1
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Huang D, Xia R, Chen C, Liao J, Chen L, Wang D, Alvarez PJJ, Yu P. Adaptive strategies and ecological roles of phages in habitats under physicochemical stress. Trends Microbiol 2024:S0966-842X(24)00042-8. [PMID: 38433027 DOI: 10.1016/j.tim.2024.02.002] [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: 12/04/2023] [Revised: 02/01/2024] [Accepted: 02/02/2024] [Indexed: 03/05/2024]
Abstract
Bacteriophages (phages) play a vital role in ecosystem functions by influencing the composition, genetic exchange, metabolism, and environmental adaptation of microbial communities. With recent advances in sequencing technologies and bioinformatics, our understanding of the ecology and evolution of phages in stressful environments has substantially expanded. Here, we review the impact of physicochemical environmental stress on the physiological state and community dynamics of phages, the adaptive strategies that phages employ to cope with environmental stress, and the ecological effects of phage-host interactions in stressful environments. Specifically, we highlight the contributions of phages to the adaptive evolution and functioning of microbiomes and suggest that phages and their hosts can maintain a mutualistic relationship in response to environmental stress. In addition, we discuss the ecological consequences caused by phages in stressful environments, encompassing biogeochemical cycling. Overall, this review advances an understanding of phage ecology in stressful environments, which could inform phage-based strategies to improve microbiome performance and ecosystem resilience and resistance in natural and engineering systems.
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Affiliation(s)
- Dan Huang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Rong Xia
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Chengyi Chen
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jingqiu Liao
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
| | - Linxing Chen
- Department of Earth and Planetary Sciences, University of California Berkeley, Berkeley, CA 94720, USA; Innovative Genomics Institute, University of California Berkeley, Berkeley, CA 94720, USA
| | - Dongsheng Wang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Pedro J J Alvarez
- Department of Civil and Environmental Engineering, Rice University, Houston, TX 77005, USA
| | - Pingfeng Yu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Innovation Center of Yangtze River Delta, Zhejiang University, Jiashan, 314100, China.
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2
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Fujiki J, Schnabl B. Phage therapy: Targeting intestinal bacterial microbiota for the treatment of liver diseases. JHEP Rep 2023; 5:100909. [PMID: 37965159 PMCID: PMC10641246 DOI: 10.1016/j.jhepr.2023.100909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/16/2023] [Accepted: 08/22/2023] [Indexed: 11/16/2023] Open
Abstract
Phage therapy has been overshadowed by antibiotics for decades. However, it is being revisited as a powerful approach against antimicrobial-resistant bacteria. As bacterial microbiota have been mechanistically linked to gastrointestinal and liver diseases, precise editing of the gut microbiota via the selective bactericidal action of phages has prompted renewed interest in phage therapy. In this review, we summarise the basic virological properties of phages and the latest findings on the composition of the intestinal phageome and the changes associated with liver diseases. We also review preclinical and clinical studies assessing phage therapy for the treatment of gastrointestinal and liver diseases, as well as future prospects and challenges.
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Affiliation(s)
- Jumpei Fujiki
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
- Department of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan
| | - Bernd Schnabl
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
- Department of Medicine, VA San Diego Healthcare System, San Diego, CA, USA
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3
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Bleriot I, Blasco L, Pacios O, Fernández-García L, López M, Ortiz-Cartagena C, Barrio-Pujante A, Fernández-Cuenca F, Pascual Á, Martínez-Martínez L, Oteo-Iglesias J, Tomás M. Proteomic Study of the Interactions between Phages and the Bacterial Host Klebsiella pneumoniae. Microbiol Spectr 2023; 11:e0397422. [PMID: 36877024 PMCID: PMC10100988 DOI: 10.1128/spectrum.03974-22] [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: 10/03/2022] [Accepted: 02/08/2023] [Indexed: 03/07/2023] Open
Abstract
Phages and bacteria have acquired resistance mechanisms for protection. In this context, the aims of the present study were to analyze the proteins isolated from 21 novel lytic phages of Klebsiella pneumoniae in search of defense mechanisms against bacteria and also to determine the infective capacity of the phages. A proteomic study was also conducted to investigate the defense mechanisms of two clinical isolates of K. pneumoniae infected by phages. For this purpose, the 21 lytic phages were sequenced and de novo assembled. The host range was determined in a collection of 47 clinical isolates of K. pneumoniae, revealing the variable infective capacity of the phages. Genome sequencing showed that all of the phages were lytic phages belonging to the order Caudovirales. Phage sequence analysis revealed that the proteins were organized in functional modules within the genome. Although most of the proteins have unknown functions, multiple proteins were associated with defense mechanisms against bacteria, including the restriction-modification system, the toxin-antitoxin system, evasion of DNA degradation, blocking of host restriction and modification, the orphan CRISPR-Cas system, and the anti-CRISPR system. Proteomic study of the phage-host interactions (i.e., between isolates K3574 and K3320, which have intact CRISPR-Cas systems, and phages vB_KpnS-VAC35 and vB_KpnM-VAC36, respectively) revealed the presence of several defense mechanisms against phage infection (prophage, defense/virulence/resistance, oxidative stress and plasmid proteins) in the bacteria, and of the Acr candidate (anti-CRISPR protein) in the phages. IMPORTANCE Researchers, including microbiologists and infectious disease specialists, require more knowledge about the interactions between phages and their bacterial hosts and about their defense mechanisms. In this study, we analyzed the molecular mechanisms of viral and bacterial defense in phages infecting clinical isolates of K. pneumoniae. Viral defense mechanisms included restriction-modification system evasion, the toxin-antitoxin (TA) system, DNA degradation evasion, blocking of host restriction and modification, and resistance to the abortive infection system, anti-CRISPR and CRISPR-Cas systems. Regarding bacterial defense mechanisms, proteomic analysis revealed expression of proteins involved in the prophage (FtsH protease modulator), plasmid (cupin phosphomannose isomerase protein), defense/virulence/resistance (porins, efflux pumps, lipopolysaccharide, pilus elements, quorum network proteins, TA systems, and methyltransferases), oxidative stress mechanisms, and Acr candidates (anti-CRISPR protein). The findings reveal some important molecular mechanisms involved in the phage-host bacterial interactions; however, further study in this field is required to improve the efficacy of phage therapy.
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Affiliation(s)
- Inés Bleriot
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Lucia Blasco
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Olga Pacios
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Laura Fernández-García
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - María López
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Concha Ortiz-Cartagena
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Antonio Barrio-Pujante
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Felipe Fernández-Cuenca
- Clinical Unit of Infectious Diseases and Microbiology, Hospital Universitario Virgen Macarena, Institute of Biomedicine of Seville (University Hospital Virgen Macarena/CSIC/University of Seville), Seville, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Álvaro Pascual
- Clinical Unit of Infectious Diseases and Microbiology, Hospital Universitario Virgen Macarena, Institute of Biomedicine of Seville (University Hospital Virgen Macarena/CSIC/University of Seville), Seville, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Luis Martínez-Martínez
- Clinical Unit of Microbiology, Reina Sofía University Hospital, Department of Agricultural Chemistry, Edaphology and Microbiology, University of Cordoba, Maimonides Biomedical Research Institute (IMIBIC), Cordoba, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Jesús Oteo-Iglesias
- Reference and Research Laboratory for Antibiotic Resistance and Health Care Infections, National Centre for Microbiology, Institute of Health Carlos III, Majadahonda, Madrid, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - María Tomás
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
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4
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Rimon A, Gelman D, Yerushalmy O, Coppenhagen-Glazer S, Katvan E, Nir-Paz R, Hazan R. Phage Therapy in Israel, Past, Present, and Future. PHAGE (NEW ROCHELLE, N.Y.) 2022; 3:85-94. [PMID: 36157284 PMCID: PMC9436258 DOI: 10.1089/phage.2022.0010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The fascinating scientific history of phage therapy has been documented in numerous publications. In this study, however, we focus on an angle of the story that hitherto has remained relatively neglected, namely, phage therapy treatments, and the protagonists that conducted these in Mandatory-Palestine and subsequently the state of Israel, as part of a global trend. We complete the story by describing efforts in the new era of phage therapy in present-day Israel.
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Affiliation(s)
- Amit Rimon
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Military Medicine, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Daniel Gelman
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Military Medicine, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ortal Yerushalmy
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shunit Coppenhagen-Glazer
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eyal Katvan
- Bar Ilan University, Ramat Gan, Israel
- Peres Academic Center, Rehovot, Israel
| | - Ran Nir-Paz
- Department of Clinical Microbiology and Infectious Diseases, Jerusalem, and the Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ronen Hazan
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
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5
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Landa KJ, Mossman LM, Whitaker RJ, Rapti Z, Clifton SM. Phage-Antibiotic Synergy Inhibited by Temperate and Chronic Virus Competition. Bull Math Biol 2022; 84:54. [PMID: 35316421 DOI: 10.1007/s11538-022-01006-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 02/10/2022] [Indexed: 12/12/2022]
Abstract
As antibiotic resistance grows more frequent for common bacterial infections, alternative treatment strategies such as phage therapy have become more widely studied in the medical field. While many studies have explored the efficacy of antibiotics, phage therapy, or synergistic combinations of phages and antibiotics, the impact of virus competition on the efficacy of antibiotic treatment has not yet been considered. Here, we model the synergy between antibiotics and two viral types, temperate and chronic, in controlling bacterial infections. We demonstrate that while combinations of antibiotic and temperate viruses exhibit synergy, competition between temperate and chronic viruses inhibits bacterial control with antibiotics. In fact, our model reveals that antibiotic treatment may counterintuitively increase the bacterial load when a large fraction of the bacteria are antibiotic resistant, and both chronic and temperate phages are present.
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Affiliation(s)
- Kylie J Landa
- Department of Mathematics, Statistics, and Computer Science, St. Olaf College, Northfield, MN, 55057, USA
| | - Lauren M Mossman
- Department of Mathematics, Statistics, and Computer Science, St. Olaf College, Northfield, MN, 55057, USA
| | - Rachel J Whitaker
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Zoi Rapti
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Mathematics, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Sara M Clifton
- Department of Mathematics, Statistics, and Computer Science, St. Olaf College, Northfield, MN, 55057, USA.
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6
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Li HM, Ghildyal R, Hu M, Tran KC, Starrs LM, Mills J, Teng MN, Jans DA. Respiratory Syncytial Virus Matrix Protein-Chromatin Association Is Key to Transcriptional Inhibition in Infected Cells. Cells 2021; 10:2786. [PMID: 34685766 PMCID: PMC8534903 DOI: 10.3390/cells10102786] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/23/2021] [Accepted: 10/06/2021] [Indexed: 01/07/2023] Open
Abstract
The morbidity and mortality caused by the globally prevalent human respiratory pathogen respiratory syncytial virus (RSV) approaches that world-wide of influenza. We previously demonstrated that the RSV matrix (M) protein shuttles, in signal-dependent fashion, between host cell nucleus and cytoplasm, and that this trafficking is central to RSV replication and assembly. Here we analyze in detail the nuclear role of M for the first time using a range of novel approaches, including quantitative analysis of de novo cell transcription in situ in the presence or absence of RSV infection or M ectopic expression, as well as in situ DNA binding. We show that M, dependent on amino acids 110-183, inhibits host cell transcription in RSV-infected cells as well as cells transfected to express M, with a clear correlation between nuclear levels of M and the degree of transcriptional inhibition. Analysis of bacterially expressed M protein and derivatives thereof mutated in key residues within M's RNA binding domain indicates that M can bind to DNA as well as RNA in a cell-free system. Parallel results for point-mutated M derivatives implicate arginine 170 and lysine 172, in contrast to other basic residues such as lysine 121 and 130, as critically important residues for inhibition of transcription and DNA binding both in situ and in vitro. Importantly, recombinant RSV carrying arginine 170/lysine 172 mutations shows attenuated infectivity in cultured cells and in an animal model, concomitant with altered inflammatory responses. These findings define an RSV M-chromatin interface critical for host transcriptional inhibition in infection, with important implications for anti-RSV therapeutic development.
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Affiliation(s)
- Hong-Mei Li
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, VIC 3800, Australia; (H.-M.L.); (R.G.); (M.H.)
| | - Reena Ghildyal
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, VIC 3800, Australia; (H.-M.L.); (R.G.); (M.H.)
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, ACT 2617, Australia;
| | - Mengjie Hu
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, VIC 3800, Australia; (H.-M.L.); (R.G.); (M.H.)
| | - Kim C. Tran
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (K.C.T.); (M.N.T.)
| | - Lora M. Starrs
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, ACT 2617, Australia;
| | - John Mills
- Department of Infectious Diseases, School of Biomedical Sciences, Monash University and the Burnet Institute, Melbourne, VIC 3004, Australia;
| | - Michael N. Teng
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (K.C.T.); (M.N.T.)
| | - David A. Jans
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, VIC 3800, Australia; (H.-M.L.); (R.G.); (M.H.)
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7
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Knezevic P, Petrovic Fabijan A, Gavric D, Pejic J, Doffkay Z, Rakhely G. Phages from Genus Bruynoghevirus and Phage Therapy: Pseudomonas Phage Delta Case. Viruses 2021; 13:1965. [PMID: 34696396 PMCID: PMC8540360 DOI: 10.3390/v13101965] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 09/23/2021] [Indexed: 11/17/2022] Open
Abstract
The applicability and safety of bacteriophage Delta as a potential anti-Pseudomonas aeruginosa agent belonging to genus Bruynoghevirus (family Podoviridae) was characterised. Phage Delta belongs to the species Pseudomonas virus PaP3, which has been described as a temperate, with cos sites at the end of the genome. The phage Delta possesses a genome of 45,970 bp that encodes tRNA for proline (Pro), aspartic acid (Asp) and asparagine (Asn) and does not encode any known protein involved in lysogeny formation or persistence. Analysis showed that phage Delta has 182 bp direct terminal repeats at the end of genome and lysogeny was confirmed, neither upon infection at low nor at high multiplicity of infection (MOI). The turbid plaques that appear on certain host lawns can result from bacteriophage insensitive mutants that occur with higher frequency (10-4). In silico analysis showed that the genome of Delta phage does not encode any known bacterial toxin or virulence factor, determinants of antibiotic resistance and known human allergens. Based on the broad host range and high lytic activity against planktonic and biofilm cells, phage Delta represents a promising candidate for phage therapy.
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Affiliation(s)
- Petar Knezevic
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, 21 000 Novi Sad, Serbia; (A.P.F.); (D.G.); (J.P.)
| | - Aleksandra Petrovic Fabijan
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, 21 000 Novi Sad, Serbia; (A.P.F.); (D.G.); (J.P.)
| | - Damir Gavric
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, 21 000 Novi Sad, Serbia; (A.P.F.); (D.G.); (J.P.)
| | - Jovana Pejic
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, 21 000 Novi Sad, Serbia; (A.P.F.); (D.G.); (J.P.)
| | - Zsolt Doffkay
- Department of Biotechnology, University of Szeged, Temesvari krt. 62, H-6726 Szeged, Hungary; (Z.D.); (G.R.)
| | - Gábor Rakhely
- Department of Biotechnology, University of Szeged, Temesvari krt. 62, H-6726 Szeged, Hungary; (Z.D.); (G.R.)
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8
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Temperate and chronic virus competition leads to low lysogen frequency. J Theor Biol 2021; 523:110710. [PMID: 33839160 DOI: 10.1016/j.jtbi.2021.110710] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 04/04/2021] [Accepted: 04/05/2021] [Indexed: 11/23/2022]
Abstract
The canonical bacteriophage is obligately lytic: the virus infects a bacterium and hijacks cell functions to produce large numbers of new viruses which burst from the cell. These viruses are well-studied, but there exist a wide range of coexisting virus lifestyles that are less understood. Temperate viruses exhibit both a lytic cycle and a latent (lysogenic) cycle, in which viral genomes are integrated into the bacterial host. Meanwhile, chronic (persistent) viruses use cell functions to produce more viruses without killing the cell; chronic viruses may also exhibit a latent stage in addition to the productive stage. Here, we study the ecology of these competing viral strategies. We demonstrate the conditions under which each strategy is dominant, which aids in control of human bacterial infections using viruses. We find that low lysogen frequencies provide competitive advantages for both virus types; however, chronic viruses maximize steady state density by eliminating lysogeny entirely, while temperate viruses exhibit a non-zero 'sweet spot' lysogen frequency. Viral steady state density maximization leads to coexistence of temperate and chronic viruses, explaining the presence of multiple viral strategies in natural environments.
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9
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Murchland IM, Ahlgren-Berg A, Pietsch JMJ, Isabel A, Dodd IB, Shearwin KE. Instability of CII is needed for efficient switching between lytic and lysogenic development in bacteriophage 186. Nucleic Acids Res 2020; 48:12030-12041. [PMID: 33211866 PMCID: PMC7708051 DOI: 10.1093/nar/gkaa1065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/18/2020] [Accepted: 10/22/2020] [Indexed: 11/13/2022] Open
Abstract
The CII protein of temperate coliphage 186, like the unrelated CII protein of phage λ, is a transcriptional activator that primes expression of the CI immunity repressor and is critical for efficient establishment of lysogeny. 186-CII is also highly unstable, and we show that in vivo degradation is mediated by both FtsH and RseP. We investigated the role of CII instability by constructing a 186 phage encoding a protease resistant CII. The stabilised-CII phage was defective in the lysis-lysogeny decision: choosing lysogeny with close to 100% frequency after infection, and forming prophages that were defective in entering lytic development after UV treatment. While lysogenic CI concentration was unaffected by CII stabilisation, lysogenic transcription and CI expression was elevated after UV. A stochastic model of the 186 network after infection indicated that an unstable CII allowed a rapid increase in CI expression without a large overshoot of the lysogenic level, suggesting that instability enables a decisive commitment to lysogeny with a rapid attainment of sensitivity to prophage induction.
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Affiliation(s)
- Iain M Murchland
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
| | - Alexandra Ahlgren-Berg
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
| | - Julian M J Pietsch
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
| | - Alejandra Isabel
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
| | - Ian B Dodd
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
| | - Keith E Shearwin
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
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10
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Bujak K, Decewicz P, Kaminski J, Radlinska M. Identification, Characterization, and Genomic Analysis of Novel Serratia Temperate Phages from a Gold Mine. Int J Mol Sci 2020; 21:ijms21186709. [PMID: 32933193 PMCID: PMC7556043 DOI: 10.3390/ijms21186709] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/04/2020] [Accepted: 09/10/2020] [Indexed: 12/14/2022] Open
Abstract
Bacteria of the genus Serratia inhabit a variety of ecological niches like water, soil, and the bodies of animals, and have a wide range of lifestyles. Currently, the complete genome sequences of 25 Serratia phages are available in the NCBI database. All of them were isolated from nutrient-rich environments like sewage, with the use of clinical Serratia strains as hosts. In this study, we identified a novel Serratia myovirus named vB_SspM_BZS1. Both the phage and its host Serratia sp. OS31 were isolated from the same oligotrophic environment, namely, an abandoned gold mine (Zloty Stok, Poland). The BZS1 phage was thoroughly characterized here in terms of its genomics, morphology, and infection kinetics. We also demonstrated that Serratia sp. OS31 was lysogenized by mitomycin-inducible siphovirus vB_SspS_OS31. Comparative analyses revealed that vB_SspM_BZS1 and vB_SspS_OS31 were remote from the known Serratia phages. Moreover, vB_SspM_BZS1 was only distantly related to other viruses. However, we discovered similar prophage sequences in genomes of various bacteria here. Additionally, a protein-based similarity network showed a high diversity of Serratia phages in general, as they were scattered across nineteen different clusters. In summary, this work broadened our knowledge on the diverse relationships of Serratia phages.
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11
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Cryan JF, O'Riordan KJ, Cowan CSM, Sandhu KV, Bastiaanssen TFS, Boehme M, Codagnone MG, Cussotto S, Fulling C, Golubeva AV, Guzzetta KE, Jaggar M, Long-Smith CM, Lyte JM, Martin JA, Molinero-Perez A, Moloney G, Morelli E, Morillas E, O'Connor R, Cruz-Pereira JS, Peterson VL, Rea K, Ritz NL, Sherwin E, Spichak S, Teichman EM, van de Wouw M, Ventura-Silva AP, Wallace-Fitzsimons SE, Hyland N, Clarke G, Dinan TG. The Microbiota-Gut-Brain Axis. Physiol Rev 2019; 99:1877-2013. [DOI: 10.1152/physrev.00018.2018] [Citation(s) in RCA: 1243] [Impact Index Per Article: 248.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The importance of the gut-brain axis in maintaining homeostasis has long been appreciated. However, the past 15 yr have seen the emergence of the microbiota (the trillions of microorganisms within and on our bodies) as one of the key regulators of gut-brain function and has led to the appreciation of the importance of a distinct microbiota-gut-brain axis. This axis is gaining ever more traction in fields investigating the biological and physiological basis of psychiatric, neurodevelopmental, age-related, and neurodegenerative disorders. The microbiota and the brain communicate with each other via various routes including the immune system, tryptophan metabolism, the vagus nerve and the enteric nervous system, involving microbial metabolites such as short-chain fatty acids, branched chain amino acids, and peptidoglycans. Many factors can influence microbiota composition in early life, including infection, mode of birth delivery, use of antibiotic medications, the nature of nutritional provision, environmental stressors, and host genetics. At the other extreme of life, microbial diversity diminishes with aging. Stress, in particular, can significantly impact the microbiota-gut-brain axis at all stages of life. Much recent work has implicated the gut microbiota in many conditions including autism, anxiety, obesity, schizophrenia, Parkinson’s disease, and Alzheimer’s disease. Animal models have been paramount in linking the regulation of fundamental neural processes, such as neurogenesis and myelination, to microbiome activation of microglia. Moreover, translational human studies are ongoing and will greatly enhance the field. Future studies will focus on understanding the mechanisms underlying the microbiota-gut-brain axis and attempt to elucidate microbial-based intervention and therapeutic strategies for neuropsychiatric disorders.
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Affiliation(s)
- John F. Cryan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Kenneth J. O'Riordan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Caitlin S. M. Cowan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Kiran V. Sandhu
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Thomaz F. S. Bastiaanssen
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Marcus Boehme
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Martin G. Codagnone
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Sofia Cussotto
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Christine Fulling
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Anna V. Golubeva
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Katherine E. Guzzetta
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Minal Jaggar
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Caitriona M. Long-Smith
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Joshua M. Lyte
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Jason A. Martin
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Alicia Molinero-Perez
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Gerard Moloney
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Emanuela Morelli
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Enrique Morillas
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Rory O'Connor
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Joana S. Cruz-Pereira
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Veronica L. Peterson
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Kieran Rea
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Nathaniel L. Ritz
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Eoin Sherwin
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Simon Spichak
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Emily M. Teichman
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Marcel van de Wouw
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Ana Paula Ventura-Silva
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Shauna E. Wallace-Fitzsimons
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Niall Hyland
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Gerard Clarke
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Timothy G. Dinan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
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12
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Abstract
Antibiotic resistance is a growing concern for management of common bacterial infections. Here, we show that antibiotics can be effective at subinhibitory levels when bacteria carry latent phage. Our findings suggest that specific treatment strategies based on the identification of latent viruses in individual bacterial strains may be an effective personalized medicine approach to antibiotic stewardship. Most bacteria and archaea are infected by latent viruses that change their physiology and responses to environmental stress. We use a population model of the bacterium-phage relationship to examine the role that latent phage play in the bacterial population over time in response to antibiotic treatment. We demonstrate that the stress induced by antibiotic administration, even if bacteria are resistant to killing by antibiotics, is sufficient to control the infection under certain conditions. This work expands the breadth of understanding of phage-antibiotic synergy to include both temperate and chronic viruses persisting in their latent form in bacterial populations. IMPORTANCE Antibiotic resistance is a growing concern for management of common bacterial infections. Here, we show that antibiotics can be effective at subinhibitory levels when bacteria carry latent phage. Our findings suggest that specific treatment strategies based on the identification of latent viruses in individual bacterial strains may be an effective personalized medicine approach to antibiotic stewardship.
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13
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Fortier LC. Bacteriophages Contribute to Shaping Clostridioides (Clostridium) difficile Species. Front Microbiol 2018; 9:2033. [PMID: 30233520 PMCID: PMC6127314 DOI: 10.3389/fmicb.2018.02033] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 08/13/2018] [Indexed: 12/13/2022] Open
Abstract
Bacteriophages (phages) are bacterial viruses that parasitize bacteria. They are highly prevalent in nature, with an estimated 1031 viral particles in the whole biosphere, and they outnumber bacteria by at least 10-fold. Hence, phages represent important drivers of bacterial evolution, although our knowledge of the role played by phages in the mammalian gut is still embryonic. Several pathogens owe their virulence to the integrated phages (prophages) they harbor, which encode diverse virulence factors such as toxins. Clostridioides (Clostridium) difficile is an important opportunistic pathogen and several phages infecting this species have been described over the last decade. However, their exact contribution to the biology and virulence of this pathogen remains elusive. Current data have shown that C. difficile phages can alter virulence-associated phenotypes, in particular toxin production, by interfering with bacterial regulatory circuits through crosstalk with phage proteins for example. One phage has also been found to encode a complete binary toxin locus. Multiple regulatory genes have also been identified in phage genomes, suggesting that their impact on the host can be complex and often subtle. In this minireview, the current state of knowledge, major findings, and pending questions regarding C. difficile phages will be presented. In addition, with the apparent role played by phages in the success of fecal microbiota transplantation and the perspective of phage therapy for treatment of recurrent C. difficile infection, it has become even more crucial to understand what C. difficile phages do in the gut, how they impact their host, and how they influence the epidemiology and evolution of this clinically important pathogen.
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Affiliation(s)
- Louis-Charles Fortier
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
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14
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Nabergoj D, Kuzmić N, Drakslar B, Podgornik A. Effect of dilution rate on productivity of continuous bacteriophage production in cellstat. Appl Microbiol Biotechnol 2018. [DOI: 10.1007/s00253-018-8893-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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15
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Williamson KE, Fuhrmann JJ, Wommack KE, Radosevich M. Viruses in Soil Ecosystems: An Unknown Quantity Within an Unexplored Territory. Annu Rev Virol 2017; 4:201-219. [PMID: 28961409 DOI: 10.1146/annurev-virology-101416-041639] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Viral abundance in soils can range from below detection limits in hot deserts to over 1 billion per gram in wetlands. Abundance appears to be strongly influenced by water availability and temperature, but a lack of informational standards creates difficulties for cross-study analysis. Soil viral diversity is severely underestimated and undersampled, although current measures of viral richness are higher for soils than for aquatic ecosystems. Both morphometric and metagenomic analyses have raised questions about the prevalence of nontailed, ssDNA viruses in soils. Soil is complex and critically important to terrestrial biodiversity and human civilization, but impacts of viral activities on soil ecosystem services are poorly understood. While information from aquatic systems and medical microbiology suggests the potential for viral influences on nutrient cycles, food web interactions, gene transfer, and other key processes in soils, very few empirical data are available. To understand the soil virome, much work remains.
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Affiliation(s)
- Kurt E Williamson
- Biology Department, College of William and Mary, Williamsburg, Virginia 23185;
| | - Jeffry J Fuhrmann
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware 19716
| | - K Eric Wommack
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware 19716.,Department Biological Sciences, University of Delaware, Newark, Delaware 19716.,College of Earth, Ocean, and Environment, University of Delaware, Newark, Delaware 19716
| | - Mark Radosevich
- Biosystems Engineering and Soil Science Department, University of Tennessee, Knoxville, Tennessee 37996
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16
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Lambda phage genetic switch as a system with critical behaviour. J Theor Biol 2017; 431:32-38. [PMID: 28754287 DOI: 10.1016/j.jtbi.2017.07.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 07/12/2017] [Accepted: 07/25/2017] [Indexed: 11/21/2022]
Abstract
Critical behaviour pervades scientific disciplines as diverse as geology, economy or sociology. The critical behaviour of cell control systems is an open issue whose role has not yet been fully explored. The control of the expression of lambda phage DNA in the host cell can be classified as a system with critical behaviour. Lambda phage is a virus that infects Escherichia coli. Its core genes maintain one of two states; lysogeny or lysis. Current knowledge of the lambda phage genetic network allows to build a computational model of transcriptional control of the genes involved in the lytic-lysogenic switch and to simulate the temporal changes of their expression. Here, we focused on the computational simulation of these gene expressions to demonstrate critical behaviour of the system.
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17
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Nwugo CC, Doud MS, Duan YP, Lin H. Proteomics analysis reveals novel host molecular mechanisms associated with thermotherapy of 'Ca. Liberibacter asiaticus'-infected citrus plants. BMC PLANT BIOLOGY 2016; 16:253. [PMID: 27842496 PMCID: PMC5109811 DOI: 10.1186/s12870-016-0942-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 11/02/2016] [Indexed: 05/22/2023]
Abstract
BACKGROUND Citrus Huanglongbing (HLB), which is linked to the bacterial pathogen 'Ca. Liberibacter asiaticus' (Las), is the most devastating disease of citrus plants, and longer-term control measures via breeding or genetic engineering have been unwieldy because all cultivated citrus species are susceptible to the disease. However, the degree of susceptibility varies among citrus species, which has prompted efforts to identify potential Las resistance/tolerance-related genes in citrus plants for application in breeding or genetic engineering programs. Plant exposure to one form of stress has been shown to serendipitously induce innate resistance to other forms of stress and a recent study showed that continuous heat treatment (40 to 42 °C) reduced Las titer and HLB-associated symptoms in citrus seedlings. The goal of the present study was to apply comparative proteomics analysis via 2-DE and mass spectrometry to elucidate the molecular processes associated with heat-induced mitigation of HLB in citrus plants. Healthy or Las-infected citrus grapefruit plants were exposed to room temperature or to continuous heat treatment of 40 °C for 6 days. RESULTS An exhaustive total protein extraction process facilitated the identification of 107 differentially-expressed proteins in response to Las and/or heat treatment, which included a strong up-regulation of chaperones including small (23.6, 18.5 and 17.9 kDa) heat shock proteins, a HSP70-like protein and a ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO)-binding 60 kDa chaperonin, particularly in response to heat treatment. Other proteins that were generally down-regulated due to Las infection but up-regulated in response to heat treatment include RuBisCO activase, chlorophyll a/b binding protein, glucosidase II beta subunit-like protein, a putative lipoxygenase protein, a ferritin-like protein, and a glutathione S-transferase. CONCLUSIONS The differentially-expressed proteins identified in this study highlights a premier characterization of the molecular mechanisms potentially involved in the reversal of Las-induced pathogenicity processes in citrus plants and are hence proposed targets for application towards the development of cisgenic Las-resistant/tolerant citrus plants.
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Affiliation(s)
- Chika C. Nwugo
- USDA, Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, 93648 CA USA
| | - Melissa S. Doud
- USDA, Agricultural Research Service, U.S. Horticultural Research Laboratory, Fort Pierce, 34945 FL USA
| | - Yong-ping Duan
- USDA, Agricultural Research Service, U.S. Horticultural Research Laboratory, Fort Pierce, 34945 FL USA
| | - Hong Lin
- USDA, Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, 93648 CA USA
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18
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Affiliation(s)
- Ido Golding
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030;
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005
- Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
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19
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Abstract
Bacteriophages (phages) are present in almost, if not all ecosystems. Some of these bacterial viruses are present as latent "prophages," either integrated within the chromosome of their host, or as episomal DNAs. Since prophages are ubiquitous throughout the bacterial world, there has been a sustained interest in trying to understand their contribution to the biology of their host. Clostridium difficile is no exception to that rule and with the recent release of hundreds of bacterial genome sequences, there has been a growing interest in trying to identify and classify these prophages. Besides their identification in bacterial genomes, there is also growing interest in determining the functionality of C. difficile prophages, i.e., their capacity to escape their host and reinfect a different strain, thereby promoting genomic evolution and horizontal transfer of genes through transduction, for example of antibiotic resistance genes. There is also some interest in using therapeutic phages to fight C. difficile infections.The objective of this chapter is to share with the broader C. difficile research community the expertise we developed in the study of C. difficile temperate phages. In this chapter, we describe a general "pipeline" comprising a series of experiments that we use in our lab to identify, induce, isolate, propagate, and characterize prophages. Our aim is to provide readers with the necessary basic tools to start studying C. difficile phages.
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Affiliation(s)
- Ognjen Sekulović
- Département de Microbiologie et d'infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3201 rue Jean Mignault, Sherbrooke, QC, Canada, J1E 4K8
| | - Louis-Charles Fortier
- Département de Microbiologie et d'infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3201 rue Jean Mignault, Sherbrooke, QC, Canada, J1E 4K8.
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20
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Bitton L, Klaiman D, Kaufmann G. Phage T4-induced DNA breaks activate a tRNA repair-defying anticodon nuclease. Mol Microbiol 2015; 97:898-910. [PMID: 26031711 DOI: 10.1111/mmi.13074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2015] [Indexed: 01/13/2023]
Abstract
The natural role of the conserved bacterial anticodon nuclease (ACNase) RloC is not known, but traits that set it apart from the homologous phage T4-excluding ACNase PrrC could provide relevant clues. PrrC is silenced by a genetically linked DNA restriction-modification (RM) protein and turned on by a phage-encoded DNA restriction inhibitor. In contrast, RloC is rarely linked to an RM protein, and its ACNase is regulated by an internal switch responsive to double-stranded DNA breaks. Moreover, PrrC nicks the tRNA substrate, whereas RloC excises the wobble nucleotide. These distinctions suggested that (i) T4 and related phage that degrade their host DNA will activate RloC and (ii) the tRNA species consequently disrupted will not be restored by phage tRNA repair enzymes that counteract PrrC. Consistent with these predictions we show that Acinetobacter baylyi RloC expressed in Escherichia coli is activated by wild-type phage T4 but not by a mutant impaired in host DNA degradation. Moreover, host and T4 tRNA species disrupted by the activated ACNase were not restored by T4's tRNA repair system. Nonetheless, T4's plating efficiency was inefficiently impaired by AbaRloC, presumably due to a decoy function of the phage encoded tRNA target, the absence of which exacerbated the restriction.
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Affiliation(s)
- Lital Bitton
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| | - Daniel Klaiman
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| | - Gabriel Kaufmann
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
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21
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Fadlallah SM, Rahal EA, Sabra A, Kissoyan KAB, Matar GM. Effect of rifampicin and gentamicin on Shiga toxin 2 expression level and the SOS response in Escherichia coli O104:H4. Foodborne Pathog Dis 2014; 12:47-55. [PMID: 25383748 DOI: 10.1089/fpd.2014.1824] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND A novel pathotype, Shiga toxin-producing Escherichia coli O104:H4, was the cause of a severe outbreak that affected European countries, mainly Germany, in 2011. The effect of different regimens of rifampicin and gentamicin were evaluated to determine possible treatment modes for the novel strain, and to evaluate the SOS response and its effect on toxin release. MATERIALS AND METHODS Pulsed-field gel electrophoresis (PFGE) was performed on the novel E. coli O104:H4 pathotype and two pre-outbreak E. coli O104:H4 CDC strains. Transcript levels of the stx2 and recA gene (SOS response inducer) were evaluated using quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) in the novel E. coli O104:H4 samples subjected to different regimens of rifampicin and gentamicin. Consequently, reverse passive latex agglutination (RPLA) was used to determine the Stx2 titers in these samples. Western blot was performed to determine the LexA levels (SOS response repressor) in E. coli O104:H4. The efficacy of treatment with antimicrobial agents was assessed in BALB/c mice. RESULTS The outbreak and pre-outbreak strains are closely related as shown by PFGE, which demonstrated slight genomic differences between the three strains. The transcription level of the stx2 gene in the new pathotype was 1.41- and 1.75-fold that of the 2009 EL-2050 and 2009 EL-2071 pre-outbreak strains, respectively. Moreover, the transcription level of the stx2 gene in the new pathotype was substantially decreased as a result of treatment with the different concentrations of the antimicrobial agents, but was enhanced when the antibiotics were administered at two subinhibitory levels. RPLA data were in accordance with the qRT-PCR results. E. coli O104:H4 exposed to gentamicin at both sub-minimum inhibitory concentration (MIC) levels led to high transcription levels of the recA gene and lack of expression of the LexA protein, implying that the SOS response was activated. Rifampicin at both sub-MIC levels resulted in low transcript levels of the recA gene, indicating that the SOS response was not induced. In vivo, the highest survival rate in BALB/c mice was observed in the group that was treated with the minimum bactericidal concentration (MBC) of gentamicin. CONCLUSION The use of antimicrobial agents in E. coli O104:H4 infection seems to be effective at the MIC and MBC levels. This provides a promising ground for treatment of E. coli O104:H4.
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Affiliation(s)
- Sukayna M Fadlallah
- Department of Experimental Pathology, Immunology, & Microbiology, Faculty of Medicine, American University of Beirut , Beirut, Lebanon
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22
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Klein G, Kobylak N, Lindner B, Stupak A, Raina S. Assembly of lipopolysaccharide in Escherichia coli requires the essential LapB heat shock protein. J Biol Chem 2014; 289:14829-53. [PMID: 24722986 DOI: 10.1074/jbc.m113.539494] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Here, we describe two new heat shock proteins involved in the assembly of LPS in Escherichia coli, LapA and LapB (lipopolysaccharide assembly protein A and B). lapB mutants were identified based on an increased envelope stress response. Envelope stress-responsive pathways control key steps in LPS biogenesis and respond to defects in the LPS assembly. Accordingly, the LPS content in ΔlapB or Δ(lapA lapB) mutants was elevated, with an enrichment of LPS derivatives with truncations in the core region, some of which were pentaacylated and exhibited carbon chain polymorphism. Further, the levels of LpxC, the enzyme that catalyzes the first committed step of lipid A synthesis, were highly elevated in the Δ(lapA lapB) mutant. Δ(lapA lapB) mutant accumulated extragenic suppressors that mapped either to lpxC, waaC, and gmhA, or to the waaQ operon (LPS biosynthesis) and lpp (Braun's lipoprotein). Increased synthesis of either FabZ (3-R-hydroxymyristoyl acyl carrier protein dehydratase), slrA (novel RpoE-regulated non-coding sRNA), lipoprotein YceK, toxin HicA, or MurA (UDP-N-acetylglucosamine 1-carboxyvinyltransferase) suppressed some of the Δ(lapA lapB) defects. LapB contains six tetratricopeptide repeats and, at the C-terminal end, a rubredoxin-like domain that was found to be essential for its activity. In pull-down experiments, LapA and LapB co-purified with LPS, Lpt proteins, FtsH (protease), DnaK, and DnaJ (chaperones). A specific interaction was also observed between WaaC and LapB. Our data suggest that LapB coordinates assembly of proteins involved in LPS synthesis at the plasma membrane and regulates turnover of LpxC, thereby ensuring balanced biosynthesis of LPS and phospholipids consistent with its essentiality.
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Affiliation(s)
- Gracjana Klein
- From the Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland and the Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, 23845 Borstel, Germany
| | - Natalia Kobylak
- From the Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland and
| | - Buko Lindner
- the Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, 23845 Borstel, Germany
| | - Anna Stupak
- From the Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland and
| | - Satish Raina
- From the Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland and the Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, 23845 Borstel, Germany
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Nassar FJ, Rahal EA, Sabra A, Matar GM. Effects of subinhibitory concentrations of antimicrobial agents on Escherichia coli O157:H7 Shiga toxin release and role of the SOS response. Foodborne Pathog Dis 2013; 10:805-12. [PMID: 23808851 DOI: 10.1089/fpd.2013.1510] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Treatment of Escherichia coli O157:H7 by certain antimicrobial agents often exacerbates the patient's condition by increasing either the release of preformed Shiga toxins (Stx) upon cell lysis or their production through the SOS response-triggered induction of Stx-producing prophages. Recommended subinhibitory concentrations (sub-MICs) of azithromycin (AZI), gentamicin (GEN), imipenem (IMI), and rifampicin (RIF) were evaluated in comparison to norfloxacin (NOR), an SOS-inducer, to assess the role of the SOS response in Stx release. Relative expression of recA (SOS-inducer), Q (late antitermination gene of Stx-producing prophage), stx1, and stx2 genes was assessed at two sub-MICs of the antimicrobials for two different strains of E. coli O157:H7 using reverse transcription-real-time polymerase chain reaction. Both strains at the two sub-MICs were also subjected to Western blotting for LexA protein expression and to reverse passive latex agglutination for Stx detection. For both strains at both sub-MICs, NOR and AZI caused SOS-induced Stx production (high recA, Q, and stx2 gene expression and high Stx2 production), so they should be avoided in E. coli O157:H7 treatment; however, sub-MICs of RIF and IMI induced Stx2 production in an SOS-independent manner except for one strain at the first twofold dilution below MIC of RIF where Stx2 production decreased. Moreover, GEN caused somewhat increased Stx2 production due to its mode of action rather than any effect on gene expression. The choice of antimicrobial therapy should rely on the antimicrobial mode of action, its concentration, and on the nature of the strain.
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Affiliation(s)
- Farah J Nassar
- Department of Experimental Pathology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
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24
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Hoffman MT, Doud MS, Williams L, Zhang MQ, Ding F, Stover E, Hall D, Zhang S, Jones L, Gooch M, Fleites L, Dixon W, Gabriel D, Duan YP. Heat treatment eliminates 'Candidatus Liberibacter asiaticus' from infected citrus trees under controlled conditions. PHYTOPATHOLOGY 2013; 103:15-22. [PMID: 23035631 DOI: 10.1094/phyto-06-12-0138-r] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Huanglongbing (HLB) is one of the most destructive diseases of citrus worldwide. The three known causal agents of HLB are species of α-proteobacteria: 'Candidatus Liberibacter asiaticus', 'Ca. L. africanus', and 'Ca. L. americanus'. Previous studies have found distinct variations in temperature sensitivity and tolerance among these species. Here, we describe the use of controlled heat treatments to cure HLB caused by 'Ca. L. asiaticus', the most prevalent and heat-tolerant species. Using temperature-controlled growth chambers, we evaluated the time duration and temperature required to suppress or eliminate the 'Ca. L. asiaticus' bacterium in citrus, using various temperature treatments for time periods ranging from 2 days to 4 months. Results of quantitative polymerase chain reaction (qPCR) after treatment illustrate significant decreases in the 'Ca. L. asiaticus' bacterial titer, combined with healthy vigorous growth by all surviving trees. Repeated qPCR testing confirmed that previously infected, heat-treated plants showed no detectable levels of 'Ca. L. asiaticus', while untreated control plants remained highly infected. Continuous thermal exposure to 40 to 42°C for a minimum of 48 h was sufficient to significantly reduce titer or eliminate 'Ca. L. asiaticus' bacteria entirely in HLB-affected citrus seedlings. This method may be useful for the control of 'Ca. Liberibacter'-infected plants in nursery and greenhouse settings.
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Affiliation(s)
- Michele T Hoffman
- United States Department of Agriculture, Agriculture Reserch Service, United States Horticultural Research Laboratory, Fort Pierce, FL 34945, USA
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25
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Panis G, Franche N, Méjean V, Ansaldi M. Insights into the functions of a prophage recombination directionality factor. Viruses 2012. [PMID: 23202488 PMCID: PMC3509656 DOI: 10.3390/v4112417] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Recombination directionality factors (RDFs), or excisionases, are essential players of prophage excisive recombination. Despite the essentially catalytic role of the integrase in both integrative and excisive recombination, RDFs are required to direct the reaction towards excision and to prevent re-integration of the prophage genome when entering a lytic cycle. KplE1, HK620 and numerous (pro)phages that integrate at the same site in enterobacteria genomes (such as the argW tRNA gene) all share a highly conserved recombination module. This module comprises the attL and attR recombination sites and the RDF and integrase genes. The KplE1 RDF was named TorI after its initial identification as a negative regulator of the tor operon. However, it was characterized as an essential factor of excisive recombination. In this study, we designed an extensive random mutagenesis protocol of the torI gene and identified key residues involved in both functions of the TorI protein. We show that, in addition to TorI-TorR protein-protein interaction, TorI interacts in solution with the IntS integrase. Moreover, in vitro, TorR and IntS appear to compete for TorI binding. Finally, our mutagenesis results suggest that the C-terminal part of the TorI protein is dedicated to protein-protein interactions with both proteins TorR and IntS.
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Affiliation(s)
- Gaël Panis
- Laboratoire de Chimie Bactérienne CNRS UMR7283, Institut de Microbiologie de la Méditerranée, Aix-Marseille University, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
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Ryall B, Eydallin G, Ferenci T. Culture history and population heterogeneity as determinants of bacterial adaptation: the adaptomics of a single environmental transition. Microbiol Mol Biol Rev 2012; 76:597-625. [PMID: 22933562 PMCID: PMC3429624 DOI: 10.1128/mmbr.05028-11] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Diversity in adaptive responses is common within species and populations, especially when the heterogeneity of the frequently large populations found in environments is considered. By focusing on events in a single clonal population undergoing a single transition, we discuss how environmental cues and changes in growth rate initiate a multiplicity of adaptive pathways. Adaptation is a comprehensive process, and stochastic, regulatory, epigenetic, and mutational changes can contribute to fitness and overlap in timing and frequency. We identify culture history as a major determinant of both regulatory adaptations and microevolutionary change. Population history before a transition determines heterogeneities due to errors in translation, stochastic differences in regulation, the presence of aged, damaged, cheating, or dormant cells, and variations in intracellular metabolite or regulator concentrations. It matters whether bacteria come from dense, slow-growing, stressed, or structured states. Genotypic adaptations are history dependent due to variations in mutation supply, contingency gene changes, phase variation, lateral gene transfer, and genome amplifications. Phenotypic adaptations underpin genotypic changes in situations such as stress-induced mutagenesis or prophage induction or in biofilms to give a continuum of adaptive possibilities. Evolutionary selection additionally provides diverse adaptive outcomes in a single transition and generally does not result in single fitter types. The totality of heterogeneities in an adapting population increases the chance that at least some individuals meet immediate or future challenges. However, heterogeneity complicates the adaptomics of single transitions, and we propose that subpopulations will need to be integrated into future population biology and systems biology predictions of bacterial behavior.
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Affiliation(s)
- Ben Ryall
- School of Molecular Bioscience, University of Sydney, New South Wales, Australia
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Abstract
Bacteriophage λ, rediscovered in the early 1950s, has served as a model in molecular biology studies for decades. Although currently more complex organisms and more complicated biological systems can be studied, this phage is still an excellent model to investigate principles of biological processes occurring at the molecular level. In fact, very few other biological models provide possibilities to examine regulations of biological mechanisms as detailed as performed with λ. In this chapter, recent advances in our understanding of mechanisms of bacteriophage λ development are summarized and discussed. Particularly, studies on (i) phage DNA injection, (ii) molecular bases of the lysis-versus-lysogenization decision and the lysogenization process itself, (iii) prophage maintenance and induction, (iv), λ DNA replication, (v) phage-encoded recombination systems, (vi) transcription antitermination, (vii) formation of the virion structure, and (viii) lysis of the host cell, as published during several past years, will be presented.
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Picozzi C, Volponi G, Vigentini I, Grassi S, Foschino R. Assessment of transduction of Escherichia coli Stx2-encoding phage in dairy process conditions. Int J Food Microbiol 2011; 153:388-94. [PMID: 22197444 DOI: 10.1016/j.ijfoodmicro.2011.11.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 11/22/2011] [Accepted: 11/30/2011] [Indexed: 11/28/2022]
Abstract
In the environment, bacteriophages are regarded as natural vector for the transmission of Shiga-toxin genes among Shiga-toxin Escherichia coli strains. The possibility of transduction has been noticed in intestinal tract of various animals but experimental observations on this phenomenon in food processes are lacking. To investigate the transduction in milk at different temperature profiles and cell concentrations, an experimental plan including two different Stx(2)-phages (ϕGV2412 and ϕL34), induced respectively from E. coli O157:H7 181181/2 and E. coli O157:H7 EC34, and two recipient E. coli strains (CNCTC 6896, WG5) was performed. The donor strains were generated by lysogenization of CNCTC 6896 with ϕGV2412 and ϕL34 respectively. Spectinomycin resistance gene (aadA) was inserted into stx(2) operon in order to select transduced cells. Transductants were never observed at 4°C up to 24 h, whereas after a treatment at 37°C for 2 h and at 25°C for 22 h they were detected in 67% of the trials with a ratio of transduction varying from 1.13 10(-6) to 7.87 10(-8). A treatment at 48°C for 2 h followed by a second step at 25°C for 22 h showed an occurrence of transduction events in only 19% of cases with a ratio of transduction varying from 2.22 10(-7) to 2.67 10(-8). The generation of transductants and the spontaneous induction of phages in milk were not affected by initial or final concentration of the donor or recipient strains. The results show that transduction phenomenon occurs when the cells are metabolically active and it does not take place at low temperatures. Therefore, the maintenance of the chilling chain proved to be a main factor to prevent the spread of Stx-genes in dairy processes.
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Affiliation(s)
- Claudia Picozzi
- Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Università degli Studi di Milano, via G. Celoria 2, 20133 Milano, Italy
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29
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Abstract
The life cycle of bacteriophage lambda serves as a simplified paradigm for cell-fate decisions. The ongoing quantitative, high-resolution experimental investigation of this life cycle has produced some important insights in recent years. These insights have to do with the way cells choose among alternative fates, how they maintain long-term memory of their gene-expression state, and how they switch from one stable state to another. The recent studies have highlighted the role of spatiotemporal effects in cellular processes and the importance of distinguishing chemical stochasticity from possible hidden variables in cellular decision making.
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Affiliation(s)
- Ido Golding
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
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Champ S, Puvirajesinghe TM, Perrody E, Menouni R, Genevaux P, Ansaldi M. Chaperone-assisted excisive recombination, a solitary role for DnaJ (Hsp40) chaperone in lysogeny escape. J Biol Chem 2011; 286:38876-85. [PMID: 21908845 DOI: 10.1074/jbc.m111.281865] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Temperate bacteriophage lytic development is intrinsically related to the stress response in particular at the DNA replication and virion maturation steps. Alternatively, temperate phages become lysogenic and integrate their genome into the host chromosome. Under stressful conditions, the prophage resumes a lytic development program, and the phage DNA is excised before being replicated. The KplE1 defective prophage of Escherichia coli K12 constitutes a model system because it is fully competent for integrative as well as excisive recombination and presents an atypical recombination module, which is conserved in various phage genomes. In this work, we identified the host-encoded stress-responsive molecular chaperone DnaJ (Hsp40) as an active participant in KplE1 prophage excision. We first show that the recombination directionality factor TorI of KplE1 specifically interacts with DnaJ. In addition, we found that DnaJ dramatically enhances both TorI binding to its DNA target and excisive recombination in vitro. Remarkably, such stimulatory effect by DnaJ was performed independently of its DnaK chaperone partner and did not require a functional DnaJ J-domain. Taken together, our results underline a novel and unsuspected functional interaction between the generic host stress-regulated chaperone and temperate bacteriophage lysogenic development.
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Affiliation(s)
- Stéphanie Champ
- Laboratoire de Chimie Bactérienne CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
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31
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Rosado H, Rahman KM, Feuerbaum EA, Hinds J, Thurston DE, Taylor PW. The minor groove-binding agent ELB-21 forms multiple interstrand and intrastrand covalent cross-links with duplex DNA and displays potent bactericidal activity against methicillin-resistant Staphylococcus aureus. J Antimicrob Chemother 2011; 66:985-96. [PMID: 21393142 PMCID: PMC3073633 DOI: 10.1093/jac/dkr044] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Objectives The antistaphylococcal pyrrolobenzodiazepine dimer ELB-21 forms multiple adducts with duplex DNA through covalent interactions with appropriately spaced guanine residues; it is now known to form interstrand and intrastrand adducts with oligonucleotide sequences of variable length. We determined the DNA sequence preferences of ELB-21 in relation to its capacity to exert a bactericidal effect by damaging DNA. Methods Formation of adducts by ELB-21 and 12- to 14-mer DNA duplexes was investigated using ion-pair reversed phase liquid chromatography and mass spectrometry. Drug-induced changes in gene expression were measured in prophage-free Staphylococcus aureus RN4220 by microarray analysis. Results ELB-21 preferentially formed intrastrand adducts with guanines separated by three nucleotide base pairs. Interstrand and intrastrand adducts were formed with duplexes both longer and shorter than the preferred target sequences. ELB-21 elicited rapid bactericidal effects against prophage-carrying and prophage-free S. aureus strains; cell lysis occurred following activation and release of resident prophages. Killing appeared to be due to irreparable damage to bacterial DNA and susceptibility to ELB-21 was governed by the capacity of staphylococci to repair DNA lesions through induction of the SOS DNA damage response mediated by the RecA-LexA pathway. Conclusions The data support the contention that ELB-21 arrests DNA replication, eliciting formation of ssDNA-RecA filaments that inactivate LexA, the SOS repressor, and phage repressors such as Cl, resulting in activation of the DNA damage response and de-repression of resident prophages. Above the MIC threshold, DNA repair is ineffective.
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Affiliation(s)
- Helena Rosado
- School of Pharmacy, University of London, London, UK
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Avlund M, Krishna S, Semsey S, Dodd IB, Sneppen K. Minimal gene regulatory circuits for a lysis-lysogeny choice in the presence of noise. PLoS One 2010; 5:e15037. [PMID: 21188148 PMCID: PMC3004801 DOI: 10.1371/journal.pone.0015037] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 10/13/2010] [Indexed: 11/18/2022] Open
Abstract
Gene regulatory networks (GRNs) that make reliable decisions should have design features to cope with random fluctuations in the levels or activities of biological molecules. The phage λ GRN makes a lysis-lysogeny decision informed by the number of phages infecting the cell. To analyse the design of decision making GRNs, we generated random in silico GRNs comprised of two or three transcriptional regulators and selected those able to perform a λ-like decision in the presence of noise. Various two-protein networks analogous to the λ CI-Cro GRN worked in noise-less conditions but failed when noise was introduced. Adding a λ CII-like protein significantly improved robustness to noise. CII relieves the CI-like protein of its 'decider' function, allowing CI to be optimized as a decision 'maintainer'. CII's lysogenic decider function was improved by its instability and rapid removal once the decision was taken, preventing its interference with maintenance. A more reliable decision also resulted from simulated co-transcription of the genes for CII and the Cro-like protein, which correlates fluctuations in these opposing decider functions and makes their ratio less noisy. Thus, the λ decision network contains design features for reducing and resisting noise.
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Affiliation(s)
- Mikkel Avlund
- Center for Models of Life, Niels Bohr Institute, Copenhagen, Denmark
| | - Sandeep Krishna
- Center for Models of Life, Niels Bohr Institute, Copenhagen, Denmark
- National Centre for Biological Sciences, Bangalore, India
| | - Szabolcs Semsey
- Center for Models of Life, Niels Bohr Institute, Copenhagen, Denmark
| | - Ian B. Dodd
- Molecular and Biomedical Sciences (Biochemistry), University of Adelaide, Adelaide, Australia
| | - Kim Sneppen
- Center for Models of Life, Niels Bohr Institute, Copenhagen, Denmark
- * E-mail:
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Panis G, Duverger Y, Courvoisier-Dezord E, Champ S, Talla E, Ansaldi M. Tight regulation of the intS gene of the KplE1 prophage: a new paradigm for integrase gene regulation. PLoS Genet 2010; 6. [PMID: 20949106 PMCID: PMC2951348 DOI: 10.1371/journal.pgen.1001149] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 09/02/2010] [Indexed: 11/18/2022] Open
Abstract
Temperate phages have the ability to maintain their genome in their host, a process called lysogeny. For most, passive replication of the phage genome relies on integration into the host's chromosome and becoming a prophage. Prophages remain silent in the absence of stress and replicate passively within their host genome. However, when stressful conditions occur, a prophage excises itself and resumes the viral cycle. Integration and excision of phage genomes are mediated by regulated site-specific recombination catalyzed by tyrosine and serine recombinases. In the KplE1 prophage, site-specific recombination is mediated by the IntS integrase and the TorI recombination directionality factor (RDF). We previously described a sub-family of temperate phages that is characterized by an unusual organization of the recombination module. Consequently, the attL recombination region overlaps with the integrase promoter, and the integrase and RDF genes do not share a common activated promoter upon lytic induction as in the lambda prophage. In this study, we show that the intS gene is tightly regulated by its own product as well as by the TorI RDF protein. In silico analysis revealed that overlap of the attL region with the integrase promoter is widely encountered in prophages present in prokaryotic genomes, suggesting a general occurrence of negatively autoregulated integrase genes. The prediction that these integrase genes are negatively autoregulated was biologically assessed by studying the regulation of several integrase genes from two different Escherichia coli strains. Our results suggest that the majority of tRNA-associated integrase genes in prokaryotic genomes could be autoregulated and that this might be correlated with the recombination efficiency as in KplE1. The consequences of this unprecedented regulation for excessive recombination are discussed.
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Affiliation(s)
- Gaël Panis
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
- Aix-Marseille Université, Marseille, France
| | - Yohann Duverger
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Elise Courvoisier-Dezord
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Stéphanie Champ
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Emmanuel Talla
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
- Aix-Marseille Université, Marseille, France
- * E-mail: (MA); (ET)
| | - Mireille Ansaldi
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
- Aix-Marseille Université, Marseille, France
- * E-mail: (MA); (ET)
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Osburne MS, Holmbeck BM, Frias-Lopez J, Steen R, Huang K, Kelly L, Coe A, Waraska K, Gagne A, Chisholm SW. UV hyper-resistance in Prochlorococcus MED4 results from a single base pair deletion just upstream of an operon encoding nudix hydrolase and photolyase. Environ Microbiol 2010; 12:1978-88. [PMID: 20345942 PMCID: PMC2955971 DOI: 10.1111/j.1462-2920.2010.02203.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 01/28/2010] [Indexed: 12/01/2022]
Abstract
Exposure to solar radiation can cause mortality in natural communities of pico-phytoplankton, both at the surface and to a depth of at least 30 m. DNA damage is a significant cause of death, mainly due to cyclobutane pyrimidine dimer formation, which can be lethal if not repaired. While developing a UV mutagenesis protocol for the marine cyanobacterium Prochlorococcus, we isolated a UV-hyper-resistant variant of high light-adapted strain MED4. The hyper-resistant strain was constitutively upregulated for expression of the mutT-phrB operon, encoding nudix hydrolase and photolyase, both of which are involved in repair of DNA damage that can be caused by UV light. Photolyase (PhrB) breaks pyrimidine dimers typically caused by UV exposure, using energy from visible light in the process known as photoreactivation. Nudix hydrolase (MutT) hydrolyses 8-oxo-dGTP, an aberrant form of GTP that results from oxidizing conditions, including UV radiation, thus impeding mispairing and mutagenesis by preventing incorporation of the aberrant form into DNA. These processes are error-free, in contrast to error-prone SOS dark repair systems that are widespread in bacteria. The UV-hyper-resistant strain contained only a single mutation: a 1 bp deletion in the intergenic region directly upstream of the mutT-phrB operon. Two subsequent enrichments for MED4 UV-hyper-resistant strains from MED4 wild-type cultures gave rise to strains containing this same 1 bp deletion, affirming its connection to the hyper-resistant phenotype. These results have implications for Prochlorococcus DNA repair mechanisms, genome stability and possibly lysogeny.
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Affiliation(s)
- Marcia S Osburne
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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Maskow T, Kiesel B, Schubert T, Yong Z, Harms H, Yao J. Calorimetric real time monitoring of lambda prophage induction. J Virol Methods 2010; 168:126-32. [PMID: 20470826 DOI: 10.1016/j.jviromet.2010.05.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 04/28/2010] [Accepted: 05/05/2010] [Indexed: 11/29/2022]
Abstract
Calorimetry can be used for a noninvasive monitoring of metabolic and energy changes in bacterial cultures in real time. This potentially includes changes occurring during phage infection cycles. To demonstrate this, the growth of Escherichia coli K124 F(-) carrying the lambda prophage was monitored in a reaction calorimeter, while inducing the shift from lysogeny to lysis using methotrexate (MTX) as the inducer. Different phases of the phage infection were distinguishable calorimetrically. The calorimetric signals corresponded well to changes in growth stoichiometry and kinetics that were measured non-calorimetrically. The comparison of the calorimetric results with other measurements of activity revealed that the calorimetric method was superior since the calorimetric data mirrored the progress of infection in more detail. Contradictions between the calorimetric data and the appearance of infectious phages could result from inactivation of phage by MTX.
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Affiliation(s)
- Thomas Maskow
- UFZ, Helmholtz Centre for Environmental Research, Department of Environmental Microbiology, Permoserstr. Leipzig, Germany.
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36
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Small stress response proteins in Escherichia coli: proteins missed by classical proteomic studies. J Bacteriol 2010; 192:46-58. [PMID: 19734316 DOI: 10.1128/jb.00872-09] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Proteins of 50 or fewer amino acids are poorly characterized in all organisms. The corresponding genes are challenging to reliably annotate, and it is difficult to purify and characterize the small protein products. Due to these technical limitations, little is known about the abundance of small proteins, not to mention their biological functions. To begin to characterize these small proteins in Escherichia coli, we assayed their accumulation under a variety of growth conditions and after exposure to stress. We found that many small proteins accumulate under specific growth conditions or are stress induced. For some genes, the observed changes in protein levels were consistent with known transcriptional regulation, such as ArcA activation of the operons encoding yccB and ybgT. However, we also identified novel regulation, such as Zur repression of ykgMO, cyclic AMP response protein (CRP) repression of azuC, and CRP activation of ykgR. The levels of 11 small proteins increase after heat shock, and induction of at least 1 of these, YobF, occurs at a posttranscriptional level. These results show that small proteins are an overlooked subset of stress response proteins in E. coli and provide information that will be valuable for determining the functions of these proteins.
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Avlund M, Dodd IB, Sneppen K, Krishna S. Minimal Gene Regulatory Circuits that Can Count like Bacteriophage Lambda. J Mol Biol 2009; 394:681-93. [DOI: 10.1016/j.jmb.2009.09.053] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Revised: 09/17/2009] [Accepted: 09/21/2009] [Indexed: 10/20/2022]
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Abstract
For many bacterial viruses, the choice of whether to kill host cells or enter a latent state depends on the multiplicity of coinfection. Here, we present a mathematical theory of how bacterial viruses can make collective decisions concerning the fate of infected cells. We base our theory on mechanistic models of gene regulatory dynamics. Unlike most previous work, we treat the copy number of viral genes as variable. Increasing the viral copy number increases the rate of transcription of viral mRNAs. When viral regulation of cell fate includes nonlinear feedback loops, very small changes in transcriptional rates can lead to dramatic changes in steady-state gene expression. Hence, we prove that deterministic decisions can be reached, e.g., lysis or latency, depending on the cellular multiplicity of infection within a broad class of gene regulatory models of viral decision-making. Comparisons of a parameterized version of the model with molecular studies of the decision structure in the temperate bacteriophage lambda are consistent with our conclusions. Because the model is general, it suggests that bacterial viruses can respond adaptively to changes in population dynamics, and that features of collective decision-making in viruses are evolvable life history traits.
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The CI repressors of Shiga toxin-converting prophages are involved in coinfection of Escherichia coli strains, which causes a down regulation in the production of Shiga toxin 2. J Bacteriol 2008; 190:4722-35. [PMID: 18469095 DOI: 10.1128/jb.00069-08] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shiga toxins (Stx) are the main virulence factors associated with a form of Escherichia coli known as Shiga toxin-producing E. coli (STEC). They are encoded in temperate lambdoid phages located on the chromosome of STEC. STEC strains can carry more than one prophage. Consequently, toxin and phage production might be influenced by the presence of more than one Stx prophage on the bacterial chromosome. To examine the effect of the number of prophages on Stx production, we produced E. coli K-12 strains carrying either one Stx2 prophage or two different Stx2 prophages. We used recombinant phages in which an antibiotic resistance gene (aph, cat, or tet) was incorporated in the middle of the Shiga toxin operon. Shiga toxin was quantified by immunoassay and by cytotoxicity assay on Vero cells (50% cytotoxic dose). When two prophages were inserted in the host chromosome, Shiga toxin production and the rate of lytic cycle activation fell. The cI repressor seems to be involved in incorporation of the second prophage. Incorporation and establishment of the lysogenic state of the two prophages, which lowers toxin production, could be regulated by the CI repressors of both prophages operating in trans. Although the sequences of the cI genes of the phages studied differed, the CI protein conformation was conserved. Results indicate that the presence of more than one prophage in the host chromosome could be regarded as a mechanism to allow genetic retention in the cell, by reducing the activation of lytic cycle and hence the pathogenicity of the strains.
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