1
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Gong C, Chakraborty D, Koudelka GB. A prophage encoded ribosomal RNA methyltransferase regulates the virulence of Shiga-toxin-producing Escherichia coli (STEC). Nucleic Acids Res 2024; 52:856-871. [PMID: 38084890 PMCID: PMC10810198 DOI: 10.1093/nar/gkad1150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 11/09/2023] [Accepted: 11/14/2023] [Indexed: 01/26/2024] Open
Abstract
Shiga toxin (Stx) released by Shiga toxin producing Escherichia coli (STEC) causes life-threatening illness. Its production and release require induction of Stx-encoding prophage resident within the STEC genome. We identified two different STEC strains, PA2 and PA8, bearing Stx-encoding prophage whose sequences primarily differ by the position of an IS629 insertion element, yet differ in their abilities to kill eukaryotic cells and whose prophages differ in their spontaneous induction frequencies. The IS629 element in ϕPA2, disrupts an ORF predicted to encode a DNA adenine methyltransferase, whereas in ϕPA8, this element lies in an intergenic region. Introducing a plasmid expressing the methyltransferase gene product into ϕPA2 bearing-strains increases both the prophage spontaneous induction frequency and virulence to those exhibited by ϕPA8 bearing-strains. However, a plasmid bearing mutations predicted to disrupt the putative active site of the methyltransferase does not complement either of these defects. When complexed with a second protein, the methyltransferase holoenzyme preferentially uses 16S rRNA as a substrate. The second subunit is responsible for directing the preferential methylation of rRNA. Together these findings reveal a previously unrecognized role for rRNA methylation in regulating induction of Stx-encoding prophage.
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Affiliation(s)
- Chen Gong
- Department of Biological Sciences University at Buffalo, Buffalo, NY 14260, USA
| | | | - Gerald B Koudelka
- Department of Biological Sciences University at Buffalo, Buffalo, NY 14260, USA
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2
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Lücking D, Alarcón-Schumacher T, Erdmann S. Distribution and Implications of Haloarchaeal Plasmids Disseminated in Self-Encoded Plasmid Vesicles. Microorganisms 2023; 12:5. [PMID: 38276173 PMCID: PMC10818511 DOI: 10.3390/microorganisms12010005] [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: 11/16/2023] [Revised: 12/14/2023] [Accepted: 12/16/2023] [Indexed: 01/27/2024] Open
Abstract
Even though viruses and plasmids are both drivers of horizontal gene transfer, they differ fundamentally in their mode of transfer. Virus genomes are enclosed in virus capsids and are not dependent on cell-to-cell contacts for their dissemination. In contrast, the transfer of plasmids most often requires physical contact between cells. However, plasmid pR1SE of Halorubrum lacusprofundi is disseminated between cells, independent of cell-cell contacts, in specialized membrane vesicles that contain plasmid proteins. In this study, we searched for pR1SE-like elements in public databases and a metagenomics dataset from Australian salt lakes and identified 40 additional pR1SE-like elements in hypersaline environments worldwide. Herein, these elements are named apHPVs (archaeal plasmids of haloarchaea potentially transferred in plasmid vesicles). They share two sets of closely related proteins with conserved synteny, strongly indicating an organization into different functional clusters. We find that apHPVs, besides transferring themselves, have the potential to transfer large fragments of DNA between host cells, including virus defense systems. Most interestingly, apHPVs likely play an important role in the evolution of viruses and plasmids in haloarchaea, as they appear to recombine with both of them. This further supports the idea that plasmids and viruses are not distinct but closely related mobile genetic elements.
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Affiliation(s)
| | | | - Susanne Erdmann
- Max-Planck Institute for Marine Microbiology, Celsiusstrasse 1, 28359 Bremen, Germany
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3
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Smug BJ, Szczepaniak K, Rocha EPC, Dunin-Horkawicz S, Mostowy RJ. Ongoing shuffling of protein fragments diversifies core viral functions linked to interactions with bacterial hosts. Nat Commun 2023; 14:7460. [PMID: 38016962 PMCID: PMC10684548 DOI: 10.1038/s41467-023-43236-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 11/03/2023] [Indexed: 11/30/2023] Open
Abstract
Biological modularity enhances evolutionary adaptability. This principle is vividly exemplified by bacterial viruses (phages), which display extensive genomic modularity. Phage genomes are composed of independent functional modules that evolve separately and recombine in various configurations. While genomic modularity in phages has been extensively studied, less attention has been paid to protein modularity-proteins consisting of distinct building blocks that can evolve and recombine, enhancing functional and genetic diversity. Here, we use a set of 133,574 representative phage proteins and highly sensitive homology detection to capture instances of domain mosaicism, defined as fragment sharing between two otherwise unrelated proteins, and to understand its relationship with functional diversity in phage genomes. We discover that unrelated proteins from diverse functional classes frequently share homologous domains. This phenomenon is particularly pronounced within receptor-binding proteins, endolysins, and DNA polymerases. We also identify multiple instances of recent diversification via domain shuffling in receptor-binding proteins, neck passage structures, endolysins and some members of the core replication machinery, often transcending distant taxonomic and ecological boundaries. Our findings suggest that ongoing diversification via domain shuffling is reflective of a co-evolutionary arms race, driven by the need to overcome various bacterial resistance mechanisms against phages.
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Affiliation(s)
- Bogna J Smug
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | | | - Eduardo P C Rocha
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, France
| | - Stanislaw Dunin-Horkawicz
- Institute of Evolutionary Biology, Faculty of Biology & Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076, Tübingen, Germany
| | - Rafał J Mostowy
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland.
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4
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Mallawaarachchi V, Roach MJ, Decewicz P, Papudeshi B, Giles SK, Grigson SR, Bouras G, Hesse RD, Inglis LK, Hutton ALK, Dinsdale EA, Edwards RA. Phables: from fragmented assemblies to high-quality bacteriophage genomes. Bioinformatics 2023; 39:btad586. [PMID: 37738590 PMCID: PMC10563150 DOI: 10.1093/bioinformatics/btad586] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/14/2023] [Accepted: 09/19/2023] [Indexed: 09/24/2023] Open
Abstract
MOTIVATION Microbial communities have a profound impact on both human health and various environments. Viruses infecting bacteria, known as bacteriophages or phages, play a key role in modulating bacterial communities within environments. High-quality phage genome sequences are essential for advancing our understanding of phage biology, enabling comparative genomics studies and developing phage-based diagnostic tools. Most available viral identification tools consider individual sequences to determine whether they are of viral origin. As a result of challenges in viral assembly, fragmentation of genomes can occur, and existing tools may recover incomplete genome fragments. Therefore, the identification and characterization of novel phage genomes remain a challenge, leading to the need of improved approaches for phage genome recovery. RESULTS We introduce Phables, a new computational method to resolve phage genomes from fragmented viral metagenome assemblies. Phables identifies phage-like components in the assembly graph, models each component as a flow network, and uses graph algorithms and flow decomposition techniques to identify genomic paths. Experimental results of viral metagenomic samples obtained from different environments show that Phables recovers on average over 49% more high-quality phage genomes compared to existing viral identification tools. Furthermore, Phables can resolve variant phage genomes with over 99% average nucleotide identity, a distinction that existing tools are unable to make. AVAILABILITY AND IMPLEMENTATION Phables is available on GitHub at https://github.com/Vini2/phables.
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Affiliation(s)
- Vijini Mallawaarachchi
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
| | - Michael J Roach
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
| | - Przemyslaw Decewicz
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
- Department of Environmental Microbiology and Biotechnology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warsaw 02-096, Poland
| | - Bhavya Papudeshi
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
| | - Sarah K Giles
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
| | - Susanna R Grigson
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
| | - George Bouras
- Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
- The Department of Surgery—Otolaryngology Head and Neck Surgery, Central Adelaide Local Health Network, Adelaide, South Australia 5000, Australia
| | - Ryan D Hesse
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
| | - Laura K Inglis
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
| | - Abbey L K Hutton
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
| | - Elizabeth A Dinsdale
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
| | - Robert A Edwards
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
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5
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Mallawaarachchi V, Roach MJ, Decewicz P, Papudeshi B, Giles SK, Grigson SR, Bouras G, Hesse RD, Inglis LK, Hutton ALK, Dinsdale EA, Edwards RA. Phables: from fragmented assemblies to high-quality bacteriophage genomes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.04.535632. [PMID: 37066369 PMCID: PMC10104058 DOI: 10.1101/2023.04.04.535632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Microbial communities influence both human health and different environments. Viruses infecting bacteria, known as bacteriophages or phages, play a key role in modulating bacterial communities within environments. High-quality phage genome sequences are essential for advancing our understanding of phage biology, enabling comparative genomics studies, and developing phage-based diagnostic tools. Most available viral identification tools consider individual sequences to determine whether they are of viral origin. As a result of the challenges in viral assembly, fragmentation of genomes can occur, leading to the need for new approaches in viral identification. Therefore, the identification and characterisation of novel phages remain a challenge. We introduce Phables, a new computational method to resolve phage genomes from fragmented viral metagenome assemblies. Phables identifies phage-like components in the assembly graph, models each component as a flow network, and uses graph algorithms and flow decomposition techniques to identify genomic paths. Experimental results of viral metagenomic samples obtained from different environments show that Phables recovers on average over 49% more high-quality phage genomes compared to existing viral identification tools. Furthermore, Phables can resolve variant phage genomes with over 99% average nucleotide identity, a distinction that existing tools are unable to make. Phables is available on GitHub at https://github.com/Vini2/phables.
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Affiliation(s)
- Vijini Mallawaarachchi
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Michael J Roach
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Przemyslaw Decewicz
- Department of Environmental Microbiology and Biotechnology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warsaw 02-096, Poland
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Bhavya Papudeshi
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Sarah K Giles
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Susanna R Grigson
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - George Bouras
- Adelaide Medical School, The University of Adelaide, North Tce, Adelaide, SA, 5000, Australia
| | - Ryan D Hesse
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Laura K Inglis
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Abbey L K Hutton
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Elizabeth A Dinsdale
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Robert A Edwards
- Flinders Accelerator for Microbiome Exploration, College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
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6
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Crum E, Merchant Z, Ene A, Miller-Ensminger T, Johnson G, Wolfe AJ, Putonti C. Coliphages of the human urinary microbiota. PLoS One 2023; 18:e0283930. [PMID: 37053131 PMCID: PMC10101464 DOI: 10.1371/journal.pone.0283930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 03/20/2023] [Indexed: 04/14/2023] Open
Abstract
Due to its frequent association with urinary tract infections (UTIs), Escherichia coli is the best characterized constituent of the urinary microbiota (urobiome). However, uropathogenic E. coli is just one member of the urobiome. In addition to bacterial constituents, the urobiome of both healthy and symptomatic individuals is home to a diverse population of bacterial viruses (bacteriophages). A prior investigation found that most bacterial species in the urobiome are lysogens, harboring one or more phages integrated into their genome (prophages). Many of these prophages are temperate phages, capable of entering the lytic cycle and thus lysing their bacterial host. This transition from the lysogenic to lytic life cycle can impact the bacterial diversity of the urobiome. While many phages that infect E. coli (coliphages) have been studied for decades in the laboratory setting, the coliphages within the urobiome have yet to be cataloged. Here, we investigated the diversity of urinary coliphages by first identifying prophages in all publicly available urinary E. coli genomes. We detected 3,038 intact prophage sequences, representative of 1,542 unique phages. These phages include both novel species as well as species also found within the gut microbiota. Ten temperate phages were isolated from urinary E. coli strains included in our analysis, and we assessed their ability to infect and lyse urinary E. coli strains. We also included in these host range assays other urinary coliphages and laboratory coliphages. The temperate phages and other urinary coliphages were successful in lysing urinary E. coli strains. We also observed that coliphages from non-urinary sources were most efficient in killing urinary E. coli strains. The two phages, T2 and N4, were capable of lysing 83.5% (n = 86) of strains isolated from females with UTI symptoms. In conclusion, our study finds a diverse community of coliphages in the urobiome, many of which are predicted to be temperate phages, ten of which were confirmed here. Their ability to infect and lyse urinary E. coli strains suggests that urinary coliphages may play a role in modulating the E. coli strain diversity of the urobiome.
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Affiliation(s)
- Elias Crum
- Bioinformatics Program, Loyola University Chicago, Chicago, Illinois, United States of America
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Zubia Merchant
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Adriana Ene
- Bioinformatics Program, Loyola University Chicago, Chicago, Illinois, United States of America
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Taylor Miller-Ensminger
- Bioinformatics Program, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Genevieve Johnson
- Bioinformatics Program, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Alan J. Wolfe
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Catherine Putonti
- Bioinformatics Program, Loyola University Chicago, Chicago, Illinois, United States of America
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, United States of America
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7
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Zaki BM, Mohamed AA, Dawoud A, Essam K, Hammouda ZK, Abdelsattar AS, El-Shibiny A. Isolation, screening and characterization of phage. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 200:13-60. [PMID: 37739553 DOI: 10.1016/bs.pmbts.2023.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Bacterial resistance threatens public health due to a lack of novel antibacterial classes since the 21st century. Bacteriophages, the most ubiquitous microorganism on Earth and natural predators of bacteria, have the potential to save the world from the post-antibiotic era. Therefore, phage isolation and characterization are in high demand to find suitable phages for therapeutic and bacterial control applications. The chapter presents brief guidance supported by recommendations on the isolation of phages, and initial screening of phage antimicrobial efficacy, in addition to, conducting comprehensive characterization addressing morphological, biological, genomic, and taxonomic features.
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Affiliation(s)
- Bishoy Maher Zaki
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, Egypt; Microbiology and Immunology Department, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt
| | - Amira A Mohamed
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, Egypt
| | - Alyaa Dawoud
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, Egypt; Biochemistry Department, Faculty of Pharmacy and Biotechnology, German University in Cairo, Cairo, Egypt
| | - Kareem Essam
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, Egypt
| | - Zainab K Hammouda
- Microbiology and Immunology Department, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt
| | - Abdallah S Abdelsattar
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, Egypt
| | - Ayman El-Shibiny
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, Egypt; Faculty of Environmental Agricultural Sciences, Arish University, Arish, Egypt
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8
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Magaziner SJ, Salmond GPC. A novel T4- and λ-based receptor binding protein family for bacteriophage therapy host range engineering. Front Microbiol 2022; 13:1010330. [PMID: 36386655 PMCID: PMC9659904 DOI: 10.3389/fmicb.2022.1010330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/10/2022] [Indexed: 11/21/2022] Open
Abstract
Widespread multidrug antimicrobial resistance in emerging pathogens has led to a renewed interest in phage therapy as an alternative or supplement to traditional small molecule drugs. The primary limiting factors of phage therapy deployment rest in the narrow host range specificity of phage as well as a poor understanding of many phages’ unintended downstream effects on host physiology and microbiota as well as on adverse pathogen evolution. Consequently, this has made assembling well-defined and safe “phage-cocktails” of solely naturally occurring phages labor- and time-intensive. To increase the speed, efficacy, and safety of therapeutic deployment, there is exceptional interest in modulating the host ranges of well-characterized lytic phages (e.g., T4 and T7) by using synthetic strategies to the swap phage tail components, the receptor binding proteins (RBPs) key for host specificity. Here we identify the RBP of the Citrobacter rodentium temperate phage ΦNP as ORF6. Through bioinformatic and phylogenetic assays, we demonstrate this RBP to be closely related to the known RBPs of T4 and λ. Further investigation reveals a novel, greater than 200 members RBP family with phages targeting several notable human pathogens, including Klebsiella pneumoniae, Escherichia coli O157:H7, Salmonella spp., and Shigella spp. With well characterized lytic members, this RBP family represents an ideal candidate for use in synthetic strategies for expanding therapeutic phage host ranges.
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9
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Use of Metagenomic Whole Genome Shotgun Sequencing Data in Taxonomic Assignment of Dipterygium glaucum Rhizosphere and Surrounding Bulk Soil Microbiomes, and Their Response to Watering. SUSTAINABILITY 2022. [DOI: 10.3390/su14148764] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The metagenomic whole genome shotgun sequencing (mWGS) approach was used to detect signatures of the rhizosphere microbiomes of Dipterygium glaucum and surrounding bulk soil microbiomes, and to detect differential microbial responses due to watering. Preliminary results reflect the reliability of the experiment and the rationality of grouping microbiomes. Based on the abundance of non-redundant genes, bacterial genomes showed the highest level, followed by Archaeal and Eukaryotic genomes, then, the least abundant viruses. Overall results indicate that most members of bacteria have a higher abundance/relative abundance (AB/RA) pattern in the rhizosphere towards plant growth promotion, while members of eukaryota have a higher pattern in bulk soil, most likely acting as pathogens. The results also indicate the contribution of mycorrhiza (genus Rhizophagus) in mediating complex mutualistic associations between soil microbes (either beneficial or harmful) and plant roots. Some of these symbiotic relationships involve microbes of different domains responding differentially to plant root exudates. Among these are included the bacterial genus Burkholderia and eukaryotic genus Trichoderma, which have antagonistic activities against the eukaryotic genus Fusarium. Another example involves Ochrobactrum phage POA1180, its bacterial host and plant roots. One of the major challenges in plant nutrition involves other microbes that manipulate nitrogen levels in the soil. Among these are the microbes that perform contraversal actions of nitrogen fixation (the methanogen Euryarchaeota) and ammonia oxidation (Crenarchaeota). The net nitrogen level in the soil is originally based on the AB/RA of these microbes and partially on the environmental condition. Watering seems to influence the AB/RA of a large number of soil microbes, where drought-sensitive microbes (members of phyla Acidobacteria and Gemmatimonadetes) showed an increased AB/RA pattern after watering, while others (Burkholderia and Trichoderma) seem to be among microbes assisting plants to withstand abiotic stresses. This study sheds light on the efficient use of mWGS in the taxonomic assignment of soil microbes and in their response to watering. It also provides new avenues for improving biotic and abiotic resistance in domestic plant germplasm via the manipulation of soil microbes.
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10
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Mäntynen S, Laanto E, Oksanen HM, Poranen MM, Díaz-Muñoz SL. Black box of phage-bacterium interactions: exploring alternative phage infection strategies. Open Biol 2021; 11:210188. [PMID: 34520699 PMCID: PMC8440029 DOI: 10.1098/rsob.210188] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The canonical lytic-lysogenic binary has been challenged in recent years, as more evidence has emerged on alternative bacteriophage infection strategies. These infection modes are little studied, and yet they appear to be more abundant and ubiquitous in nature than previously recognized, and can play a significant role in the ecology and evolution of their bacterial hosts. In this review, we discuss the extent, causes and consequences of alternative phage lifestyles, and clarify conceptual and terminological confusion to facilitate research progress. We propose distinct definitions for the terms 'pseudolysogeny' and 'productive or non-productive chronic infection', and distinguish them from the carrier state life cycle, which describes a population-level phenomenon. Our review also finds that phages may change their infection modes in response to environmental conditions or the physiological state of the host cell. We outline known molecular mechanisms underlying the alternative phage-host interactions, including specific genetic pathways and their considerable biotechnological potential. Moreover, we discuss potential implications of the alternative phage lifestyles for microbial biology and ecosystem functioning, as well as applied topics such as phage therapy.
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Affiliation(s)
- Sari Mäntynen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland,Department of Microbiology and Molecular Genetics, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Elina Laanto
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland,Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Survontie 9, 40014 Jyväskylä, Finland
| | - Hanna M. Oksanen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland
| | - Minna M. Poranen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland
| | - Samuel L. Díaz-Muñoz
- Department of Microbiology and Molecular Genetics, University of California, One Shields Avenue, Davis, CA 95616, USA,Genome Center, University of California, One Shields Avenue, Davis, CA 95616, USA
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11
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Townsend EM, Kelly L, Muscatt G, Box JD, Hargraves N, Lilley D, Jameson E. The Human Gut Phageome: Origins and Roles in the Human Gut Microbiome. Front Cell Infect Microbiol 2021; 11:643214. [PMID: 34150671 PMCID: PMC8213399 DOI: 10.3389/fcimb.2021.643214] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 05/19/2021] [Indexed: 12/14/2022] Open
Abstract
The investigation of the microbial populations of the human body, known as the microbiome, has led to a revolutionary field of science, and understanding of its impacts on human development and health. The majority of microbiome research to date has focussed on bacteria and other kingdoms of life, such as fungi. Trailing behind these is the interrogation of the gut viruses, specifically the phageome. Bacteriophages, viruses that infect bacterial hosts, are known to dictate the dynamics and diversity of bacterial populations in a number of ecosystems. However, the phageome of the human gut, while of apparent importance, remains an area of many unknowns. In this paper we discuss the role of bacteriophages within the human gut microbiome. We examine the methods used to study bacteriophage populations, how this evolved over time and what we now understand about the phageome. We review the phageome development in infancy, and factors that may influence phage populations in adult life. The role and action of the phageome is then discussed at both a biological-level, and in the broader context of human health and disease.
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Affiliation(s)
- Eleanor M Townsend
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - Lucy Kelly
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - George Muscatt
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - Joshua D Box
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - Nicole Hargraves
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - Daniel Lilley
- Warwick Medical School, The University of Warwick, Coventry, United Kingdom
| | - Eleanor Jameson
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
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12
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Song K. Classifying the Lifestyle of Metagenomically-Derived Phages Sequences Using Alignment-Free Methods. Front Microbiol 2020; 11:567769. [PMID: 33304326 PMCID: PMC7693541 DOI: 10.3389/fmicb.2020.567769] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 10/22/2020] [Indexed: 01/20/2023] Open
Abstract
Phages are viruses that infect bacteria. The phages can be classified into two different categories based on their lifestyles: temperate and lytic. Now, the metavirome can generate a large number of fragments from the viral genomic sequences of entire environmental community, which makes it impossible to determine their lifestyles through experiments. Thus, there is a need to development computational methods for annotating phage contigs and making prediction of their lifestyles. Alignment-based methods for classifying phage lifestyle are limited by incomplete assembled genomes and nucleotide databases. Alignment-free methods based on the frequencies of k-mers were widely used for genome and metagenome comparison which did not rely on the completeness of genome or nucleotide databases. To mimic fragmented metagenomic sequences, the temperate and lytic phages genomic sequences were split into non-overlapping fragments with different lengths, then, I comprehensively compared nine alignment-free dissimilarity measures with a wide range of choices of k-mer length and Markov orders for predicting the lifestyles of these phage contigs. The dissimilarity measure, d2S, performed better than other dissimilarity measures for classifying the lifestyles of phages. Thus, I propose that the alignment-free method, d2S, can be used for predicting the lifestyles of phages which derived from the metagenomic data.
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Affiliation(s)
- Kai Song
- School of Mathematics and Statistics, Qingdao University, Qingdao, China
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13
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Laanto E, Ravantti JJ, Sundberg LR. Prophages and Past Prophage-Host Interactions Revealed by CRISPR Spacer Content in a Fish Pathogen. Microorganisms 2020; 8:E1919. [PMID: 33276599 PMCID: PMC7761591 DOI: 10.3390/microorganisms8121919] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/26/2020] [Accepted: 11/30/2020] [Indexed: 12/20/2022] Open
Abstract
The role of prophages in the evolution, diversification, or virulence of the fish pathogen Flavobacterium columnare has not been studied thus far. Here, we describe a functional spontaneously inducing prophage fF4 from the F. columnare type strain ATCC 23463, which is not detectable with commonly used prophage search methods. We show that this prophage type has a global distribution and is present in strains isolated from Finland, Thailand, Japan, and North America. The virions of fF4 are myoviruses with contractile tails and infect only bacterial strains originating from Northern Finland. The fF4 resembles transposable phages by similar genome organization and several gene orthologs. Additional bioinformatic analyses reveal several species in the phylum Bacteroidetes that host a similar type of putative prophage, including bacteria that are important animal and human pathogens. Furthermore, a survey of F. columnare Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) spacers indicate a shared evolutionary history between F. columnare strains and the fF4 phage, and another putative prophage in the F. columnare strain ATCC 49512, named p49512. First, CRISPR spacer content from the two CRISPR loci (types II-C and VI-B) of the fF4 lysogen F. columnare ATCC 23463 revealed a phage terminase protein-matching spacer in the VI-B locus. This spacer is also present in two Chinese F. columnare strains. Second, CRISPR analysis revealed four F. columnare strains that contain unique spacers targeting different regions of the putative prophage p49512 in the F. columnare strain ATCC 49512, despite the geographical distance or genomovar of the different strains. This suggests a common ancestry for the F. columnare prophages and different host strains.
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Affiliation(s)
- Elina Laanto
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland;
| | - Janne J. Ravantti
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland;
| | - Lotta-Riina Sundberg
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, 40014 Jyvaskyla, Finland;
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14
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Palmer M, Hedlund BP, Roux S, Tsourkas PK, Doss RK, Stamereilers C, Mehta A, Dodsworth JA, Lodes M, Monsma S, Glavina del Rio T, Schoenfeld TW, Eloe-Fadrosh EA, Mead DA. Diversity and Distribution of a Novel Genus of Hyperthermophilic Aquificae Viruses Encoding a Proof-Reading Family-A DNA Polymerase. Front Microbiol 2020; 11:583361. [PMID: 33281778 PMCID: PMC7689252 DOI: 10.3389/fmicb.2020.583361] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/16/2020] [Indexed: 12/27/2022] Open
Abstract
Despite the high abundance of Aquificae in many geothermal systems, these bacteria are difficult to culture and no viruses infecting members of this phylum have been isolated. Here, we describe the complete, circular dsDNA Uncultivated Virus Genome (UViG) of Thermocrinis Octopus Spring virus (TOSV), derived from metagenomic data, along with eight related UViGs representing three additional viral species. Despite low overall similarity among viruses from different hot springs, the genomes shared a high degree of synteny, and encoded numerous genes for nucleotide metabolism, including a PolA-type DNA polymerase polyprotein with likely accessory functions, a DNA Pol III sliding clamp, a thymidylate kinase, a DNA gyrase, a helicase, and a DNA methylase. Also present were conserved genes predicted to code for phage capsid, large and small subunits of terminase, portal protein, holin, and lytic transglycosylase, all consistent with a distant relatedness to cultivated Caudovirales. These viruses are predicted to infect Aquificae, as multiple CRISPR spacers matching the viral genomes were identified within the genomes and metagenomic contigs from these bacteria. Based on the predicted atypical bi-directional replication strategy, low sequence similarity to known viral genomes, and unique position in gene-sharing networks, we propose a new putative genus, "Pyrovirus," in the order Caudovirales.
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Affiliation(s)
- Marike Palmer
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Brian P. Hedlund
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, United States
- Nevada Institute of Personalized Medicine, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Simon Roux
- Department of Energy Joint Genome Institute, Berkeley, CA, United States
| | - Philippos K. Tsourkas
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, United States
- Nevada Institute of Personalized Medicine, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Ryan K. Doss
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Casey Stamereilers
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Astha Mehta
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Jeremy A. Dodsworth
- Department of Biology, California State University, San Bernardino, CA, United States
| | | | - Scott Monsma
- Lucigen Corporation, Middleton, WI, United States
| | | | | | | | - David A. Mead
- Varigen Biosciences Corporation, Madison, WI, United States
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15
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Characterization and Genome Analysis of a Novel Mu-like Phage VW-6B Isolated from the Napahai Plateau Wetland of China. Curr Microbiol 2020; 78:150-158. [PMID: 33150466 DOI: 10.1007/s00284-020-02277-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 10/27/2020] [Indexed: 10/23/2022]
Abstract
Although bacteriophages are more numerous and have smaller genomes than their bacterial hosts, relatively few have their genomes sequenced. Here, we isolated the Pseudomonas fluorescens bacteriophage from Napahai plateau wetland and performed de novo genome sequencing. Based on the previous biological characteristics and bioinformatics analysis, it was determined that VW-6B was a linear double-stranded DNA (dsDNA) phage with 35,306 bp, with 56.76% G+C content and 197 bp tandem repeats. The VW-6B genome contained 46 open-reading frames (ORFs), and no tRNA genes were found. Based on phage genome structure, sequence comparison, and collinear analysis, VW-6B should be classified into the family Siphoviridae and be considered as a member of a new species in the Mu-like phage. The newly isolated bacteriophage can specifically infect P. fluorescens, which further enriches the diversity of known bacteriophages and provides a basis for the subsequent research and application of bacteriophages.
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16
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Guerin E, Hill C. Shining Light on Human Gut Bacteriophages. Front Cell Infect Microbiol 2020; 10:481. [PMID: 33014897 PMCID: PMC7511551 DOI: 10.3389/fcimb.2020.00481] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/04/2020] [Indexed: 12/15/2022] Open
Abstract
The human gut is a complex environment that contains a multitude of microorganisms that are collectively termed the microbiome. Multiple factors have a role to play in driving the composition of human gut bacterial communities either toward homeostasis or the instability that is associated with many disease states. One of the most important forces are likely to be bacteriophages, bacteria-infecting viruses that constitute by far the largest portion of the human gut virome. Despite this, bacteriophages (phages) are the one of the least studied residents of the gut. This is largely due to the challenges associated with studying these difficult to culture entities. Modern high throughput sequencing technologies have played an important role in improving our understanding of the human gut phageome but much of the generated sequencing data remains uncharacterised. Overcoming this requires database-independent bioinformatic pipelines and even those phages that are successfully characterized only provide limited insight into their associated biological properties, and thus most viral sequences have been characterized as “viral dark matter.” Fundamental to understanding the role of phages in shaping the human gut microbiome, and in turn perhaps influencing human health, is how they interact with their bacterial hosts. An essential aspect is the isolation of novel phage-bacteria host pairs by direct isolation through various screening methods, which can transform in silico phages into a biological reality. However, this is also beset with multiple challenges including culturing difficulties and the use of traditional methods, such as plaquing, which may bias which phage-host pairs that can be successfully isolated. Phage-bacteria interactions may be influenced by many aspects of complex human gut biology which can be difficult to reproduce under laboratory conditions. Here we discuss some of the main findings associated with the human gut phageome to date including composition, our understanding of phage-host interactions, particularly the observed persistence of virulent phages and their hosts, as well as factors that may influence these highly intricate relationships. We also discuss current methodologies and bottlenecks hindering progression in this field and identify potential steps that may be useful in overcoming these hurdles.
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Affiliation(s)
- Emma Guerin
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
| | - Colin Hill
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
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17
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Carr VR, Shkoporov A, Hill C, Mullany P, Moyes DL. Probing the Mobilome: Discoveries in the Dynamic Microbiome. Trends Microbiol 2020; 29:158-170. [PMID: 32448763 DOI: 10.1016/j.tim.2020.05.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 02/06/2023]
Abstract
There has been an explosion of metagenomic data representing human, animal, and environmental microbiomes. This provides an unprecedented opportunity for comparative and longitudinal studies of many functional aspects of the microbiome that go beyond taxonomic classification, such as profiling genetic determinants of antimicrobial resistance, interactions with the host, potentially clinically relevant functions, and the role of mobile genetic elements (MGEs). One of the most important but least studied of these aspects are the MGEs, collectively referred to as the 'mobilome'. Here we elaborate on the benefits and limitations of using different metagenomic protocols, discuss the relative merits of various sequencing technologies, and highlight relevant bioinformatics tools and pipelines to predict the presence of MGEs and their microbial hosts.
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Affiliation(s)
- Victoria R Carr
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK; The Alan Turing Institute, British Library, London, UK.
| | - Andrey Shkoporov
- APC Microbiome Ireland, School of Microbiology, University College Cork, Cork, Ireland
| | - Colin Hill
- APC Microbiome Ireland, School of Microbiology, University College Cork, Cork, Ireland
| | - Peter Mullany
- Eastman Dental Institute, University College London, London, UK
| | - David L Moyes
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK.
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18
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Shkoporov AN, Hill C. Bacteriophages of the Human Gut: The "Known Unknown" of the Microbiome. Cell Host Microbe 2019; 25:195-209. [PMID: 30763534 DOI: 10.1016/j.chom.2019.01.017] [Citation(s) in RCA: 339] [Impact Index Per Article: 67.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The human gut microbiome is a dense and taxonomically diverse consortium of microorganisms. While the bacterial components of the microbiome have received considerable attention, comparatively little is known about the composition and physiological significance of human gut-associated bacteriophage populations (phageome). By extrapolating our knowledge of phage-host interactions from other environments, one could expect that >1012 viruses reside in the human gut, and we can predict that they play important roles in regulating the complex microbial networks operating in this habitat. Before delving into their function, we need to first overcome the challenges associated with studying and characterizing the phageome. In this Review, we summarize the available methods and main findings regarding taxonomic composition, community structure, and population dynamics in the human gut phageome. We also discuss the main challenges in the field and identify promising avenues for future research.
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Affiliation(s)
- Andrey N Shkoporov
- APC Microbiome Ireland & School of Microbiology, University College Cork, Co. Cork, Ireland.
| | - Colin Hill
- APC Microbiome Ireland & School of Microbiology, University College Cork, Co. Cork, Ireland
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19
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The Human Gut Virome Is Highly Diverse, Stable, and Individual Specific. Cell Host Microbe 2019; 26:527-541.e5. [DOI: 10.1016/j.chom.2019.09.009] [Citation(s) in RCA: 278] [Impact Index Per Article: 55.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/09/2019] [Accepted: 09/16/2019] [Indexed: 01/09/2023]
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20
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Magaziner SJ, Zeng Z, Chen B, Salmond GPC. The Prophages of Citrobacter rodentium Represent a Conserved Family of Horizontally Acquired Mobile Genetic Elements Associated with Enteric Evolution towards Pathogenicity. J Bacteriol 2019; 201:e00638-18. [PMID: 30782635 PMCID: PMC6456863 DOI: 10.1128/jb.00638-18] [Citation(s) in RCA: 15] [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: 10/25/2018] [Accepted: 01/23/2019] [Indexed: 01/08/2023] Open
Abstract
Prophage-mediated horizontal gene transfer (HGT) plays a key role in the evolution of bacteria, enabling access to new environmental niches, including pathogenicity. Citrobacter rodentium is a host-adapted intestinal mouse pathogen and important model organism for attaching and effacing (A/E) pathogens, including the clinically significant enterohaemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC, respectively). Even though C. rodentium contains 10 prophage genomic regions, including an active temperate phage, ΦNP, little was known regarding the nature of C. rodentium prophages in the bacterium's evolution toward pathogenicity. In this study, our characterization of ΦNP led to the discovery of a second, fully functional temperate phage, named ΦSM. We identify the bacterial host receptor for both phages as lipopolysaccharide (LPS). ΦNP and ΦSM are likely important mediators of HGT in C. rodentium Bioinformatic analysis of the 10 prophage regions reveals cargo genes encoding known virulence factors, including several type III secretion system (T3SS) effectors. C. rodentium prophages are conserved across a wide range of pathogenic enteric bacteria, including EPEC and EHEC as well as pathogenic strains of Salmonella enterica, Shigella boydii, and Klebsiella pneumoniae Phylogenetic analysis of core enteric backbone genes compared against prophage evolutionary models suggests that these prophages represent an important, conserved family of horizontally acquired enteric-bacterium-associated pathogenicity determinants. In addition to highlighting the transformative role of bacteriophage-mediated HGT in C. rodentium's evolution toward pathogenicity, these data suggest that the examination of conserved families of prophages in other pathogenic bacteria and disease outbreaks might provide deeper evolutionary and pathological insights otherwise obscured by more classical analysis.IMPORTANCE Bacteriophages are obligate intracellular parasites of bacteria. Some bacteriophages can confer novel bacterial phenotypes, including pathogenicity, through horizontal gene transfer (HGT). The pathogenic bacterium Citrobacter rodentium infects mice using mechanisms similar to those employed by human gastrointestinal pathogens, making it an important model organism. Here, we examined the 10 prophages of C. rodentium, investigating their roles in its evolution toward virulence. We characterized ΦNP and ΦSM, two endogenous active temperate bacteriophages likely important for HGT. We showed that the 10 prophages encode predicted virulence factors and are conserved within other intestinal pathogens. Phylogenetic analysis suggested that they represent a conserved family of horizontally acquired enteric-bacterium-associated pathogenic determinants. Consequently, similar analysis of prophage elements in other pathogens might further understanding of their evolution and pathology.
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Affiliation(s)
- Samuel J Magaziner
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Ziyue Zeng
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Bihe Chen
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - George P C Salmond
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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21
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Isolation and characterisation of pVa-21, a giant bacteriophage with anti-biofilm potential against Vibrio alginolyticus. Sci Rep 2019; 9:6284. [PMID: 31000791 PMCID: PMC6472347 DOI: 10.1038/s41598-019-42681-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 04/01/2019] [Indexed: 12/11/2022] Open
Abstract
There is an increasing emergence of antibiotic-resistant Vibrio alginolyticus, a zoonotic pathogen that causes mass mortality in aquatic animals and infects humans; therefore, there is a demand for alternatives to antibiotics for the treatment and prevention of infections caused by this pathogen. One possibility is through the exploitation of bacteriophages. In the present study, the novel bacteriophage pVa-21 was classified as Myoviridae and characterised as a candidate biocontrol agent against V. alginolyticus. Its morphology, host range and infectivity, growth characteristics, planktonic or biofilm lytic activity, stability under various conditions, and genome were investigated. Its latent period and burst size were estimated to be approximately 70 min and 58 plaque-forming units/cell, respectively. In addition, phage pVa-21 can inhibit bacterial growth in both the planktonic and biofilm states. Furthermore, phylogenetic and genome analysis revealed that the phage is closely related to the giant phiKZ-like phages and can be classified as a new member of the phiKZ-like bacteriophages that infect bacteria belonging to the family Vibrionaceae.
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22
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The disparate effects of bacteriophages on antibiotic-resistant bacteria. Emerg Microbes Infect 2018; 7:168. [PMID: 30302018 PMCID: PMC6177407 DOI: 10.1038/s41426-018-0169-z] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 08/30/2018] [Accepted: 09/05/2018] [Indexed: 01/21/2023]
Abstract
Faced with the crisis of multidrug-resistant bacteria, bacteriophages, viruses that infect and replicate within bacteria, have been reported to have both beneficial and detrimental effects with respect to disease management. Bacteriophages (phages) have important ecological and evolutionary impacts on their bacterial hosts and have been associated with therapeutic use to kill bacterial pathogens, but can lead to the transmission of antibiotic resistance. Although the process known as transduction has been reported for many bacterial species by classic and modern genetic approaches, its contribution to the spread of antibiotic resistance in nature remains unclear. In addition, detailed molecular studies have identified phages residing in bacterial genomes, revealing unexpected interactions between phages and their bacterial hosts. Importantly, antibiotics can induce the production of phages and phage-encoded products, disseminating these viruses and virulence-related genes, which have dangerous consequences for disease severity. These unwanted side-effects of antibiotics cast doubt on the suitability of some antimicrobial treatments and may require new strategies to prevent and limit the selection for virulence. Foremost among these treatments is phage therapy, which could be used to treat many bacterial infectious diseases and confront the pressing problem of antibiotic resistance in pathogenic bacteria. This review discusses the interactions between bacteriophages, antibiotics, and bacteria and provides an integrated perspective that aims to inspire the development of successful antibacterial therapies.
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23
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Aiewsakun P, Adriaenssens EM, Lavigne R, Kropinski AM, Simmonds P. Evaluation of the genomic diversity of viruses infecting bacteria, archaea and eukaryotes using a common bioinformatic platform: steps towards a unified taxonomy. J Gen Virol 2018; 99:1331-1343. [PMID: 30016225 PMCID: PMC6230767 DOI: 10.1099/jgv.0.001110] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/13/2018] [Indexed: 01/01/2023] Open
Abstract
Genome Relationship Applied to Virus Taxonomy (GRAViTy) is a genetics-based tool that computes sequence relatedness between viruses. Composite generalized Jaccard (CGJ) distances combine measures of homology between encoded viral genes and similarities in genome organizational features (gene orders and orientations). This scoring framework effectively recapitulates the current, largely morphology and phenotypic-based, family-level classification of eukaryotic viruses. Eukaryotic virus families typically formed monophyletic groups with consistent CGJ distance cut-off dividing between and within family divergence ranges. In the current study, a parallel analysis of prokaryotic virus families revealed quite different sequence relationships, particularly those of tailed phage families (Siphoviridae, Myoviridae and Podoviridae), where members of the same family were generally far more divergent and often not detectably homologous to each other. Analysis of the 20 currently classified prokaryotic virus families indeed split them into 70 separate clusters of tailed phages genetically equivalent to family-level assignments of eukaryotic viruses. It further divided several bacterial (Sphaerolipoviridae, Tectiviridae) and archaeal (Lipothrixviridae) families. We also found that the subfamily-level groupings of tailed phages were generally more consistent with the family assignments of eukaryotic viruses, and this supports ongoing reclassifications, including Spounavirinae and Vi1virus taxa as new virus families. The current study applied a common benchmark with which to compare taxonomies of eukaryotic and prokaryotic viruses. The findings support the planned shift away from traditional morphology-based classifications of prokaryotic viruses towards a genome-based taxonomy. They demonstrate the feasibility of a unified taxonomy of viruses into which the vast body of metagenomic viral sequences may be consistently assigned.
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Affiliation(s)
- Pakorn Aiewsakun
- Nuffield Department of Medicine, University of Oxford, Peter Medawar Building, South Parks, Oxford, OX1 3SY, UK
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Evelien M. Adriaenssens
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, L69 7ZB Liverpool, UK
| | - Rob Lavigne
- Department of Biosystems, Laboratory of Gene Technology, KU Leuven. Kasteelpark Arenberg 21, Box 2462, 3001 Leuven, Belgium
| | - Andrew M. Kropinski
- Departments of Food Science, and Pathobiology, University of Guelph, 50 Stone Rd E, Guelph, ON, N1G 2W1, Canada
| | - Peter Simmonds
- Nuffield Department of Medicine, University of Oxford, Peter Medawar Building, South Parks, Oxford, OX1 3SY, UK
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24
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Abstract
Bacteriophages are the most abundant and diverse biological entities on the planet, and new phage genomes are being discovered at a rapid pace. As more phage genomes are published, new methods are needed for placing these genomes in an ecological and evolutionary context. Phages are difficult to study by phylogenetic methods, because they exchange genes regularly, and no single gene is conserved across all phages. Here, we demonstrate how gene-level networks can provide a high-resolution view of phage genetic diversity and offer a novel perspective on virus ecology. We focus our analyses on virus host range and show how network topology corresponds to host relatedness, how to find groups of genes with the strongest host-specific signatures, and how this perspective can complement phage host prediction tools. We discuss extensions of gene network analysis to predicting the emergence of phages on new hosts, as well as applications to features of phage biology beyond host range. Bacteriophages (phages) are viruses that infect bacteria, and they are critical drivers of bacterial evolution and community structure. It is generally difficult to study phages by using tree-based methods, because gene exchange is common, and no single gene is shared among all phages. Instead, networks offer a means to compare phages while placing them in a broader ecological and evolutionary context. In this work, we build a network that summarizes gene sharing across phages and test how a key constraint on phage ecology, host range, corresponds to the structure of the network. We find that the network reflects the relatedness among phage hosts, and phages with genes that are closer in the network are likelier to infect similar hosts. This approach can also be used to identify genes that affect host range, and we discuss possible extensions to analyze other aspects of viral ecology.
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25
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Abstract
Phage Mu is the paradigm of a growing family of bacteriophages that infect a wide range of bacterial species and replicate their genome by replicative transposition. This molecular process, which is used by other mobile genetic elements to move within genomes, involves the profound rearrangement of the host genome [chromosome(s) and plasmid(s)] and can be exploited for the genetic analysis of the host bacteria and the in vivo cloning of host genes. In this chapter we review Mu-derived constructs that optimize the phage as a series of genetic tools that could inspire the development of similarly efficient tools from other transposable phages for a large spectrum of bacteria.
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26
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Toussaint A, Van Gijsegem F. Extension of the transposable bacterial virus family: two genomic organisations among phages and prophages with a Tn552-related transposase. Res Microbiol 2017; 169:495-499. [PMID: 29158161 DOI: 10.1016/j.resmic.2017.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 10/26/2017] [Accepted: 11/02/2017] [Indexed: 11/28/2022]
Abstract
Mu-like transposable phages and prophages have been isolated from, or predicted, in a wide range of bacterial phyla. However, related B3-like transposable phages, which differ in their genome organisation and the DDE transposase and transposition activator they code for have thus far been restricted to a very limited set of hosts. Through sequence similarity searches, we have now expanded the number of predicted B3-like prophages and uncovered a third genomic organisation. These new genomes, although only prophages, further illustrate the previously reported mosaicism existing in the proposed "Saltoviridae" family of Caudovirales, and further support the proposal to move morphology criteria (contractile vs. flexible or short tail, i.e. Myo-vs. Sipho- or Podoviridae) from the family to the subfamily level in the taxonomic classification of the Caudovirales.
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Affiliation(s)
- Ariane Toussaint
- Université Libre de Bruxelles, Génétique et Physiologie Bactérienne (LGPB), 12 Rue des Professeurs Jeener et Brachet, 6041 Charleroi Gosselies, Belgium.
| | - Frédérique Van Gijsegem
- Sorbonne Universités, UPMC Univ Paris 06, Diderot Univ Paris 07, UPEC Univ Paris 12, CNRS, INRA, IRD, Institut d'Ecologie et des Sciences de l'Environnement de Paris (UMR7618), 4 Place Jussieu, 75252 Paris Cedex 05, France
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27
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Jäckel C, Hertwig S, Scholz HC, Nöckler K, Reetz J, Hammerl JA. Prevalence, Host Range, and Comparative Genomic Analysis of Temperate Ochrobactrum Phages. Front Microbiol 2017; 8:1207. [PMID: 28713341 PMCID: PMC5492332 DOI: 10.3389/fmicb.2017.01207] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 06/14/2017] [Indexed: 11/13/2022] Open
Abstract
Ochrobactrum and Brucella are closely related bacteria that populate different habitats and differ in their pathogenic properties. Only little is known about mobile genetic elements in these genera which might be important for survival and virulence. Previous studies on Brucella lysogeny indicated that active phages are rare in this genus. To gain insight into the presence and nature of prophages in Ochrobactrum, temperate phages were isolated from various species and characterized in detail. In silico analyses disclosed numerous prophages in published Ochrobactrum genomes. Induction experiments showed that Ochrobactrum prophages can be induced by various stress factors and that some strains released phage particles even under non-induced conditions. Sixty percent of lysates prepared from 125 strains revealed lytic activity. The host range and DNA similarities of 19 phages belonging to the families Myoviridae, Siphoviridae, or Podoviridae were determined suggesting that they are highly diverse. Some phages showed relationship to the temperate Brucella inopinata phage BiPB01. The genomic sequences of the myovirus POA1180 (41,655 bp) and podovirus POI1126 (60,065 bp) were analyzed. Phage POA1180 is very similar to a prophage recently identified in a Brucella strain isolated from an exotic frog. The POA1180 genome contains genes which may confer resistance to chromate and the ability to take up sulfate. Phage POI1126 is related to podoviruses of Sinorhizobium meliloti (PCB5), Erwinia pyrifoliae (Pep14), and Burkholderia cenocepacia (BcepIL02) and almost identical to an unnamed plasmid of the Ochrobactrum intermedium strain LMG 3301. Further experiments revealed that the POI1126 prophage indeed replicates as an extrachromosomal element. The data demonstrate for the first time that active prophages are common in Ochrobactrum and suggest that atypical brucellae also may be a reservoir for temperate phages.
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Affiliation(s)
- Claudia Jäckel
- Department of Biological Safety, German Federal Institute for Risk AssessmentBerlin, Germany
| | - Stefan Hertwig
- Department of Biological Safety, German Federal Institute for Risk AssessmentBerlin, Germany
| | - Holger C Scholz
- German Center for Infection Research, Bundeswehr Institute of MicrobiologyMunich, Germany
| | - Karsten Nöckler
- Department of Biological Safety, German Federal Institute for Risk AssessmentBerlin, Germany
| | - Jochen Reetz
- Department of Biological Safety, German Federal Institute for Risk AssessmentBerlin, Germany
| | - Jens A Hammerl
- Department of Biological Safety, German Federal Institute for Risk AssessmentBerlin, Germany
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Toussaint A, Rice PA. Transposable phages, DNA reorganization and transfer. Curr Opin Microbiol 2017; 38:88-94. [PMID: 28551392 DOI: 10.1016/j.mib.2017.04.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/13/2017] [Accepted: 04/19/2017] [Indexed: 02/07/2023]
Abstract
Transposable bacteriophages have long been known to necessarily and randomly integrate their DNA in their host genome, where they amplify by successive rounds of replicative transposition, profoundly reorganizing that genome. As a result of such transposition, a conjugative element (plasmid or genomic island), can either become integrated in the chromosome or receive chromosome segments, which can then be transferred to new hosts by conjugation. In recent years, more and more transposable phages have been isolated or detected by sequence similarity searches in a wide range of bacteria, supporting the idea that this mode of HGT may be pervasive in natural bacterial populations.
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Affiliation(s)
- Ariane Toussaint
- Génétique et Physiologie Bactérienne, Université Libre de Bruxelles, IBMM-DBM, 12 Rue des Professeurs Jeneer et Brachet, B 6041 Gosselies, Belgium.
| | - Phoebe A Rice
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 E. 57th St., Chicago, IL 60637, USA
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Jobling MG. The chromosomal nature of LT-II enterotoxins solved: a lambdoid prophage encodes both LT-II and one of two novel pertussis-toxin-like toxin family members in type II enterotoxigenic Escherichia coli. Pathog Dis 2016; 74:ftw001. [PMID: 26755534 PMCID: PMC4957749 DOI: 10.1093/femspd/ftw001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2016] [Indexed: 01/06/2023] Open
Abstract
Heat-labile enterotoxins (LT) of enterotoxigenic Escherichia coli (ETEC) are structurally and functionally related to cholera toxin (CT). LT-I toxins are plasmid-encoded and flanked by IS elements, while LT-II toxins of type II ETEC are chromosomally encoded with flanking genes that appear phage related. Here, I determined the complete genomic sequence of the locus for the LT-IIa type strain SA53, and show that the LT-IIa genes are encoded by a 51 239 bp lambdoid prophage integrated at the rac locus, the site of a defective prophage in E. coli K12 strains. Of 50 LT-IIa and LT-IIc, 46 prophages also encode one member of two novel two-gene ADP-ribosyltransferase toxin families that are both related to pertussis toxin, which I named eplBA or ealAB, respectively. The eplBA and ealAB genes are syntenic with the Shiga toxin loci in their lambdoid prophages of the enteric pathogen enterohemorrhagic E. coli. These novel AB5 toxins show pertussis-toxin-like activity on tissue culture cells, and like pertussis toxin bind to sialic acid containing glycoprotein ligands. Type II ETEC are the first mucosal pathogens known to simultaneously produce two ADP-ribosylating toxins predicted to act on and modulate activity of both stimulatory and inhibitory alpha subunits of host cell heterotrimeric G-proteins. Two novel pertussis-toxin-like toxins are also present in the genome of the prophage that also encodes the LT-II enterotoxin genes in type II enterotoxigenic Escherichi coli.
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Affiliation(s)
- Michael G Jobling
- Department of Immunology and Microbiology, University of Colorado School of Medicine, 12800 E 19th Ave, Aurora CO 80045, USA
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Lee JS, Jang HB, Kim KS, Kim TH, Im SP, Kim SW, Lazarte JMS, Kim JS, Jung TS. Complete Genomic and Lysis-Cassette Characterization of the Novel Phage, KBNP1315, which Infects Avian Pathogenic Escherichia coli (APEC). PLoS One 2015; 10:e0142504. [PMID: 26555076 PMCID: PMC4640515 DOI: 10.1371/journal.pone.0142504] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/22/2015] [Indexed: 11/18/2022] Open
Abstract
Avian pathogenic Escherichia coli (APEC) is a major pathogen that causes avian colibacillosis and is associated with severe economic losses in the chicken-farming industry. Here, bacteriophage KBNP1315, infecting APEC strain KBP1315, was genomically and functionally characterized. The evolutionary relationships of KBNP1315 were analyzed at the genomic level using gene (protein)-sharing networks, the Markov clustering (MCL) algorithm, and comparative genomics. Our network analysis showed that KBNP1315 was connected to 30 members of the Autographivirinae subfamily, which comprises the SP6-, T7-, P60-, phiKMV-, GAP227- and KP34-related groups. Network decomposition suggested that KBNP1315 belongs to the SP6-like phages, but our comparison of putative encoded proteins revealed that key proteins of KBNP1315, including the tail spike protein and endolysin, had relative low levels of amino acid sequence similarity with other members of the SP6-like phages. Thus KBNP1315 may only be distantly related to the SP6-like phages, and (based on the difference in endolysin) its lysis mechanism may differ from theirs. To characterize the lytic functions of the holin and endolysin proteins from KBNP1315, we expressed these proteins individually or simultaneously in E. coli BL21 (DE3) competent cell. Interestingly, the expressed endolysin was secreted into the periplasm and caused a high degree of host cell lysis that was dose-dependently delayed/blocked by NaN3-mediated inhibition of the SecA pathway. The expressed holin triggered only a moderate inhibition of cell growth, whereas coexpression of holin and endolysin enhanced the lytic effect of endolysin. Together, these results revealed that KBNP1315 appears to use a pin-holin/signal-arrest-release (SAR) endolysin pathway to trigger host cell lysis.
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Affiliation(s)
- Jung Seok Lee
- Laboratory of Aquatic Animal Diseases, Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, South Korea
| | - Ho Bin Jang
- Laboratory of Gene Technology, KU Leuven, Kasteelpark Arenberg 21, 3001, Leuven, Belgium
| | - Ki Sei Kim
- KBNP Technology Institute, KBNP, Inc., Yesan, Choongcheongnam-do, South Korea
| | - Tae Hwan Kim
- KBNP Technology Institute, KBNP, Inc., Yesan, Choongcheongnam-do, South Korea
| | - Se Pyeong Im
- Laboratory of Aquatic Animal Diseases, Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, South Korea
| | - Si Won Kim
- Laboratory of Aquatic Animal Diseases, Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, South Korea
| | - Jassy Mary S. Lazarte
- Laboratory of Aquatic Animal Diseases, Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, South Korea
| | - Jae Sung Kim
- Laboratory of Aquatic Animal Diseases, Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, South Korea
| | - Tae Sung Jung
- Laboratory of Aquatic Animal Diseases, Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, South Korea
- * E-mail:
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Alves DR, Perez-Esteban P, Kot W, Bean JE, Arnot T, Hansen LH, Enright MC, Jenkins ATA. A novel bacteriophage cocktail reduces and disperses Pseudomonas aeruginosa biofilms under static and flow conditions. Microb Biotechnol 2015; 9:61-74. [PMID: 26347362 PMCID: PMC4720417 DOI: 10.1111/1751-7915.12316] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Revised: 08/10/2015] [Accepted: 08/11/2015] [Indexed: 01/21/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic human pathogen that forms highly stable communities - biofilms, which contribute to the establishment and maintenance of infections. The biofilm state and intrinsic/acquired bacterial resistance mechanisms contribute to resistance/tolerance to antibiotics that is frequently observed in P. aeruginosa isolates. Here we describe the isolation and characterization of six novel lytic bacteriophages: viruses that infect bacteria, which together efficiently infect and kill a wide range of P. aeruginosa clinical isolates. The phages were used to formulate a cocktail with the potential to eliminate P. aeruginosa PAO1 planktonic cultures. Two biofilm models were studied, one static and one dynamic, and the phage cocktail was assessed for its ability to reduce and disperse the biofilm biomass. For the static model, after 4 h of contact with the phage suspension (MOI 10) more than 95% of biofilm biomass was eliminated. In the flow biofilm model, a slower rate of activity by the phage was observed, but 48 h after addition of the phage cocktail the biofilm was dispersed, with most cells eliminated (> 4 logs) comparing with the control. This cocktail has the potential for development as a therapeutic to control P. aeruginosa infections, which are predominantly biofilm centred.
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Affiliation(s)
- Diana R Alves
- Department of Chemistry, University of Bath, Bath, Claverton Down, BA2 7AY, UK
| | - P Perez-Esteban
- Department of Chemical Engineering, University of Bath, Bath, Claverton Down, BA2 7AY, UK
| | - W Kot
- Department of Environmental Science, Aarhus Universitet, Frederiksborgvej 399, Postboks, 358, Roskilde, DK-4000, Denmark
| | - J E Bean
- Department of Chemistry, University of Bath, Bath, Claverton Down, BA2 7AY, UK
| | - T Arnot
- Department of Chemical Engineering, University of Bath, Bath, Claverton Down, BA2 7AY, UK
| | - L H Hansen
- Department of Environmental Science, Aarhus Universitet, Frederiksborgvej 399, Postboks, 358, Roskilde, DK-4000, Denmark
| | - Mark C Enright
- School of Healthcare Sciences, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, M1 5GD, UK
| | - A Tobias A Jenkins
- Department of Chemistry, University of Bath, Bath, Claverton Down, BA2 7AY, UK
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Jäckel C, Hammerl JA, Reetz J, Kropinski AM, Hertwig S. Campylobacter group II phage CP21 is the prototype of a new subgroup revealing a distinct modular genome organization and host specificity. BMC Genomics 2015; 16:629. [PMID: 26296758 PMCID: PMC4546147 DOI: 10.1186/s12864-015-1837-1] [Citation(s) in RCA: 12] [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: 03/11/2015] [Accepted: 08/13/2015] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND The application of phages is a promising tool to reduce the number of Campylobacter along the food chain. Besides the efficacy against a broad range of strains, phages have to be safe in terms of their genomes. Thus far, no genes with pathogenic potential (e.g., genes encoding virulence factors) have been detected in Campylobacter phages. However, preliminary studies suggested that the genomes of group II phages may be diverse and prone to genomic rearrangements. RESULTS We determined and analysed the genomic sequence (182,761 bp) of group II phage CP21 that is closely related to the already characterized group II phages CP220 and CPt10. The genomes of these phages are comprised of four modules separated by very similar repeat regions, some of which harbouring open reading frames (ORFs). Though, the arrangement of the modules and the location of some ORFs on the genomes are different in CP21 and in CP220/CPt10. In this work, a PCR system was established to study the modular genome organization of other group II phages demonstrating that they belong to different subgroups of the CP220-like virus genus, the prototypes of which are CP21 and CP220. The subgroups revealed different restriction patterns and, interestingly enough, also distinct host specificities, tail fiber proteins and tRNA genes. We additionally analysed the genome of group II phage vB_CcoM-IBB_35 (IBB_35) for which to date only five individual contigs could be determined. We show that the contigs represent modules linked by long repeat regions enclosing some yet not identified ORFs (e.g., for a head completion protein). The data suggest that IBB_35 is a member of the CP220 subgroup. CONCLUSION Campylobacter group II phages are diverse regarding their genome organization. Since all hitherto characterized group II phages contain numerous genes for transposases and homing endonucleases as well as similar repeat regions, it cannot be excluded that these phages are genetically unstable. To answer this question, further experiments and sequencing of more group II phages should be performed.
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Affiliation(s)
- Claudia Jäckel
- ᅟ, Federal Institute for Risk Assessment, Department of Biological Safety, Berlin, Germany.
| | - Jens A Hammerl
- ᅟ, Federal Institute for Risk Assessment, Department of Biological Safety, Berlin, Germany.
| | - Jochen Reetz
- ᅟ, Federal Institute for Risk Assessment, Department of Biological Safety, Berlin, Germany.
| | - Andrew M Kropinski
- Departments of Food Science & Molecular and Cellular Biology & Pathobiology, University of Guelph, Ontario, Canada.
| | - Stefan Hertwig
- ᅟ, Federal Institute for Risk Assessment, Department of Biological Safety, Berlin, Germany.
- Abteilung Biologische Sicherheit, Bundesinstitut für Risikobewertung, Diagnostik und Erregercharakterisierung, Diedersdorfer Weg 1, D-12277, Berlin, Germany.
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33
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A proposed new bacteriophage subfamily: “Jerseyvirinae”. Arch Virol 2015; 160:1021-33. [DOI: 10.1007/s00705-015-2344-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 01/17/2015] [Indexed: 01/21/2023]
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34
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Hulo C, Masson P, Le Mercier P, Toussaint A. A structured annotation frame for the transposable phages: a new proposed family "Saltoviridae" within the Caudovirales. Virology 2014; 477:155-163. [PMID: 25500185 DOI: 10.1016/j.virol.2014.10.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/02/2014] [Accepted: 10/06/2014] [Indexed: 11/17/2022]
Abstract
Enterobacteriophage Mu is the best studied and paradigm member of the transposable phages. Mu-encoded proteins have been annotated in detail in UniProtKB and linked to a controlled vocabulary describing the various steps involved in the phage lytic and lysogenic cycles. Transposable phages are ubiquitous temperate bacterial viruses with a dsDNA linear genome. Twenty-six of them, that infect α, β and γ-proteobacteria, have been sequenced. Their conserved properties are described. Based on these characteristics, we propose a reorganization of the Caudovirales, to allow for the inclusion of a "Saltoviridae" family and two newly proposed subfamilies, the "Myosaltovirinae" and "Siphosaltovirinae". The latter could temporarily be included in the existing Myoviridae and Siphoviridae families.
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Affiliation(s)
- Chantal Hulo
- Swiss-Prot Group, Swiss Institute of Bioinformatics, Centre Médical Universitaire, CH-1211 Geneva 4, Switzerland
| | - Patrick Masson
- Swiss-Prot Group, Swiss Institute of Bioinformatics, Centre Médical Universitaire, CH-1211 Geneva 4, Switzerland
| | - Philippe Le Mercier
- Swiss-Prot Group, Swiss Institute of Bioinformatics, Centre Médical Universitaire, CH-1211 Geneva 4, Switzerland
| | - Ariane Toussaint
- Université Libre de Bruxelles, Génétique et Physiologie Bactérienne (LGPB), 12 rue des Professeurs Jeener et Brachet, 6041 Charleroi (Gosselies), Belgium.
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35
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Combined use of bacteriophage K and a novel bacteriophage to reduce Staphylococcus aureus biofilm formation. Appl Environ Microbiol 2014; 80:6694-703. [PMID: 25149517 DOI: 10.1128/aem.01789-14] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Biofilms are major causes of impairment of wound healing and patient morbidity. One of the most common and aggressive wound pathogens is Staphylococcus aureus, displaying a large repertoire of virulence factors and commonly reduced susceptibility to antibiotics, such as the spread of methicillin-resistant S. aureus (MRSA). Bacteriophages are obligate parasites of bacteria. They multiply intracellularly and lyse their bacterial host, releasing their progeny. We isolated a novel phage, DRA88, which has a broad host range among S. aureus bacteria. Morphologically, the phage belongs to the Myoviridae family and comprises a large double-stranded DNA (dsDNA) genome of 141,907 bp. DRA88 was mixed with phage K to produce a high-titer mixture that showed strong lytic activity against a wide range of S. aureus isolates, including representatives of the major international MRSA clones and coagulase-negative Staphylococcus. Its efficacy was assessed both in planktonic cultures and when treating established biofilms produced by three different biofilm-producing S. aureus isolates. A significant reduction of biofilm biomass over 48 h of treatment was recorded in all cases. The phage mixture may form the basis of an effective treatment for infections caused by S. aureus biofilms.
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Phylogenomic network and comparative genomics reveal a diverged member of the ΦKZ-related group, marine vibrio phage ΦJM-2012. J Virol 2013; 87:12866-78. [PMID: 24067958 DOI: 10.1128/jvi.02656-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Bacteriophages are the largest reservoir of genetic diversity. Here we describe the novel phage ΦJM-2012. This natural isolate from marine Vibrio cyclitrophicus possesses very few gene contents relevant to other well-studied marine Vibrio phages. To better understand its evolutionary history, we built a mathematical model of pairwise relationships among 1,221 phage genomes, in which the genomes (nodes) are linked by edges representing the normalized number of shared orthologous protein families. This weighted network revealed that ΦJM-2012 was connected to only five members of the Pseudomonas ΦKZ-like phage family in an isolated network, strongly indicating that it belongs to this phage group. However, comparative genomic analyses highlighted an almost complete loss of colinearity with the ΦKZ-related genomes and little conservation of gene order, probably reflecting the action of distinct evolutionary forces on the genome of ΦJM-2012. In this phage, typical conserved core genes, including six RNA polymerase genes, were frequently displaced and the hyperplastic regions were rich in both unique genes and predicted unidirectional promoters with highly correlated orientations. Further, analysis of the ΦJM-2012 genome showed that segments of the conserved N-terminal parts of ΦKZ tail fiber paralogs exhibited evidence of combinatorial assortment, having switched transcriptional orientation, and there was recruitment and/or structural changes among phage endolysins and tail spike protein. Thus, this naturally occurring phage appears to have branched from a common ancestor of the ΦKZ-related groups, showing a distinct genomic architecture and unique genes that most likely reflect adaptation to its chosen host and environment.
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37
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Toussaint A. Transposable Mu-like phages in Firmicutes: new instances of divergence generating retroelements. Res Microbiol 2013; 164:281-7. [DOI: 10.1016/j.resmic.2013.01.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Accepted: 01/09/2013] [Indexed: 10/27/2022]
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Abstract
Due to their crucial role in pathogenesis and virulence, phages of Staphylococcus aureus have been extensively studied. Most of them encode and disseminate potent staphylococcal virulence factors. In addition, their movements contribute to the extraordinary versatility and adaptability of this prominent pathogen by improving genome plasticity. In addition to S. aureus, phages from coagulase-negative Staphylococci (CoNS) are gaining increasing interest. Some of these species, such as S. epidermidis, cause nosocomial infections and are therefore problematic for public health. This review provides an overview of the staphylococcal phages family extended to CoNS phages. At the morphological level, all these phages characterized so far belong to the Caudovirales order and are mainly temperate Siphoviridae. At the molecular level, comparative genomics revealed an extensive mosaicism, with genes organized into functional modules that are frequently exchanged between phages. Evolutionary relationships within this family, as well as with other families, have been highlighted. All these aspects are of crucial importance for our understanding of evolution and emergence of pathogens among bacterial species such as Staphylococci.
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Affiliation(s)
- Marie Deghorain
- Author to whom correspondence should be addressed; (L.V.M.); (M.D.); Tel.: +32-2-650-97-76 (M.D.); +32-2-650-97-78 (L.V.M.); Fax: +32-2-650-97-70
| | - Laurence Van Melderen
- Author to whom correspondence should be addressed; (L.V.M.); (M.D.); Tel.: +32-2-650-97-76 (M.D.); +32-2-650-97-78 (L.V.M.); Fax: +32-2-650-97-70
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Mebrhatu MT, Cenens W, Aertsen A. An overview of the domestication and impact of the Salmonella mobilome. Crit Rev Microbiol 2013; 40:63-75. [PMID: 23356413 DOI: 10.3109/1040841x.2012.755949] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Salmonella spp. are accountable for a large fraction of the global infectious disease burden, with most of their infections being food- or water-borne. The phenotypic features and adaptive potential of Salmonella spp. appear to be driven to a large extent by mobile or laterally acquired genetic elements. A better understanding of the conduct and diversification of these important pathogens consequently requires a more profound insight into the different mechanisms by which these pivotal elements establish themselves in the cell and affect its behavior. This review, therefore, provides an overview of the physiological impact and domestication of the Salmonella mobilome.
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Affiliation(s)
- Mehari Tesfazgi Mebrhatu
- Laboratory of Food Microbiology, Department of Microbial and Molecular Systems (M2S), Faculty of Bioscience Engineering, KU Leuven , Leuven , Belgium
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Samson JE, Moineau S. Bacteriophages in food fermentations: new frontiers in a continuous arms race. Annu Rev Food Sci Technol 2012; 4:347-68. [PMID: 23244395 DOI: 10.1146/annurev-food-030212-182541] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phage contamination represents an important risk to any process requiring bacterial growth, particularly in the biotechnology and food industries. The presence of unwanted phages may lead to manufacturing delays, lower quality product, or, in the worst cases, total production loss. Thus, constant phage monitoring and stringent application of the appropriate control measures are indispensable. In fact, a systematic preventive approach to phage contamination [phage analysis and critical control points (PACCP)] should be put in place. In this review, sources of phage contamination and novel phage detection methods are described, with an emphasis on bacterial viruses that infect lactic acid bacteria used in food fermentations. Recent discoveries related to antiphage systems that are changing our views on phage-host interactions are highlighted. Finally, future directions are also discussed.
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Affiliation(s)
- Julie E Samson
- Département debiochimie, de microbiologie et de bio-informatique, Université Laval, Québec, Canada.
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Characterization of novel phages isolated in coagulase-negative staphylococci reveals evolutionary relationships with Staphylococcus aureus phages. J Bacteriol 2012; 194:5829-39. [PMID: 22923589 DOI: 10.1128/jb.01085-12] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Despite increasing interest in coagulase-negative staphylococci (CoNS), little information is available about their bacteriophages. We isolated and sequenced three novel temperate Siphoviridae phages (StB12, StB27, and StB20) from the CoNS Staphylococcus hominis and S. capitis species. The genome sizes are around 40 kb, and open reading frames (ORFs) are arranged in functional modules encoding lysogeny, DNA metabolism, morphology, and cell lysis. Bioinformatics analysis allowed us to assign a potential function to half of the predicted proteins. Structural elements were further identified by proteomic analysis of phage particles, and DNA-packaging mechanisms were determined. Interestingly, the three phages show identical integration sites within their host genomes. In addition to this experimental characterization, we propose a novel classification based on the analysis of 85 phage and prophage genomes, including 15 originating from CoNS. Our analysis established 9 distinct clusters and revealed close relationships between S. aureus and CoNS phages. Genes involved in DNA metabolism and lysis and potentially in phage-host interaction appear to be widespread, while structural genes tend to be cluster specific. Our findings support the notion of a possible reciprocal exchange of genes between phages originating from S. aureus and CoNS, which may be of crucial importance for pathogenesis in staphylococci.
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Conservation of gene cassettes among diverse viruses of the human gut. PLoS One 2012; 7:e42342. [PMID: 22900013 PMCID: PMC3416800 DOI: 10.1371/journal.pone.0042342] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 07/03/2012] [Indexed: 01/13/2023] Open
Abstract
Viruses are a crucial component of the human microbiome, but large population sizes, high sequence diversity, and high frequencies of novel genes have hindered genomic analysis by high-throughput sequencing. Here we investigate approaches to metagenomic assembly to probe genome structure in a sample of 5.6 Gb of gut viral DNA sequence from six individuals. Tests showed that a new pipeline based on DeBruijn graph assembly yielded longer contigs that were able to recruit more reads than the equivalent non-optimized, single-pass approach. To characterize gene content, the database of viral RefSeq proteins was compared to the assembled viral contigs, generating a bipartite graph with functional cassettes linking together viral contigs, which revealed a high degree of connectivity between diverse genomes involving multiple genes of the same functional class. In a second step, open reading frames were grouped by their co-occurrence on contigs in a database-independent manner, revealing conserved cassettes of co-oriented ORFs. These methods reveal that free-living bacteriophages, while usually dissimilar at the nucleotide level, often have significant similarity at the level of encoded amino acid motifs, gene order, and gene orientation. These findings thus connect contemporary metagenomic analysis with classical studies of bacteriophage genomic cassettes. Software is available at https://sourceforge.net/projects/optitdba/.
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Diemer GS, Stedman KM. A novel virus genome discovered in an extreme environment suggests recombination between unrelated groups of RNA and DNA viruses. Biol Direct 2012; 7:13. [PMID: 22515485 PMCID: PMC3372434 DOI: 10.1186/1745-6150-7-13] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 04/19/2012] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Viruses are known to be the most abundant organisms on earth, yet little is known about their collective origin and evolutionary history. With exceptionally high rates of genetic mutation and mosaicism, it is not currently possible to resolve deep evolutionary histories of the known major virus groups. Metagenomics offers a potential means of establishing a more comprehensive view of viral evolution as vast amounts of new sequence data becomes available for comparative analysis. RESULTS Bioinformatic analysis of viral metagenomic sequences derived from a hot, acidic lake revealed a circular, putatively single-stranded DNA virus encoding a major capsid protein similar to those found only in single-stranded RNA viruses. The presence and circular configuration of the complete virus genome was confirmed by inverse PCR amplification from native DNA extracted from lake sediment. The virus genome appears to be the result of a RNA-DNA recombination event between two ostensibly unrelated virus groups. Environmental sequence databases were examined for homologous genes arranged in similar configurations and three similar putative virus genomes from marine environments were identified. This result indicates the existence of a widespread but previously undetected group of viruses. CONCLUSIONS This unique viral genome carries implications for theories of virus emergence and evolution, as no mechanism for interviral RNA-DNA recombination has yet been identified, and only scant evidence exists that genetic exchange occurs between such distinct virus lineages. REVIEWERS This article was reviewed by EK, MK (nominated by PF) and AM. For the full reviews, please go to the Reviewers' comments section.
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Affiliation(s)
- Geoffrey S Diemer
- Department of Biology, and the Center for Life in Extreme Environments, Portland State University, 1719 SW 10th Avenue, SRTC room 246, Portland, OR 97201, USA
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McNair K, Bailey BA, Edwards RA. PHACTS, a computational approach to classifying the lifestyle of phages. ACTA ACUST UNITED AC 2012; 28:614-8. [PMID: 22238260 PMCID: PMC3289917 DOI: 10.1093/bioinformatics/bts014] [Citation(s) in RCA: 171] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Motivation: Bacteriophages have two distinct lifestyles: virulent and temperate. The virulent lifestyle has many implications for phage therapy, genomics and microbiology. Determining which lifestyle a newly sequenced phage falls into is currently determined using standard culturing techniques. Such laboratory work is not only costly and time consuming, but also cannot be used on phage genomes constructed from environmental sequencing. Therefore, a computational method that utilizes the sequence data of phage genomes is needed. Results: Phage Classification Tool Set (PHACTS) utilizes a novel similarity algorithm and a supervised Random Forest classifier to make a prediction whether the lifestyle of a phage, described by its proteome, is virulent or temperate. The similarity algorithm creates a training set from phages with known lifestyles and along with the lifestyle annotation, trains a Random Forest to classify the lifestyle of a phage. PHACTS predictions are shown to have a 99% precision rate. Availability and implementation: PHACTS was implemented in the PERL programming language and utilizes the FASTA program (Pearson and Lipman, 1988) and the R programming language library ‘Random Forest’ (Liaw and Weiner, 2010). The PHACTS software is open source and is available as downloadable stand-alone version or can be accessed online as a user-friendly web interface. The source code, help files and online version are available at http://www.phantome.org/PHACTS/. Contact:katelyn@rohan.sdsu.edu; redwards@sciences.sdsu.edu Supplementary information:Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Katelyn McNair
- Computational Science Research Center, Department of Mathematics and Statistics, San Diego State University, San Diego, CA 92182, USA.
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Bezuidt O, Pierneef R, Mncube K, Lima-Mendez G, Reva ON. Mainstreams of horizontal gene exchange in enterobacteria: consideration of the outbreak of enterohemorrhagic E. coli O104:H4 in Germany in 2011. PLoS One 2011; 6:e25702. [PMID: 22022434 PMCID: PMC3195076 DOI: 10.1371/journal.pone.0025702] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 09/08/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Escherichia coli O104:H4 caused a severe outbreak in Europe in 2011. The strain TY-2482 sequenced from this outbreak allowed the discovery of its closest relatives but failed to resolve ways in which it originated and evolved. On account of the previous statement, may we expect similar upcoming outbreaks to occur recurrently or spontaneously in the future? The inability to answer these questions shows limitations of the current comparative and evolutionary genomics methods. PRINCIPAL FINDINGS The study revealed oscillations of gene exchange in enterobacteria, which originated from marine γ-Proteobacteria. These mobile genetic elements have become recombination hotspots and effective 'vehicles' ensuring a wide distribution of successful combinations of fitness and virulence genes among enterobacteria. Two remarkable peculiarities of the strain TY-2482 and its relatives were observed: i) retaining the genetic primitiveness by these strains as they somehow avoided the main fluxes of horizontal gene transfer which effectively penetrated other enetrobacteria; ii) acquisition of antibiotic resistance genes in a plasmid genomic island of β-Proteobacteria origin which ontologically is unrelated to the predominant genomic islands of enterobacteria. CONCLUSIONS Oscillations of horizontal gene exchange activity were reported which result from a counterbalance between the acquired resistance of bacteria towards existing mobile vectors and the generation of new vectors in the environmental microflora. We hypothesized that TY-2482 may originate from a genetically primitive lineage of E. coli that has evolved in confined geographical areas and brought by human migration or cattle trade onto an intersection of several independent streams of horizontal gene exchange. Development of a system for monitoring the new and most active gene exchange events was proposed.
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Affiliation(s)
- Oliver Bezuidt
- Bioinformatics and Computational Biology Unit, Department of Biochemistry, University of Pretoria, Pretoria, South Africa
| | - Rian Pierneef
- Bioinformatics and Computational Biology Unit, Department of Biochemistry, University of Pretoria, Pretoria, South Africa
| | - Kingdom Mncube
- Bioinformatics and Computational Biology Unit, Department of Biochemistry, University of Pretoria, Pretoria, South Africa
| | - Gipsi Lima-Mendez
- Laboratoire de Bioinformatique des Génomes et des Réseaux (BiGRe), Université Libre de Bruxelles, Bruxelles, Belgium
| | - Oleg N. Reva
- Bioinformatics and Computational Biology Unit, Department of Biochemistry, University of Pretoria, Pretoria, South Africa
- * E-mail:
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