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Zamakhaev M, Bespyatykh J, Goncharenko A, Shumkov M. The Benefits of Toxicity: M. smegmatis VapBC TA Module Is Induced by Tetracycline Exposure and Promotes Survival. Microorganisms 2023; 11:2863. [PMID: 38138007 PMCID: PMC10745673 DOI: 10.3390/microorganisms11122863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/15/2023] [Accepted: 11/22/2023] [Indexed: 12/24/2023] Open
Abstract
Toxin-antitoxin (TA) systems are widely present in bacterial genomes. Mycolicibacterium smegmatis, a common model organism for studying Mycobacterium tuberculosis physiology, has eight TA loci, including mazEF and vapBC. This study aims to investigate the physiological significance of these TA systems. Proteomic profiling was conducted on a culture overexpressing the VapC toxin, and the involvement of VapC in M. smegmatis stress responses to heat shock and antibiotic treatment was examined. While deciphering the underlying mechanisms of the altered stress resistance, we assessed the antibiotic susceptibility of vapBC, mazEF, and double vapBC-mazEF deletion mutants. Additionally, the mRNA levels of vapC and mazF were measured following tetracycline supplementation. The results reveal changes in the abundance of metabolic enzymes and stress response proteins associated with VapC overexpression. This activation of the general stress response leads to reduced thermosensitivity in M. smegmatis, but does not affect susceptibility to ciprofloxacin and isoniazid. Under tetracycline treatment, both vapC and mazF expression levels are increased, and the fate of the cell depends on the interaction between the corresponding TA systems.
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Affiliation(s)
- Mikhail Zamakhaev
- Federal Research Center Fundamentals of Biotechnology of the Russian Academy of Sciences, 33, bld. 2 Leninsky Ave., 119071 Moscow, Russia; (A.G.); (M.S.)
| | - Julia Bespyatykh
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1A Malaya Pirogovskaya St., 119435 Moscow, Russia;
- Expertise Department in Anti-Doping and Drug Control, Mendeleev University of Chemical Technology of Russia, 9, Miusskaya Sq., 125047 Moscow, Russia
| | - Anna Goncharenko
- Federal Research Center Fundamentals of Biotechnology of the Russian Academy of Sciences, 33, bld. 2 Leninsky Ave., 119071 Moscow, Russia; (A.G.); (M.S.)
| | - Mikhail Shumkov
- Federal Research Center Fundamentals of Biotechnology of the Russian Academy of Sciences, 33, bld. 2 Leninsky Ave., 119071 Moscow, Russia; (A.G.); (M.S.)
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2
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Pagani TD, Corrêa PR, Lima C, Gomes LHF, Schwarz MGA, Galvão TC, Degrave WM, Valadares NF, Mendonça-Lima L. Impact of Genomic Deletion RD16 on the Expression of the Mycobacterium bovis BCG Moreau VapBC47 Toxin-Antitoxin System. Curr Issues Mol Biol 2023; 45:6538-6549. [PMID: 37623231 PMCID: PMC10453824 DOI: 10.3390/cimb45080412] [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: 04/20/2023] [Revised: 05/23/2023] [Accepted: 05/27/2023] [Indexed: 08/26/2023] Open
Abstract
Mycobacterium bovis BCG is the only vaccine against tuberculosis. The variable forms of cultivation throughout the years, before seed-lots were developed, allowed in vitro evolution of the original strain, generating a family of vaccines with different phenotypic and genotypic characteristics. Molecular studies revealed regions of difference (RDs) in the genomes of the various BCG strains. This work aims to characterize the gene pair rv3407-rv3408 (vapB47-vapC47), coding for a toxin-antitoxin system of the VapBC family, and to evaluate possible transcriptional effects due to the adjacent BCG Moreau-specific genomic deletion RD16. We show that these genes are co-transcribed in BCG strains Moreau and Pasteur, and that the inactivation of an upstream transcriptional repressor (Rv3405c) due to RD16 has a polar effect, leading to increased vapBC47 expression. Furthermore, we detect VapB47 DNA binding in vitro, dependent on a 5' vapB47 sequence that contributes to a palindrome, spanning the promoter and coding region. Our data shed light on the regulation of VapBC systems and on the impact of the BCG Moreau RD16 deletion in the expression of adjacent genes, contributing to a better understanding of BCG Moreau physiology.
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Affiliation(s)
- Talita Duarte Pagani
- Laboratório de Genômica Funcional e Bioinformática, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, RJ, Brazil; (T.D.P.); (P.R.C.); (C.L.); (L.H.F.G.); (M.G.A.S.); (W.M.D.)
| | - Paloma Rezende Corrêa
- Laboratório de Genômica Funcional e Bioinformática, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, RJ, Brazil; (T.D.P.); (P.R.C.); (C.L.); (L.H.F.G.); (M.G.A.S.); (W.M.D.)
| | - Cristiane Lima
- Laboratório de Genômica Funcional e Bioinformática, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, RJ, Brazil; (T.D.P.); (P.R.C.); (C.L.); (L.H.F.G.); (M.G.A.S.); (W.M.D.)
| | - Leonardo Henrique Ferreira Gomes
- Laboratório de Genômica Funcional e Bioinformática, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, RJ, Brazil; (T.D.P.); (P.R.C.); (C.L.); (L.H.F.G.); (M.G.A.S.); (W.M.D.)
| | - Marcos Gustavo Araujo Schwarz
- Laboratório de Genômica Funcional e Bioinformática, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, RJ, Brazil; (T.D.P.); (P.R.C.); (C.L.); (L.H.F.G.); (M.G.A.S.); (W.M.D.)
| | - Teca Calcagno Galvão
- Laboratório de Bacteriologia, Centro de Referência Prof. Hélio Fraga, Escola Nacional de Saúde Pública Sergio Arouca, Fiocruz, Rio de Janeiro 21041-210, RJ, Brazil;
| | - Wim Maurits Degrave
- Laboratório de Genômica Funcional e Bioinformática, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, RJ, Brazil; (T.D.P.); (P.R.C.); (C.L.); (L.H.F.G.); (M.G.A.S.); (W.M.D.)
| | | | - Leila Mendonça-Lima
- Laboratório de Genômica Funcional e Bioinformática, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, RJ, Brazil; (T.D.P.); (P.R.C.); (C.L.); (L.H.F.G.); (M.G.A.S.); (W.M.D.)
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3
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VapC toxin switches M. smegmatis cells into dormancy through 23S rRNA cleavage. Arch Microbiol 2023; 205:28. [DOI: 10.1007/s00203-022-03363-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/18/2022] [Accepted: 12/04/2022] [Indexed: 12/23/2022]
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4
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Mishra S, Saito K. Clinically encountered growth phenotypes of tuberculosis-causing bacilli and their in vitro study: A review. Front Cell Infect Microbiol 2022; 12:1029111. [DOI: 10.3389/fcimb.2022.1029111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 10/20/2022] [Indexed: 11/11/2022] Open
Abstract
The clinical manifestations of tuberculosis (TB) vary widely in severity, site of infection, and outcomes of treatment—leading to simultaneous efforts to individualize therapy safely and to search for shorter regimens that can be successfully used across the clinical spectrum. In these endeavors, clinicians and researchers alike employ mycobacterial culture in rich media. However, even within the same patient, individual bacilli among the population can exhibit substantial variability in their culturability. Bacilli in vitro also demonstrate substantial heterogeneity in replication rate and cultivation requirements, as well as susceptibility to killing by antimicrobials. Understanding parallels in clinical, ex vivo and in vitro growth phenotype diversity may be key to identifying those phenotypes responsible for treatment failure, relapse, and the reactivation of bacilli that progresses TB infection to disease. This review briefly summarizes the current role of mycobacterial culture in the care of patients with TB and the ex vivo evidence of variability in TB culturability. We then discuss current advances in in vitro models that study heterogenous subpopulations within a genetically identical bulk culture, with an emphasis on the effect of oxidative stress on bacillary cultivation requirements. The review highlights the complexity that heterogeneity in mycobacterial growth brings to the interpretation of culture in clinical settings and research. It also underscores the intricacies present in the interplay between growth phenotypes and antimicrobial susceptibility. Better understanding of population dynamics and growth requirements over time and space promises to aid both the attempts to individualize TB treatment and to find uniformly effective therapies.
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5
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Golmoradi Zadeh R, Mirshekar M, Sadeghi Kalani B, Pourghader J, Barati M, Masjedian Jazi F. The expression of type II TA system genes following persister cell formation in Pseudomonas aeruginosa isolates in the exponential and stationary phases. Arch Microbiol 2022; 204:451. [PMID: 35781545 DOI: 10.1007/s00203-022-03038-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 05/30/2022] [Accepted: 06/01/2022] [Indexed: 11/02/2022]
Abstract
Failure of infection therapy in the presence of antibiotics has become a major problem which has been mostly attributed to the ability of bacterial persister cell formation. Bacteria use various mechanisms to form persister cells in different phases, among which is the toxin-antitoxin (TA) systems. This study aimed at investigating the expression of type II TA system genes under the stress of ciprofloxacin and colistin antibiotics in the exponential and stationary phases. To determine the effects of ciprofloxacin and colistin on persister cell formation in the exponential and stationary phases of Pseudomonas aeruginosa strains, colony counting was performed at different time intervals in the presence of fivefold MIC of ciprofloxacin and colistin. In addition, the expression of relBE, Xre-COG5654, vapBC, and Xre-GNAT genes in P. aeruginosa isolates was assessed 3.5 h after antibiotic treatment in the exponential and stationary phases using qRT-PCR. Our results indicated the presence of persister phenotype of P. aeruginosa strains in the presence of fivefold MIC of ciprofloxacin and colistin compared to the control after 3.5 h of incubation in the exponential and stationary phases. Also, the number of persister cells in the stationary phase was higher than that of the exponential phase. According to the results of qRT-PCR, ciprofloxacin and colistin may induce persister cells by increasing the expression of type II TA systems in stationary and exponential phases. Ciprofloxacin and colistin may increase the formation of persister cells by affecting the expression of type II TA systems.
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Affiliation(s)
- Rezvan Golmoradi Zadeh
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Maryam Mirshekar
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Behrooz Sadeghi Kalani
- Department of Microbiology, School of Medicine, Ilam University of Medical Science, Ilam, Iran.,Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
| | - Johar Pourghader
- Mechanical Engineering Department, Binghamton University, Binghamton, NY, 13902, USA
| | - Mahmood Barati
- Cellular and Molecular Research Center, Iran University of Medical Science, Tehran, Iran.,Department of Medical Biotechnology, Faculty of Allied Medicine, Iran University of Medical Science, Tehran, Iran
| | - Faramarz Masjedian Jazi
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
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6
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Identification of Type II Toxin-Antitoxin Loci in Levilactobacillus brevis. Interdiscip Sci 2021; 14:80-88. [PMID: 34664198 DOI: 10.1007/s12539-021-00486-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/30/2021] [Accepted: 10/05/2021] [Indexed: 10/20/2022]
Abstract
Levilactobacillus brevis are present in various environments, such as beer, fermented foods, silage, and animal host. Like other lactic acid bacteria, L. brevis might adopt the viable but nonculturable (VBNC) state under unfavorable conditions. The toxin-antitoxin (TA) system, known to regulate cell growth in response to environmental stresses, is found to control the dynamic of the VBNC state. Here, we investigate the type II TA locus prevalence and compare the TA diversity in L. brevis genomes. Using the TAfinder software, we identified a total of 273 putative type II TA loci in 110 replicons of 21 completely sequenced genomes. Genome size does not appear to correlate with the amount of putative type II TA in L. brevis. Besides, type II TA loci are distributed differently among the chromosomes and plasmids. The most prevalent toxin domain is MazF-like in the chromosomes, and RelE/RelE-like in the plasmids; while for antitoxin, Xre-like and Phd-like domains are the most common in the chromosomes and plasmids, respectively. We also observed a unique GNAT-like/ArsR-like TA pair that presents only in the L. brevis chromosome. Detection of 273 putative type II TA loci in 21 complete genomes of Levilactobacillus brevis.
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7
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Chebotar' IV, Emelyanova MA, Bocharova JA, Mayansky NA, Kopantseva EE, Mikhailovich VM. The classification of bacterial survival strategies in the presence of antimicrobials. Microb Pathog 2021; 155:104901. [PMID: 33930413 DOI: 10.1016/j.micpath.2021.104901] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 04/05/2021] [Accepted: 04/06/2021] [Indexed: 01/14/2023]
Abstract
The survival of bacteria under antibiotic therapy varies in nature and is based on the bacterial ability to employ a wide range of fundamentally different resistance mechanisms. This great diversity requires a disambiguation of the term 'resistance' and the development of a more precise classification of bacterial survival strategies during contact with antibiotics. The absence of a unified definition for the terms 'resistance', 'tolerance' and 'persistence' further aggravates the imperfections of the current classification system. This review suggests a number of original classification criteria that will take into account (1) the bacterial ability to replicate in the presence of antimicrobial agents, (2) existing evolutionary stability of a trait within a species, and (3) the presence or absence of specialized genes that determine the ability of a microorganism to decrease its own metabolism or switch it completely off. This review describes potential advantages of the suggested classification system, which include a better understanding of the relationship between bacterial survival in the presence of antibiotics and molecular mechanisms of cellular metabolism suppression, the opportunity to pinpoint targets to identify a true bacterial resistance profile. The true resistance profile in turn, could be used to develop effective diagnostic and antimicrobial therapy methods, while taking into consideration specific bacterial survival mechanisms.
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Affiliation(s)
- Igor V Chebotar'
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilova St., Moscow, 119991, Russian Federation; Pirogov Russian National Research Medical University, 1 Ostrovitianov St., Moscow, 117997, Russian Federation
| | - Marina A Emelyanova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilova St., Moscow, 119991, Russian Federation
| | - Julia A Bocharova
- Pirogov Russian National Research Medical University, 1 Ostrovitianov St., Moscow, 117997, Russian Federation
| | - Nikolay A Mayansky
- Pirogov Russian National Research Medical University, 1 Ostrovitianov St., Moscow, 117997, Russian Federation
| | - Elena E Kopantseva
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilova St., Moscow, 119991, Russian Federation
| | - Vladimir M Mikhailovich
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilova St., Moscow, 119991, Russian Federation.
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8
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Kang SM, Moon H, Han SW, Kim BW, Kim DH, Kim BM, Lee BJ. Toxin-Activating Stapled Peptides Discovered by Structural Analysis Were Identified as New Therapeutic Candidates That Trigger Antibacterial Activity against Mycobacterium tuberculosis in the Mycobacterium smegmatis Model. Microorganisms 2021; 9:microorganisms9030568. [PMID: 33801872 PMCID: PMC8000039 DOI: 10.3390/microorganisms9030568] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 11/17/2022] Open
Abstract
The structure-function relationships of toxin-antitoxin (TA) systems from Mycobacterium tuberculosis have prompted the development of novel and effective antimicrobial agents that selectively target this organism. The artificial activation of toxins by peptide inhibitors can lead to the growth arrest and eventual death of bacterial cells. Optimizing candidate peptides by hydrocarbon α-helix stapling based on structural information from the VapBC TA system and in vitro systematic validation led to V26-SP-8, a VapC26 activator of M. tuberculosis. This compound exhibited highly enhanced activity and cell permeability owing to the stabilizing helical propensity of the peptide. These characteristics will increase its efficacy against multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis. Similar approaches utilizing structural and biochemical information for new antibiotic targets opens a new era for developing TB therapies.
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Affiliation(s)
- Sung-Min Kang
- College of Pharmacy, Duksung Women’s University, Seoul 01369, Korea;
| | - Heejo Moon
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Korea; (H.M.); (B.W.K.)
| | - Sang-Woo Han
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea;
| | - Byeong Wook Kim
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Korea; (H.M.); (B.W.K.)
| | - Do-Hee Kim
- College of Pharmacy, Jeju National University, Jeju 63243, Korea;
- Interdisciplinary Graduate Program in Advanced Convergence Technology & Science, Jeju National University, Jeju 63243, Korea
| | - Byeong Moon Kim
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Korea; (H.M.); (B.W.K.)
- Correspondence: (B.M.K.); (B.-J.L.); Tel.: +82-2-880-6634 (B.M.K.); +82-2-880-7868 (B.-J.L.)
| | - Bong-Jin Lee
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea;
- Correspondence: (B.M.K.); (B.-J.L.); Tel.: +82-2-880-6634 (B.M.K.); +82-2-880-7868 (B.-J.L.)
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9
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Sizikov S, Burgsdorf I, Handley KM, Lahyani M, Haber M, Steindler L. Characterization of sponge-associated Verrucomicrobia: microcompartment-based sugar utilization and enhanced toxin-antitoxin modules as features of host-associated Opitutales. Environ Microbiol 2020; 22:4669-4688. [PMID: 32840024 DOI: 10.1111/1462-2920.15210] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 08/18/2020] [Accepted: 08/22/2020] [Indexed: 12/13/2022]
Abstract
Bacteria of the phylum Verrucomicrobia are ubiquitous in marine environments and can be found as free-living organisms or as symbionts of eukaryotic hosts. Little is known about host-associated Verrucomicrobia in the marine environment. Here we reconstructed two genomes of symbiotic Verrucomicrobia from bacterial metagenomes derived from the Atlanto-Mediterranean sponge Petrosia ficiformis and three genomes from strains that we isolated from offshore seawater of the Eastern Mediterranean Sea. Phylogenomic analysis of these five strains indicated that they are all members of Verrucomicrobia subdivision 4, order Opitutales. We compared these novel sponge-associated and seawater-isolated genomes to closely related Verrucomicrobia. Genomic analysis revealed that Planctomycetes-Verrucomicrobia microcompartment gene clusters are enriched in the genomes of symbiotic Opitutales including sponge symbionts but not in free-living ones. We hypothesize that in sponge symbionts these microcompartments are used for degradation of l-fucose and l-rhamnose, which are components of algal and bacterial cell walls and therefore may be found at high concentrations in the sponge tissue. Furthermore, we observed an enrichment of toxin-antitoxin modules in symbiotic Opitutales. We suggest that, in sponges, verrucomicrobial symbionts utilize these modules as a defence mechanism against antimicrobial activity deriving from the abundant microbial community co-inhabiting the host.
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Affiliation(s)
- Sofia Sizikov
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | - Ilia Burgsdorf
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | - Kim Marie Handley
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Matan Lahyani
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | - Markus Haber
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel.,Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, České Budějovice, Czech Republic
| | - Laura Steindler
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
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10
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iTRAQ-based proteomic analyses of the plant-pathogenic bacterium Acidovorax citrulli during entrance into and resuscitation from the viable but nonculturable state. J Proteomics 2020; 211:103547. [DOI: 10.1016/j.jprot.2019.103547] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 09/28/2019] [Accepted: 10/07/2019] [Indexed: 12/26/2022]
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11
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Dong K, Pan H, Yang D, Rao L, Zhao L, Wang Y, Liao X. Induction, detection, formation, and resuscitation of viable but non‐culturable state microorganisms. Compr Rev Food Sci Food Saf 2019; 19:149-183. [DOI: 10.1111/1541-4337.12513] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 10/21/2019] [Accepted: 11/14/2019] [Indexed: 01/05/2023]
Affiliation(s)
- Kai Dong
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Hanxu Pan
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Dong Yang
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Lei Rao
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Liang Zhao
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Yongtao Wang
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Xiaojun Liao
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
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12
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Deep A, Tiwari P, Agarwal S, Kaundal S, Kidwai S, Singh R, Thakur KG. Structural, functional and biological insights into the role of Mycobacterium tuberculosis VapBC11 toxin-antitoxin system: targeting a tRNase to tackle mycobacterial adaptation. Nucleic Acids Res 2019; 46:11639-11655. [PMID: 30329074 PMCID: PMC6265470 DOI: 10.1093/nar/gky924] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/04/2018] [Indexed: 01/10/2023] Open
Abstract
Toxin–antitoxin (TA) systems are involved in diverse physiological processes in prokaryotes, but their exact role in Mycobacterium tuberculosis (Mtb) virulence and in vivo stress adaptation has not been extensively studied. Here, we demonstrate that the VapBC11 TA module is essential for Mtb to establish infection in guinea pigs. RNA-sequencing revealed that overexpression of VapC11 toxin results in metabolic slowdown, suggesting that modulation of the growth rate is an essential strategy for in vivo survival. Interestingly, overexpression of VapC11 resulted in the upregulation of chromosomal TA genes, suggesting the existence of highly coordinated crosstalk among TA systems. In this study, we also present the crystal structure of the VapBC11 heterooctameric complex at 1.67 Å resolution. Binding kinetic studies suggest that the binding affinities of toxin–substrate and toxin–antitoxin interactions are comparable. We used a combination of structural studies, molecular docking, mutational analysis and in vitro ribonuclease assays to enhance our understanding of the mode of substrate recognition by the VapC11 toxin. Furthermore, we have also designed peptide-based inhibitors to target VapC11 ribonuclease activity. Taken together, we propose that the structure-guided design of inhibitors against in vivo essential ribonucleases might be a novel strategy to hasten clearance of intracellular Mtb.
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Affiliation(s)
- Amar Deep
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh 160036, India
| | - Prabhakar Tiwari
- Tuberculosis Research Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurgaon Expressway, Faridabad 121001, India
| | - Sakshi Agarwal
- Tuberculosis Research Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurgaon Expressway, Faridabad 121001, India
| | - Soni Kaundal
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh 160036, India
| | - Saqib Kidwai
- Tuberculosis Research Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurgaon Expressway, Faridabad 121001, India
| | - Ramandeep Singh
- Tuberculosis Research Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurgaon Expressway, Faridabad 121001, India
| | - Krishan G Thakur
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh 160036, India
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13
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Gample SP, Agrawal S, Sarkar D. Evidence of nitrite acting as a stable and robust inducer of non-cultivability in Mycobacterium tuberculosis with physiological relevance. Sci Rep 2019; 9:9261. [PMID: 31239517 PMCID: PMC6593118 DOI: 10.1038/s41598-019-45652-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 05/30/2019] [Indexed: 11/21/2022] Open
Abstract
Tuberculosis (TB) is the ninth leading cause of death worldwide, ranking above human immunodeficiency virus. Latency is the major obstacle in the eradication of this disease. How the physiology of the pathogen changes in transition to the latent stage needs to be understood. The latent bacteria extracted from animal hosts exist in a nonculturable (NC) phase, whereas bacteria extracted from most in vitro models are culture-positive. In the present study, we observed that nitrite, up to a concentration of 5 mM, shows the growth of Mycobacterium tuberculosis (MTB) in liquid media, but this effect starts reversing at higher concentrations. At a concentration of 10 mM, nitrite induces rapid nonculturability of MTB at the aerobic stage. This noncultivable dormancy was confirmed by analyzing the characteristics of NC bacteria. Further differential gene expression analyses clearly supported the formation of a dormancy phenotype. This study will be helpful for the use of this bacillus as a dormancy model in future studies on TB latency.
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Affiliation(s)
- Suwarna P Gample
- CSIR-National Chemical Laboratory, Organic Chemistry Division, Pune, 411008, Maharashtra, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sonia Agrawal
- CSIR-National Chemical Laboratory, Organic Chemistry Division, Pune, 411008, Maharashtra, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Dhiman Sarkar
- CSIR-National Chemical Laboratory, Organic Chemistry Division, Pune, 411008, Maharashtra, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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Relationship between the Viable but Nonculturable State and Antibiotic Persister Cells. J Bacteriol 2018; 200:JB.00249-18. [PMID: 30082460 DOI: 10.1128/jb.00249-18] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bacteria have evolved numerous means of survival in adverse environments with dormancy, as represented by "persistence" and the "viable but nonculturable" (VBNC) state, now recognized to be common modes for such survival. VBNC cells have been defined as cells which, induced by some stress, become nonculturable on media that would normally support their growth but which can be demonstrated by various methods to be alive and capable of returning to a metabolically active and culturable state. Persister cells have been described as a population of cells which, while not being antibiotic resistant, are antibiotic tolerant. This drug-tolerant phenotype is thought to be a result of stress-induced and stochastic physiological changes as opposed to mutational events leading to true resistance. In this review, we describe these two dormancy strategies, characterize the molecular underpinnings of each state, and highlight the similarities and differences between them. We believe these survival modes represent a continuum between actively growing and dead cells, with VBNC cells being in a deeper state of dormancy than persister cells.
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15
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Tkachenko AG. Stress Responses of Bacterial Cells as Mechanism of Development of Antibiotic Tolerance (Review). APPL BIOCHEM MICRO+ 2018. [DOI: 10.1134/s0003683818020114] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Kang SM, Kim DH, Lee KY, Park SJ, Yoon HJ, Lee SJ, Im H, Lee BJ. Functional details of the Mycobacterium tuberculosis VapBC26 toxin-antitoxin system based on a structural study: insights into unique binding and antibiotic peptides. Nucleic Acids Res 2017; 45:8564-8580. [PMID: 28575388 PMCID: PMC5737657 DOI: 10.1093/nar/gkx489] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/25/2017] [Indexed: 11/16/2022] Open
Abstract
Toxin-antitoxin (TA) systems are essential for bacterial persistence under stressful conditions. In particular, Mycobacterium tuberculosis express VapBC TA genes that encode the stable VapC toxin and the labile VapB antitoxin. Under normal conditions, these proteins interact to form a non-toxic TA complex, but the toxin is activated by release from the antitoxin in response to unfavorable conditions. Here, we present the crystal structure of the M. tuberculosis VapBC26 complex and show that the VapC26 toxin contains a pilus retraction protein (PilT) N-terminal (PIN) domain that is essential for ribonuclease activity and that, the VapB26 antitoxin folds into a ribbon-helix-helix DNA-binding motif at the N-terminus. The active site of VapC26 is sterically blocked by the flexible C-terminal region of VapB26. The C-terminal region of free VapB26 adopts an unfolded conformation but forms a helix upon binding to VapC26. The results of RNase activity assays show that Mg2+ and Mn2+ are essential for the ribonuclease activity of VapC26. As shown in the nuclear magnetic resonance spectra, several residues of VapB26 participate in the specific binding to the promoter region of the VapBC26 operon. In addition, toxin-mimicking peptides were designed that inhibit TA complex formation and thereby increase toxin activity, providing a novel approach to the development of new antibiotics.
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Affiliation(s)
- Sung-Min Kang
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Do-Hee Kim
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Ki-Young Lee
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Sung Jean Park
- College of Pharmacy, Gachon University, 534-2 Yeonsu-dong, Yeonsu-gu, Incheon 406-799, Republic of Korea
| | - Hye-Jin Yoon
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Sang Jae Lee
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Hookang Im
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Bong-Jin Lee
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul 151-742, Republic of Korea
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17
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Klimina KM, Poluektova EU, Danilenko VN. Bacterial toxin–antitoxin systems: Properties, functional significance, and possibility of use (Review). APPL BIOCHEM MICRO+ 2017. [DOI: 10.1134/s0003683817050076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Gupta A, Venkataraman B, Vasudevan M, Gopinath Bankar K. Co-expression network analysis of toxin-antitoxin loci in Mycobacterium tuberculosis reveals key modulators of cellular stress. Sci Rep 2017; 7:5868. [PMID: 28724903 PMCID: PMC5517426 DOI: 10.1038/s41598-017-06003-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 06/07/2017] [Indexed: 11/09/2022] Open
Abstract
Research on toxin-antitoxin loci (TA loci) is gaining impetus due to their ubiquitous presence in bacterial genomes and their observed roles in stress survival, persistence and drug tolerance. The present study investigates the expression profile of all the seventy-nine TA loci found in Mycobacterium tuberculosis. The bacterium was subjected to multiple stress conditions to identify key players of cellular stress response and elucidate a TA-coexpression network. This study provides direct experimental evidence for transcriptional activation of each of the seventy-nine TA loci following mycobacterial exposure to growth-limiting environments clearly establishing TA loci as stress-responsive modules in M. tuberculosis. TA locus activation was found to be stress-specific with multiple loci activated in a duration-based response to a particular stress. Conditions resulting in arrest of cellular translation led to greater up-regulation of TA genes suggesting that TA loci have a primary role in arresting translation in the cell. Our study identifed higBA2 and vapBC46 as key loci that were activated in all the conditions tested. Besides, relBE1, higBA3, vapBC35, vapBC22 and higBA1 were also upregulated in multpile stresses. Certain TA modules exhibited co-activation across multiple conditions suggestive of a common regulatory mechanism.
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Affiliation(s)
- Amita Gupta
- Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India. .,Department of Biochemistry and Centre for Innovation in Infectious Diseases Research, Education and Training (CIIDRET), University of Delhi South Campus, New Delhi, 110021, India.
| | - Balaji Venkataraman
- Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Madavan Vasudevan
- Genome Informatics Research Group, Bionivid Technology Pvt Ltd, Bengaluru, 560043, India
| | - Kiran Gopinath Bankar
- Genome Informatics Research Group, Bionivid Technology Pvt Ltd, Bengaluru, 560043, India
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19
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Abstract
Mycobacterium tuberculosis (M. tuberculosis), the causative agent of tuberculosis, uses various tactics to resist on antibiotics and evade host immunity. To control tuberculosis, antibiotics with novel mechanisms of action are urgently needed. Emerging new antibiotics and underlying novel drug targets are summarized in this paper.
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Affiliation(s)
- Nzungize Lambert
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China
| | - Abualgasim Elgaili Abdalla
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China.,b Department of Clinical Microbiology, College of Medical Laboratory Sciences, Omdurman , Islamic University , Omdurman , Sudan
| | - Xiangke Duan
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China
| | - Jianping Xie
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China
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20
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Demidenok OI, Shumkov MS, Goncharenko AV. VapC toxin inhibition as a method for prevention of the formation of resting forms of mycobacteria. APPL BIOCHEM MICRO+ 2016. [DOI: 10.1134/s0003683816060041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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Lobato-Márquez D, Díaz-Orejas R, García-Del Portillo F. Toxin-antitoxins and bacterial virulence. FEMS Microbiol Rev 2016; 40:592-609. [PMID: 27476076 DOI: 10.1093/femsre/fuw022] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2016] [Indexed: 12/25/2022] Open
Abstract
Bacterial virulence relies on a delicate balance of signals interchanged between the invading microbe and the host. This communication has been extensively perceived as a battle involving harmful molecules produced by the pathogen and host defenses. In this review, we focus on a largely unexplored element of this dialogue, as are toxin-antitoxin (TA) systems of the pathogen. TA systems are reported to respond to stresses that are also found in the host and, as a consequence, could modulate the physiology of the intruder microbe. This view is consistent with recent studies that demonstrate a contribution of distinct TA systems to virulence since their absence alters the course of the infection. TA loci are stress response modules that, therefore, could readjust pathogen metabolism to favor the generation of slow-growing or quiescent cells 'before' host defenses irreversibly block essential pathogen activities. Some toxins of these TA modules have been proposed as potential weapons used by the pathogen to act on host targets. We discuss all these aspects based on studies that support some TA modules as important regulators in the pathogen-host interface.
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Affiliation(s)
- Damián Lobato-Márquez
- Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), Darwin 3, 28049 Madrid, Spain Centro de Investigaciones Biológicas-CSIC (CIB-CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Ramón Díaz-Orejas
- Centro de Investigaciones Biológicas-CSIC (CIB-CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Francisco García-Del Portillo
- Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), Darwin 3, 28049 Madrid, Spain
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22
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Characterization of the Deep-Sea Streptomyces sp. SCSIO 02999 Derived VapC/VapB Toxin-Antitoxin System in Escherichia coli. Toxins (Basel) 2016; 8:toxins8070195. [PMID: 27376329 PMCID: PMC4963828 DOI: 10.3390/toxins8070195] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 06/13/2016] [Accepted: 06/20/2016] [Indexed: 11/16/2022] Open
Abstract
Toxin-antitoxin (TA) systems are small genetic elements that are ubiquitous in prokaryotes. Most studies on TA systems have focused on commensal and pathogenic bacteria; yet very few studies have focused on TAs in marine bacteria, especially those isolated from a deep sea environment. Here, we characterized a type II VapC/VapB TA system from the deep-sea derived Streptomyces sp. SCSIO 02999. The VapC (virulence-associated protein) protein belongs to the PIN (PilT N-terminal) superfamily. Overproduction of VapC strongly inhibited cell growth and resulted in a bleb-containing morphology in E. coli. The toxicity of VapC was neutralized through direct protein-protein interaction by a small protein antitoxin VapB encoded by a neighboring gene. Antitoxin VapB alone or the VapB/VapC complex negatively regulated the vapBC promoter activity. We further revealed that three conserved Asp residues in the PIN domain were essential for the toxic effect of VapC. Additionally, the VapC/VapB TA system stabilized plasmid in E. coli. Furthermore, VapC cross-activated transcription of several TA operons via a partially Lon-dependent mechanism in E. coli, and the activated toxins accumulated more preferentially than their antitoxin partners. Collectively, we identified and characterized a new deep sea TA system in the deep sea Streptomyces sp. and demonstrated that the VapC toxin in this system can cross-activate TA operons in E. coli.
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23
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Emerging Roles of Toxin-Antitoxin Modules in Bacterial Pathogenesis. Molecules 2016; 21:molecules21060790. [PMID: 27322231 PMCID: PMC6273597 DOI: 10.3390/molecules21060790] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/06/2016] [Accepted: 06/13/2016] [Indexed: 11/17/2022] Open
Abstract
Toxin-antitoxin (TA) cassettes are encoded widely by bacteria. The modules typically comprise a protein toxin and protein or RNA antitoxin that sequesters the toxin factor. Toxin activation in response to environmental cues or other stresses promotes a dampening of metabolism, most notably protein translation, which permits survival until conditions improve. Emerging evidence also implicates TAs in bacterial pathogenicity. Bacterial persistence involves entry into a transient semi-dormant state in which cells survive unfavorable conditions including killing by antibiotics, which is a significant clinical problem. TA complexes play a fundamental role in inducing persistence by downregulating cellular metabolism. Bacterial biofilms are important in numerous chronic inflammatory and infectious diseases and cause serious therapeutic problems due to their multidrug tolerance and resistance to host immune system actions. Multiple TAs influence biofilm formation through a network of interactions with other factors that mediate biofilm production and maintenance. Moreover, in view of their emerging contributions to bacterial virulence, TAs are potential targets for novel prophylactic and therapeutic approaches that are required urgently in an era of expanding antibiotic resistance. This review summarizes the emerging evidence that implicates TAs in the virulence profiles of a diverse range of key bacterial pathogens that trigger serious human disease.
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24
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Ayrapetyan M, Oliver JD. The viable but non-culturable state and its relevance in food safety. Curr Opin Food Sci 2016. [DOI: 10.1016/j.cofs.2016.04.010] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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25
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Duan X, Li Y, Du Q, Huang Q, Guo S, Xu M, Lin Y, Liu Z, Xie J. Mycobacterium Lysine ε-aminotransferase is a novel alarmone metabolism related persister gene via dysregulating the intracellular amino acid level. Sci Rep 2016; 6:19695. [PMID: 26806099 PMCID: PMC4726150 DOI: 10.1038/srep19695] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 12/16/2015] [Indexed: 01/07/2023] Open
Abstract
Bacterial persisters, usually slow-growing, non-replicating cells highly tolerant to antibiotics, play a crucial role contributing to the recalcitrance of chronic infections and treatment failure. Understanding the molecular mechanism of persister cells formation and maintenance would obviously inspire the discovery of new antibiotics. The significant upregulation of Mycobacterium tuberculosis Rv3290c, a highly conserved mycobacterial lysine ε-aminotransferase (LAT) during hypoxia persistent model, suggested a role of LAT in persistence. To test this, a lat deleted Mycobacterium smegmatis was constructed. The expression of transcriptional regulator leucine-responsive regulatory protein (LrpA) and the amino acids abundance in M. smegmatis lat deletion mutants were lowered. Thus, the persistence capacity of the deletion mutant was impaired upon norfloxacin exposure under nutrient starvation. In summary, our study firstly reported the involvement of mycobacterium LAT in persister formation, and possibly through altering the intracellular amino acid metabolism balance.
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Affiliation(s)
- Xiangke Duan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, key laboratory of Eco-environment three gorges reservoir, Ministry of Education, School of Life Sciences, Southwest University. Chongqing 400715, China
| | - Yunsong Li
- Department of thoracic surgery, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China
| | - Qinglin Du
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, key laboratory of Eco-environment three gorges reservoir, Ministry of Education, School of Life Sciences, Southwest University. Chongqing 400715, China
| | - Qinqin Huang
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, key laboratory of Eco-environment three gorges reservoir, Ministry of Education, School of Life Sciences, Southwest University. Chongqing 400715, China
| | - Siyao Guo
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, key laboratory of Eco-environment three gorges reservoir, Ministry of Education, School of Life Sciences, Southwest University. Chongqing 400715, China.,Hanhong College, Southwest University. Chongqing 400715, China
| | - Mengmeng Xu
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, key laboratory of Eco-environment three gorges reservoir, Ministry of Education, School of Life Sciences, Southwest University. Chongqing 400715, China
| | - Yanping Lin
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, key laboratory of Eco-environment three gorges reservoir, Ministry of Education, School of Life Sciences, Southwest University. Chongqing 400715, China
| | - Zhidong Liu
- Department of thoracic surgery, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, key laboratory of Eco-environment three gorges reservoir, Ministry of Education, School of Life Sciences, Southwest University. Chongqing 400715, China
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26
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Zaychikova MV, Zakharevich NV, Sagaidak MO, Bogolubova NA, Smirnova TG, Andreevskaya SN, Larionova EE, Alekseeva MG, Chernousova LN, Danilenko VN. Mycobacterium tuberculosis Type II Toxin-Antitoxin Systems: Genetic Polymorphisms and Functional Properties and the Possibility of Their Use for Genotyping. PLoS One 2015; 10:e0143682. [PMID: 26658274 PMCID: PMC4680722 DOI: 10.1371/journal.pone.0143682] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/08/2015] [Indexed: 12/05/2022] Open
Abstract
Various genetic markers such as IS-elements, DR-elements, variable number tandem repeats (VNTR), single nucleotide polymorphisms (SNPs) in housekeeping genes and other groups of genes are being used for genotyping. We propose a different approach. We suggest the type II toxin-antitoxin (TA) systems, which play a significant role in the formation of pathogenicity, tolerance and persistence phenotypes, and thus in the survival of Mycobacterium tuberculosis in the host organism at various developmental stages (colonization, infection of macrophages, etc.), as the marker genes. Most genes of TA systems function together, forming a single network: an antitoxin from one pair may interact with toxins from other pairs and even from other families. In this work a bioinformatics analysis of genes of the type II TA systems from 173 sequenced genomes of M. tuberculosis was performed. A number of genes of type II TA systems were found to carry SNPs that correlate with specific genotypes. We propose a minimally sufficient set of genes of TA systems for separation of M. tuberculosis strains at nine basic genotype and for further division into subtypes. Using this set of genes, we genotyped a collection consisting of 62 clinical isolates of M. tuberculosis. The possibility of using our set of genes for genotyping using PCR is also demonstrated.
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Affiliation(s)
- Marina V. Zaychikova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
- Scientific Research Center for Biotechnology of Antibiotics "BIOAN", Moscow, Russia
| | | | - Maria O. Sagaidak
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
- State University, Moscow Institute of Physics and Technology, Moscow, Russia
| | | | | | | | | | - Maria G. Alekseeva
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
| | | | - Valery N. Danilenko
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
- Scientific Research Center for Biotechnology of Antibiotics "BIOAN", Moscow, Russia
- * E-mail:
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27
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The Mycobacterium tuberculosis relBE toxin:antitoxin genes are stress-responsive modules that regulate growth through translation inhibition. J Microbiol 2015; 53:783-95. [PMID: 26502963 DOI: 10.1007/s12275-015-5333-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/30/2015] [Accepted: 10/05/2015] [Indexed: 12/11/2022]
Abstract
Toxin-antitoxin (TA) genes are ubiquitous among bacteria and are associated with persistence and dormancy. Following exposure to unfavorable environmental stimuli, several species (Escherichia coli, Staphylococcus aureus, Myxococcus xanthus) employ toxin proteins such as RelE and MazF to downregulate growth or initiate cell death. Mycobacterium tuberculosis possesses three Rel TA modules (Rel Mtb ): RelBE Mtb , RelFG Mtb and RelJK Mtb (Rv1246c-Rv1247c, Rv2865-Rv2866, and Rv3357-Rv3358, respectively), which inhibit mycobacterial growth when the toxin gene (relE, relG, relK) is expressed independently of the antitoxin gene (relB, relF, relJ). In the present study, we examined the in vivo mechanism of the RelE Mtb toxin protein, the impact of RelE Mtb on M. tuberculosis physiology and the environmental conditions that regulate all three rel Mtb modules. RelE Mtb negatively impacts growth and the structural integrity of the mycobacterial envelope, generating cells with aberrant forms that are prone to extensive aggregation. At a time coincident with growth defects, RelE Mtb mediates mRNA degradation in vivo resulting in significant changes to the proteome. We establish that rel Mtb modules are stress responsive, as all three operons are transcriptionally activated following mycobacterial exposure to oxidative stress or nitrogen-limiting growth environments. Here we present evidence that the rel Mtb toxin:antitoxin family is stress-responsive and, through the degradation of mRNA, the RelE Mtb toxin influences the growth, proteome and morphology of mycobacterial cells.
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Viable but Nonculturable and Persister Cells Coexist Stochastically and Are Induced by Human Serum. Infect Immun 2015; 83:4194-203. [PMID: 26283335 DOI: 10.1128/iai.00404-15] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 08/05/2015] [Indexed: 01/09/2023] Open
Abstract
Dormancy holds a vital role in the ecological dynamics of microorganisms. Specifically, entry into dormancy allows cells to withstand times of stress while maintaining the potential for reentry into an active existence. The viable but nonculturable (VBNC) state and antibiotic persistence are two well-recognized conditions of dormancy demonstrated to contribute to bacterial stress tolerance and, as a consequence, yield populations that are tolerant to high-dose antibiotics. Aside from this commonality, more evidence is being presented that indicates the relatedness of these two states. Here, we demonstrate that VBNC cells are present during persister isolation experiments, further indicating that these cells coexist and are induced by the same conditions. Interestingly, we reveal that VBNC cells can exist stochastically in unstressed growing cultures, a finding that is characteristic of persisters. Furthermore, human serum induces the formation of both VBNC cells and persisters, a finding not previously described for either dormancy state. Lastly, we describe the role of toxin-antitoxin systems (TAS) in the induction of the VBNC state and report that these TAS, which are classically implicated in persister cell formation, are also induced during incubation in human serum. This study provides evidence for the recently proposed "dormancy continuum hypothesis" and substantiates the physical and molecular relatedness of VBNC and persister cells in a standardized model organism. Notably, these results provide new evidence for the clinical significance of VBNC and persister cells.
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29
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Lee IG, Lee SJ, Chae S, Lee KY, Kim JH, Lee BJ. Structural and functional studies of the Mycobacterium tuberculosis VapBC30 toxin-antitoxin system: implications for the design of novel antimicrobial peptides. Nucleic Acids Res 2015; 43:7624-37. [PMID: 26150422 PMCID: PMC4551927 DOI: 10.1093/nar/gkv689] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 06/24/2015] [Indexed: 12/21/2022] Open
Abstract
Toxin-antitoxin (TA) systems play important roles in bacterial physiology, such as multidrug tolerance, biofilm formation, and arrest of cellular growth under stress conditions. To develop novel antimicrobial agents against tuberculosis, we focused on VapBC systems, which encompass more than half of TA systems in Mycobacterium tuberculosis. Here, we report that theMycobacterium tuberculosis VapC30 toxin regulates cellular growth through both magnesium and manganese ion-dependent ribonuclease activity and is inhibited by the cognate VapB30 antitoxin. We also determined the 2.7-Å resolution crystal structure of the M. tuberculosis VapBC30 complex, which revealed a novel process of inactivation of the VapC30 toxin via swapped blocking by the VapB30 antitoxin. Our study on M. tuberculosis VapBC30 leads us to design two kinds of VapB30 and VapC30-based novel peptides which successfully disrupt the toxin-antitoxin complex and thus activate the ribonuclease activity of the VapC30 toxin. Our discovery herein possibly paves the way to treat tuberculosis for next generation.
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Affiliation(s)
- In-Gyun Lee
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Sang Jae Lee
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Susanna Chae
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Ki-Young Lee
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Ji-Hun Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Bong-Jin Lee
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
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30
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Ayrapetyan M, Williams TC, Oliver JD. Bridging the gap between viable but non-culturable and antibiotic persistent bacteria. Trends Microbiol 2014; 23:7-13. [PMID: 25449050 DOI: 10.1016/j.tim.2014.09.004] [Citation(s) in RCA: 186] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 09/17/2014] [Accepted: 09/19/2014] [Indexed: 11/25/2022]
Abstract
Microbial dormancy is a widespread phenomenon employed by bacteria to evade environmental threats including antibiotics. This intrinsic mechanism of antibiotic tolerance has drawn special attention to the role of dormancy in human disease, particularly in regards to recurrent infections. Two dormancy states, the viable but non-culturable state and bacterial persistence, both produce antibiotic-tolerant populations capable of withstanding prolonged lethal treatment. Currently described as two distinct forms of dormancy, they are rarely discussed in the same context. We argue here that these two dormant states are closely related phenomena which are part of a shared 'dormancy continuum'. This discussion is intended to stimulate discourse about these seemingly different but very similar dormant states.
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Affiliation(s)
- Mesrop Ayrapetyan
- Department of Biological Sciences, The University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, NC 28223, USA
| | - Tiffany C Williams
- Department of Biological Sciences, The University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, NC 28223, USA
| | - James D Oliver
- Department of Biological Sciences, The University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, NC 28223, USA.
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31
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Latent tuberculosis infection: What we know about its genetic control? Tuberculosis (Edinb) 2014; 94:462-8. [DOI: 10.1016/j.tube.2014.06.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 06/10/2014] [Accepted: 06/20/2014] [Indexed: 11/23/2022]
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