observed that the M. smegmatis strain expressing Rv2387 exhibited altered colony morphology and cell wall lipid composition, leading to a marked decrease in the resistance against acidic conditions. This study demonstrates that due to its impact on cell wall remodeling, Rv2387 might play an important role in mycobacterial physiology.
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Mycobacterium tuberculosis toxin Rv2872 is an RNase involved in vancomycin stress response and biofilm development. Appl Microbiol Biotechnol 2018; 102:7123-7133. [PMID: 29948114 DOI: 10.1007/s00253-018-9132-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 10/14/2022]
Abstract
Bacterial toxin-antitoxin (TA) systems are emerging important regulators of multiple cellular physiological events and candidates for novel antibiotic targets. To explore the role of Mycobacterium tuberculosis function, unknown toxin gene Rv2872 was heterologously expressed in Mycobacterium smegmatis (MS_Rv2872). Upon induction, MS_Rv2872 phenotype differed significantly from the control, such as increased vancomycin resistance, retarded growth, cell wall, and biofilm structure. This phenotype change might result from the RNase activity of Rv2872 as purified Rv2872 toxin protein can cleave the products of several key genes involved in abovementioned phenotypes. In summary, toxin Rv2872 was firstly reported to be a endonuclease involved in antibiotic stress responses, cell wall structure, and biofilm development.
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Singh P, Rameshwaram NR, Ghosh S, Mukhopadhyay S. Cell envelope lipids in the pathophysiology of Mycobacterium tuberculosis. Future Microbiol 2018; 13:689-710. [PMID: 29771143 DOI: 10.2217/fmb-2017-0135] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Mycobacterium tuberculosis is an intracellular bacterium that persists and replicates inside macrophages. The bacterium possesses an unusual lipid-rich cell envelope that provides a hydrophobic impermeable barrier against many environmental stressors and allows it to survive extremely hostile intracellular surroundings. Since the lipid-rich envelope is crucial for M. tuberculosis virulence, the components of the cell wall lipid biogenesis pathways constitute an attractive target for the development of vaccines and antimycobacterial chemotherapeutics. In this review, we provide a detailed description of the mycobacterial cell envelope lipid components and their contributions to the physiology and pathogenicity of mycobacteria. We also discussed the current status of the antimycobacterial drugs that target biosynthesis, export and regulation of cell envelope lipids.
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Affiliation(s)
- Parul Singh
- Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting & Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad, 500 039, India.,Graduate Studies, Manipal Academy of Higher Education, Manipal, Karnataka, 576 104, India
| | - Nagender Rao Rameshwaram
- Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting & Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad, 500 039, India
| | - Sudip Ghosh
- Molecular Biology Division, National Institute of Nutrition (ICMR), Jamai-Osmania PO, Hyderabad, 500 007, India
| | - Sangita Mukhopadhyay
- Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting & Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad, 500 039, India
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Llorens-Fons M, Julián E, Luquin M, Pérez-Trujillo M. Molecule confirmation and structure characterization of pentatriacontatrienyl mycolate in Mycobacterium smegmatis. Chem Phys Lipids 2018; 212:138-143. [PMID: 29291384 DOI: 10.1016/j.chemphyslip.2017.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/15/2017] [Accepted: 12/26/2017] [Indexed: 12/01/2022]
Abstract
Mycobacterium smegmatis is often used to study the different components of mycobacterial cell wall. Mycolic acids are important components of mycobacterial cell wall that have been associated with virulence. Recently, a novel lipid containing mycolic acids has been described in M. smegmatis. However, some uncertainties regarding the structure of this molecule named mycolate ester wax have been reported. The objective of this work was to perform an in depth structural study of this molecule for its precise characterization. Using 1H and 13C NMR spectroscopy, the molecular structure of mycolate ester wax found in M. smegmatis has been elucidated. The characterization was complemented with MS analyses. This molecule is formed by a carbon chain with three methyl substituted olefinic units and a mycolate structure with trans double bonds and cis cyclopropane rings. The present molecular study will facilitate the detection and identification of pentatriacontatrienyl mycolate in future studies by the performance of a simple 1D 1H NMR experiment.
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Affiliation(s)
- Marta Llorens-Fons
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Barcelona, Spain
| | - Esther Julián
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Barcelona, Spain
| | - Marina Luquin
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Barcelona, Spain.
| | - Míriam Pérez-Trujillo
- Servei de Ressonància Magnètica Nuclear i Departament de Química, Facultat de Ciències i Biociències, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Barcelona, Spain.
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Coronado-Aceves EW, Gigliarelli G, Garibay-Escobar A, Zepeda RER, Curini M, López Cervantes J, Inés Espitia-Pinzón CI, Superchi S, Vergura S, Marcotullio MC. New Isoflavonoids from the extract of Rhynchosia precatoria (Humb. & Bonpl. ex Willd.) DC. and their antimycobacterial activity. JOURNAL OF ETHNOPHARMACOLOGY 2017; 206:92-100. [PMID: 28506901 DOI: 10.1016/j.jep.2017.05.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 05/05/2017] [Accepted: 05/11/2017] [Indexed: 05/23/2023]
Abstract
ETHNOPHARMACOLOGY RELEVANCE The evaluation of the antimycobacterial activity of extracts of medicinal plants used by Mayos against tuberculosis and respiratory problems, allowed the identification of Rhynchosia precatoria (Humb. & Bonpl. ex Willd.) DC (Fabaceae) as the best candidate to find new antimycobacterial compounds. AIM OF THE STUDY To isolate and characterize the compounds of R. precatoria responsible for the inhibitory and bactericidal activity against Mycobacterium tuberculosis H37Rv and Mycobacterium smegmatis ATCC 700084. To determine antimycobacterial synergistic effect of pure compounds and their selectivity index towards Vero cells. MATERIALS AND METHODS A total of six flavonoids were purified by silica gel column chromatography. Structural elucidation of the isolated compounds was achieved by using 1D and 2D NMR spectroscopy techniques. The configuration at the C-3 chiral center was established by quantum mechanical calculation of the electronic circular dichroism (ECD) spectrum. In vitro inhibitory and bactericidal activity against M. tuberculosis and M. smegmatis were determined with the redox indicator Alamar Blue (resazurin). Synergy was determined by X/Y quotient. Cytotoxicity was measured by MTT assay. RESULTS The isolated compounds were identified as precatorin A (1), precatorin B (2), precatorin C (3), lupinifolin (4), cajanone (5) and lupinifolinol (6). Compounds 1-3 are new. Compounds 1 to 5 inhibited the growth of M. tuberculosis (MIC ≥31.25µg/mL); compounds 1, 2, 4 and 5 killed the bacteria (MBC ≥31.25µg/mL) and also inhibited M. smegmatis (MIC ≥125µg/mL), while 1 and 4 also resulted bactericidal (MBC ≥125µg/mL). Compounds 4 and 5 presented synergistic effect (X/Y quotient value <0.5) at a concentration of 1/2 MIC of each compound in the combination. Cytotoxicity in murine macrophages (RAW 264.7 cells) gave IC50 values of 13.3-46.98µM, for compounds 1-5. CONCLUSIONS In this work we isolated two new isoflavanones (1 and 2), and one new isoflavone (3) with a weak antimycobacterial activity. The (3R) absolute configuration was assigned to 1 by computational analysis of its ECD spectrum and to 2 and 5 by similarity of their ECD spectra with that of 1. We are also reporting by first time, activity against virulent strain of M. tuberculosis for compounds 4 and 5 and their antimycobacterial synergistic effect.
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Affiliation(s)
- Enrique Wenceslao Coronado-Aceves
- Department of Chemistry-Biology, University of Sonora, Blvd. Luis Encinas y Rosales s/n, Hermosillo, Sonora 83000, Mexico; Department of Biotechnology and Alimentary Sciences, Technological Institute of Sonora, 5 de Febrero 818 Sur, 85000 Ciudad Obregon, Sonora, Mexico
| | - Giulia Gigliarelli
- Department of Pharmaceutical Sciences, University of Perugia, via del Liceo, 1-06123 Perugia, Italy
| | - Adriana Garibay-Escobar
- Department of Chemistry-Biology, University of Sonora, Blvd. Luis Encinas y Rosales s/n, Hermosillo, Sonora 83000, Mexico
| | - Ramón Enrique Robles Zepeda
- Department of Chemistry-Biology, University of Sonora, Blvd. Luis Encinas y Rosales s/n, Hermosillo, Sonora 83000, Mexico
| | - Massimo Curini
- Department of Pharmaceutical Sciences, University of Perugia, via del Liceo, 1-06123 Perugia, Italy
| | - Jaime López Cervantes
- Department of Biotechnology and Alimentary Sciences, Technological Institute of Sonora, 5 de Febrero 818 Sur, 85000 Ciudad Obregon, Sonora, Mexico
| | - Clara Inés Inés Espitia-Pinzón
- Immunology Department, Biomedical Research Institute, National Autonomous University of Mexico, 04510 DF, Mexico, Mexico
| | - Stefano Superchi
- Department of Sciences, University of Basilicata, Via dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - Stefania Vergura
- Department of Sciences, University of Basilicata, Via dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - Maria Carla Marcotullio
- Department of Pharmaceutical Sciences, University of Perugia, via del Liceo, 1-06123 Perugia, Italy.
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Yang Y, Thomas J, Li Y, Vilchèze C, Derbyshire KM, Jacobs WR, Ojha AK. Defining a temporal order of genetic requirements for development of mycobacterial biofilms. Mol Microbiol 2017. [PMID: 28628249 DOI: 10.1111/mmi.13734] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Most mycobacterial species spontaneously form biofilms, inducing unique growth physiologies and reducing drug sensitivity. Biofilm growth progresses through three genetically programmed stages: substratum attachment, intercellular aggregation and architecture maturation. Growth of Mycobacterium smegmatis biofilms requires multiple factors including a chaperonin (GroEL1) and a nucleoid-associated protein (Lsr2), although how their activities are linked remains unclear. Here it is shown that Lsr2 participates in intercellular aggregation, but substratum attachment of Lsr2 mutants is unaffected, thereby genetically distinguishing these developmental stages. Further, a suppressor mutation in a glycopeptidolipid synthesis gene (mps) that results in hyperaggregation of cells and fully restores the form and functions of Δlsr2 mutant biofilms was identified. Suppression by the mps mutation is specific to Δlsr2; it does not rescue the maturation-deficient biofilms of a ΔgroEL1 mutant, thereby differentiating the process of aggregation from maturation. Gene expression analysis supports a stepwise process of maturation, highlighted by temporally separated, transient inductions of iron and nitrogen import genes. Furthermore, GroEL1 activity is required for induction of nitrogen, but not iron, import genes. Together, the findings begin to define molecular checkpoints during development of mycobacterial biofilms.
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Affiliation(s)
- Yong Yang
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Joseph Thomas
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Yunlong Li
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Catherine Vilchèze
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Keith M Derbyshire
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - William R Jacobs
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA.,Howard Hughes Medical Institute, Bronx, NY, USA
| | - Anil K Ojha
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, USA.,Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA, USA
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