1
|
Yang M, Du S, Zhang Z, Xia Q, Liu H, Qin F, Wu Z, Ying H, Wu Y, Shao J, Zhao Y. Genomic diversity and biogeographic distributions of a novel lineage of bacteriophages that infect marine OM43 bacteria. Microbiol Spectr 2023; 11:e0494222. [PMID: 37607063 PMCID: PMC10580990 DOI: 10.1128/spectrum.04942-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 07/07/2023] [Indexed: 08/24/2023] Open
Abstract
The marine methylotrophic OM43 clade is considered an important bacterial group in coastal microbial communities. OM43 bacteria, which are closely related to phytoplankton blooms, have small cell sizes and streamlined genomes. Bacteriophages profoundly shape the evolutionary trajectories, population dynamics, and physiology of microbes. The prevalence and diversity of several phages that infect OM43 bacteria have been reported. In this study, we isolated and sequenced two novel OM43 phages, MEP401 and MEP402. These phages share 90% of their open reading frames (ORFs) and are distinct from other known phage isolates. Furthermore, a total of 99 metagenomic viral genomes (MVGs) closely related to MEP401 and MEP402 were identified. Phylogenomic analyses suggest that MEP401, MEP402, and these identified MVGs belong to a novel subfamily in the family Zobellviridae and that they can be separated into two groups. Group I MVGs show conserved whole-genome synteny with MEP401, while group II MVGs possess the MEP401-type DNA replication module and a distinct type of morphogenesis and packaging module, suggesting that genomic recombination occurred between phages. Most members in these two groups were predicted to infect OM43 bacteria. Metagenomic read-mapping analysis revealed that the phages in these two groups are globally ubiquitous and display distinct biogeographic distributions, with some phages being predominant in cold regions, some exclusively detected in estuarine stations, and others displaying wider distributions. This study expands our knowledge of the diversity and ecology of a novel phage lineage that infects OM43 bacteria by describing their genomic diversity and global distribution patterns. IMPORTANCE OM43 phages that infect marine OM43 bacteria are important for host mortality, community structure, and physiological functions. In this study, two OM43 phages were isolated and characterized. Metagenomic viral genome (MVG) retrieval using these two OM43 phages as baits led to the identification of two phage groups of a new subfamily in the family Zobellviridae. We found that group I MVGs share similar genomic content and arrangement with MEP401 and MEP402, whereas group II MVGs only possess the MEP401-type DNA replication module. Metagenomic mapping analysis suggests that members in these two groups are globally ubiquitous with distinct distribution patterns. This study provides important insights into the genomic diversity and biogeography of the OM43 phages in the global ocean.
Collapse
Affiliation(s)
- Mingyu Yang
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Sen Du
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zefeng Zhang
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qian Xia
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - He Liu
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Fang Qin
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zuqing Wu
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Hanqi Ying
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yin Wu
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jiabing Shao
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yanlin Zhao
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou, China
| |
Collapse
|
2
|
Kupczok A, Bailey ZM, Refardt D, Wendling CC. Co-transfer of functionally interdependent genes contributes to genome mosaicism in lambdoid phages. Microb Genom 2022; 8:mgen000915. [PMID: 36748576 PMCID: PMC9836094 DOI: 10.1099/mgen.0.000915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Lambdoid (or Lambda-like) phages are a group of related temperate phages that can infect Escherichia coli and other gut bacteria. A key characteristic of these phages is their mosaic genome structure, which served as the basis for the 'modular genome hypothesis'. Accordingly, lambdoid phages evolve by transferring genomic regions, each of which constitutes a functional unit. Nevertheless, it is unknown which genes are preferentially transferred together and what drives such co-transfer events. Here we aim to characterize genome modularity by studying co-transfer of genes among 95 distantly related lambdoid (pro-)phages. Based on gene content, we observed that the genomes cluster into 12 groups, which are characterized by a highly similar gene content within the groups and highly divergent gene content across groups. Highly similar proteins can occur in genomes of different groups, indicating that they have been transferred. About 26 % of homologous protein clusters in the four known operons (i.e. the early left, early right, immunity and late operon) engage in gene transfer, which affects all operons to a similar extent. We identified pairs of genes that are frequently co-transferred and observed that these pairs tend to be near one another on the genome. We find that frequently co-transferred genes are involved in related functions and highlight interesting examples involving structural proteins, the cI repressor and Cro regulator, proteins interacting with DNA, and membrane-interacting proteins. We conclude that epistatic effects, where the functioning of one protein depends on the presence of another, play an important role in the evolution of the modular structure of these genomes.
Collapse
Affiliation(s)
- Anne Kupczok
- Bioinformatics Group, Wageningen University & Research, Wageningen, Netherlands,*Correspondence: Anne Kupczok,
| | - Zachary M. Bailey
- ETH Zürich, Institute of Integrative Biology, Universitätstrasse 16, Zürich, Switzerland
| | - Dominik Refardt
- Institute of Natural Resource Sciences, Zürich University of Applied Sciences, Campus Grüental, Wädenswil, Switzerland
| | - Carolin C. Wendling
- ETH Zürich, Institute of Integrative Biology, Universitätstrasse 16, Zürich, Switzerland
| |
Collapse
|
3
|
Phenotypic characterization and genome analysis of a novel Salmonella Typhimurium phage having unique tail fiber genes. Sci Rep 2022; 12:5732. [PMID: 35388062 PMCID: PMC8986868 DOI: 10.1038/s41598-022-09733-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 03/28/2022] [Indexed: 11/25/2022] Open
Abstract
Salmonella enterica serovar Typhimurium is a foodborne pathogen causing occasional outbreaks of enteric infections in humans. Salmonella has one of the largest pools of temperate phages in its genome that possess evolutionary significance for pathogen. In this study, we characterized a novel temperate phage Salmonella phage BIS20 (BIS20) with unique tail fiber genes. It belongs to the subfamily Peduovirinae genus Eganvirus and infects Salmonella Typhimurium strain (SE-BS17; Acc. NO MZ503545) of poultry origin. Phage BIS20 was viable only at biological pH and temperature ranges (pH7 and 37 °C). Despite being temperate BIS20 significantly slowed down the growth of host strain for 24 h as compared to control (P < 0.009). Phage BIS20 features 29,477-base pair (bp) linear DNA genome with 53% GC content and encodes for 37 putative ORFs. These ORFs have mosaic arrangement as indicated by its ORF similarity to various phages and prophages in NCBI. Genome analysis indicates its similarity to Salmonella enterica serovar Senftenberg prophage (SEStP) sequence (Nucleotide similarity 87.7%) and Escherichia virus 186 (~ 82.4% nucleotide similarity). Capsid genes were conserved however those associated with tail fiber formation and assembly were unique to all members of genus Eganvirus. We found strong evidence of recombination hotspot in tail fiber gene. Our study identifies BIS20 as a new species of genus Eganvirus temperate phages as its maximum nucleotide similarity is 82.4% with any phage in NCBI. Our findings may contribute to understanding of origin of new temperate phages.
Collapse
|
4
|
Boeckman J, Korn A, Yao G, Ravindran A, Gonzalez C, Gill J. Sheep in wolves’ clothing: Temperate T7-like bacteriophages and the origins of the Autographiviridae. Virology 2022; 568:86-100. [DOI: 10.1016/j.virol.2022.01.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/14/2022] [Accepted: 01/22/2022] [Indexed: 12/25/2022]
|
5
|
Genomic Characterization of Two Novel RCA Phages Reveals New Insights into the Diversity and Evolution of Marine Viruses. Microbiol Spectr 2021; 9:e0123921. [PMID: 34668749 PMCID: PMC8528129 DOI: 10.1128/spectrum.01239-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Viruses are the most abundant living entities in marine ecosystems, playing critical roles in altering the structure and function of microbial communities and driving ocean biogeochemistry. Phages that infect Roseobacter clade-affiliated (RCA) cluster strains are an important component of marine viral communities. Here, we characterize the genome sequences of two new RCA phages, CRP-9 and CRP-13, which infect RCA strain FZCC0023. Genomic analysis reveals that CRP-9 and CRP-13 represent a novel evolutionary lineage of marine phages. They both have a DNA replication module most similar to those in Cobavirus group phages. In contrast, their morphogenesis and packaging modules are distinct from those in cobaviruses but homologous to those in HMO-2011-type phages. The genomic architecture of CRP-9 and CRP-13 suggests a genomic recombination event between distinct phage groups. Metagenomic data sets were examined for metagenome-assembled viral genomes (MAVGs) with similar recombinant genome architectures. Fifteen CRP-9-type MAVGs were identified from marine viromes. Additionally, 158 MAVGs were identified containing HMO-2011-type morphogenesis and packaging modules with other types of DNA replication genes, providing more evidence that recombination between different phage groups is a major driver of phage evolution. Altogether, this study significantly expands the understanding of diversity and evolution of marine roseophages. Meanwhile, the analysis of these novel RCA phages and MAVGs highlights the critical role of recombination in shaping phage diversity. These phage sequences are valuable resources for inferring the evolutionary connection of distinct phage groups. IMPORTANCE Diversity and evolution of phages that infect the relatively slow-growing but dominant Roseobacter lineages are largely unknown. In this study, RCA phages CRP-9 and CRP-13 have been isolated on a Roseobacter RCA strain and shown to have a unique genomic architecture, which appears to be the result of a recombination event. CRP-9 and CRP-13 have a DNA replication module most similar to those in Cobavirus group phages and morphogenesis and packaging modules most similar to those in HMO-2011-type phages. HMO-2011-type morphogenesis and packaging modules are found in combination with distinct types of DNA replication genes, suggesting compatibility with various DNA replication modules. Altogether, this study contributes toward a better understanding of marine viral diversity and evolution.
Collapse
|
6
|
Naorem RS, Goswami G, Gyorgy S, Fekete C. Comparative analysis of prophages carried by human and animal-associated Staphylococcus aureus strains spreading across the European regions. Sci Rep 2021; 11:18994. [PMID: 34556764 PMCID: PMC8460829 DOI: 10.1038/s41598-021-98432-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 07/08/2021] [Indexed: 02/08/2023] Open
Abstract
Staphylococcus aureus is a major human and animal pathogen although the animal-associated S. aureus can be a potential risk of human zoonoses. Acquisition of phage-related genomic islands determines the S. aureus species diversity. This study characterized and compared the genome architecture, distribution nature, and evolutionary relationship of 65 complete prophages carried by human and animal-associated S. aureus strains spreading across the European regions. The analyzed prophage genomes showed mosaic architecture with extensive variation in genome size. The phylogenetic analyses generated seven clades in which prophages of the animal-associated S. aureus scattered in all the clades. The S. aureus strains with the same SCCmec type, and clonal complex favored the harboring of similar prophage sequences and suggested that the frequency of phage-mediated horizontal gene transfer is higher between them. The presence of various virulence factors in prophages of animal-associated S. aureus suggested that these prophages could have more pathogenic potential than prophages of human-associated S. aureus. This study showed that the S. aureus phages are dispersed among the several S. aureus serotypes and around the European regions. Further, understanding the phage functional genomics is necessary for the phage-host interactions and could be used for tracing the S. aureus strains transmission.
Collapse
Affiliation(s)
- Romen Singh Naorem
- grid.9679.10000 0001 0663 9479Department of General and Environmental Microbiology, Institute of Biology and Sport Biology, University of Pécs, Ifjusag utja. 6, Pecs, 7624 Hungary
| | - Gunajit Goswami
- Multidisciplinary Research Unit, Jorhat Medical College and Hospital, Jorhat, Assam India
| | - Schneider Gyorgy
- grid.9679.10000 0001 0663 9479Department of Medical Microbiology and Immunology, Medical School, University of Pécs, Pecs, Hungary
| | - Csaba Fekete
- grid.9679.10000 0001 0663 9479Department of General and Environmental Microbiology, Institute of Biology and Sport Biology, University of Pécs, Ifjusag utja. 6, Pecs, 7624 Hungary
| |
Collapse
|
7
|
Hanemaaijer L, Kelleher P, Neve H, Franz CMAP, de Waal PP, van Peij NNME, van Sinderen D, Mahony J. Biodiversity of Phages Infecting the Dairy Bacterium Streptococcus thermophilus. Microorganisms 2021; 9:microorganisms9091822. [PMID: 34576718 PMCID: PMC8470116 DOI: 10.3390/microorganisms9091822] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 12/26/2022] Open
Abstract
Streptococcus thermophilus-infecting phages represent a major problem in the dairy fermentation industry, particularly in relation to thermophilic production systems. Consequently, numerous studies have been performed relating to the biodiversity of such phages in global dairy operations. In the current review, we provide an overview of the genetic and morphological diversity of these phages and highlight the source and extent of genetic mosaicism among phages infecting this species through comparative proteome analysis of the replication and morphogenesis modules of representative phages. The phylogeny of selected phage-encoded receptor binding proteins (RBPs) was assessed, indicating that in certain cases RBP-encoding genes have been acquired separately to the morphogenesis modules, thus highlighting the adaptability of these phages. This review further highlights the significant advances that have been made in defining emergent genetically diverse groups of these phages, while it additionally summarizes remaining knowledge gaps in this research area.
Collapse
Affiliation(s)
| | - Philip Kelleher
- School of Microbiology and APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland;
| | - Horst Neve
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Centre of Nutrition and Food, 24103 Kiel, Germany; (H.N.); (C.M.A.P.F.)
| | - Charles M. A. P. Franz
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Centre of Nutrition and Food, 24103 Kiel, Germany; (H.N.); (C.M.A.P.F.)
| | | | | | - Douwe van Sinderen
- School of Microbiology and APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland;
- Correspondence: (D.v.S.); (J.M.); Tel.: +353-20-4901365 (D.v.S.); +353-21-4902730 (J.M.)
| | - Jennifer Mahony
- School of Microbiology and APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland;
- Correspondence: (D.v.S.); (J.M.); Tel.: +353-20-4901365 (D.v.S.); +353-21-4902730 (J.M.)
| |
Collapse
|
8
|
Moura de Sousa JA, Pfeifer E, Touchon M, Rocha EPC. Causes and Consequences of Bacteriophage Diversification via Genetic Exchanges across Lifestyles and Bacterial Taxa. Mol Biol Evol 2021; 38:2497-2512. [PMID: 33570565 PMCID: PMC8136500 DOI: 10.1093/molbev/msab044] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Bacteriophages (phages) evolve rapidly by acquiring genes from other phages. This results in mosaic genomes. Here, we identify numerous genetic transfers between distantly related phages and aim at understanding their frequency, consequences, and the conditions favoring them. Gene flow tends to occur between phages that are enriched for recombinases, transposases, and nonhomologous end joining, suggesting that both homologous and illegitimate recombination contribute to gene flow. Phage family and host phyla are strong barriers to gene exchange, but phage lifestyle is not. Even if we observe four times more recent transfers between temperate phages than between other pairs, there is extensive gene flow between temperate and virulent phages, and between the latter. These predominantly involve virulent phages with large genomes previously classed as low gene flux, and lead to the preferential transfer of genes encoding functions involved in cell energetics, nucleotide metabolism, DNA packaging and injection, and virion assembly. Such exchanges may contribute to the observed twice larger genomes of virulent phages. We used genetic transfers, which occur upon coinfection of a host, to compare phage host range. We found that virulent phages have broader host ranges and can mediate genetic exchanges between narrow host range temperate phages infecting distant bacterial hosts, thus contributing to gene flow between virulent phages, as well as between temperate phages. This gene flow drastically expands the gene repertoires available for phage and bacterial evolution, including the transfer of functional innovations across taxa.
Collapse
Affiliation(s)
| | - Eugen Pfeifer
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
| | - Marie Touchon
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
| | - Eduardo P C Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
| |
Collapse
|
9
|
Pavesi A. Origin, Evolution and Stability of Overlapping Genes in Viruses: A Systematic Review. Genes (Basel) 2021; 12:genes12060809. [PMID: 34073395 PMCID: PMC8227390 DOI: 10.3390/genes12060809] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/22/2021] [Accepted: 05/24/2021] [Indexed: 12/11/2022] Open
Abstract
During their long evolutionary history viruses generated many proteins de novo by a mechanism called “overprinting”. Overprinting is a process in which critical nucleotide substitutions in a pre-existing gene can induce the expression of a novel protein by translation of an alternative open reading frame (ORF). Overlapping genes represent an intriguing example of adaptive conflict, because they simultaneously encode two proteins whose freedom to change is constrained by each other. However, overlapping genes are also a source of genetic novelties, as the constraints under which alternative ORFs evolve can give rise to proteins with unusual sequence properties, most importantly the potential for novel functions. Starting with the discovery of overlapping genes in phages infecting Escherichia coli, this review covers a range of studies dealing with detection of overlapping genes in small eukaryotic viruses (genomic length below 30 kb) and recognition of their critical role in the evolution of pathogenicity. Origin of overlapping genes, what factors favor their birth and retention, and how they manage their inherent adaptive conflict are extensively reviewed. Special attention is paid to the assembly of overlapping genes into ad hoc databases, suitable for future studies, and to the development of statistical methods for exploring viral genome sequences in search of undiscovered overlaps.
Collapse
Affiliation(s)
- Angelo Pavesi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 23/A, I-43124 Parma, Italy
| |
Collapse
|
10
|
Novel Genus of Phages Infecting Streptococcus thermophilus: Genomic and Morphological Characterization. Appl Environ Microbiol 2020; 86:AEM.00227-20. [PMID: 32303549 DOI: 10.1128/aem.00227-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/13/2020] [Indexed: 12/26/2022] Open
Abstract
Streptococcus thermophilus is a lactic acid bacterium commonly used for the manufacture of yogurt and specialty cheeses. Virulent phages represent a major risk for milk fermentation processes worldwide, as they can inactivate the added starter bacterial cells, leading to low-quality fermented dairy products. To date, four genetically distinct groups of phages infecting S. thermophilus have been described. Here, we describe a fifth group. Phages P738 and D4446 are virulent siphophages that infect a few industrial strains of S. thermophilus The genomes of phages P738 and D4446 were sequenced and found to contain 34,037 and 33,656 bp as well as 48 and 46 open reading frames, respectively. Comparative genomic analyses revealed that the two phages are closely related to each other but display very limited similarities to other S. thermophilus phages. In fact, these two novel S. thermophilus phages share similarities with streptococcal phages of nondairy origin, suggesting that they emerged recently in the dairy environment.IMPORTANCE Despite decades of research and adapted antiphage strategies such as CRISPR-Cas systems, virulent phages are still a persistent risk for the milk fermentation industry worldwide, as they can cause manufacturing failures and alter product quality. Phages P738 and D4446 are novel virulent phages that infect the food-grade Gram-positive bacterial species Streptococcus thermophilus These two related viruses represent a fifth group of S. thermophilus phages, as they are significantly distinct from other known S. thermophilus phages. Both phages share similarities with phages infecting nondairy streptococci, suggesting their recent emergence and probable coexistence in dairy environments. These findings highlight the necessity of phage surveillance programs as the phage population evolves in response to the application of antiphage strategies.
Collapse
|
11
|
Abril AG, Carrera M, Böhme K, Barros-Velázquez J, Cañas B, Rama JLR, Villa TG, Calo-Mata P. Characterization of Bacteriophage Peptides of Pathogenic Streptococcus by LC-ESI-MS/MS: Bacteriophage Phylogenomics and Their Relationship to Their Host. Front Microbiol 2020; 11:1241. [PMID: 32582130 PMCID: PMC7296060 DOI: 10.3389/fmicb.2020.01241] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/14/2020] [Indexed: 01/21/2023] Open
Abstract
The present work focuses on LC-ESI-MS/MS (liquid chromatography-electrospray ionization-tandem mass spectrometry) analysis of phage-origin tryptic digestion peptides from mastitis-causing Streptococcus spp. isolated from milk. A total of 2,546 non-redundant peptides belonging to 1,890 proteins were identified and analyzed. Among them, 65 phage-origin peptides were determined as specific Streptococcus spp. peptides. These peptides belong to proteins such as phage repressors, phage endopeptidases, structural phage proteins, and uncharacterized phage proteins. Studies involving bacteriophage phylogeny and the relationship between phages encoding the peptides determined and the bacteria they infect were also performed. The results show how specific peptides are present in closely related phages, and a link exists between bacteriophage phylogeny and the Streptococcus spp. they infect. Moreover, the phage peptide M∗ATNLGQAYVQIM∗PSAK is unique and specific for Streptococcus agalactiae. These results revealed that diagnostic peptides, among others, could be useful for the identification and characterization of mastitis-causing Streptococcus spp., particularly peptides that belong to specific functional proteins, such as phage-origin proteins, because of their specificity to bacterial hosts.
Collapse
Affiliation(s)
- Ana G. Abril
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Mónica Carrera
- Department of Food Technology, Spanish National Research Council, Marine Research Institute, Vigo, Spain
| | - Karola Böhme
- Agroalimentary Technological Center of Lugo, Lugo, Spain
| | - Jorge Barros-Velázquez
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences, University of Santiago de Compostela, Lugo, Spain
| | - Benito Cañas
- Department of Analytical Chemistry, Complutense University of Madrid, Madrid, Spain
| | - Jose L. R. Rama
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Tomás G. Villa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Pilar Calo-Mata
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences, University of Santiago de Compostela, Lugo, Spain
| |
Collapse
|
12
|
Cornuault JK, Moncaut E, Loux V, Mathieu A, Sokol H, Petit MA, De Paepe M. The enemy from within: a prophage of Roseburia intestinalis systematically turns lytic in the mouse gut, driving bacterial adaptation by CRISPR spacer acquisition. THE ISME JOURNAL 2020; 14:771-787. [PMID: 31827247 PMCID: PMC7031369 DOI: 10.1038/s41396-019-0566-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 11/28/2019] [Indexed: 12/13/2022]
Abstract
Despite an overall temporal stability in time of the human gut microbiota at the phylum level, strong variations in species abundance have been observed. We are far from a clear understanding of what promotes or disrupts the stability of microbiome communities. Environmental factors, like food or antibiotic use, modify the gut microbiota composition, but their overall impacts remain relatively low. Phages, the viruses that infect bacteria, might constitute important factors explaining temporal variations in species abundance. Gut bacteria harbour numerous prophages, or dormant viruses, which can evolve to become ultravirulent phage mutants, potentially leading to important bacterial death. Whether such phenomenon occurs in the mammal's microbiota has been largely unexplored. Here we studied temperate phage-bacteria coevolution in gnotoxenic mice colonised with Roseburia intestinalis, a dominant symbiont of the human gut microbiota, and Escherichia coli, a sub-dominant member of the same microbiota. We show that R. intestinalis L1-82 harbours two active prophages, Jekyll and Shimadzu. We observed the systematic evolution in mice of ultravirulent Shimadzu phage mutants, which led to a collapse of R. intestinalis population. In a second step, phage infection drove the fast counter-evolution of host phage resistance mainly through phage-derived spacer acquisition in a clustered regularly interspaced short palindromic repeats array. Alternatively, phage resistance was conferred by a prophage originating from an ultravirulent phage with a restored ability to lysogenize. Our results demonstrate that prophages are a potential source of ultravirulent phages that can successfully infect most of the susceptible bacteria. This suggests that prophages can play important roles in the short-term temporal variations observed in the composition of the gut microbiota.
Collapse
Affiliation(s)
- Jeffrey K Cornuault
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Elisabeth Moncaut
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Valentin Loux
- Université Paris-Saclay, INRAE, MaIAGE, 78350, Jouy-en-Josas, France
| | - Aurélie Mathieu
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Harry Sokol
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
- Sorbonne Université, Inserm, Centre de Recherche Saint-Antoine, CRSA, AP-HP, Hôpital Saint Antoine, Service de Gastroenterologie, F-75012, Paris, France
- Department of Gastroenterology, Saint-Antoine Hospital, Assistance Publique - Hôpitaux de Paris, UPMC, Paris, France
| | - Marie-Agnès Petit
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Marianne De Paepe
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France.
| |
Collapse
|
13
|
A Specific Sugar Moiety in the Lactococcus lactis Cell Wall Pellicle Is Required for Infection by CHPC971, a Member of the Rare 1706 Phage Species. Appl Environ Microbiol 2019; 85:AEM.01224-19. [PMID: 31350317 DOI: 10.1128/aem.01224-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 07/17/2019] [Indexed: 12/29/2022] Open
Abstract
Lactococcus lactis is a Gram-positive bacterium widely used as a starter culture for the production of different dairy products, especially a large variety of cheeses. Infection of lactococcal starter cultures by bacteriophages is one of the major causes of fermentation failure and often leads to production halt. Lactococcal bacteriophages belonging to the c2, 936, and P335 species are the most commonly isolated in dairy plants and have been extensively investigated in the past three decades. Information regarding bacteriophages belonging to less commonly isolated species is, on the other hand, less extensive, although these phages can also contribute to starter culture infection. Here, we report the nucleotide sequence of the newly isolated L. lactis phage CHPC971, belonging to the rare 1706 species of lactococcal phages. We investigated the nature of the host receptor recognized by the phage and collected evidence that strongly suggests that it binds to a specific sugar moiety in the cell wall pellicle of its host. An in silico analysis of the genome of phage CHPC971 identified the hypothetical genes involved in receptor binding.IMPORTANCE Gathering information on how lactococcal bacteriophages recognize their host and proliferate in the dairy environment is of vital importance for the establishment of proper starter culture rotation plans and to avoid fermentation failure and consequent great economic losses for dairy industries. We provide strong evidence on the type of receptor recognized by a newly isolated 1706-type lactococcal bacteriophage, increasing knowledge of phage-host interactions relevant to dairying. This information can help to prevent phage infection events that, so far, are hard to predict and avoid.
Collapse
|
14
|
da Silva Duarte V, Giaretta S, Campanaro S, Treu L, Armani A, Tarrah A, Oliveira de Paula S, Giacomini A, Corich V. A Cryptic Non-Inducible Prophage Confers Phage-Immunity on the Streptococcus thermophilus M17PTZA496. Viruses 2018; 11:v11010007. [PMID: 30583530 PMCID: PMC6356513 DOI: 10.3390/v11010007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/14/2018] [Accepted: 12/19/2018] [Indexed: 12/26/2022] Open
Abstract
Streptococcus thermophilus is considered one of the most important species for the dairy industry. Due to their diffusion in dairy environments, bacteriophages can represent a threat to this widely used bacterial species. Despite the presence of a CRISPR-Cas system in the S. thermophilus genome, some lysogenic strains harbor cryptic prophages that can increase the phage-host resistance defense. This characteristic was identified in the dairy strain S. thermophilus M17PTZA496, which contains two integrated prophages 51.8 and 28.3 Kb long, respectively. In the present study, defense mechanisms, such as a lipoprotein-encoding gene and Siphovirus Gp157, the last associated to the presence of a noncoding viral DNA element, were identified in the prophage M17PTZA496 genome. The ability to overexpress genes involved in these defense mechanisms under specific stressful conditions, such as phage attack, has been demonstrated. Despite the addition of increasing amounts of Mitomycin C, M17PTZA496 was found to be non-inducible. However, the transcriptional activity of the phage terminase large subunit was detected in the presence of the antagonist phage vB_SthS-VA460 and of Mitomycin C. The discovery of an additional immune mechanism, associated with bacteriophage-insensitive strains, is of utmost importance, for technological applications and industrial processes. To our knowledge, this is the first study reporting the capability of a prophage integrated into the S. thermophilus genome expressing different phage defense mechanisms. Bacteriophages are widespread entities that constantly threaten starter cultures in the dairy industry. In cheese and yogurt manufacturing, the lysis of Streptococcus thermophilus cultures by viral attacks can lead to huge economic losses. Nowadays S. thermophilus is considered a well-stablished model organism for the study of natural adaptive immunity (CRISPR-Cas) against phage and plasmids, however, the identification of novel bacteriophage-resistance mechanisms, in this species, is strongly desirable. Here, we demonstrated that the presence of a non-inducible prophage confers phage-immunity to an S. thermophilus strain, by the presence of ltp and a viral noncoding region. S. thermophilus M17PTZA496 arises as an unconventional model to study phage resistance and potentially represents an alternative starter strain for dairy productions.
Collapse
Affiliation(s)
- Vinícius da Silva Duarte
- Department of Microbiology, Universidade Federal de Viçosa, Av. Peter Henry Rolfs, s/n, Campus Universitário, Viçosa-MG 36570-900, Brazil.
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
| | - Sabrina Giaretta
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
| | | | - Laura Treu
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
- Department of Biology, University of Padova, 35121 Padova, Italy.
| | - Andrea Armani
- Venetian Institute of Molecular Medicine, 35129 Padova, Italy.
| | - Armin Tarrah
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
| | | | - Alessio Giacomini
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
| | - Viviana Corich
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
| |
Collapse
|
15
|
Biodiversity of Streptococcus thermophilus Phages in Global Dairy Fermentations. Viruses 2018; 10:v10100577. [PMID: 30360457 PMCID: PMC6213268 DOI: 10.3390/v10100577] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 12/26/2022] Open
Abstract
Streptococcus thermophilus strains are among the most widely employed starter cultures in dairy fermentations, second only to those of Lactococcus lactis. The extensive application of this species provides considerable opportunity for the proliferation of its infecting (bacterio)phages. Until recently, dairy streptococcal phages were classified into two groups (cos and pac groups), while more recently, two additional groups have been identified (5093 and 987 groups). This highlights the requirement for consistent monitoring of phage populations in the industry. Here, we report a survey of 35 samples of whey derived from 27 dairy fermentation facilities in ten countries against a panel of S. thermophilus strains. This culminated in the identification of 172 plaque isolates, which were characterized by multiplex PCR, restriction fragment length polymorphism analysis, and host range profiling. Based on this characterisation, 39 distinct isolates representing all four phage groups were selected for genome sequencing. Genetic diversity was observed among the cos isolates and correlations between receptor binding protein phylogeny and host range were also clear within this phage group. The 987 phages isolated within this study shared high levels of sequence similarity, yet displayed reduced levels of similarity to those identified in previous studies, indicating that they are subject to ongoing genetic diversification.
Collapse
|
16
|
Manning KA, Quiles-Puchalt N, Penadés JR, Dokland T. A novel ejection protein from bacteriophage 80α that promotes lytic growth. Virology 2018; 525:237-247. [PMID: 30308422 DOI: 10.1016/j.virol.2018.09.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 09/28/2018] [Accepted: 09/28/2018] [Indexed: 12/30/2022]
Abstract
Many staphylococcal bacteriophages encode a minor capsid protein between the genes for the portal and scaffolding proteins. In Staphylococcus aureus bacteriophage 80α, this protein, called gp44, is essential for the production of viable phage, but dispensable for the phage-mediated mobilization of S. aureus pathogenicity islands. We show here that gp44 is not required for capsid assembly, DNA packaging or ejection of the DNA, nor for generalized transduction of plasmids. An 80α Δ44 mutant could be complemented in trans by gp44 expressed from a plasmid, indicating that gp44 plays a post-injection role in the host. Our results show that gp44 is an ejection (pilot) protein that is involved in deciding the fate of the phage DNA after injection. Our data are consistent with a model in which gp44 acts as a regulatory protein that promotes progression to the lytic cycle.
Collapse
Affiliation(s)
- Keith A Manning
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Nuria Quiles-Puchalt
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - José R Penadés
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Terje Dokland
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| |
Collapse
|
17
|
Abstract
Phages of Streptococcus thermophilus present a major threat to the production of many fermented dairy products. To date, only a few studies have assessed the biodiversity of S. thermophilus phages in dairy fermentations. In order to develop strategies to limit phage predation in this important industrial environment, it is imperative that such studies are undertaken and that phage-host interactions of this species are better defined. The present study investigated the biodiversity and evolution of phages within an Irish dairy fermentation facility over an 11-year period. This resulted in the isolation of 17 genetically distinct phages, all of which belong to the so-called cos group. The evolution of phages within the factory appears to be influenced by phages from other dairy plants introduced into the factory for whey protein powder production. Modular exchange, primarily within the regions encoding lysogeny and replication functions, was the major observation among the phages isolated between 2006 and 2016. Furthermore, the genotype of the first isolate in 2006 was observed continuously across the following decade, highlighting the ability of these phages to prevail in the factory setting for extended periods of time. The proteins responsible for host recognition were analyzed, and carbohydrate-binding domains (CBDs) were identified in the distal tail (Dit), the baseplate proteins, and the Tail-associated lysin (Tal) variable regions (VR1 and VR2) of many isolates. This supports the notion that S. thermophilus phages recognize a carbohydrate receptor on the cell surface of their host.IMPORTANCE Dairy fermentations are consistently threatened by the presence of bacterial viruses (bacteriophages or phages), which may lead to a reduction in acidification rates or even complete loss of the fermentate. These phages may persist in factories for long periods of time. The objective of the current study was to monitor the progression of phages infecting the dairy bacterium Streptococcus thermophilus over a period of 11 years in an Irish dairy plant so as to understand how these phages evolve. A focused analysis of the genomic region that encodes host recognition functions highlighted that the associated proteins harbor a variety of carbohydrate-binding domains, which corroborates the notion that phages of S. thermophilus recognize carbohydrate receptors at the initial stages of the phage cycle.
Collapse
|
18
|
McDonnell B, Mahony J, Hanemaaijer L, Neve H, Noben JP, Lugli GA, Ventura M, Kouwen TR, van Sinderen D. Global Survey and Genome Exploration of Bacteriophages Infecting the Lactic Acid Bacterium Streptococcus thermophilus. Front Microbiol 2017; 8:1754. [PMID: 28955321 PMCID: PMC5601072 DOI: 10.3389/fmicb.2017.01754] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 08/29/2017] [Indexed: 01/31/2023] Open
Abstract
Despite the persistent and costly problem caused by (bacterio)phage predation of Streptococcus thermophilus in dairy plants, DNA sequence information relating to these phages remains limited. Genome sequencing is necessary to better understand the diversity and proliferative strategies of virulent phages. In this report, whole genome sequences of 40 distinct bacteriophages infecting S. thermophilus were analyzed for general characteristics, genomic structure and novel features. The bacteriophage genomes display a high degree of conservation within defined groupings, particularly across the structural modules. Supporting this observation, four novel members of a recently discovered third group of S. thermophilus phages (termed the 5093 group) were found to be conserved relative to both phage 5093 and to each other. Replication modules of S. thermophilus phages generally fall within two main groups, while such phage genomes typically encode one putative transcriptional regulator. Such features are indicative of widespread functional synteny across genetically distinct phage groups. Phage genomes also display nucleotide divergence between groups, and between individual phages of the same group (within replication modules and at the 3′ end of the lysis module)—through various insertions and/or deletions. A previously described multiplex PCR phage detection system was updated to reflect current knowledge on S. thermophilus phages. Furthermore, the structural protein complement as well as the antireceptor (responsible for the initial attachment of the phage to the host cell) of a representative of the 5093 group was defined. Our data more than triples the currently available genomic information on S. thermophilus phages, being of significant value to the dairy industry, where genetic knowledge of lytic phages is crucial for phage detection and monitoring purposes. In particular, the updated PCR detection methodology for S. thermophilus phages is highly useful in monitoring particular phage group(s) present in a given whey sample. Studies of this nature therefore not only provide information on the prevalence and associated threat of known S. thermophilus phages, but may also uncover newly emerging and genomically distinct phages infecting this dairy starter bacterium.
Collapse
Affiliation(s)
- Brian McDonnell
- School of Microbiology, College of Science, Engineering and Food Science, University College CorkCork, Ireland
| | - Jennifer Mahony
- School of Microbiology, College of Science, Engineering and Food Science, University College CorkCork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| | | | - Horst Neve
- Department of Microbiology and Biotechnology, Max Rubner-InstitutKiel, Germany
| | - Jean-Paul Noben
- Biomedical Research Institute, Hasselt UniversityDiepenbeek, Belgium
| | - Gabriele A Lugli
- Laboratory of Probiogenomics, Department of Life Sciences, University of ParmaParma, Italy
| | - Marco Ventura
- Laboratory of Probiogenomics, Department of Life Sciences, University of ParmaParma, Italy
| | | | - Douwe van Sinderen
- School of Microbiology, College of Science, Engineering and Food Science, University College CorkCork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| |
Collapse
|
19
|
The Contribution of Bacteriophages to the Biology and Virulence of Pathogenic Clostridia. ADVANCES IN APPLIED MICROBIOLOGY 2017; 101:169-200. [PMID: 29050666 DOI: 10.1016/bs.aambs.2017.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bacteriophages are key players in the evolution of most bacteria. Temperate phages have been associated with virulence of some of the deadliest pathogenic bacteria. Among the most notorious cases, the genes encoding the botulinum neurotoxin produced by Clostridium botulinum types C and D and the α-toxin (TcnA) produced by Clostridium novyi are both encoded within prophage genomes. Clostridium difficile is another important human pathogen and the recent identification of a complete binary toxin locus (CdtLoc) carried on a C. difficile prophage raises the potential for horizontal transfer of toxin genes by mobile genetic elements. Although the TcdA and TcdB toxins produced by C. difficile have never been found outside the pathogenicity locus (PaLoc), some prophages can still influence their production. Prophages can alter the expression of several metabolic and regulatory genes in C. difficile, as well as cell surface proteins such as CwpV, which confers phage resistance. Homologs of an Agr-like quorum sensing system have been identified in a C. difficile prophage, suggesting that it could possibly participate in cell-cell communication. Yet, other C. difficile prophages contain riboswitches predicted to recognize the secondary messenger molecule c-di-GMP involved in bacterial multicellular behaviors. Altogether, recent findings on clostridial phages underline the diversity of mechanisms and intricate relationship linking phages with their host. Here, milestone discoveries linking phages and virulence of some of the most pathogenic clostridial species will be retraced, with a focus on C. botulinum, C. novyi, C. difficile, and Clostridium perfringens phages, for which evidences are mostly available.
Collapse
|
20
|
YMC-2011, a Temperate Phage of Streptococcus salivarius 57.I. Appl Environ Microbiol 2017; 83:AEM.03186-16. [PMID: 28062463 DOI: 10.1128/aem.03186-16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 01/04/2017] [Indexed: 11/20/2022] Open
Abstract
Streptococcus salivarius is an abundant isolate of the oral cavity. The genome of S. salivarius 57.I consists of a 2-Mb chromosome and a 40,758-bp circular molecule, designated YMC-2011. Annotation of YMC-2011 revealed 55 open reading frames, most of them associated with phage production, although plaque formation is not observed in S. salivarius 57.I after lytic induction using mitomycin C. Results from Southern hybridization and quantitative real-time PCR confirmed that YMC-2011 exists extrachromosomally, with an estimated copy number of 3 to 4. Phage particles were isolated from the supernatant of mitomycin C-treated S. salivarius 57.I cultures, and transmission electron microscopic examination indicated that YMC-2011 belongs to the Siphoviridae family. Phylogenetic analysis suggests that phage YMC-2011 and the cos-type phages of Streptococcus thermophilus originated from a common ancestor. An extended -10 element (p L ) and a σ70-like promoter (p R ) were mapped 5' to Ssal_phage00013 (encoding a CI-like repressor) and Ssal_phage00014 (encoding a hypothetical protein), respectively, using 5' rapid amplification of cDNA ends, indicating that YMC-2011 transcribes at least two mRNAs in opposite orientations. Studies using promoter-chloramphenicol acetyltransferase reporter gene fusions revealed that p R , but not p L , was sensitive to mitomycin C induction, suggesting that the switch from lysogenic growth to lytic growth was controlled mainly by the activity of these two promoters. In conclusion, a lysogenic state is maintained in S. salivarius 57.I, presumably by the repression of genes encoding proteins for lytic growth.IMPORTANCE The movement of mobile genetic elements such as bacteriophages and the establishment of lysogens may have profound effects on the balance of microbial ecology where lysogenic bacteria reside. The discovery of phage YMC-2011 from Streptococcus salivarius 57.I suggests that YMC-2011 and Streptococcus thermophilus-infecting phages share an ancestor. Although S. salivarius and S. thermophilus are close phylogenetically, S. salivarius is a natural inhabitant of the human mouth, whereas S. thermophilus is commonly found in the mammary mucosa of bovine species. Thus, the identification of YMC-2011 suggests that horizontal gene transfer via phage infection could take place between species from different ecological niches.
Collapse
|
21
|
Identification and Analysis of a Novel Group of Bacteriophages Infecting the Lactic Acid Bacterium Streptococcus thermophilus. Appl Environ Microbiol 2016; 82:5153-65. [PMID: 27316953 DOI: 10.1128/aem.00835-16] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 06/09/2016] [Indexed: 01/18/2023] Open
Abstract
UNLABELLED We present the complete genome sequences of four members of a novel group of phages infecting Streptococcus thermophilus, designated here as the 987 group. Members of this phage group appear to have resulted from genetic exchange events, as evidenced by their "hybrid" genomic architecture, exhibiting DNA sequence relatedness to the morphogenesis modules of certain P335 group Lactococcus lactis phages and to the replication modules of S. thermophilus phages. All four identified members of the 987 phage group were shown to elicit adsorption affinity to both their cognate S. thermophilus hosts and a particular L. lactis starter strain. The receptor binding protein of one of these phages (as a representative of this novel group) was defined using an adsorption inhibition assay. The emergence of a novel phage group infecting S. thermophilus highlights the continuous need for phage monitoring and development of new phage control measures. IMPORTANCE Phage predation of S. thermophilus is an important issue for the dairy industry, where viral contamination can lead to fermentation inefficiency or complete fermentation failure. Genome information and phage-host interaction studies of S. thermophilus phages, particularly those emerging in the marketplace, are an important part of limiting the detrimental impact of these viruses in the dairy environment.
Collapse
|
22
|
Different patterns of codon usage in the overlapping polymerase and surface genes of hepatitis B virus suggest a de novo origin by modular evolution. J Gen Virol 2015; 96:3577-3586. [DOI: 10.1099/jgv.0.000307] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The polymerase (P) and surface (S) genes of hepatitis B virus (HBV) show the longest gene overlap in animal viruses. Gene overlaps originate by the overprinting of a novel frame onto an ancestral pre-existing frame. Identifying which frame is ancestral and which frame is de novo (the genealogy of the overlap) is an appealing topic. However, the P/S overlap of HBV is an intriguing paradox, because both genes are indispensable for virus survival. Thus, the hypothesis of a primordial virus without the surface protein or without the polymerase makes no biological sense. With the aim to determine the genealogy of the overlap, the codon usage of the overlapping frames P and S was compared to that of the non-overlapping region. It was found that the overlap of human HBV had two patterns of codon usage. One was localized in the 5′ one-third of the overlap and the other in the 3′ two-thirds. By extending the analysis to non-human HBVs, it was found that this feature occurred in all hepadnaviruses. Under the assumption that the ancestral frame has a codon usage significantly closer to that of the non-overlapping region than the de novo frame, the ancestral frames in the 5′ and 3′ region of the overlap could be predicted. They were, respectively, frame S and frame P. These results suggest that the spacer domain of the polymerase and the S domain of the surface protein originated de novo by overprinting. They support a modular evolution hypothesis for the origin of the overlap.
Collapse
|
23
|
Abstract
UNLABELLED Many bacteria rely on CRISPR-Cas systems to provide adaptive immunity against phages, predation by which can shape the ecology and functioning of microbial communities. To characterize the impact of CRISPR immunization on phage genome evolution, we performed long-term bacterium-phage (Streptococcus thermophilus-phage 2972) coevolution experiments. We found that in this species, CRISPR immunity drives fixation of single nucleotide polymorphisms that accumulate exclusively in phage genome regions targeted by CRISPR. Mutation rates in phage genomes highly exceed those of the host. The presence of multiple phages increased phage persistence by enabling recombination-based formation of chimeric phage genomes in which sequences heavily targeted by CRISPR were replaced. Collectively, our results establish CRISPR-Cas adaptive immunity as a key driver of phage genome evolution under the conditions studied and highlight the importance of multiple coexisting phages for persistence in natural systems. IMPORTANCE Phages remain an enigmatic part of the biosphere. As predators, they challenge the survival of host bacteria and archaea and set off an "arms race" involving host immunization countered by phage mutation. The CRISPR-Cas system is adaptive: by capturing fragments of a phage genome upon exposure, the host is positioned to counteract future infections. To investigate this process, we initiated massive deep-sequencing experiments with a host and infective phage and tracked the coevolution of both populations over hundreds of days. In the present study, we found that CRISPR immunity drives the accumulation of phage genome rearrangements (which enable longer phage survival) and escape mutations, establishing CRISPR as one of the fundamental drivers of phage evolution.
Collapse
|
24
|
Magill DJ, Shaburova OV, Chesnokova EN, Pleteneva EA, Krylov VN, Kulakov LA. Complete nucleotide sequence of phiCHU: a Luz24likevirus infecting Pseudomonas aeruginosa and displaying a unique host range. FEMS Microbiol Lett 2015; 362:fnv045. [PMID: 25825475 DOI: 10.1093/femsle/fnv045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2015] [Indexed: 11/13/2022] Open
Abstract
A complete nucleotide sequence of the new Pseudomonas aeruginosa Luz24likevirus phiCHU was obtained. This virus was shown to have a unique host range whereby it grew poorly on the standard laboratory strain PAO1, but infected 26 of 46 clinical isolates screened, and strains harbouring IncP2 plasmid pMG53. It was demonstrated that phiCHU has single-strand interruptions in its genome. Analysis of the phiCHU genome also suggested that recombination event(s) participated in the evolution of the leftmost portion of the genome, presumably encoding early genes.
Collapse
Affiliation(s)
- Damian J Magill
- Queen's University Belfast, School of Biological Sciences, Medical Biology Centre, Belfast BT9 7BL, Northern Ireland, UK
| | - Olga V Shaburova
- Department of Microbiology, Laboratory for Genetics of Bacteriophages, I.I. Mechnikov Research Institute for Vaccines and Sera, Moscow 105064, Russia
| | - Elena N Chesnokova
- Department of Microbiology, Laboratory for Genetics of Bacteriophages, I.I. Mechnikov Research Institute for Vaccines and Sera, Moscow 105064, Russia
| | - Elena A Pleteneva
- Department of Microbiology, Laboratory for Genetics of Bacteriophages, I.I. Mechnikov Research Institute for Vaccines and Sera, Moscow 105064, Russia
| | - Victor N Krylov
- Department of Microbiology, Laboratory for Genetics of Bacteriophages, I.I. Mechnikov Research Institute for Vaccines and Sera, Moscow 105064, Russia
| | - Leonid A Kulakov
- Queen's University Belfast, School of Biological Sciences, Medical Biology Centre, Belfast BT9 7BL, Northern Ireland, UK
| |
Collapse
|
25
|
Adriaenssens EM, Edwards R, Nash JHE, Mahadevan P, Seto D, Ackermann HW, Lavigne R, Kropinski AM. Integration of genomic and proteomic analyses in the classification of the Siphoviridae family. Virology 2014; 477:144-154. [PMID: 25466308 DOI: 10.1016/j.virol.2014.10.016] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/08/2014] [Accepted: 10/17/2014] [Indexed: 11/26/2022]
Abstract
Using a variety of genomic (BLASTN, ClustalW) and proteomic (Phage Proteomic Tree, CoreGenes) tools we have tackled the taxonomic status of members of the largest bacteriophage family, the Siphoviridae. In all over 400 phages were examined and we were able to propose 39 new genera, comprising 216 phage species, and add 62 species to two previously defined genera (Phic3unalikevirus; L5likevirus) grouping, in total, 390 fully sequenced phage isolates. Many of the remainders are orphans which the Bacterial and Archaeal Viruses Subcommittee of the International Committee on Taxonomy of Viruses (ICTV) chooses not to ascribe genus status at the time being.
Collapse
Affiliation(s)
- Evelien M Adriaenssens
- Centre for Microbial Ecology and Genomics, Genomics Research Institute, University of Pretoria, Lynnwood Road, Pretoria 0028, South Africa
| | - Rob Edwards
- Geology, Mathematics, and Computer Science, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - John H E Nash
- Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, 110 Stone Road West, Guelph, ON, Canada N1G 3W4
| | | | - Donald Seto
- Bioinformatics and Computational Biology Program, School of Systems Biology, George Mason University, 10900 University Blvd, Manassas, VA 20110, USA
| | - Hans-Wolfgang Ackermann
- Département de Microbiologie-infectiologie et immunologie, Faculté de médecine, Université Laval, Québec, QC, Canada G1K 7P4
| | - Rob Lavigne
- Department of Biosystems, Laboratory of Gene Technology, KU Leuven, KasteelparkArenberg 21 - b2462, Heverlee 3001, Belgium.
| | - Andrew M Kropinski
- Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, 110 Stone Road West, Guelph, ON, Canada N1G 3W4; Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada N1G 2A1.
| |
Collapse
|
26
|
Ishlimova D, Urshev Z, Stoyancheva G, Petrova P, Minkova S, Doumanova L. Genetic Diversity of Bacteriophages Highly Specific forStreptococcus ThermophilusStrain Lbb.A. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.1080/13102818.2009.10817666] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
27
|
Ali Y, Koberg S, Heßner S, Sun X, Rabe B, Back A, Neve H, Heller KJ. Temperate Streptococcus thermophilus phages expressing superinfection exclusion proteins of the Ltp type. Front Microbiol 2014; 5:98. [PMID: 24659988 PMCID: PMC3952083 DOI: 10.3389/fmicb.2014.00098] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 02/23/2014] [Indexed: 11/17/2022] Open
Abstract
Lipoprotein Ltp encoded by temperate Streptococcus thermophilus phage TP-J34 is the prototype of the wide-spread family of host cell surface-exposed lipoproteins involved in superinfection exclusion (sie). When screening for other S. thermophilus phages expressing this type of lipoprotein, three temperate phages—TP-EW, TP-DSM20617, and TP-778—were isolated. In this communication we present the total nucleotide sequences of TP-J34 and TP-778L. For TP-EW, a phage almost identical to TP-J34, besides the ltp gene only the two regions of deviation from TP-J34 DNA were analyzed: the gene encoding the tail protein causing an assembly defect in TP-J34 and the gene encoding the lysin, which in TP-EW contains an intron. For TP-DSM20617 only the sequence of the lysogeny module containing the ltp gene was determined. The region showed high homology to the same region of TP-778. For TP-778 we could show that absence of the attR region resulted in aberrant excision of phage DNA. The amino acid sequence of mature LtpTP-EW was shown to be identical to that of mature LtpTP-J34, whereas the amino acid sequence of mature LtpTP-778 was shown to differ from mature LtpTP-J34 in eight amino acid positions. LtpTP-DSM20617 was shown to differ from LtpTP-778 in just one amino acid position. In contrast to LtpTP-J34, LtpTP-778 did not affect infection of lactococcal phage P008 instead increased activity against phage P001 was noticed.
Collapse
Affiliation(s)
- Yahya Ali
- Department of Microbiology and Biotechnology, Max Rubner-Institut (Federal Research Institute of Nutrition and Food) Kiel, Germany ; Medical Biology Department, Faculty of Medicine, Jazan University Jazan, Kingdom of Saudi Arabia ; Department of Biotechnology, Agricultural Research Center, Animal Health Research Institute Cairo, Egypt
| | - Sabrina Koberg
- Department of Microbiology and Biotechnology, Max Rubner-Institut (Federal Research Institute of Nutrition and Food) Kiel, Germany
| | - Stefanie Heßner
- Department of Microbiology and Biotechnology, Max Rubner-Institut (Federal Research Institute of Nutrition and Food) Kiel, Germany
| | - Xingmin Sun
- Department of Microbiology and Biotechnology, Max Rubner-Institut (Federal Research Institute of Nutrition and Food) Kiel, Germany
| | - Björn Rabe
- Department of Microbiology and Biotechnology, Max Rubner-Institut (Federal Research Institute of Nutrition and Food) Kiel, Germany
| | - Angela Back
- Department of Microbiology and Biotechnology, Max Rubner-Institut (Federal Research Institute of Nutrition and Food) Kiel, Germany
| | - Horst Neve
- Department of Microbiology and Biotechnology, Max Rubner-Institut (Federal Research Institute of Nutrition and Food) Kiel, Germany
| | - Knut J Heller
- Department of Microbiology and Biotechnology, Max Rubner-Institut (Federal Research Institute of Nutrition and Food) Kiel, Germany
| |
Collapse
|
28
|
Mahony J, van Sinderen D. Current taxonomy of phages infecting lactic acid bacteria. Front Microbiol 2014; 5:7. [PMID: 24478767 PMCID: PMC3900856 DOI: 10.3389/fmicb.2014.00007] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 01/07/2014] [Indexed: 01/29/2023] Open
Abstract
Phages infecting lactic acid bacteria have been the focus of significant research attention over the past three decades. Through the isolation and characterization of hundreds of phage isolates, it has been possible to classify phages of the dairy starter and adjunct bacteria Lactococus lactis, Streptococcus thermophilus, Leuconostoc spp., and Lactobacillus spp. Among these, phages of L. lactis have been most thoroughly scrutinized and serve as an excellent model system to address issues that arise when attempting taxonomic classification of phages infecting other LAB species. Here, we present an overview of the current taxonomy of phages infecting LAB genera of industrial significance, the methods employed in these taxonomic efforts and how these may be employed for the taxonomy of phages of currently underrepresented and emerging phage species.
Collapse
Affiliation(s)
- Jennifer Mahony
- Department of Microbiology, University College Cork Cork, Ireland
| | - Douwe van Sinderen
- Department of Microbiology, University College Cork Cork, Ireland ; Alimentary Pharmabiotic Centre, Biosciences Institute, University College Cork Cork, Ireland
| |
Collapse
|
29
|
Yuan Y, Gao M, Peng Q, Wu D, Liu P, Wu Y. Genomic analysis of a phage and prophage from a Bacillus thuringiensis strain. J Gen Virol 2013; 95:751-761. [PMID: 24285088 DOI: 10.1099/vir.0.058735-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bacteriophages have been found to be the most abundant and also potentially most diverse biological entities on Earth. In the present study, Bacillus phages were isolated rapidly and shown to have a high degree of diversity. The genomes of a newly isolated phage, phiCM3, and a prophage, proCM3, from the Bacillus thuringiensis strain YM-03 were sequenced and characterized. Comparative genome analysis showed that the phiCM3 genome is highly similar to the genomes of eight other Bacillus phages and seven of these phages were classified as the Wβ group of phages. Analysis of the differential evolution of the genes in the Wβ-group phages indicated that the genes encoding the antirepressor and tail fibre protein were more highly conserved than those encoding the major capsid protein, DNA replication protein, and RNA polymerase σ factor, which might have diverged to acquire mechanisms suitable for survival in different microbial hosts. Genome analysis of proCM3 revealed that proCM3 might be a defective phage because of mutations in the minor structural protein, and it was not inducible by mitomycin C treatment. The proCM3 genome was similar to those of two lytic Bacillus phages in sequence, but had a different genomic structure, composed of three regions in a different order. These data suggest that the three phages might have had a common ancestor and that genome rearrangement might have occurred during evolution. The findings of this study enrich our current knowledge of Bacillus phage diversity and evolution, especially for the Wβ-group and TP21-L-like phages, and may help the development of practical applications of Bacillus phages.
Collapse
Affiliation(s)
- Yihui Yuan
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Meiying Gao
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Qin Peng
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Dandan Wu
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Pengming Liu
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Yan Wu
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| |
Collapse
|
30
|
Abstract
Bacteriophages, or simply phages, are viruses infecting bacteria. With an estimated 1031 particles in the biosphere, phages outnumber bacteria by a factor of at least 10 and not surprisingly, they influence the evolution of most bacterial species, sometimes in unexpected ways. “Temperate” phages have the ability to integrate into the chromosome of their host upon infection, where they can reside as “quiescent” prophages until conditions favor their reactivation. Lysogenic conversion resulting from the integration of prophages encoding powerful toxins is probably the most determinant contribution of prophages to the evolution of pathogenic bacteria. We currently grasp only a small fraction of the total phage diversity. Phage biologists keep unraveling novel mechanisms developed by phages to parasitize their host. The purpose of this review is to give an overview of some of the various ways by which prophages change the lifestyle and boost virulence of some of the most dangerous bacterial pathogens.
Collapse
Affiliation(s)
- Louis-Charles Fortier
- Département de Microbiologie et d'Infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC Canada.
| | | |
Collapse
|
31
|
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/.
Collapse
|
32
|
Casas V, Maloy S. Role of bacteriophage-encoded exotoxins in the evolution of bacterial pathogens. Future Microbiol 2012; 6:1461-73. [PMID: 22122442 DOI: 10.2217/fmb.11.124] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Recent advances in metagenomics research have generated a bounty of information that provides insight into the dynamic genetic exchange occurring between bacteriophage (phage) and their bacterial hosts. Metagenomic studies of the microbiomes from a variety of environments have shown that many of the genes sequenced are of phage origin. Among these genes are phage-encoded exotoxin genes. When phage that carry these genes infect an appropriate bacterial host, the bacterium undergoes lysogenic conversion, converting the bacterium from an avirulent strain to a pathogen that can cause human disease. Transfer of the exotoxin genes between bacteria has been shown to occur in marine environments, animal and human intestines and sewage treatment plants. Surprisingly, phage that encode exotoxin genes are commonly found in environments that lack the cognate bacteria commonly associated with the specific toxin-mediated disease and have been found to be associated with alternative environmental bacterial hosts. These findings suggest that the exotoxin genes may play a beneficial role for the bacterial host in nature, and that this environmental reservoir of exotoxin genes may play a role in the evolution of new bacterial pathogens.
Collapse
Affiliation(s)
- Veronica Casas
- Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | | |
Collapse
|
33
|
Mills S, Griffin C, O’Sullivan O, Coffey A, McAuliffe O, Meijer W, Serrano L, Ross R. A new phage on the ‘Mozzarella’ block: Bacteriophage 5093 shares a low level of homology with other Streptococcus thermophilus phages. Int Dairy J 2011. [DOI: 10.1016/j.idairyj.2011.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
34
|
Sillankorva S, Kluskens LD, Lingohr EJ, Kropinski AM, Neubauer P, Azeredo J. Complete genome sequence of the lytic Pseudomonas fluorescens phage ϕIBB-PF7A. Virol J 2011; 8:142. [PMID: 21439081 PMCID: PMC3080317 DOI: 10.1186/1743-422x-8-142] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 03/26/2011] [Indexed: 12/11/2022] Open
Abstract
Background Phage ϕIBB-PF7A is a T7-like bacteriophage capable of infecting several Pseudomonas fluorescens dairy isolates and is extremely efficient in lysing this bacterium even when growing in biofilms attached to surfaces. This work describes the complete genome sequence of this phage. Results The genome consists of a linear double-stranded DNA of 40,973 bp, with 985 bp long direct terminal repeats and a GC content of approximately 56%. There are 52 open reading frames which occupy 94.6% of the genome ranging from 137 to 3995 nucleotides. Twenty eight (46.7%) of the proteins encoded by this virus exhibit sequence similarity to coliphage T7 proteins while 34 (81.0%) are similar to proteins of Pseudomonas phage gh-1. Conclusions That this phage is closely related to Pseudomonas putida phage gh-1 and coliphage T7 places it in the "T7-like viruses" genus of the subfamily Autographivirinae within the family Podoviridae. Compared to the genome of gh-1, the sequence of ϕIBB-PF7A is longer and contains more genes with unassigned function and lacks a few potentially essential and non-essential T7 genes, such as gene1.1, 3.8, and 7.
Collapse
Affiliation(s)
- Sanna Sillankorva
- IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar 4710-057, Braga, Portugal
| | | | | | | | | | | |
Collapse
|
35
|
Prophage-stimulated toxin production in Clostridium difficile NAP1/027 lysogens. J Bacteriol 2011; 193:2726-34. [PMID: 21441508 DOI: 10.1128/jb.00787-10] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
TcdA and TcdB exotoxins are the main virulence factors of Clostridium difficile, one of the most deadly nosocomial pathogens. Recent data suggest that prophages can influence the regulation of toxin expression. Here we present the characterization of ϕCD38-2, a pac-type temperate Siphoviridae phage that stimulates toxin expression when introduced as a prophage into C. difficile. Host range analysis showed that ϕCD38-2 was able to infect 99/207 isolates of C. difficile representing 11 different PCR ribotypes. Of 89 isolates corresponding to the NAP1/027 hypervirulent strain, which recently caused several outbreaks in North America and Europe, 79 (89%) were sensitive to ϕCD38-2. The complete double-stranded DNA (dsDNA) genome was determined, and a putative function could be assigned to 24 of the 55 open reading frames. No toxins or virulence factors could be identified based on bioinformatics analyses. Our data also suggest that ϕCD38-2 replicates as a circular plasmid in C. difficile lysogens. Upon introduction of ϕCD38-2 into a NAP1/027 representative isolate, up to 1.6- and 2.1-fold more TcdA and TcdB, respectively, were detected by immunodot blotting in culture supernatants of the lysogen than in the wild-type strain. In addition, real-time quantitative reverse transcriptase PCR (qRT-PCR) analyses showed that the mRNA levels of all five pathogenicity locus (PaLoc) genes were higher in the CD274 lysogen. Our study provides the first genomic sequence of a new pac-type Siphoviridae phage family member infecting C. difficile and brings further evidence supporting the role of prophages in toxin production in this important nosocomial pathogen.
Collapse
|
36
|
Ecogenomics and genome landscapes of marine Pseudoalteromonas phage H105/1. ISME JOURNAL 2010; 5:107-21. [PMID: 20613791 DOI: 10.1038/ismej.2010.94] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Marine phages have an astounding global abundance and ecological impact. However, little knowledge is derived from phage genomes, as most of the open reading frames in their small genomes are unknown, novel proteins. To infer potential functional and ecological relevance of sequenced marine Pseudoalteromonas phage H105/1, two strategies were used. First, similarity searches were extended to include six viral and bacterial metagenomes paired with their respective environmental contextual data. This approach revealed 'ecogenomic' patterns of Pseudoalteromonas phage H105/1, such as its estuarine origin. Second, intrinsic genome signatures (phylogenetic, codon adaptation and tetranucleotide (tetra) frequencies) were evaluated on a resolved intra-genomic level to shed light on the evolution of phage functional modules. On the basis of differential codon adaptation of Phage H105/1 proteins to the sequenced Pseudoalteromonas spp., regions of the phage genome with the most 'host'-adapted proteins also have the strongest bacterial tetra signature, whereas the least 'host'-adapted proteins have the strongest phage tetra signature. Such a pattern may reflect the evolutionary history of the respective phage proteins and functional modules. Finally, analysis of the structural proteome identified seven proteins that make up the mature virion, four of which were previously unknown. This integrated approach combines both novel and classical strategies and serves as a model to elucidate ecological inferences and evolutionary relationships from phage genomes that typically abound with unknown gene content.
Collapse
|
37
|
Genome analysis of the Clostridium difficile phage PhiCD6356, a temperate phage of the Siphoviridae family. Gene 2010; 462:34-43. [PMID: 20438817 DOI: 10.1016/j.gene.2010.04.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 04/21/2010] [Accepted: 04/21/2010] [Indexed: 11/23/2022]
Abstract
The temperate phages PhiCD6356 and PhiCD6365 were isolated and characterised following mitomycin C induction of 43 Clostridium difficile strains. Both phages belong to the Siphoviridae family and have genome sizes of 37,664 bp for PhiCD6356 based on sequence data and approximately 50 kb for PhiCD6365 based on restriction analysis. Protein analysis revealed similar protein profiles and indicated posttranslational processing of the PhiCD6356 major capsid protein. The genome sequence of PhiCD6356 is substantially different from other previously reported phage sequences and a putative function could be assigned to only 21 out of 59 predicted open reading frames. However, the genome organisation closely resembles that of other members of the Siphoviridae family which infect low GC-content Gram-positive bacteria. The modular organisation, genome synteny, presence of cohesive ends and posttranslational processing of the capsid protein suggest PhiCD6356 is a member of the proposed Sfi21-like genera. To our knowledge, this report represents the first C. difficile phage of the Siphoviridae family to be sequenced.
Collapse
|
38
|
Szczepańska AK. Bacteriophage-encoded functions engaged in initiation of homologous recombination events. Crit Rev Microbiol 2010; 35:197-220. [PMID: 19563302 DOI: 10.1080/10408410902983129] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Recombination plays a significant role in bacteriophage biology. Functions promoting recombination are involved in key stages of phage multiplication and drive phage evolution. Their biological role is reflected by the great variety of phages existing in the environment. This work presents the role of recombination in the phage life cycle and highlights the discrete character of phage-encoded recombination functions (anti-RecBCD activities, 5' --> 3' DNA exonucleases, single-stranded DNA binding proteins, single-stranded DNA annealing proteins, and recombinases). The focus of this review is on phage proteins that initiate genetic exchange. Importance of recombination is reviewed based on the accepted coli-phages T4 and lambda models, the recombination system of phage P22, and the recently characterized recombination functions of Bacillus subtilis phage SPP1 and mycobacteriophage Che9c. Key steps of the molecular mechanisms involving phage recombination functions and their application in molecular engineering are discussed.
Collapse
Affiliation(s)
- Agnieszka K Szczepańska
- Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
| |
Collapse
|
39
|
Lysogeny and sporulation in Bacillus isolates from the Gulf of Mexico. Appl Environ Microbiol 2009; 76:829-42. [PMID: 20008174 DOI: 10.1128/aem.01710-09] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Eleven Bacillus isolates from the surface and subsurface waters of the Gulf of Mexico were examined for their capacity to sporulate and harbor prophages. Occurrence of sporulation in each isolate was assessed through decoyinine induction, and putative lysogens were identified by prophage induction by mitomycin C treatment. No obvious correlation between ability to sporulate and prophage induction was found. Four strains that contained inducible virus-like particles (VLPs) were shown to sporulate. Four strains did not produce spores upon induction by decoyinine but contained inducible VLPs. Two of the strains did not produce virus-like particles or sporulate significantly upon induction. Isolate B14905 had a high level of virus-like particle production and a high occurrence of sporulation and was further examined by genomic sequencing in an attempt to shed light on the relationship between sporulation and lysogeny. In silico analysis of the B14905 genome revealed four prophage-like regions, one of which was independently sequenced from a mitomycin C-induced lysate. Based on PCR and transmission electron microscopy (TEM) analysis of an induced phage lysate, one is a noninducible phage remnant, one may be a defective phage-like bacteriocin, and two were inducible prophages. One of the inducible phages contained four putative transcriptional regulators, one of which was a SinR-like regulator that may be involved in the regulation of host sporulation. Isolates that both possess the capacity to sporulate and contain temperate phage may be well adapted for survival in the oligotrophic ocean.
Collapse
|
40
|
Guglielmotti DM, Deveau H, Binetti AG, Reinheimer JA, Moineau S, Quiberoni A. Genome analysis of two virulent Streptococcus thermophilus phages isolated in Argentina. Int J Food Microbiol 2009; 136:101-9. [DOI: 10.1016/j.ijfoodmicro.2009.09.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 08/31/2009] [Accepted: 09/06/2009] [Indexed: 11/30/2022]
|
41
|
Brüssow H. The not so universal tree of life or the place of viruses in the living world. Philos Trans R Soc Lond B Biol Sci 2009; 364:2263-74. [PMID: 19571246 DOI: 10.1098/rstb.2009.0036] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Darwin provided a great unifying theory for biology; its visual expression is the universal tree of life. The tree concept is challenged by the occurrence of horizontal gene transfer and-as summarized in this review -- by the omission of viruses. Microbial ecologists have demonstrated that viruses are the most numerous biological entities on earth, outnumbering cells by a factor of 10. Viral genomics have revealed an unexpected size and distinctness of the viral DNA sequence space. Comparative genomics has shown elements of vertical evolution in some groups of viruses. Furthermore, structural biology has demonstrated links between viruses infecting the three domains of life pointing to a very ancient origin of viruses. However, presently viruses do not find a place on the universal tree of life, which is thus only a tree of cellular life. In view of the polythetic nature of current life definitions, viruses cannot be dismissed as non-living material. On earth we have therefore at least two large DNA sequence spaces, one represented by capsid-encoding viruses and another by ribosome-encoding cells. Despite their probable distinct evolutionary origin, both spheres were and are connected by intensive two-way gene transfers.
Collapse
Affiliation(s)
- Harald Brüssow
- Chemin de la Chaumény 13, La Tour de Peilz, Switzerland.
| |
Collapse
|
42
|
Kunisaki H, Tanji Y. Intercrossing of phage genomes in a phage cocktail and stable coexistence with Escherichia coli O157:H7 in anaerobic continuous culture. Appl Microbiol Biotechnol 2009; 85:1533-40. [DOI: 10.1007/s00253-009-2230-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 08/31/2009] [Accepted: 09/02/2009] [Indexed: 11/29/2022]
|
43
|
Mills S, Griffin C, Coffey A, Meijer WC, Hafkamp B, Ross RP. CRISPR analysis of bacteriophage-insensitive mutants (BIMs) of industrial Streptococcus thermophilus--implications for starter design. J Appl Microbiol 2009; 108:945-955. [PMID: 19709335 DOI: 10.1111/j.1365-2672.2009.04486.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
AIMS An efficient approach for generation of bacteriophage-insensitive mutants (BIMs) of Streptococcus thermophilus starters was described in our laboratory [Mills et al. (2007) J Microbiol Methods70, 159-164]. The aim of this study was to analyse the phage resistance mechanism responsible for BIM formation. METHODS AND RESULTS Three clustered regularly interspaced short palindromic repeat (CRISPR) regions have been identified in Strep. thermophilus, and Strep. thermophilus can integrate novel spacers into these loci in response to phage attack. Characterization of three sets of BIMs indicated that two sets had altered CRISPR1 and/or CRISPR3 loci. A range of BIMs of yoghurt starter CSK938 were generated with the same phage in different phage challenge experiments, and each acquired unique spacer regions ranging between one and four new spacers in CRISPR1. In addition, the BIM that acquired only one new spacer in CRISPR1 also acquired an additional spacer in CRISPR3. A fourth BIM, generated with a different phage, had two spacers deleted from CRISPR1 but acquired two spacers in CRISPR3. Analysis of the Mozzarella starter CSK939 and its associated BIMs indicated that formation of second generation BIMs does not lead to increases in spacer number but to alterations in spacer regions. BIMs of an exopolysaccharide (EPS)-producing strain that lost the ability to produce EPS did not harbour an altered CRISPR, suggesting that phage sensitivity may be related to the EPS-producing phenotype. CONCLUSIONS Acquisition/deletion of new spacers in CRISPR loci in response to phage attack generates distinctly individual variants. It also demonstrates that other modifications may be responsible for the phage resistance of Strep. thermophilus BIMs. SIGNIFICANCE AND IMPACT OF THE STUDY Isolation of individual BIMs that have unique spacers towards the leader region of the CRISPR locus may be a very useful approach for rotation strategies with the same starter backbone. Upon phage infection, BIMs 'in reserve' can be slotted into the rotation scheme.
Collapse
Affiliation(s)
- S Mills
- Teagasc, Moorepark Food Research Centre, Fermoy, Co. Cork, Ireland., CSK Food Enrichment, Ede, the Netherlands
| | - C Griffin
- Teagasc, Moorepark Food Research Centre, Fermoy, Co. Cork, Ireland., CSK Food Enrichment, Ede, the Netherlands
| | - A Coffey
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland
| | - W C Meijer
- CSK Food Enrichment, Ede, the Netherlands
| | - B Hafkamp
- CSK Food Enrichment, Ede, the Netherlands
| | - R P Ross
- Teagasc, Moorepark Food Research Centre, Fermoy, Co. Cork, Ireland., Alimentary Pharmabiotic Centre, Cork, Ireland
| |
Collapse
|
44
|
Identification of a tail assembly gene cluster from deep-sea thermophilic bacteriophage GVE2. Virus Genes 2009; 38:507-14. [DOI: 10.1007/s11262-009-0351-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2008] [Accepted: 03/15/2009] [Indexed: 10/21/2022]
|
45
|
Prestel E, Salamitou S, DuBow MS. An examination of the bacteriophages and bacteria of the Namib desert. J Microbiol 2008; 46:364-72. [PMID: 18758725 DOI: 10.1007/s12275-008-0007-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Accepted: 06/13/2008] [Indexed: 10/21/2022]
Abstract
Bacteria and their viruses (called bacteriophages, or phages), have been found in virtually every ecological niche on Earth. Arid regions, including their most extreme form called deserts, represent the single largest ecosystem type on the Earth's terrestrial surface. The Namib desert is believed to be the oldest (80 million years) desert. We report here an initial analysis of bacteriophages isolated from the Namib desert using a combination of electron microscopy and genomic approaches. The virus-like particles observed by electron microscopy revealed 20 seemingly different phage-like morphologies and sizes belonging to the Myoviridae and Siphoviridae families of tailed phages. Pulsed-field gel electrophoresis revealed a majority of phage genomes of 55-65 kb in length, with genomes of approximately 200, 300, and 350 kb also observable. Sample sequencing of cloned phage DNA fragments revealed that approximately 50% appeared to be of bacterial origin. Of the remaining DNA sequences, approximately 50% displayed no significant match to any sequence in the databases. The majority of the 16S rDNA sequences amplified from DNA extracted from the sand displayed considerable (94-98%) homology to members of the Firmicutes, and in particular to members of the genus Bacillus, though members of the Bacteroidetes, Planctomycetes, Chloroflexi, and delta-Proteobacteria groups were also observed.
Collapse
Affiliation(s)
- Eric Prestel
- Laboratoire de Génomique et Biodiversité Microbienne des Biofilms, Université Paris-Sud 11, Institut de Génétique et Microbiologie, CNRS UMR 8621, Bâtiment 409, 91405 Orsay, France
| | | | | |
Collapse
|
46
|
Two different Panton-Valentine leukocidin phage lineages predominate in Japan. J Clin Microbiol 2008; 46:3246-58. [PMID: 18685010 DOI: 10.1128/jcm.00136-08] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We determined the entire nucleotide sequence of phiSa2958-carrying Panton-Valentine leukocidin (PVL) gene, which was lysogenized in a sequence type 5 staphylococcal cassette chromosome mec (SCCmec) type II strain of methicillin-resistant Staphylococcus aureus (MRSA). Based on the nucleotide sequences of PVL phages, we developed PCRs to discriminate among five PVL phages, with a preliminary classification into two morphological groups (elongated-head type and icosahedral-head type) with four PCRs, including two PCRs for identifying the gene lineage between lukS-PV and the tail gene. The phages were then classified into five types by four PCRs identifying each phage-specific structure. With these PCRs, we examined the PVL phage types of 67 MRSA strains isolated in Japan from 1979 through 1985 and since 2000 and found that two morphologically distinct phages were predominant in Japan. The icosahedral-head-type phage, represented by the phi108PVL type, was identified for 39 of 53 strains isolated from 1979 through 1985. Of 26 other Japanese isolates, 25 belonged either definitively or presumably to elongated-head types as follows: 3 belonged to the phiSa2958 type; 8 were determined to belong to an elongated-head type, but a determination of greater specificity was not made; and 14 belonged to a phiSa2958-like phage of unknown type. We induced prophages by treatment with mitomycin C from six strains of the phiSa2958 type or of phiSa2958-like unknown-type phages; five of six strains carried intact PVL-carrying phages, which can infect other S. aureus strains and might generate novel PVL-positive strains of S. aureus. That various SCCmec elements were carried by different strains of the same phage type suggests that S. aureus strains might independently acquire PVL phages before they acquire various SCCmec elements.
Collapse
|
47
|
Abstract
Thermophilic viruses were reported decades ago; however, knowledge of their diversity, biology, and ecological impact is limited. Previous research on thermophilic viruses focused on cultivated strains. This study examined metagenomic profiles of viruses directly isolated from two mildly alkaline hot springs, Bear Paw (74 degrees C) and Octopus (93 degrees C). Using a new method for constructing libraries from picograms of DNA, nearly 30 Mb of viral DNA sequence was determined. In contrast to previous studies, sequences were assembled at 50% and 95% identity, creating composite contigs up to 35 kb and facilitating analysis of the inherent heterogeneity in the populations. Lowering the assembly identity reduced the estimated number of viral types from 1,440 and 1,310 to 548 and 283, respectively. Surprisingly, the diversity of viral species in these springs approaches that in moderate-temperature environments. While most known thermophilic viruses have a chronic, nonlytic infection lifestyle, analysis of coding sequences suggests lytic viruses are more common in geothermal environments than previously thought. The 50% assembly included one contig with high similarity and perfect synteny to nine genes from Pyrobaculum spherical virus (PSV). In fact, nearly all the genes of the 28-kb genome of PSV have apparent homologs in the metagenomes. Similarities to thermoacidophilic viruses isolated on other continents were limited to specific open reading frames but were equally strong. Nearly 25% of the reads showed significant similarity between the hot springs, suggesting a common subterranean source. To our knowledge, this is the first application of metagenomics to viruses of geothermal origin.
Collapse
|
48
|
Plasmid transfer via transduction from Streptococcus thermophilus to Lactococcus lactis. J Bacteriol 2008; 190:3083-7. [PMID: 18263725 DOI: 10.1128/jb.01448-07] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using Streptococcus thermophilus phages, plasmid transduction in Lactococcus lactis was demonstrated. The transduction frequencies were 4 orders of magnitude lower in L. lactis than in S. thermophilus. These results are the first evidence that there is phage-mediated direct transfer of DNA from S. thermophilus to L. lactis. The implications of these results for phage evolution are discussed.
Collapse
|
49
|
Sturino JM, Klaenhammer TR. Inhibition of bacteriophage replication in Streptococcus thermophilus by subunit poisoning of primase. MICROBIOLOGY-SGM 2007; 153:3295-3302. [PMID: 17906129 DOI: 10.1099/mic.0.2007/007567-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Invariant and highly conserved amino acids within a primase consensus sequence were targeted by site-specific mutations within the putative primase of Streptococcus thermophilus phage kappa3. PCR products containing the desired mutation(s) within putative ATPase/helicase and/or oligomerization domains of the kappa3-encoded primase gene were cloned into a high-copy-number vector and expressed in S. thermophilus NCK1125. The majority of the plasmid constructs failed to alter phage sensitivity; however, four of the constructs conferred strong phage resistance upon the host. Expression of the K238(A/T) and RR340-341AA mutant proteins in trans suppressed the function of the native phage primase protein in a dominant negative fashion via a proposed subunit poisoning mechanism. These constructs completely inhibited phage genome synthesis and reduced the efficiencies of plaquing and centre of infection formation by more than 9 and 3.5 logs, respectively. Amber mutations introduced upstream of the transdominant RR340-341AA and K238(A/T) mutations restored phage genome replication and sensitivity of the host, indicating that translation was required to confer phage resistance. Introduction of an E437A mutation in a putative oligomerization domain located downstream of the transdominant K238T mutation also completely suppressed phage resistance. This study appears to represent the first use of transdominant proteins to inhibit phages that are disruptive to cultures used in industrial fermentations.
Collapse
Affiliation(s)
- Joseph M Sturino
- Genomic Sciences Program, Department of Food Science, Southeast Dairy Foods Research Center, North Carolina State University, Raleigh, NC 27695-7624, USA
| | - Todd R Klaenhammer
- Genomic Sciences Program, Department of Food Science, Southeast Dairy Foods Research Center, North Carolina State University, Raleigh, NC 27695-7624, USA
| |
Collapse
|
50
|
Comparative analyses of prophage-like elements present in two Lactococcus lactis strains. Appl Environ Microbiol 2007; 73:7771-80. [PMID: 17933937 DOI: 10.1128/aem.01273-07] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, we describe the genetic organizations of six and five apparent prophage-like elements present in the genomes of the Lactococcus lactis subsp. cremoris strains MG1363 and SK11, respectively. Phylogenetic investigation as well bioinformatic analyses indicates that all 11 prophages belong to subdivisions of the lactococcal P335 group of temperate bacteriophages.
Collapse
|