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Quantification of Lysogeny Caused by Phage Coinfections in Microbial Communities from Biophysical Principles. mSystems 2020; 5:5/5/e00353-20. [PMID: 32934113 PMCID: PMC7498681 DOI: 10.1128/msystems.00353-20] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The association of temperate phages and bacterial hosts during lysogeny manipulates microbial dynamics from the oceans to the human gut. Lysogeny is well studied in laboratory models, but its environmental drivers remain unclear. Here, we quantified the probability of lysogenization caused by phage coinfections, a well-known trigger of lysogeny, in marine and gut microbial environments. Coinfections were quantified by developing a biophysical model that incorporated the traits of viral and bacterial communities. Lysogenization via coinfection was more frequent in highly productive environments like the gut, due to higher microbial densities and higher phage adsorption rates. At low cell densities, lysogenization occurred in bacteria with long duplication times. These results bridge the molecular understanding of lysogeny with the ecology of complex microbial communities. Temperate phages can associate with their bacterial host to form a lysogen, often modifying the phenotype of the host. Lysogens are dominant in the microbially dense environment of the mammalian gut. This observation contrasts with the long-standing hypothesis of lysogeny being favored at low microbial densities, such as in oligotrophic marine environments. Here, we hypothesized that phage coinfections—a well-understood molecular mechanism of lysogenization—increase at high microbial abundances. To test this hypothesis, we developed a biophysical model of coinfection for marine and gut microbiomes. The model stochastically sampled ranges of phage and bacterial concentrations, adsorption rates, lysogenic commitment times, and community diversity from each environment. In 90% of the sampled marine communities, less than 10% of the bacteria were predicted to be lysogenized via coinfection. In contrast, 25% of the sampled gut communities displayed more than 25% of lysogenization. The probability of lysogenization in the gut was a consequence of the higher densities and higher adsorption rates. These results suggest that, on average, coinfections can form two trillion lysogens in the human gut every day. In marine microbiomes, which were characterized by lower densities and phage adsorption rates, lysogeny via coinfection was still possible for communities with long lysogenic commitment times. Our study indicates that different physical factors causing coinfections can reconcile the traditional view of lysogeny at poor host growth (long commitment times) and the recent Piggyback-the-Winner framework proposing that lysogeny is favored in rich environments (high densities and adsorption rates). IMPORTANCE The association of temperate phages and bacterial hosts during lysogeny manipulates microbial dynamics from the oceans to the human gut. Lysogeny is well studied in laboratory models, but its environmental drivers remain unclear. Here, we quantified the probability of lysogenization caused by phage coinfections, a well-known trigger of lysogeny, in marine and gut microbial environments. Coinfections were quantified by developing a biophysical model that incorporated the traits of viral and bacterial communities. Lysogenization via coinfection was more frequent in highly productive environments like the gut, due to higher microbial densities and higher phage adsorption rates. At low cell densities, lysogenization occurred in bacteria with long duplication times. These results bridge the molecular understanding of lysogeny with the ecology of complex microbial communities.
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52
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Guerin E, Hill C. Shining Light on Human Gut Bacteriophages. Front Cell Infect Microbiol 2020; 10:481. [PMID: 33014897 PMCID: PMC7511551 DOI: 10.3389/fcimb.2020.00481] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/04/2020] [Indexed: 12/15/2022] Open
Abstract
The human gut is a complex environment that contains a multitude of microorganisms that are collectively termed the microbiome. Multiple factors have a role to play in driving the composition of human gut bacterial communities either toward homeostasis or the instability that is associated with many disease states. One of the most important forces are likely to be bacteriophages, bacteria-infecting viruses that constitute by far the largest portion of the human gut virome. Despite this, bacteriophages (phages) are the one of the least studied residents of the gut. This is largely due to the challenges associated with studying these difficult to culture entities. Modern high throughput sequencing technologies have played an important role in improving our understanding of the human gut phageome but much of the generated sequencing data remains uncharacterised. Overcoming this requires database-independent bioinformatic pipelines and even those phages that are successfully characterized only provide limited insight into their associated biological properties, and thus most viral sequences have been characterized as “viral dark matter.” Fundamental to understanding the role of phages in shaping the human gut microbiome, and in turn perhaps influencing human health, is how they interact with their bacterial hosts. An essential aspect is the isolation of novel phage-bacteria host pairs by direct isolation through various screening methods, which can transform in silico phages into a biological reality. However, this is also beset with multiple challenges including culturing difficulties and the use of traditional methods, such as plaquing, which may bias which phage-host pairs that can be successfully isolated. Phage-bacteria interactions may be influenced by many aspects of complex human gut biology which can be difficult to reproduce under laboratory conditions. Here we discuss some of the main findings associated with the human gut phageome to date including composition, our understanding of phage-host interactions, particularly the observed persistence of virulent phages and their hosts, as well as factors that may influence these highly intricate relationships. We also discuss current methodologies and bottlenecks hindering progression in this field and identify potential steps that may be useful in overcoming these hurdles.
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Affiliation(s)
- Emma Guerin
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
| | - Colin Hill
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
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53
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Federici S, Nobs SP, Elinav E. Phages and their potential to modulate the microbiome and immunity. Cell Mol Immunol 2020; 18:889-904. [PMID: 32901128 DOI: 10.1038/s41423-020-00532-4] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/06/2020] [Indexed: 02/07/2023] Open
Abstract
Bacteriophages (hence termed phages) are viruses that target bacteria and have long been considered as potential future treatments against antibiotic-resistant bacterial infection. However, the molecular nature of phage interactions with bacteria and the human host has remained elusive for decades, limiting their therapeutic application. While many phages and their functional repertoires remain unknown, the advent of next-generation sequencing has increasingly enabled researchers to decode new lytic and lysogenic mechanisms by which they attack and destroy bacteria. Furthermore, the last decade has witnessed a renewed interest in the utilization of phages as therapeutic vectors and as a means of targeting pathogenic or commensal bacteria or inducing immunomodulation. Importantly, the narrow host range, immense antibacterial repertoire, and ease of manipulating phages may potentially allow for their use as targeted modulators of pathogenic, commensal and pathobiont members of the microbiome, thereby impacting mammalian physiology and immunity along mucosal surfaces in health and in microbiome-associated diseases. In this review, we aim to highlight recent advances in phage biology and how a mechanistic understanding of phage-bacteria-host interactions may facilitate the development of novel phage-based therapeutics. We provide an overview of the challenges of the therapeutic use of phages and how these could be addressed for future use of phages as specific modulators of the human microbiome in a variety of infectious and noncommunicable human diseases.
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Affiliation(s)
- Sara Federici
- Immunology Department, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Samuel P Nobs
- Immunology Department, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Eran Elinav
- Immunology Department, Weizmann Institute of Science, Rehovot, 7610001, Israel. .,Cancer-Microbiome Division Deutsches Krebsforschungszentrum (DKFZ), Neuenheimer Feld 280, 69120, Heidelberg, Germany.
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54
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Kim JY, Whon TW, Lim MY, Kim YB, Kim N, Kwon MS, Kim J, Lee SH, Choi HJ, Nam IH, Chung WH, Kim JH, Bae JW, Roh SW, Nam YD. The human gut archaeome: identification of diverse haloarchaea in Korean subjects. MICROBIOME 2020; 8:114. [PMID: 32753050 PMCID: PMC7409454 DOI: 10.1186/s40168-020-00894-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 07/17/2020] [Indexed: 05/11/2023]
Abstract
BACKGROUND Archaea are one of the least-studied members of the gut-dwelling autochthonous microbiota. Few studies have reported the dominance of methanogens in the archaeal microbiome (archaeome) of the human gut, although limited information regarding the diversity and abundance of other archaeal phylotypes is available. RESULTS We surveyed the archaeome of faecal samples collected from 897 East Asian subjects living in South Korea. In total, 42.47% faecal samples were positive for archaeal colonisation; these were subsequently subjected to archaeal 16S rRNA gene deep sequencing and real-time quantitative polymerase chain reaction-based abundance estimation. The mean archaeal relative abundance was 10.24 ± 4.58% of the total bacterial and archaeal abundance. We observed extensive colonisation of haloarchaea (95.54%) in the archaea-positive faecal samples, with 9.63% mean relative abundance in archaeal communities. Haloarchaea were relatively more abundant than methanogens in some samples. The presence of haloarchaea was also verified by fluorescence in situ hybridisation analysis. Owing to large inter-individual variations, we categorised the human gut archaeome into four archaeal enterotypes. CONCLUSIONS The study demonstrated that the human gut archaeome is indigenous, responsive, and functional, expanding our understanding of the archaeal signature in the gut of human individuals. Video Abstract.
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Affiliation(s)
- Joon Yong Kim
- Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju, 61755 Republic of Korea
| | - Tae Woong Whon
- Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju, 61755 Republic of Korea
| | - Mi Young Lim
- Research Group of Healthcare, Research Division of Food Functionality, Korea Food Research Institute, Jeollabuk-do, 55365 Republic of Korea
| | - Yeon Bee Kim
- Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju, 61755 Republic of Korea
| | - Namhee Kim
- Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju, 61755 Republic of Korea
| | - Min-Sung Kwon
- Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju, 61755 Republic of Korea
| | - Juseok Kim
- Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju, 61755 Republic of Korea
| | - Se Hee Lee
- Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju, 61755 Republic of Korea
| | - Hak-Jong Choi
- Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju, 61755 Republic of Korea
| | - In-Hyun Nam
- Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources, Daejeon, 34132 Republic of Korea
| | - Won-Hyong Chung
- Research Group of Healthcare, Research Division of Food Functionality, Korea Food Research Institute, Jeollabuk-do, 55365 Republic of Korea
| | - Jung-Ha Kim
- Department of Family Medicine, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, 06973 Republic of Korea
| | - Jin-Woo Bae
- Department of Biology, Kyung Hee University, Seoul, 02447 Republic of Korea
| | - Seong Woon Roh
- Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju, 61755 Republic of Korea
| | - Young-Do Nam
- Research Group of Healthcare, Research Division of Food Functionality, Korea Food Research Institute, Jeollabuk-do, 55365 Republic of Korea
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55
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Devaux CA, Million M, Raoult D. The Butyrogenic and Lactic Bacteria of the Gut Microbiota Determine the Outcome of Allogenic Hematopoietic Cell Transplant. Front Microbiol 2020; 11:1642. [PMID: 32793150 PMCID: PMC7387665 DOI: 10.3389/fmicb.2020.01642] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/24/2020] [Indexed: 12/12/2022] Open
Abstract
Graft versus host disease (GVHD) is a post-transplant pathology in which donor-derived T cells present in the Peyer's patches target the cell-surface alloantigens of the recipient, causing host tissue damages. Therefore, the GVHD has long been considered only a purely immunological process whose prevention requires an immunosuppressive treatment. However, since the early 2010s, the impact of gut microbiota on GVHD has received increased attention. Both a surprising fall in gut microbiota diversity and a shift toward Enterobacteriaceae were described in this disease. Recently, unexpected results were reported that further link GVHD with changes in bacterial composition in the gut and disruption of intestinal epithelial tight junctions leading to abnormal intestinal barrier permeability. Patients receiving allogenic hematopoietic stem cell transplant (allo-HCT) as treatment of hematologic malignancies showed a decrease of the overall diversity of the gut microbiota that affects Clostridia and Blautia spp. and a predominance of lactic acid bacteria (LAB) of the Enterococcus genus, in particular the lactose auxotroph Enterococcus faecium. The reduced microbiota diversity (likely including Actinobacteria, such as Bifidobacterium adolescentis that cross feed butyrogenic bacteria) deprives the butyrogenic bacteria (such as Roseburia intestinalis or Eubacterium) of their capacity to metabolize acetate to butyrate. Indeed, administration of butyrate protects against the GVHD. Here, we review the data highlighting the possible link between GVHD and lactase defect, accumulation of lactose in the gut lumen, reduction of Reg3 antimicrobial peptides, narrower enzyme equipment of bacteria that predominate post-transplant, proliferation of En. faecium that use lactose as metabolic fuels, induction of innate and adaptive immune response against these bacteria which maintains an inflammatory process, elevated expression of myosin light chain kinase 210 (MLCK210) and subsequent disruption of intestinal barrier, and translocation of microbial products (lactate) or transmigration of LAB within the liver. The analysis of data from the literature confirms that the gut microbiota plays a major role in the GVHD. Moreover, the most recent publications uncover that the LAB, butyrogenic bacteria and bacterial cross feeding were the missing pieces in the puzzle. This opens new bacteria-based strategies in the treatment of GVHD.
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Affiliation(s)
- Christian Albert Devaux
- Aix-Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), Marseille, France
| | - Matthieu Million
- Aix-Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France
| | - Didier Raoult
- Aix-Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France
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56
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Antioxidant, Anti-Inflammatory, and Microbial-Modulating Activities of Essential Oils: Implications in Colonic Pathophysiology. Int J Mol Sci 2020; 21:ijms21114152. [PMID: 32532055 PMCID: PMC7313461 DOI: 10.3390/ijms21114152] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/29/2020] [Accepted: 06/04/2020] [Indexed: 02/06/2023] Open
Abstract
Essential oils (EOs) are a complex mixture of hydrophobic and volatile compounds synthesized from aromatic plants, most of them commonly used in the human diet. In recent years, many studies have analyzed their antimicrobial, antioxidant, anti-inflammatory, immunomodulatory and anticancer properties in vitro and on experimentally induced animal models of colitis and colorectal cancer. However, there are still few clinical studies aimed to understand their role in the modulation of the intestinal pathophysiology. Many EOs and some of their molecules have demonstrated their efficacy in inhibiting bacterial, fungi and virus replication and in modulating the inflammatory and oxidative processes that take place in experimental colitis. In addition to this, their antitumor activity against colorectal cancer models makes them extremely interesting compounds for the modulation of the pathophysiology of the large bowel. The characterization of these EOs is made difficult by their complexity and by the different compositions present in the same oil having different geographical origins. This review tries to shift the focus from the EOs to their individual compounds, to expand their possible applications in modulating colon pathophysiology.
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57
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Liang G, Zhao C, Zhang H, Mattei L, Sherrill-Mix S, Bittinger K, Kessler LR, Wu GD, Baldassano RN, DeRusso P, Ford E, Elovitz MA, Kelly MS, Patel MZ, Mazhani T, Gerber JS, Kelly A, Zemel BS, Bushman FD. The stepwise assembly of the neonatal virome is modulated by breastfeeding. Nature 2020; 581:470-474. [PMID: 32461640 PMCID: PMC7263352 DOI: 10.1038/s41586-020-2192-1] [Citation(s) in RCA: 152] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 02/14/2020] [Indexed: 01/01/2023]
Abstract
The gut of healthy human neonates is usually devoid of viruses at birth, but quickly becomes colonized, in some cases leading to gastrointestinal disorders1–4. Here we report that viral community assembly in neonates takes place in distinct steps. Fluorescent staining of virus-like particles purified from infant meconium/early stool samples show few or no particles, but by one month of life particle numbers achieve 109 per gram, and these numbers appear to persist through life5–7. We investigated the origin of these viral populations using shotgun metagenomic sequencing of viral-enriched preparations and whole microbial communities, and followed up with targeted microbiological analyses. Results indicate that, early after birth, pioneer bacteria colonize the infant gut, and by one month prophage induced from these bacteria provide the predominant population of virus-like particles. By four months of life, identifiable viruses that replicate in human cells become more prominent. Multiple human viruses were more abundant in stool samples from babies exclusively fed formula versus those fed partially or fully on breast milk, paralleling reports that breast milk can be protective against viral infections8–10. Phage populations also differed associated with breastfeeding. Evidently colonization of the infant gut is stepwise, first mainly by temperate bacteriophages induced from pioneer bacteria, and later by viruses that replicate in human cells, with the second phase modulated by breastfeeding.
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Affiliation(s)
- Guanxiang Liang
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Chunyu Zhao
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Huanjia Zhang
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Lisa Mattei
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Scott Sherrill-Mix
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kyle Bittinger
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Lyanna R Kessler
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Gary D Wu
- Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Robert N Baldassano
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Patricia DeRusso
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Eileen Ford
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Michal A Elovitz
- Maternal and Child Health Research Center, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Matthew S Kelly
- Division of Pediatric Infectious Diseases, Duke University, Durham, NC, USA
| | - Mohamed Z Patel
- Department of Paediatric and Adolescent Health, Faculty of Medicine, University of Botswana, Gaborone, Botswana
| | - Tiny Mazhani
- Department of Paediatric and Adolescent Health, Faculty of Medicine, University of Botswana, Gaborone, Botswana
| | - Jeffrey S Gerber
- Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Andrea Kelly
- Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Babette S Zemel
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Frederic D Bushman
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Beyond Just Bacteria: Functional Biomes in the Gut Ecosystem Including Virome, Mycobiome, Archaeome and Helminths. Microorganisms 2020; 8:microorganisms8040483. [PMID: 32231141 PMCID: PMC7232386 DOI: 10.3390/microorganisms8040483] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 03/26/2020] [Accepted: 03/26/2020] [Indexed: 12/20/2022] Open
Abstract
Gut microbiota refers to a complex network of microbes, which exerts a marked influence on the host’s health. It is composed of bacteria, fungi, viruses, and helminths. Bacteria, or collectively, the bacteriome, comprises a significant proportion of the well-characterized microbiome. However, the other communities referred to as ‘dark matter’ of microbiomes such as viruses (virome), fungi (mycobiome), archaea (archaeome), and helminths have not been completely elucidated. Development of new and improved metagenomics methods has allowed the identification of complete genomes from the genetic material in the human gut, opening new perspectives on the understanding of the gut microbiome composition, their importance, and potential clinical applications. Here, we review the recent evidence on the viruses, fungi, archaea, and helminths found in the mammalian gut, detailing their interactions with the resident bacterial microbiota and the host, to explore the potential impact of the microbiome on host’s health. The role of fecal virome transplantations, pre-, pro-, and syn-biotic interventions in modulating the microbiome and their related concerns are also discussed.
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Rouse MD, Stanbro J, Roman JA, Lipinski MA, Jacobs A, Biswas B, Regeimbal J, Henry M, Stockelman MG, Simons MP. Impact of Frequent Administration of Bacteriophage on Therapeutic Efficacy in an A. baumannii Mouse Wound Infection Model. Front Microbiol 2020; 11:414. [PMID: 32256472 PMCID: PMC7090133 DOI: 10.3389/fmicb.2020.00414] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/27/2020] [Indexed: 01/21/2023] Open
Abstract
The spread of multidrug antibiotic resistance (MDR) is a widely recognized crisis in the treatment of bacterial infections, including those occurring in military communities. Recently, the World Health Organization published its first ever list of antibiotic-resistant “priority pathogens” – a catalog of 12 families of bacteria that pose the greatest threat to human health with A. baumannii listed in the “Priority 1: Critical” category of pathogens. With the increasing prevalence of antibiotic resistance and limited development of new classes of antibiotics, alternative antimicrobial therapies are needed, with lytic bacteriophage (phage) specifically targeted against each of the high priority bacterial infections as a potential approach currently in development toward regulatory approval for clinical use. Balb/c mice were prophylactically administered PBS or phage selected against A. baumannii strain AB5075. After 3 weeks, mice were anesthetized, wounded (dorsal), and challenged topically with AB5075. Following infection, mice were subsequently treated with PBS or phage for three consecutive days, and evaluated for 3 weeks to assess the safety and efficacy of the phage treatment relative to the control. We assessed mortality, bacterial burden, time to wound closure, systemic and local cytokine profiles, alterations in host cellular immunity, and finally presence of neutralizing antibodies to the phage mixture. In our study, we found that prophylactic phage administration led to a significant reduction in monocyte-related cytokines in serum compared to mice given PBS. However, we detected no significant changes to circulating blood populations or immune cell populations of secondary lymphoid organs compared to PBS-treated mice. Following prophylactic phage administration, we detected a marked increase in total immunoglobulins in serum, particularly IgG2a and IgG2b. Furthermore, we determined that these antibodies were able to specifically target phage and effectively neutralize their ability to lyse their respective target. In regards to their therapeutic efficacy, administration of phage treatment effectively decreased wound size of mice infected with AB5075 without adverse effects. In conclusion, our data demonstrate that phage can serve as a safe and effective novel therapeutic agent against A. baumannii without adverse reactions to the host and pre-exposure to phage does not seem to adversely affect therapeutic efficacy. This study is an important proof of concept to support the efforts to develop phage as a novel therapeutic product for treatment of complex bacterial wound infections.
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Affiliation(s)
- Michael D Rouse
- Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Naval Medical Research Center, Silver Spring, MD, United States
| | - Joshua Stanbro
- Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Naval Medical Research Center, Silver Spring, MD, United States
| | - Jessica A Roman
- Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Naval Medical Research Center, Silver Spring, MD, United States
| | - Michelle A Lipinski
- Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Naval Medical Research Center, Silver Spring, MD, United States
| | - Anna Jacobs
- Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Biswaijt Biswas
- Biological Defense Research Directorate, Naval Medical Research Center, Fort Detrick, MD, United States
| | | | - Matthew Henry
- Naval Medical Research Center, Silver Spring, MD, United States.,Biological Defense Research Directorate, Naval Medical Research Center, Fort Detrick, MD, United States
| | | | - Mark P Simons
- Naval Medical Research Center, Silver Spring, MD, United States
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Abstract
Colorectal cancer (CRC) is a leading cause of cancer-related deaths in both the USA and the world. Recent research has demonstrated the involvement of the gut microbiota in CRC development and progression. Microbial biomarkers of disease have focused primarily on the bacterial component of the microbiome; however, the viral portion of the microbiome, consisting of both bacteriophages and eukaryotic viruses, together known as the virome, has been lesser studied. Here we review the recent advancements in high-throughput sequencing (HTS) technologies and bioinformatics, which have enabled scientists to better understand how viruses might influence the development of colorectal cancer. We discuss the contemporary findings revealing modulations in the virome and their correlation with CRC development and progression. While a variety of challenges still face viral HTS detection in clinical specimens, we consider herein numerous next steps for future basic and clinical research. Clinicians need to move away from a single infectious agent model for disease etiology by grasping new, more encompassing etiological paradigms, in which communities of various microbial components interact with each other and the host. The reporting and indexing of patient health information, socioeconomic data, and other relevant metadata will enable identification of predictive variables and covariates of viral presence and CRC development. Altogether, the virome has a more profound role in carcinogenesis and cancer progression than once thought, and viruses, specific for either human cells or bacteria, are clinically relevant in understanding CRC pathology, patient prognosis, and treatment development.
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61
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Sausset R, Petit MA, Gaboriau-Routhiau V, De Paepe M. New insights into intestinal phages. Mucosal Immunol 2020; 13:205-215. [PMID: 31907364 PMCID: PMC7039812 DOI: 10.1038/s41385-019-0250-5] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/13/2019] [Accepted: 12/05/2019] [Indexed: 02/07/2023]
Abstract
The intestinal microbiota plays important roles in human health. This last decade, the viral fraction of the intestinal microbiota, composed essentially of phages that infect bacteria, received increasing attention. Numerous novel phage families have been discovered in parallel with the development of viral metagenomics. However, since the discovery of intestinal phages by d'Hérelle in 1917, our understanding of the impact of phages on gut microbiota structure remains scarce. Changes in viral community composition have been observed in several diseases. However, whether these changes reflect a direct involvement of phages in diseases etiology or simply result from modifications in bacterial composition is currently unknown. Here we present an overview of the current knowledge in intestinal phages, their identity, lifestyles, and their possible effects on the gut microbiota. We also gather the main data on phage interactions with the immune system, with a particular emphasis on recent findings.
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Affiliation(s)
- R Sausset
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
- Myriade, 68 boulevard de Port Royal, 75005, Paris, France
| | - M A Petit
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - V Gaboriau-Routhiau
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
- Laboratory of Intestinal Immunity, INSERM UMR 1163, Institut Imagine, Paris, France
- Université Paris Descartes-Sorbonne Paris Cité, 75006, Paris, France
| | - M De Paepe
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France.
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62
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Mathieu A, Dion M, Deng L, Tremblay D, Moncaut E, Shah SA, Stokholm J, Krogfelt KA, Schjørring S, Bisgaard H, Nielsen DS, Moineau S, Petit MA. Virulent coliphages in 1-year-old children fecal samples are fewer, but more infectious than temperate coliphages. Nat Commun 2020; 11:378. [PMID: 31953385 PMCID: PMC6969025 DOI: 10.1038/s41467-019-14042-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 12/10/2019] [Indexed: 01/08/2023] Open
Abstract
Bacteriophages constitute an important part of the human gut microbiota, but their impact on this community is largely unknown. Here, we cultivate temperate phages produced by 900 E. coli strains isolated from 648 fecal samples from 1-year-old children and obtain coliphages directly from the viral fraction of the same fecal samples. We find that 63% of strains hosted phages, while 24% of the viromes contain phages targeting E. coli. 150 of these phages, half recovered from strain supernatants, half from virome (73% temperate and 27% virulent) were tested for their host range on 75 E. coli strains isolated from the same cohort. Temperate phages barely infected the gut strains, whereas virulent phages killed up to 68% of them. We conclude that in fecal samples from children, temperate coliphages dominate, while virulent ones have greater infectivity and broader host range, likely playing a role in gut microbiota dynamics. The impact of bacteriophages in the human gut microbiome remains poorly understood. Here, the authors characterize coliphages isolated from a large cohort of 1-year-old infants and show that temperate coliphages dominate, while virulent ones have greater infectivity and broader host range.
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Affiliation(s)
- Aurélie Mathieu
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Moïra Dion
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, QC, G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Ling Deng
- Department of Food Science, University of Copenhagen, Copenhagen, Denmark
| | - Denise Tremblay
- Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada.,Félix d'Hérelle Reference Center for Bacterial Viruses, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Elisabeth Moncaut
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Shiraz A Shah
- Copenhagen Prospective Studies on Asthma in Childhood, Copenhagen University Hospital, Herlev-Gentofte, Ledreborg Allé 34, DK-2820, Gentofte, Denmark
| | - Jakob Stokholm
- Copenhagen Prospective Studies on Asthma in Childhood, Copenhagen University Hospital, Herlev-Gentofte, Ledreborg Allé 34, DK-2820, Gentofte, Denmark
| | - Karen A Krogfelt
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Artillerivej5, 2300S, Copenhagen, Denmark
| | - Susanne Schjørring
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Artillerivej5, 2300S, Copenhagen, Denmark
| | - Hans Bisgaard
- Copenhagen Prospective Studies on Asthma in Childhood, Copenhagen University Hospital, Herlev-Gentofte, Ledreborg Allé 34, DK-2820, Gentofte, Denmark
| | - Dennis S Nielsen
- Department of Food Science, University of Copenhagen, Copenhagen, Denmark
| | - Sylvain Moineau
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, QC, G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada.,Félix d'Hérelle Reference Center for Bacterial Viruses, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Marie-Agnès Petit
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France.
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63
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Soundararajan M, von Bünau R, Oelschlaeger TA. K5 Capsule and Lipopolysaccharide Are Important in Resistance to T4 Phage Attack in Probiotic E. coli Strain Nissle 1917. Front Microbiol 2019; 10:2783. [PMID: 31849915 PMCID: PMC6895014 DOI: 10.3389/fmicb.2019.02783] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 11/15/2019] [Indexed: 12/14/2022] Open
Abstract
Rapidly growing antibiotic resistance among gastrointestinal pathogens, and the ability of antibiotics to induce the virulence of these pathogens makes it increasingly difficult to rely on antibiotics to treat gastrointestinal infections. The probiotic Escherichia coli strain Nissle 1917 (EcN) is the active component of the pharmaceutical preparation Mutaflor® and has been successfully used in the treatment of gastrointestinal disorders. Gut bacteriophages are dominant players in maintaining the microbial homeostasis in the gut, however, their interaction with incoming probiotic bacteria remains to be at conception. The presence of bacteriophages in the gut makes it inevitable for any probiotic bacteria to be phage resistant, in order to survive and successfully colonize the gut. This study addresses the phage resistance of EcN, specifically against lytic T4 phage infection. From various experiments we could show that (i) EcN is resistant toward T4 phage infection, (ii) EcN's K5 polysaccharide capsule plays a crucial role in T4 phage resistance and (iii) EcN's lipopolysaccharide (LPS) inactivates T4 phages and notably, treatment with the antibiotic polymyxin B which neutralizes the LPS destroyed the phage inactivation ability of isolated LPS from EcN. Combination of these identified properties in EcN was not found in other tested commensal E. coli strains. Our results further indicated that N-acetylglucosamine at the distal end of O6 antigen in EcN's LPS could be the interacting partner with T4 phages. From our findings, we have reported for the first time, the role of EcN's K5 capsule and LPS in its defense against T4 phages. In addition, by inactivating the T4 phages, EcN also protects E. coli K-12 strains from phage infection in tri-culture experiments. Our research highlights phage resistance as an additional safety feature of EcN, a clinically successful probiotic E. coli strain.
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Affiliation(s)
- Manonmani Soundararajan
- Institute for Molecular Infection Biology, Julius Maximilian University of Würzburg, Würzburg, Germany
| | | | - Tobias A Oelschlaeger
- Institute for Molecular Infection Biology, Julius Maximilian University of Würzburg, Würzburg, Germany
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64
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Lin DM, Koskella B, Ritz NL, Lin D, Carroll-Portillo A, Lin HC. Transplanting Fecal Virus-Like Particles Reduces High-Fat Diet-Induced Small Intestinal Bacterial Overgrowth in Mice. Front Cell Infect Microbiol 2019; 9:348. [PMID: 31750259 PMCID: PMC6843071 DOI: 10.3389/fcimb.2019.00348] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 09/30/2019] [Indexed: 12/30/2022] Open
Abstract
Fecal microbiota transplantation (FMT) is an effective tool for treating Clostridium difficile infection in the setting of dysbiosis of the intestinal microbiome. FMT for other forms of human disorders linked to dysbiosis have been less effective. The fecal microbiota contains a high density of virus-like particles (VLP), up to 90% of which are bacteriophages, thought to have a role in regulating gut bacterial populations. We hypothesized that transplantation of the phage-containing fecal VLP fraction may reduce bacterial density in the dysbiotic setting of small intestinal bacterial overgrowth (SIBO). In an experiment using fecal transplantation, we compared the effect of the fecal VLP fraction (bacteria removed) against “Whole” FMT (bacteria intact) on the ileal microbiome. Recipients were either treated with a 30-day high-fat diet (HFD) as a model of dysbiosis to induce SIBO or were on a standard diet (SD). We observed that transplantation of fecal VLPs from donors on a HFD was sufficient to alter the ileal microbiota, but the effect was dependent on diet of the recipient. In recipients on a HFD, ileal bacterial density was reduced. In recipients on a SD, the ileal microbiome transitioned toward the composition associated with a HFD. In both recipient groups, transplantation of fecal VLP fraction alone produced the same outcome as whole FMT. Neither treatment altered expression of antimicrobial peptides. These findings demonstrated a potential role of VLPs, likely phages, for modifying the gut microbiome during dysbiosis.
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Affiliation(s)
- Derek M Lin
- Medicine Service, New Mexico VA Health Care System, Albuquerque, NM, United States
| | - Britt Koskella
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Nathaniel L Ritz
- Medicine Service, New Mexico VA Health Care System, Albuquerque, NM, United States
| | - Dongdong Lin
- Mind Research Network, University of New Mexico, Albuquerque, NM, United States
| | | | - Henry C Lin
- Medicine Service, New Mexico VA Health Care System, Albuquerque, NM, United States.,Division of Gastroenterology and Hepatology, The University of New Mexico, Albuquerque, NM, United States
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65
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O'Brien S, Kümmerli R, Paterson S, Winstanley C, Brockhurst MA. Transposable temperate phages promote the evolution of divergent social strategies in Pseudomonas aeruginosa populations. Proc Biol Sci 2019; 286:20191794. [PMID: 31594506 DOI: 10.1098/rspb.2019.1794] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Transposable temperate phages randomly insert into bacterial genomes, providing increased supply and altered spectra of mutations available to selection, thus opening alternative evolutionary trajectories. Transposable phages accelerate bacterial adaptation to new environments, but their effect on adaptation to the social environment is unclear. Using experimental evolution of Pseudomonas aeruginosa in iron-limited and iron-rich environments, where the cost of producing cooperative iron-chelating siderophores is high and low, respectively, we show that transposable phages promote divergence into extreme siderophore production phenotypes. Iron-limited populations with transposable phages evolved siderophore overproducing clones alongside siderophore non-producing cheats. Low siderophore production was associated with parallel mutations in pvd genes, encoding pyoverdine biosynthesis, and pqs genes, encoding quinolone signalling, while high siderophore production was associated with parallel mutations in phenazine-associated gene clusters. Notably, some of these parallel mutations were caused by phage insertional inactivation. These data suggest that transposable phages, which are widespread in microbial communities, can mediate the evolutionary divergence of social strategies.
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Affiliation(s)
- Siobhán O'Brien
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Rolf Kümmerli
- Department of Plant and Microbial Biology, University of Zürich, Switzerland
| | - Steve Paterson
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Craig Winstanley
- Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7BE, UK
| | - Michael A Brockhurst
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
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66
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Cryan JF, O'Riordan KJ, Cowan CSM, Sandhu KV, Bastiaanssen TFS, Boehme M, Codagnone MG, Cussotto S, Fulling C, Golubeva AV, Guzzetta KE, Jaggar M, Long-Smith CM, Lyte JM, Martin JA, Molinero-Perez A, Moloney G, Morelli E, Morillas E, O'Connor R, Cruz-Pereira JS, Peterson VL, Rea K, Ritz NL, Sherwin E, Spichak S, Teichman EM, van de Wouw M, Ventura-Silva AP, Wallace-Fitzsimons SE, Hyland N, Clarke G, Dinan TG. The Microbiota-Gut-Brain Axis. Physiol Rev 2019; 99:1877-2013. [DOI: 10.1152/physrev.00018.2018] [Citation(s) in RCA: 1243] [Impact Index Per Article: 248.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The importance of the gut-brain axis in maintaining homeostasis has long been appreciated. However, the past 15 yr have seen the emergence of the microbiota (the trillions of microorganisms within and on our bodies) as one of the key regulators of gut-brain function and has led to the appreciation of the importance of a distinct microbiota-gut-brain axis. This axis is gaining ever more traction in fields investigating the biological and physiological basis of psychiatric, neurodevelopmental, age-related, and neurodegenerative disorders. The microbiota and the brain communicate with each other via various routes including the immune system, tryptophan metabolism, the vagus nerve and the enteric nervous system, involving microbial metabolites such as short-chain fatty acids, branched chain amino acids, and peptidoglycans. Many factors can influence microbiota composition in early life, including infection, mode of birth delivery, use of antibiotic medications, the nature of nutritional provision, environmental stressors, and host genetics. At the other extreme of life, microbial diversity diminishes with aging. Stress, in particular, can significantly impact the microbiota-gut-brain axis at all stages of life. Much recent work has implicated the gut microbiota in many conditions including autism, anxiety, obesity, schizophrenia, Parkinson’s disease, and Alzheimer’s disease. Animal models have been paramount in linking the regulation of fundamental neural processes, such as neurogenesis and myelination, to microbiome activation of microglia. Moreover, translational human studies are ongoing and will greatly enhance the field. Future studies will focus on understanding the mechanisms underlying the microbiota-gut-brain axis and attempt to elucidate microbial-based intervention and therapeutic strategies for neuropsychiatric disorders.
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Affiliation(s)
- John F. Cryan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Kenneth J. O'Riordan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Caitlin S. M. Cowan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Kiran V. Sandhu
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Thomaz F. S. Bastiaanssen
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Marcus Boehme
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Martin G. Codagnone
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Sofia Cussotto
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Christine Fulling
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Anna V. Golubeva
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Katherine E. Guzzetta
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Minal Jaggar
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Caitriona M. Long-Smith
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Joshua M. Lyte
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Jason A. Martin
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Alicia Molinero-Perez
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Gerard Moloney
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Emanuela Morelli
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Enrique Morillas
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Rory O'Connor
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Joana S. Cruz-Pereira
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Veronica L. Peterson
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Kieran Rea
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Nathaniel L. Ritz
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Eoin Sherwin
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Simon Spichak
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Emily M. Teichman
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Marcel van de Wouw
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Ana Paula Ventura-Silva
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Shauna E. Wallace-Fitzsimons
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Niall Hyland
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Gerard Clarke
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Timothy G. Dinan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
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67
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Sinha A, Maurice CF. Bacteriophages: Uncharacterized and Dynamic Regulators of the Immune System. Mediators Inflamm 2019; 2019:3730519. [PMID: 31582898 PMCID: PMC6754933 DOI: 10.1155/2019/3730519] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 08/06/2019] [Indexed: 12/23/2022] Open
Abstract
The human gut is an extremely active immunological site interfacing with the densest microbial community known to colonize the human body, the gut microbiota. Despite tremendous advances in our comprehension of how the gut microbiota is involved in human health and interacts with the mammalian immune system, most studies are incomplete as they typically do not consider bacteriophages. These bacterial viruses are estimated to be as numerous as their bacterial hosts, with tremendous and mostly uncharacterized genetic diversity. In addition, bacteriophages are not passive members of the gut microbiota, as highlighted by the recent evidence for their active involvement in human health. Yet, how bacteriophages interact with their bacterial hosts and the immune system in the human gut remains poorly described. Here, we aim to fill this gap by providing an overview of bacteriophage communities in the gut during human development, detailing recent findings for their bacterial-mediated effects on the immune response and summarizing the latest evidence for direct interactions between them and the immune system. The dramatic increase in antibiotic-resistant bacterial pathogens has spurred a renewed interest in using bacteriophages for therapy, despite the many unknowns about bacteriophages in the human body. Going forward, more studies encompassing the communities of bacteria, bacteriophages, and the immune system in diverse health and disease settings will provide invaluable insight into this dynamic trio essential for human health.
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Affiliation(s)
- Anshul Sinha
- Department of Microbiology & Immunology, McGill University, Montreal, QC, Canada
| | - Corinne F. Maurice
- Department of Microbiology & Immunology, McGill University, Montreal, QC, Canada
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68
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Claverie S, Ouattara A, Hoareau M, Filloux D, Varsani A, Roumagnac P, Martin DP, Lett JM, Lefeuvre P. Exploring the diversity of Poaceae-infecting mastreviruses on Reunion Island using a viral metagenomics-based approach. Sci Rep 2019; 9:12716. [PMID: 31481704 PMCID: PMC6722101 DOI: 10.1038/s41598-019-49134-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 08/20/2019] [Indexed: 01/22/2023] Open
Abstract
Mostly found in Africa and its surrounding islands, African streak viruses (AfSV) represent the largest group of known mastreviruses. Of the thirteen AfSV species that are known to infect either cultivated or wild Poaceae plant species, six have been identified on Reunion Island. To better characterize AfSV diversity on this island, we undertook a survey of a small agroecosystem using a new metagenomics-based approach involving rolling circle amplification with random PCR amplification tagging (RCA-RA-PCR), high-throughput sequencing (Illumina HiSeq) and the mastrevirus reads classification using phylogenetic placement. Mastreviruses that likely belong to three new species were discovered and full genome sequences of these were determined by Sanger sequencing. The geminivirus-focused metagenomics approach we applied in this study was useful in both the detection of known and novel mastreviruses. The results confirm that Reunion Island is indeed a hotspot of AfSV diversity and that many of the mastrevirus species have likely been introduced multiple times. Applying a similar approach in other natural and agricultural environments should yield sufficient detail on the composition and diversity of geminivirus communities to precipitate major advances in our understanding of the ecology and the evolutionary history of this important group of viruses.
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Affiliation(s)
- Sohini Claverie
- CIRAD, UMR PVBMT, F-97410, St Pierre, La Réunion, France.,Université de La Réunion, UMR PVBMT, Pôle de Protection des Plantes, 7 Chemin de l'IRAT, Saint-Pierre, 97410, France
| | - Alassane Ouattara
- INERA, 01 BP 476, Ouagadougou 01, Burkina Faso.,Laboratoire Biosciences, Université Joseph KI-ZERBO, 03 BP 7021, Ouagadougou 03, Burkina Faso
| | | | - Denis Filloux
- CIRAD, UMR BGPI, F-34398, Montpellier, France.,BGPI, Université de Montpellier, INRA, CIRAD, Montpellier SupAgro, F-34398, Montpellier, France
| | - Arvind Varsani
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, 1001 S. McAllister Ave, Tempe, AZ 85287-5001, USA.,Structural Biology Research Unit, Departement of Integrative Biomedical Sciences, University of Cape Town, Observatory, Cape Town, South Africa
| | - Philippe Roumagnac
- CIRAD, UMR BGPI, F-34398, Montpellier, France.,BGPI, Université de Montpellier, INRA, CIRAD, Montpellier SupAgro, F-34398, Montpellier, France
| | - Darren P Martin
- Computational Biology Division, Departement of Integrative Biomedical Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Observatory, South Africa
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69
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Suzuki Y, Nishijima S, Furuta Y, Yoshimura J, Suda W, Oshima K, Hattori M, Morishita S. Long-read metagenomic exploration of extrachromosomal mobile genetic elements in the human gut. MICROBIOME 2019; 7:119. [PMID: 31455406 PMCID: PMC6712665 DOI: 10.1186/s40168-019-0737-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 08/16/2019] [Indexed: 05/13/2023]
Abstract
BACKGROUND Elucidating the ecological and biological identity of extrachromosomal mobile genetic elements (eMGEs), such as plasmids and bacteriophages, in the human gut remains challenging due to their high complexity and diversity. RESULTS Here, we show efficient identification of eMGEs as complete circular or linear contigs from PacBio long-read metagenomic data. De novo assembly of PacBio long reads from 12 faecal samples generated 82 eMGE contigs (2.5~666.7-kb), which were classified as 71 plasmids and 11 bacteriophages, including 58 novel plasmids and six bacteriophages, and complete genomes of five diverse crAssphages with terminal direct repeats. In a dataset of 413 gut metagenomes from five countries, many of the identified plasmids were highly abundant and prevalent. The ratio of gut plasmids by our plasmid data is more than twice that in the public database. Plasmids outnumbered bacterial chromosomes three to one on average in this metagenomic dataset. Host prediction suggested that Bacteroidetes-associated plasmids predominated, regardless of microbial abundance. The analysis found several plasmid-enriched functions, such as inorganic ion transport, while antibiotic resistance genes were harboured mostly in low-abundance Proteobacteria-associated plasmids. CONCLUSIONS Overall, long-read metagenomics provided an efficient approach for unravelling the complete structure of human gut eMGEs, particularly plasmids.
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Affiliation(s)
- Yoshihiko Suzuki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8568 Japan
| | - Suguru Nishijima
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8568 Japan
- AIST-Waseda University Computational Bio Big-Data Open Innovation Laboratory, Tokyo, 169-8555 Japan
- Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, 169-8555 Japan
| | - Yoshikazu Furuta
- Division of Infection and Immunity, Research Center for Zoonosis Control, Hokkaido University, Sapporo, 001-0020 Japan
| | - Jun Yoshimura
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8568 Japan
| | - Wataru Suda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8568 Japan
- Laboratory for Microbiome Sciences, RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045 Japan
| | - Kenshiro Oshima
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8568 Japan
| | - Masahira Hattori
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8568 Japan
- Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, 169-8555 Japan
- Laboratory for Microbiome Sciences, RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045 Japan
| | - Shinichi Morishita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8568 Japan
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70
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d'Humières C, Touchon M, Dion S, Cury J, Ghozlane A, Garcia-Garcera M, Bouchier C, Ma L, Denamur E, P C Rocha E. A simple, reproducible and cost-effective procedure to analyse gut phageome: from phage isolation to bioinformatic approach. Sci Rep 2019; 9:11331. [PMID: 31383878 PMCID: PMC6683287 DOI: 10.1038/s41598-019-47656-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 07/18/2019] [Indexed: 01/08/2023] Open
Abstract
The microbiota of the human gut is a complex and rich community where bacteria and their viruses, the bacteriophages, are dominant. There are few studies on the phage community and no clear standard for isolating them, sequencing and analysing their genomes. Since this makes comparisons between studies difficult, we aimed at defining an easy, low-cost, and reproducible methodology. We analysed five different techniques to isolate phages from human adult faeces and developed an approach to analyse their genomes in order to quantify contamination and classify phage contigs in terms of taxonomy and lifestyle. We chose the polyethylene glycol concentration method to isolate phages because of its simplicity, low cost, reproducibility, and of the high number and diversity of phage sequences that we obtained. We also tested the reproducibility of this method with multiple displacement amplification (MDA) and showed that MDA severely decreases the phage genetic diversity of the samples and the reproducibility of the method. Lastly, we studied the influence of sequencing depth on the analysis of phage diversity and observed the beginning of a plateau for phage contigs at 20,000,000 reads. This work contributes to the development of methods for the isolation of phages in faeces and for their comparative analysis.
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Affiliation(s)
- Camille d'Humières
- IAME, UMR 1137, INSERM, Université Paris Diderot, 75018, Paris, France. .,AP-HP, Laboratoire de Bactériologie, Hôpital Bichat, 75018, Paris, France. .,Ecole doctorale Frontières du vivant, Université Paris Diderot, 75013, Paris, France. .,Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, 75015, France.
| | - Marie Touchon
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, 75015, France
| | - Sara Dion
- IAME, UMR 1137, INSERM, Université Paris Diderot, 75018, Paris, France
| | - Jean Cury
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, 75015, France
| | - Amine Ghozlane
- Hub de Bioinformatique et Biostatistique - Département Biologie Computationnelle, Institut Pasteur, USR 3756 CNRS, Paris, France
| | - Marc Garcia-Garcera
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, 75015, France
| | - Christiane Bouchier
- Genomics Platform, BIOMICS, Institut Pasteur, 25-28 rue Dr Roux, Paris, 75015, France
| | - Laurence Ma
- Genomics Platform, BIOMICS, Institut Pasteur, 25-28 rue Dr Roux, Paris, 75015, France
| | - Erick Denamur
- IAME, UMR 1137, INSERM, Université Paris Diderot, 75018, Paris, France.,AP-HP, Laboratoire de Génétique Moléculaire, Hôpital Bichat, Paris, France
| | - Eduardo P C Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, 75015, France
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71
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What is (not) known about the dynamics of the human gut virome in health and disease. Curr Opin Virol 2019; 37:52-57. [DOI: 10.1016/j.coviro.2019.05.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 01/21/2023]
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72
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Viruses as key reservoirs of antibiotic resistance genes in the environment. ISME JOURNAL 2019; 13:2856-2867. [PMID: 31358910 DOI: 10.1038/s41396-019-0478-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 06/03/2019] [Accepted: 06/21/2019] [Indexed: 11/08/2022]
Abstract
Antibiotic resistance is a rapidly growing health care problem globally and causes many illnesses and deaths. Bacteria can acquire antibiotic resistance genes (ARGs) by horizontal transfer mediated by mobile genetic elements, where the role of phages in their dissemination in natural environments has not yet been clearly resolved. From metagenomic studies, we showed that the mean proportion of predicted ARGs found in prophages (0-0.0028%) was lower than those present in the free viruses (0.001-0.1%). Beta-lactamase, from viruses in the swine gut, represented 0.10 % of the predicted genes. Overall, in the environment, the ARG distribution associated with viruses was strongly linked to human activity, and the low dN/dS ratio observed advocated for a negative selection of the ARGs harbored by the viruses. Our network approach showed that viruses were linked to putative pathogens (Enterobacterales and vibrionaceae) and were considered key vehicles in ARG transfer, similar to plasmids. Therefore, these ARGs could then be disseminated at larger temporal and spatial scales than those included in the bacterial genomes, allowing for time-delayed genetic exchanges.
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73
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Seo SU, Kweon MN. Virome-host interactions in intestinal health and disease. Curr Opin Virol 2019; 37:63-71. [PMID: 31295677 DOI: 10.1016/j.coviro.2019.06.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/03/2019] [Accepted: 06/04/2019] [Indexed: 02/06/2023]
Abstract
The enteric virome consists largely of bacteriophages and prophages related to commensal bacteria. Bacteriophages indirectly affect the host immune system by targeting their associated bacteria; however, studies suggest that bacteriophages also have distinct pathways that enable them to interact directly with the host. Eukaryotic viruses are less abundant than bacteriophages but are more efficient in the stimulation of host immune responses. Acute, permanent, and latent viral infections are detected by different types of pattern recognition receptors and induce host immune responses, including the antiviral type I interferon response. Understanding the complex interplay between commensal microorganisms and the host immune system is a prerequisite to elucidating their role in intestinal diseases.
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Affiliation(s)
- Sang-Uk Seo
- Mucosal Immunology Laboratory, Department of Convergence Medicine, University of Ulsan College of Medicine/Asan Medical Center, Seoul 05505, South Korea.
| | - Mi-Na Kweon
- Mucosal Immunology Laboratory, Department of Convergence Medicine, University of Ulsan College of Medicine/Asan Medical Center, Seoul 05505, South Korea.
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74
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Neil JA, Cadwell K. The Intestinal Virome and Immunity. THE JOURNAL OF IMMUNOLOGY 2019; 201:1615-1624. [PMID: 30181300 DOI: 10.4049/jimmunol.1800631] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 05/21/2018] [Indexed: 12/12/2022]
Abstract
The composition of the human microbiome is considered a major source of interindividual variation in immunity and, by extension, susceptibility to diseases. Intestinal bacteria have been the major focus of research. However, diverse communities of viruses that infect microbes and the animal host cohabitate the gastrointestinal tract and collectively constitute the gut virome. Although viruses are typically investigated as pathogens, recent studies highlight a relationship between the host and animal viruses in the gut that is more akin to host-microbiome interactions and includes both beneficial and detrimental outcomes for the host. These viruses are likely sources of immune variation, both locally and extraintestinally. In this review, we describe the components of the gut virome, in particular mammalian viruses, and their ability to modulate host responses during homeostasis and disease.
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Affiliation(s)
- Jessica A Neil
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016; and Department of Microbiology, New York University School of Medicine, New York, NY 10016
| | - Ken Cadwell
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016; and Department of Microbiology, New York University School of Medicine, New York, NY 10016
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75
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Garcia-Carbonell R, Yao SJ, Das S, Guma M. Dysregulation of Intestinal Epithelial Cell RIPK Pathways Promotes Chronic Inflammation in the IBD Gut. Front Immunol 2019; 10:1094. [PMID: 31164887 PMCID: PMC6536010 DOI: 10.3389/fimmu.2019.01094] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/29/2019] [Indexed: 12/22/2022] Open
Abstract
Crohn's disease (CD) and ulcerative colitis (UC) are common intestinal bowel diseases (IBD) characterized by intestinal epithelial injury including extensive epithelial cell death, mucosal erosion, ulceration, and crypt abscess formation. Several factors including activated signaling pathways, microbial dysbiosis, and immune deregulation contribute to disease progression. Although most research efforts to date have focused on immune cells, it is becoming increasingly clear that intestinal epithelial cells (IEC) are important players in IBD pathogenesis. Aberrant or exacerbated responses to how IEC sense IBD-associated microbes, respond to TNF stimulation, and regenerate and heal the injured mucosa are critical to the integrity of the intestinal barrier. The role of several genes and pathways in which single nucleotide polymorphisms (SNP) showed strong association with IBD has recently been studied in the context of IEC. In patients with IBD, it has been shown that the expression of specific dysregulated genes in IECs plays an important role in TNF-induced cell death and microbial sensing. Among them, the NF-κB pathway and its target gene TNFAIP3 promote TNF-induced and receptor interacting protein kinase (RIPK1)-dependent intestinal epithelial cell death. On the other hand, RIPK2 functions as a key signaling protein in host defense responses induced by activation of the cytosolic microbial sensors nucleotide-binding oligomerization domain-containing proteins 1 and 2 (NOD1 and NOD2). The RIPK2-mediated signaling pathway leads to the activation of NF-κB and MAP kinases that induce autophagy following infection. This article will review these dysregulated RIPK pathways in IEC and their role in promoting chronic inflammation. It will also highlight future research directions and therapeutic approaches involving RIPKs in IBD.
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Affiliation(s)
| | - Shih-Jing Yao
- Department of Pathology, University of California, San Diego, San Diego, CA, United States
| | - Soumita Das
- Department of Pathology, University of California, San Diego, San Diego, CA, United States
| | - Monica Guma
- Medicine, School of Medicine, University of California, San Diego, San Diego, CA, United States
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76
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Mukhopadhya I, Segal JP, Carding SR, Hart AL, Hold GL. The gut virome: the 'missing link' between gut bacteria and host immunity? Therap Adv Gastroenterol 2019; 12:1756284819836620. [PMID: 30936943 PMCID: PMC6435874 DOI: 10.1177/1756284819836620] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 02/14/2019] [Indexed: 02/04/2023] Open
Abstract
The human gut virome includes a diverse collection of viruses that infect our own cells as well as other commensal organisms, directly impacting on our well-being. Despite its predominance, the virome remains one of the least understood components of the gut microbiota, with appropriate analysis toolkits still in development. Based on its interconnectivity with all living cells, it is clear that the virome cannot be studied in isolation. Here we review the current understanding of the human gut virome, specifically in relation to other constituents of the microbiome, its evolution and life-long association with its host, and our current understanding in the context of inflammatory bowel disease and associated therapies. We propose that the gut virome and the gut bacterial microbiome share similar trajectories and interact in both health and disease and that future microbiota studies should in parallel characterize the gut virome to uncover its role in health and disease.
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Affiliation(s)
- Indrani Mukhopadhya
- Gastrointestinal Research Group, Division of Applied Medicine, University of Aberdeen, Foresterhill, Aberdeen, UK Gut Health Group, The Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, UK
| | - Jonathan P. Segal
- St. Mark’s Hospital, Watford Road, Harrow, UK Imperial College London, South Kensington Campus, Department of Surgery and Cancer, London, UK
| | - Simon R. Carding
- Gut Microbes and Health Research Programme, The Quadram Institute, Norwich Research Park, Norwich, Norfolk, UK Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, UK
| | - Ailsa L. Hart
- St. Mark’s Hospital, Watford Road, Harrow, UK Imperial College London, South Kensington Campus, Department of Surgery and Cancer, London, UK
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77
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Abstract
In general, the last step in the vegetative cycle of bacterial viruses, or bacteriophages, is lysis of the host. dsDNA phages require multiple lysis proteins, including at least one enzyme that degrades the cell wall (peptidoglycan (PG)). In contrast, the lytic ssDNA and ssRNA phages have a single lysis protein that achieves cell lysis without enzymatically degrading the PG. Here, we review four "single-gene lysis" or Sgl proteins. Three of the Sgls block bacterial cell wall synthesis by binding to and inhibiting several enzymes in the PG precursor pathway. The target of the fourth Sgl, L from bacteriophage MS2, is still unknown, but we review evidence indicating that it is likely a protein involved in maintaining cell wall integrity. Although only a few phage genomes are available to date, the ssRNA Leviviridae are a rich source of novel Sgls, which may facilitate further unraveling of bacterial cell wall biosynthesis and discovery of new antibacterial agents.
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Affiliation(s)
- Karthik Chamakura
- From the Department of Biochemistry and Biophysics and
- the Center for Phage Technology, Texas A&M AgriLife Research, Texas A&M University, College Station, Texas 77843-2128
| | - Ry Young
- From the Department of Biochemistry and Biophysics and
- the Center for Phage Technology, Texas A&M AgriLife Research, Texas A&M University, College Station, Texas 77843-2128
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78
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Wandro S, Oliver A, Gallagher T, Weihe C, England W, Martiny JBH, Whiteson K. Predictable Molecular Adaptation of Coevolving Enterococcus faecium and Lytic Phage EfV12-phi1. Front Microbiol 2019; 9:3192. [PMID: 30766528 PMCID: PMC6365445 DOI: 10.3389/fmicb.2018.03192] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 12/10/2018] [Indexed: 01/21/2023] Open
Abstract
Bacteriophages are highly abundant in human microbiota where they coevolve with resident bacteria. Phage predation can drive the evolution of bacterial resistance, which can then drive reciprocal evolution in the phage to overcome that resistance. Such coevolutionary dynamics have not been extensively studied in human gut bacteria, and are of particular interest for both understanding and eventually manipulating the human gut microbiome. We performed experimental evolution of an Enterococcus faecium isolate from healthy human stool in the absence and presence of a single infecting Myoviridae bacteriophage, EfV12-phi1. Four replicates of E. faecium and phage were grown with twice daily serial transfers for 8 days. Genome sequencing revealed that E. faecium evolved resistance to phage through mutations in the yqwD2 gene involved in exopolysaccharide biogenesis and export, and the rpoC gene which encodes the RNA polymerase β’ subunit. In response to bacterial resistance, phage EfV12-phi1 evolved varying numbers of 1.8 kb tandem duplications within a putative tail fiber gene. Host range assays indicated that coevolution of this phage-host pair resulted in arms race dynamics in which bacterial resistance and phage infectivity increased over time. Tracking mutations from population sequencing of experimental coevolution can quickly illuminate phage entry points along with resistance strategies in both phage and host – critical information for using phage to manipulate microbial communities.
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Affiliation(s)
- Stephen Wandro
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, United States
| | - Andrew Oliver
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, United States
| | - Tara Gallagher
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, United States
| | - Claudia Weihe
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA, United States
| | - Whitney England
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, United States.,Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, CA, United States
| | - Jennifer B H Martiny
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA, United States
| | - Katrine Whiteson
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, United States
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79
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Van Belleghem JD, Dąbrowska K, Vaneechoutte M, Barr JJ, Bollyky PL. Interactions between Bacteriophage, Bacteria, and the Mammalian Immune System. Viruses 2018; 11:E10. [PMID: 30585199 PMCID: PMC6356784 DOI: 10.3390/v11010010] [Citation(s) in RCA: 197] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 12/19/2018] [Accepted: 12/21/2018] [Indexed: 02/07/2023] Open
Abstract
The human body is host to large numbers of bacteriophages (phages)⁻a diverse group of bacterial viruses that infect bacteria. Phage were previously regarded as bystanders that only impacted immunity indirectly via effects on the mammalian microbiome. However, it has become clear that phages also impact immunity directly, in ways that are typically anti-inflammatory. Phages can modulate innate immunity via phagocytosis and cytokine responses, but also impact adaptive immunity via effects on antibody production and effector polarization. Phages may thereby have profound effects on the outcome of bacterial infections by modulating the immune response. In this review we highlight the diverse ways in which phages interact with human cells. We present a computational model for predicting these complex and dynamic interactions. These models predict that the phageome may play important roles in shaping mammalian-bacterial interactions.
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Affiliation(s)
- Jonas D Van Belleghem
- Laboratory Bacteriology Research, Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, 9000 Ghent, Belgium.
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Krystyna Dąbrowska
- Bacteriophage Laboratory, Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland.
| | - Mario Vaneechoutte
- Laboratory Bacteriology Research, Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, 9000 Ghent, Belgium.
| | - Jeremy J Barr
- School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia.
| | - Paul L Bollyky
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
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80
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Abstract
The human body is colonized by a diverse collective of microorganisms, including bacteria, fungi, protozoa and viruses. The smallest entity of this microbial conglomerate are the bacterial viruses. Bacteriophages, or phages for short, exert significant selective pressure on their bacterial hosts, undoubtedly influencing the human microbiome and its impact on our health and well-being. Phages colonize all niches of the body, including the skin, oral cavity, lungs, gut, and urinary tract. As such our bodies are frequently and continuously exposed to diverse collections of phages. Despite the prevalence of phages throughout our bodies, the extent of their interactions with human cells, organs, and immune system is still largely unknown. Phages physically interact with our mucosal surfaces, are capable of bypassing epithelial cell layers, disseminate throughout the body and may manipulate our immune system. Here, I establish the novel concept of an "intra-body phageome," which encompasses the collection of phages residing within the classically "sterile" regions of the body. This review will take a phage-centric view of the microbiota, human body, and immune system with the ultimate goal of inspiring a greater appreciation for both the indirect and direct interactions between bacteriophages and their mammalian hosts.
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Affiliation(s)
- Jeremy J Barr
- School of Biological Sciences, Monash University, Melbourne, VIC, Australia
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81
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Vitetta L, Vitetta G, Hall S. Immunological Tolerance and Function: Associations Between Intestinal Bacteria, Probiotics, Prebiotics, and Phages. Front Immunol 2018; 9:2240. [PMID: 30356736 PMCID: PMC6189397 DOI: 10.3389/fimmu.2018.02240] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 09/10/2018] [Indexed: 12/12/2022] Open
Abstract
Post-birth there is a bacterial assault on all mucosal surfaces. The intestinal microbiome is an important participant in health and disease. The pattern of composition and concentration of the intestinal microbiome varies greatly. Therefore, achieving immunological tolerance in the first 3-4 years of life is critical for maintaining health throughout a lifetime. Probiotic bacteria are organisms that afford beneficial health effects to the host and in certain instances may protect against the development of disease. The potential benefits of modifying the composition of the intestinal microbial cohort for therapeutic benefit is evident in the use in high risks groups such as premature infants, children receiving antibiotics, rotavirus infections in non-vaccinated children and traveler's diarrhea in adults. Probiotics and prebiotics are postulated to have immunomodulating capabilities by influencing the intestinal microbial cohort and dampening the activity of pathobiont intestinal microbes, such as Klebsiella pneumonia and Clostridia perfringens. Lactobacilli and Bifidobacteria are examples of probiotics found in the large intestine and so far, the benefits afforded to probiotics have varied in efficacy. Most likely the efficacy of probiotic bacteria has a multifactorial dependency, namely on a number of factors that include agents used, the dose, the pattern of dosing, and the characteristics of the host and the underlying luminal microbial environment and the activity of bacteriophages. Bacteriophages, are small viruses that infect and lyse intestinal bacteria. As such it can be posited that these viruses display an effective local protective control mechanism for the intestinal barrier against commensal pathobionts that indirectly may assist the host in controlling bacterial concentrations in the gut. A co-operative activity may be envisaged between the intestinal epithelia, mucosal immunity and the activity of bacteriophages to eliminate pathobiots, highlighting the potential role of bacteriophages in assisting with maintaining intestinal homeostasis. Hence bacteriophage local control of inflammation and immune responses may be an additional immunological defense mechanism that exploits bacteriophage-mucin glycoprotein interactions that controls bacterial diversity and abundance in the mucin layers of the gut. Moreover, and importantly the efficacy of probiotics may be dependent on the symbiotic incorporation of prebiotics, and the abundance and diversity of the intestinal microbiome encountered. The virome may be an important factor that determines the efficacy of some probiotic formulations.
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Affiliation(s)
- Luis Vitetta
- Discipline of Pharmacology, Faculty of Medicine and Health, School of Medicine, The University of Sydney, Camperdown, NSW, Australia
- Medlab Clinical Ltd., Sydney, NSW, Australia
| | | | - Sean Hall
- Medlab Clinical Ltd., Sydney, NSW, Australia
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82
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Creasy A, Rosario K, Leigh BA, Dishaw LJ, Breitbart M. Unprecedented Diversity of ssDNA Phages from the Family Microviridae Detected within the Gut of a Protochordate Model Organism ( Ciona robusta). Viruses 2018; 10:v10080404. [PMID: 30065169 PMCID: PMC6116155 DOI: 10.3390/v10080404] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 07/23/2018] [Accepted: 07/27/2018] [Indexed: 12/13/2022] Open
Abstract
Phages (viruses that infect bacteria) play important roles in the gut ecosystem through infection of bacterial hosts, yet the gut virome remains poorly characterized. Mammalian gut viromes are dominated by double-stranded DNA (dsDNA) phages belonging to the order Caudovirales and single-stranded DNA (ssDNA) phages belonging to the family Microviridae. Since the relative proportion of each of these phage groups appears to correlate with age and health status in humans, it is critical to understand both ssDNA and dsDNA phages in the gut. Building upon prior research describing dsDNA viruses in the gut of Ciona robusta, a marine invertebrate model system used to study gut microbial interactions, this study investigated ssDNA phages found in the Ciona gut. We identified 258 Microviridae genomes, which were dominated by novel members of the Gokushovirinae subfamily, but also represented several proposed phylogenetic groups (Alpavirinae, Aravirinae, Group D, Parabacteroides prophages, and Pequeñovirus) and a novel group. Comparative analyses between Ciona specimens with full and cleared guts, as well as the surrounding water, indicated that Ciona retains a distinct and highly diverse community of ssDNA phages. This study significantly expands the known diversity within the Microviridae family and demonstrates the promise of Ciona as a model system for investigating their role in animal health.
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Affiliation(s)
- Alexandria Creasy
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA.
- Department of Pediatrics, Children's Research Institute, University of South Florida, St. Petersburg, FL 33701, USA.
| | - Karyna Rosario
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA.
| | - Brittany A Leigh
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA.
- Department of Pediatrics, Children's Research Institute, University of South Florida, St. Petersburg, FL 33701, USA.
| | - Larry J Dishaw
- Department of Pediatrics, Children's Research Institute, University of South Florida, St. Petersburg, FL 33701, USA.
| | - Mya Breitbart
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA.
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83
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Bettarel Y, Combe M, Adingra A, Ndiaye A, Bouvier T, Panfili J, Durand JD. Hordes of Phages in the Gut of the Tilapia Sarotherodon melanotheron. Sci Rep 2018; 8:11311. [PMID: 30054519 PMCID: PMC6063890 DOI: 10.1038/s41598-018-29643-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 07/16/2018] [Indexed: 02/02/2023] Open
Abstract
Preliminary studies conducted on the human gastro-intestinal tract have revealed that enteric viral communities play a preponderant role in microbial homeostatis. However to date, such communities have never been investigated in the fish gut. Herein, we examined the main ecological traits of viruses in the digestive tract of a euryhaline fish, the tilapia Sarotherodon melanotheron. Individuals were collected at 8 different sites in Senegal covering a salinity gradient from 3 to 104‰, and showing large disparities in their organic pollutant concentrations. Results showed that the gut of S. melanotheron is home to a highly abundant viral community (0.2-10.7 × 109 viruses ml-1), distinct from the surrounding water, and essentially composed of phages of which a substantial proportion is temperate (the fraction of lysogenized cells-FLC ranging from 8.1 to 33.0%). Also, a positive and significant correlation was detected between FLC and the concentrations of polycyclic aromatic hydrocarbon in sediment, while no clear relationships were found between salinity and any of the microbial parameters considered. Finally, our data suggest that virus-bacteria interactions within the fish intestine are likely sensitive to the presence of particular xenobiotics, which may compromise the balance in the gut microbiota, and subsequently affect the health of their host.
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Affiliation(s)
- Yvan Bettarel
- MARBEC, Univ. Montpellier, CNRS, Ifremer, IRD, Montpellier, France.
| | - Marine Combe
- MIVEGEC, Univ. Montpellier, CNRS, IRD, Centre IRD de Cayenne, French Guiana, Cayenne, France
| | | | - Awa Ndiaye
- MARBEC, Univ. Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Thierry Bouvier
- MARBEC, Univ. Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Jacques Panfili
- MARBEC, Univ. Montpellier, CNRS, Ifremer, IRD, Montpellier, France
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84
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Mills S, Ross RP, Hill C. Bacteriocins and bacteriophage; a narrow-minded approach to food and gut microbiology. FEMS Microbiol Rev 2018; 41:S129-S153. [PMID: 28830091 DOI: 10.1093/femsre/fux022] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 04/20/2017] [Indexed: 12/11/2022] Open
Abstract
Bacteriocins and bacteriophage (phage) are biological tools which exhibit targeted microbial killing, a phenomenon which until recently was seen as a major drawback for their use as antimicrobial agents. However, in an age when the deleterious consequences of broad-spectrum antibiotics on human health have become apparent, there is an urgent need to develop narrow-spectrum substitutes. Indeed, disruption of the microbial communities which exist on and in our bodies can generate immediate and long-term negative effects and this is particularly borne out in the gut microbiota community whose disruption has been linked to a number of disorders reaching as far as the brain. Moreover, the antibiotic resistance crisis has resulted in our inability to treat many bacterial infections and has triggered the search for damage-limiting alternatives. As bacteriocins and phage are natural entities they are relatively easy to isolate and characterise and are also ideal candidates for improving food safety and quality, forfeiting the need for largely unpopular chemical preservatives. This review highlights the efficacy of both antimicrobial agents in terms of gut health and food safety and explores the body of scientific evidence supporting their effectiveness in both environments.
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Affiliation(s)
- Susan Mills
- APC Microbiome Institute and School of Microbiology, University College Cork, Western Road, Cork T12 YN60, Ireland
| | - R Paul Ross
- APC Microbiome Institute and School of Microbiology, University College Cork, Western Road, Cork T12 YN60, Ireland
| | - Colin Hill
- APC Microbiome Institute and School of Microbiology, University College Cork, Western Road, Cork T12 YN60, Ireland
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85
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Shkoporov AN, Ryan FJ, Draper LA, Forde A, Stockdale SR, Daly KM, McDonnell SA, Nolan JA, Sutton TD, Dalmasso M, McCann A, Ross RP, Hill C. Reproducible protocols for metagenomic analysis of human faecal phageomes. MICROBIOME 2018; 6:68. [PMID: 29631623 PMCID: PMC5892011 DOI: 10.1186/s40168-018-0446-z] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 03/13/2018] [Indexed: 05/07/2023]
Abstract
BACKGROUND Recent studies have demonstrated that the human gut is populated by complex, highly individual and stable communities of viruses, the majority of which are bacteriophages. While disease-specific alterations in the gut phageome have been observed in IBD, AIDS and acute malnutrition, the human gut phageome remains poorly characterised. One important obstacle in metagenomic studies of the human gut phageome is a high level of discrepancy between results obtained by different research groups. This is often due to the use of different protocols for enriching virus-like particles, nucleic acid purification and sequencing. The goal of the present study is to develop a relatively simple, reproducible and cost-efficient protocol for the extraction of viral nucleic acids from human faecal samples, suitable for high-throughput studies. We also analyse the effect of certain potential confounding factors, such as storage conditions, repeated freeze-thaw cycles, and operator bias on the resultant phageome profile. Additionally, spiking of faecal samples with an exogenous phage standard was employed to quantitatively analyse phageomes following metagenomic sequencing. Comparative analysis of phageome profiles to bacteriome profiles was also performed following 16S rRNA amplicon sequencing. RESULTS Faecal phageome profiles exhibit an overall greater individual specificity when compared to bacteriome profiles. The phageome and bacteriome both exhibited moderate change when stored at + 4 °C or room temperature. Phageome profiles were less impacted by multiple freeze-thaw cycles than bacteriome profiles, but there was a greater chance for operator effect in phageome processing. The successful spiking of faecal samples with exogenous bacteriophage demonstrated large variations in the total viral load between individual samples. CONCLUSIONS The faecal phageome sequencing protocol developed in this study provides a valuable additional view of the human gut microbiota that is complementary to 16S amplicon sequencing and/or metagenomic sequencing of total faecal DNA. The protocol was optimised for several confounding factors that are encountered while processing faecal samples, to reduce discrepancies observed within and between research groups studying the human gut phageome. Rapid storage, limited freeze-thaw cycling and spiking of faecal samples with an exogenous phage standard are recommended for optimum results.
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Affiliation(s)
| | - Feargal J. Ryan
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | | | - Amanda Forde
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Stephen R. Stockdale
- Department of Food Biosciences, Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork Ireland
| | - Karen M. Daly
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | | | - James A. Nolan
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | | | - Marion Dalmasso
- APC Microbiome Institute, University College Cork, Cork, Ireland
- Normandie Univ, UNICAEN, EA4651 ABTE, F-14032 Caen, France
| | - Angela McCann
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - R. Paul Ross
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Colin Hill
- APC Microbiome Institute, University College Cork, Cork, Ireland
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86
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Anonye BO. Commentary: Bacteriophage transfer during faecal microbiota transplantation in Clostridium difficile infection is associated with treatment outcome. Front Cell Infect Microbiol 2018; 8:104. [PMID: 29670863 PMCID: PMC5893759 DOI: 10.3389/fcimb.2018.00104] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 03/19/2018] [Indexed: 01/21/2023] Open
Affiliation(s)
- Blessing O Anonye
- Microbiology and Infection Unit, Division of Biomedical Sciences, Warwick Medical School, Coventry, United Kingdom.,Warwick Integrative Synthetic Biology Centre, School of Life Sciences, University of Warwick, Coventry, United Kingdom
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87
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Cornuault JK, Petit MA, Mariadassou M, Benevides L, Moncaut E, Langella P, Sokol H, De Paepe M. Phages infecting Faecalibacterium prausnitzii belong to novel viral genera that help to decipher intestinal viromes. MICROBIOME 2018; 6:65. [PMID: 29615108 PMCID: PMC5883640 DOI: 10.1186/s40168-018-0452-1] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 03/21/2018] [Indexed: 05/11/2023]
Abstract
BACKGROUND Viral metagenomic studies have suggested a role for bacteriophages in intestinal dysbiosis associated with several human diseases. However, interpretation of viral metagenomic studies is limited by the lack of knowledge of phages infecting major human gut commensal bacteria, such as Faecalibacterium prausnitzii, a bacterial symbiont repeatedly found depleted in inflammatory bowel disease (IBD) patients. In particular, no complete genomes of phages infecting F. prausnitzii are present in viral databases. METHODS We identified 18 prophages in 15 genomes of F. prausnitzii, used comparative genomics to define eight phage clades, and annotated the genome of the type phage of each clade. For two of the phages, we studied prophage induction in vitro and in vivo in mice. Finally, we aligned reads from already published viral metagenomic data onto the newly identified phages. RESULTS We show that each phage clade represents a novel viral genus and that a surprisingly large fraction of them (10 of the 18 phages) codes for a diversity-generating retroelement, which could contribute to their adaptation to the digestive tract environment. We obtained either experimental or in silico evidence of activity for at least one member of each genus. In addition, four of these phages are either significantly more prevalent or more abundant in stools of IBD patients than in those of healthy controls. CONCLUSION Since IBD patients generally have less F. prausnitzii in their microbiota than healthy controls, the higher prevalence or abundance of some of its phages may indicate that they are activated during disease. This in turn suggests that phages could trigger or aggravate F. prausnitzii depletion in patients. Our results show that prophage detection in sequenced strains of the microbiota can usefully complement viral metagenomic studies.
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Affiliation(s)
- Jeffrey K Cornuault
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Marie-Agnès Petit
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | | | - Leandro Benevides
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Elisabeth Moncaut
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Philippe Langella
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Harry Sokol
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
- Sorbonne Universités, UPMC Univ. Paris 06, École normale supérieure, CNRS, INSERM, APHP Laboratoire des Biomolécules (LBM), 27 rue de Chaligny, 75012, Paris, France
- Department of Gastroenterology, Saint Antoine Hospital, Assistance Publique - Hopitaux de Paris, UPMC, Paris, France
| | - Marianne De Paepe
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France.
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88
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Kim MS, Bae JW. Lysogeny is prevalent and widely distributed in the murine gut microbiota. THE ISME JOURNAL 2018; 12:1127-1141. [PMID: 29416123 PMCID: PMC5864201 DOI: 10.1038/s41396-018-0061-9] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/14/2017] [Accepted: 11/23/2017] [Indexed: 01/21/2023]
Abstract
Bacteriophages are central members and potential modulators of the gut microbiome; however, the ecological and evolutionary relationships of gut bacteria and phages are poorly understood. Here we investigated the abundance and diversity of lysogenic bacteria (lysogens) in the bacterial community of C57BL/6J mice by detecting integrated prophages in genomes reconstructed from the metagenome of commensal bacteria. For the activities of lysogens and prophages, we compared the prophage genomes with the metagenome of free phages. The majority of commensal bacteria in different taxa were identified as lysogens. More lysogens were found among Firmicutes and Proteobacteria, than among Bacteroidetes and Actinobacteria. The prophage genomes shared high sequence similarity with the metagenome of free phages, indicating that most lysogens appeared to be active, and that prophages are spontaneously induced as active phages; dietary interventions changed the composition of the induced prophages. By contrast, CRISPR-Cas systems were present in few commensal bacteria, and were rarely active against gut phages. The structure of the bacteria-phage infection networks was "nested-modular", with modularity emerging across taxonomic scales, indicating that temperate phage features have developed over a long phylogenetic timescale. We concluded that phage generalists contribute to the prevalence of lysogeny in the gut ecosystem.
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Affiliation(s)
- Min-Soo Kim
- Department of Biology and Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Jin-Woo Bae
- Department of Biology and Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
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89
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Fernandez-Cassi X, Timoneda N, Martínez-Puchol S, Rusiñol M, Rodriguez-Manzano J, Figuerola N, Bofill-Mas S, Abril JF, Girones R. Metagenomics for the study of viruses in urban sewage as a tool for public health surveillance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 618:870-880. [PMID: 29108696 DOI: 10.1016/j.scitotenv.2017.08.249] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/23/2017] [Accepted: 08/24/2017] [Indexed: 04/14/2023]
Abstract
The application of next-generation sequencing (NGS) techniques for the identification of viruses present in urban sewage has not been fully explored. This is partially due to a lack of reliable and sensitive protocols for studying viral diversity and to the highly complex analysis required for NGS data processing. One important step towards this goal is finding methods that can efficiently concentrate viruses from sewage samples. Here the application of a virus concentration method based on skimmed milk organic flocculation (SMF) using 10L of sewage collected in different seasons enabled the detection of many viruses. However, some viruses, such as human adenoviruses, could not always be detected using metagenomics, even when quantitative PCR (qPCR) assessments were positive. A targeted metagenomic assay for adenoviruses was conducted and 59.41% of the obtained reads were assigned to murine adenoviruses. However, up to 20 different human adenoviruses (HAdV) were detected by this targeted assay being the most abundant HAdV-41 (29.24%) and HAdV-51 (1.63%). To improve metagenomics' sensitivity, two different protocols for virus concentration were comparatively analysed: an ultracentrifugation protocol and a lower-volume SMF protocol. The sewage virome contained 41 viral families, including pathogenic viral species from families Caliciviridae, Adenoviridae, Astroviridae, Picornaviridae, Polyomaviridae, Papillomaviridae and Hepeviridae. The contribution of urine to sewage metavirome seems to be restricted to a few specific DNA viral families, including the polyomavirus and papillomavirus species. In experimental infections with sewage in a rhesus macaque model, infective human hepatitis E and JC polyomavirus were identified. Urban raw sewage consists of the excreta of thousands of inhabitants; therefore, it is a representative sample for epidemiological surveillance purposes. The knowledge of the metavirome is of significance to public health, highlighting the presence of viral strains that are circulating within a population while acting as a complex matrix for viral discovery.
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Affiliation(s)
- X Fernandez-Cassi
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Catalonia, Spain.
| | - N Timoneda
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Catalonia, Spain; Computational Genomics Lab, University of Barcelona and Institute of Biomedicine (IBUB), University of Barcelona, Barcelona, Catalonia, Spain
| | - S Martínez-Puchol
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Catalonia, Spain
| | - M Rusiñol
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Catalonia, Spain
| | - J Rodriguez-Manzano
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Imperial College London, London, United Kingdom
| | - N Figuerola
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Catalonia, Spain
| | - S Bofill-Mas
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Catalonia, Spain
| | - J F Abril
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Catalonia, Spain; Computational Genomics Lab, University of Barcelona and Institute of Biomedicine (IBUB), University of Barcelona, Barcelona, Catalonia, Spain
| | - R Girones
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Catalonia, Spain
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90
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Abstract
The human GI tract harbors a diverse and dynamic microbial community comprising bacteria, archaea, viruses and eukaryotic microbes, which varies in composition from individual to individual. A healthy microbiota metabolizes various indigestible dietary components of the host, maintains host immune homeostasis and nutrient intake, but, an imbalanced microbiota has been reported to be associated with many diseases, including obesity. Rodent studies have produced evidence in support of the causal role of the gut microbiota in the development of obesity, however, such causal relationship is lacking in humans. The objective of this review is to critically analyze the vast information available on the composition, function and alterations of the gut microbiota in obesity and explore the future prospects of this research area.
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Affiliation(s)
- Shabana
- Department of Microbiology & Molecular Genetics, University of the Punjab, Lahore 54590, Pakistan
| | - Saleem U Shahid
- Department of Microbiology & Molecular Genetics, University of the Punjab, Lahore 54590, Pakistan
| | - Uzma Irfan
- Women University Multan, Multan 66000, Pakistan
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91
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Abstract
Myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) (ME/CFS) is a disabling and debilitating disease of unknown aetiology. It is a heterogeneous disease characterized by various inflammatory, immune, viral, neurological and endocrine symptoms. Several microbiome studies have described alterations in the bacterial component of the microbiome (dysbiosis) consistent with a possible role in disease development. However, in focusing on the bacterial components of the microbiome, these studies have neglected the viral constituent known as the virome. Viruses, particularly those infecting bacteria (bacteriophages), have the potential to alter the function and structure of the microbiome via gene transfer and host lysis. Viral-induced microbiome changes can directly and indirectly influence host health and disease. The contribution of viruses towards disease pathogenesis is therefore an important area for research in ME/CFS. Recent advancements in sequencing technology and bioinformatics now allow more comprehensive and inclusive investigations of human microbiomes. However, as the number of microbiome studies increases, the need for greater consistency in study design and analysis also increases. Comparisons between different ME/CFS microbiome studies are difficult because of differences in patient selection and diagnosis criteria, sample processing, genome sequencing and downstream bioinformatics analysis. It is therefore important that microbiome studies adopt robust, reproducible and consistent study design to enable more reliable and valid comparisons and conclusions to be made between studies. This article provides a comprehensive review of the current evidence supporting microbiome alterations in ME/CFS patients. Additionally, the pitfalls and challenges associated with microbiome studies are discussed.
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92
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Mayo-Muñoz D. Viral Genome Isolation from Human Faeces for Succession Assessment of the Human Gut Virome. Methods Mol Biol 2018; 1838:97-108. [PMID: 30128992 DOI: 10.1007/978-1-4939-8682-8_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Despite the important role of the microbiota in the human gastrointestinal tract (GIT) and its impact on life-long health, the successional process through which this microbial community develops during infancy is still poorly understood. Specially, little is known about how the amount and type of viruses present in the GIT, i.e., the virome, varies throughout this period and about the role this collection of viruses may play in the assembly of the GIT microbiota.The patterns of taxonomic change of the GIT viral community can be analyzed in a birth cohort of infants during the first year of life. The present chapter presents a detailed protocol for the isolation and extraction of viral nucleic acids from collected human faecal samples, whole genome amplification (WGA) using phi29 DNA polymerase and preparation for sequencing through high-throughput 454 pyrosequencing. The sequencing data can be posteriorly used for taxonomic classification in order to establish the composition of the virome present in each sample and to assess the process of viral dynamics through time.
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Affiliation(s)
- David Mayo-Muñoz
- Danish Archaea Centre, Department of Biology, University of Copenhagen, Copenhagen, Capital Region, Denmark.
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93
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The human gut virome: form and function. Emerg Top Life Sci 2017; 1:351-362. [PMID: 33525769 DOI: 10.1042/etls20170039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/18/2017] [Accepted: 10/20/2017] [Indexed: 01/15/2023]
Abstract
Advances in next-generation sequencing technologies and the application of metagenomic approaches have fuelled an exponential increase in our understanding of the human gut microbiome. These approaches are now also illuminating features of the diverse and abundant collection of viruses (termed the virome) subsisting with the microbial ecosystems residing within the human holobiont. Here, we focus on the current and emerging knowledge of the human gut virome, in particular on viruses infecting bacteria (bacteriophage or phage), which are a dominant component of this viral community. We summarise current insights regarding the form and function of this 'human gut phageome' and highlight promising avenues for future research. In doing so, we discuss the potential for phage to drive ecological functioning and evolutionary change within this important microbial ecosystem, their contribution to modulation of host-microbiome interactions and stability of the community as a whole, as well as the potential role of the phageome in human health and disease. We also consider the emerging concepts of a 'core healthy gut phageome' and the putative existence of 'viral enterotypes' and 'viral dysbiosis'.
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94
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Abstract
Bacterial viruses are among the most numerous biological entities within the human body. These viruses are found within regions of the body that have conventionally been considered sterile, including the blood, lymph, and organs. However, the primary mechanism that bacterial viruses use to bypass epithelial cell layers and access the body remains unknown. Here, we used in vitro studies to demonstrate the rapid and directional transcytosis of diverse bacteriophages across confluent cell layers originating from the gut, lung, liver, kidney, and brain. Bacteriophage transcytosis across cell layers had a significant preferential directionality for apical-to-basolateral transport, with approximately 0.1% of total bacteriophages applied being transcytosed over a 2-h period. Bacteriophages were capable of crossing the epithelial cell layer within 10 min with transport not significantly affected by the presence of bacterial endotoxins. Microscopy and cellular assays revealed that bacteriophages accessed both the vesicular and cytosolic compartments of the eukaryotic cell, with phage transcytosis suggested to traffic through the Golgi apparatus via the endomembrane system. Extrapolating from these results, we estimated that 31 billion bacteriophage particles are transcytosed across the epithelial cell layers of the gut into the average human body each day. The transcytosis of bacteriophages is a natural and ubiquitous process that provides a mechanistic explanation for the occurrence of phages within the body. Bacteriophages (phages) are viruses that infect bacteria. They cannot infect eukaryotic cells but can penetrate epithelial cell layers and spread throughout sterile regions of our bodies, including the blood, lymph, organs, and even the brain. Yet how phages cross these eukaryotic cell layers and gain access to the body remains unknown. In this work, epithelial cells were observed to take up and transport phages across the cell, releasing active phages on the opposite cell surface. Based on these results, we posit that the human body is continually absorbing phages from the gut and transporting them throughout the cell structure and subsequently the body. These results reveal that phages interact directly with the cells and organs of our bodies, likely contributing to human health and immunity.
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95
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François S, Filloux D, Frayssinet M, Roumagnac P, Martin DP, Ogliastro M, Froissart R. Increase in taxonomic assignment efficiency of viral reads in metagenomic studies. Virus Res 2017; 244:230-234. [PMID: 29154906 DOI: 10.1016/j.virusres.2017.11.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 11/10/2017] [Accepted: 11/10/2017] [Indexed: 12/17/2022]
Abstract
Metagenomics studies have revolutionized the field of biology by revealing the presence of many previously unisolated and uncultured micro-organisms. However, one of the main problems encountered in metagenomic studies is the high percentage of sequences that cannot be assigned taxonomically using commonly used similarity-based approaches (e.g. BLAST or HMM). These unassigned sequences are allegorically called « dark matter » in the metagenomic literature and are often referred to as being derived from new or unknown organisms. Here, based on published and original metagenomic datasets coming from virus-like particle enriched samples, we present and quantify the improvement of viral taxonomic assignment that is achievable with a new similarity-based approach. Indeed, prior to any use of similarity based taxonomic assignment methods, we propose assembling contigs from short reads as is currently routinely done in metagenomic studies, but then to further map unassembled reads to the assembled contigs. This additional mapping step increases significantly the proportions of taxonomically assignable sequence reads from a variety -plant, insect and environmental (estuary, lakes, soil, feces) - of virome studies.
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Affiliation(s)
- S François
- INRA-Université de Montpellier UMR DGIMI 34095 Montpellier, France
| | - D Filloux
- CIRAD-INRA-Supagro, UMR BGPI, Campus International de Baillarguet, 34398 Montpellier, France
| | - M Frayssinet
- INRA-Université de Montpellier UMR DGIMI 34095 Montpellier, France
| | - P Roumagnac
- CIRAD-INRA-Supagro, UMR BGPI, Campus International de Baillarguet, 34398 Montpellier, France
| | - D P Martin
- Computational Biology Group, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa
| | - M Ogliastro
- INRA-Université de Montpellier UMR DGIMI 34095 Montpellier, France
| | - R Froissart
- CNRS-IRD-Université de Montpellier, UMR MIVEGEC, 911 avenue Agropolis, 34394, Montpellier, France.
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96
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Grasis JA. The Intra-Dependence of Viruses and the Holobiont. Front Immunol 2017; 8:1501. [PMID: 29170664 PMCID: PMC5684104 DOI: 10.3389/fimmu.2017.01501] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 10/24/2017] [Indexed: 12/30/2022] Open
Abstract
Animals live in symbiosis with the microorganisms surrounding them. This symbiosis is necessary for animal health, as a symbiotic breakdown can lead to a disease state. The functional symbiosis between the host, and associated prokaryotes, eukaryotes, and viruses in the context of an environment is the holobiont. Deciphering these holobiont associations has proven to be both difficult and controversial. In particular, holobiont association with viruses has been of debate even though these interactions have been occurring since cellular life began. The controversy stems from the idea that all viruses are parasitic, yet their associations can also be beneficial. To determine viral involvement within the holobiont, it is necessary to identify and elucidate the function of viral populations in symbiosis with the host. Viral metagenome analyses identify the communities of eukaryotic and prokaryotic viruses that functionally associate within a holobiont. Similarly, analyses of the host in response to viral presence determine how these interactions are maintained. Combined analyses reveal how viruses interact within the holobiont and how viral symbiotic cooperation occurs. To understand how the holobiont serves as a functional unit, one must consider viruses as an integral part of disease, development, and evolution.
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Affiliation(s)
- Juris A Grasis
- Department of Biology, San Diego State University, San Diego, CA, United States.,School of Natural Sciences, University of California at Merced, Merced, CA, United States
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97
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Zárate S, Taboada B, Yocupicio-Monroy M, Arias CF. Human Virome. Arch Med Res 2017; 48:701-716. [DOI: 10.1016/j.arcmed.2018.01.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 01/22/2018] [Indexed: 12/16/2022]
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98
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Carding SR, Davis N, Hoyles L. Review article: the human intestinal virome in health and disease. Aliment Pharmacol Ther 2017; 46:800-815. [PMID: 28869283 PMCID: PMC5656937 DOI: 10.1111/apt.14280] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Revised: 04/07/2017] [Accepted: 08/07/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND The human virome consists of animal-cell viruses causing transient infections, bacteriophage (phage) predators of bacteria and archaea, endogenous retroviruses and viruses causing persistent and latent infections. High-throughput, inexpensive, sensitive sequencing methods and metagenomics now make it possible to study the contribution dsDNA, ssDNA and RNA virus-like particles make to the human virome, and in particular the intestinal virome. AIM To review and evaluate the pioneering studies that have attempted to characterise the human virome and generated an increased interest in understanding how the intestinal virome might contribute to maintaining health, and the pathogenesis of chronic diseases. METHODS Relevant virome-related articles were selected for review following extensive language- and date-unrestricted, electronic searches of the literature. RESULTS The human intestinal virome is personalised and stable, and dominated by phages. It develops soon after birth in parallel with prokaryotic communities of the microbiota, becoming established during the first few years of life. By infecting specific populations of bacteria, phages can alter microbiota structure by killing host cells or altering their phenotype, enabling phages to contribute to maintaining intestinal homeostasis or microbial imbalance (dysbiosis), and the development of chronic infectious and autoimmune diseases including HIV infection and Crohn's disease, respectively. CONCLUSIONS Our understanding of the intestinal virome is fragmented and requires standardised methods for virus isolation and sequencing to provide a more complete picture of the virome, which is key to explaining the basis of virome-disease associations, and how enteric viruses can contribute to disease aetiologies and be rationalised as targets for interventions.
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Affiliation(s)
- S. R. Carding
- Norwich Medical SchoolUniversity of East AngliaNorwichUK,The Gut Health and Food Safety Research ProgrammeThe Quadram InstituteNorwich Research ParkNorwichUK
| | - N. Davis
- Norwich Medical SchoolUniversity of East AngliaNorwichUK
| | - L. Hoyles
- Department of Surgery and CancerImperial College LondonLondonUK
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99
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Aggarwala V, Liang G, Bushman FD. Viral communities of the human gut: metagenomic analysis of composition and dynamics. Mob DNA 2017; 8:12. [PMID: 29026445 PMCID: PMC5627405 DOI: 10.1186/s13100-017-0095-y] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 09/24/2017] [Indexed: 01/17/2023] Open
Abstract
Background The numerically most abundant biological entities on Earth are viruses. Vast populations prey on the cellular microbiota in all habitats, including the human gut. Main body Here we review approaches for studying the human virome, and some recent results on movement of viral sequences between bacterial cells and eukaryotic hosts. We first overview biochemical and bioinformatic methods, emphasizing that specific choices in the methods used can have strong effects on the results obtained. We then review studies characterizing the virome of the healthy human gut, which reveal that most of the viruses detected are typically uncharacterized phage - the viral dark matter - and that viruses that infect human cells are encountered only rarely. We then review movement of phage between bacterial cells during antibiotic treatment. Here a radical proposal for extensive movement of antibiotic genes on phage has been challenged by a careful reanalysis of the metagenomic annotation methods used. We then review two recent studies of movement of whole phage communities between human individuals during fecal microbial transplantation, which emphasize the possible role of lysogeny in dispersal. Short conclusion Methods for studying the human gut virome are improving, yielding interesting data on movement of phage genes between cells and mammalian host organisms. However, viral populations are vast, and studies of their composition and function are just beginning.
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Affiliation(s)
- Varun Aggarwala
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA 19104-6076 USA
| | - Guanxiang Liang
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA 19104-6076 USA.,Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA 19104-4319 USA
| | - Frederic D Bushman
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA 19104-6076 USA
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100
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Lepczyńska M, Białkowska J, Dzika E, Piskorz-Ogórek K, Korycińska J. Blastocystis: how do specific diets and human gut microbiota affect its development and pathogenicity? Eur J Clin Microbiol Infect Dis 2017; 36:1531-1540. [PMID: 28326446 PMCID: PMC5554277 DOI: 10.1007/s10096-017-2965-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/08/2017] [Indexed: 12/31/2022]
Abstract
Blastocystis is an enteric parasite that inhabits the gastrointestinal tract of humans and many animals. This emerging parasite has a worldwide distribution. It is often identified as the most common eukaryotic organism reported in human fecal samples. This parasite is recognized and diagnosed more often than ever before. Furthermore, some strains develop resistance against currently recommended drugs, such as metronidazole; therefore, the use of natural remedies or special diets has many positive aspects that may address this problem. The goal of this review is to compare natural treatments and various diets against the efficacy of drugs, and describe their influence on the composition of the gut microbiota, which affects Blastocystis growth and the occurrence of symptoms. This article reviews important work in the literature, including the classification, life cycle, epidemiology, pathogenesis, pathogenicity, genetics, biology, and treatment of Blastocystis. It also includes a review of the current knowledge about human gut microbiota and various diets proposed for Blastocystis eradication. The literature has revealed that garlic, ginger, some medical plants, and many spices contain the most effective organic compounds for parasite eradication. They work by inhibiting parasitic enzymes and nucleic acids, as well as by inhibiting protein synthesis. The efficacy of any specific organic compound depends on the Blastocystis subtype, and, consequently, on its immunity to treatment. In conclusion, the article discusses the findings that human gut microbiota composition triggers important mechanisms at the molecular level, and, thus, has a crucial influence on the parasitic pathogenicity.
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Affiliation(s)
- M Lepczyńska
- Department of Medical Biology, Faculty of Medical Sciences, University of Warmia and Mazury, Żołnierska 14 C, Olsztyn, 10-561, Poland.
| | - J Białkowska
- Department of Neurology and Neurosurgery, Faculty of Medical Sciences, University of Warmia and Mazury, Warszawska 30, Olsztyn, Poland
| | - E Dzika
- Department of Medical Biology, Faculty of Medical Sciences, University of Warmia and Mazury, Żołnierska 14 C, Olsztyn, 10-561, Poland
| | - K Piskorz-Ogórek
- Department of Nursing, Faculty of Medical Sciences, University of Warmia and Mazury, Żołnierska 14 C, Olsztyn, Poland
- Regional Specialized Children's Hospital in Olsztyn, Żołnierska 18A, Olsztyn, Poland
| | - J Korycińska
- Department of Medical Biology, Faculty of Medical Sciences, University of Warmia and Mazury, Żołnierska 14 C, Olsztyn, 10-561, Poland
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