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Lamont RJ. Three's a crowd: Saccharibacteria episymbiosis modulates phage predation of host bacteria. Proc Natl Acad Sci U S A 2024; 121:e2405822121. [PMID: 38684001 PMCID: PMC11087802 DOI: 10.1073/pnas.2405822121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024] Open
Affiliation(s)
- Richard J. Lamont
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY40202
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Zhong Q, Liao B, Liu J, Shen W, Wang J, Wei L, Ma Y, Dong PT, Bor B, McLean JS, Chang Y, Shi W, Cen L, Wu M, Liu J, Li Y, He X, Le S. Episymbiotic Saccharibacteria TM7x modulates the susceptibility of its host bacteria to phage infection and promotes their coexistence. Proc Natl Acad Sci U S A 2024; 121:e2319790121. [PMID: 38593079 PMCID: PMC11032452 DOI: 10.1073/pnas.2319790121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 02/21/2024] [Indexed: 04/11/2024] Open
Abstract
Bacteriophages (phages) play critical roles in modulating microbial ecology. Within the human microbiome, the factors influencing the long-term coexistence of phages and bacteria remain poorly investigated. Saccharibacteria (formerly TM7) are ubiquitous members of the human oral microbiome. These ultrasmall bacteria form episymbiotic relationships with their host bacteria and impact their physiology. Here, we showed that during surface-associated growth, a human oral Saccharibacteria isolate (named TM7x) protects its host bacterium, a Schaalia odontolytica strain (named XH001) against lytic phage LC001 predation. RNA-Sequencing analysis identified in XH001 a gene cluster with predicted functions involved in the biogenesis of cell wall polysaccharides (CWP), whose expression is significantly down-regulated when forming a symbiosis with TM7x. Through genetic work, we experimentally demonstrated the impact of the expression of this CWP gene cluster on bacterial-phage interaction by affecting phage binding. In vitro coevolution experiments further showed that the heterogeneous populations of TM7x-associated and TM7x-free XH001, which display differential susceptibility to LC001 predation, promote bacteria and phage coexistence. Our study highlights the tripartite interaction between the bacterium, episymbiont, and phage. More importantly, we present a mechanism, i.e., episymbiont-mediated modulation of gene expression in host bacteria, which impacts their susceptibility to phage predation and contributes to the formation of "source-sink" dynamics between phage and bacteria in biofilm, promoting their long-term coexistence within the human microbiome.
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Affiliation(s)
- Qiu Zhong
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing400038, China
| | - Binyou Liao
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan610041, China
| | - Jiazhen Liu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing400038, China
| | - Wei Shen
- Department of Infectious Diseases, Institute for Viral Hepatitis, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, the Second Affiliated Hospital of Chongqing Medical University, Chongqing401336, China
| | - Jing Wang
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing400038, China
| | - Leilei Wei
- Department of Laboratory Medicine, Daping Hospital, Army Medical University, Chongqing400038, China
| | - Yansong Ma
- Department of Orthodontics, Capital Medical University, Beijing100050, China
| | - Pu-Ting Dong
- Department of Microbiology, The American Dental Association Forsyth Institute, Cambridge, MA02142
| | - Batbileg Bor
- Department of Microbiology, The American Dental Association Forsyth Institute, Cambridge, MA02142
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA02115
| | - Jeffrey S. McLean
- Department of Periodontics, University of Washington, Seattle, WA98119
- Department of Microbiology, University of Washington, Seattle, WA98195
| | - Yunjie Chang
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang310058, China
- Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang310058, China
| | - Wenyuan Shi
- Department of Microbiology, The American Dental Association Forsyth Institute, Cambridge, MA02142
| | - Lujia Cen
- Department of Microbiology, The American Dental Association Forsyth Institute, Cambridge, MA02142
| | - Miaomiao Wu
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan610041, China
| | - Jun Liu
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT06536
| | - Yan Li
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan610041, China
| | - Xuesong He
- Department of Microbiology, The American Dental Association Forsyth Institute, Cambridge, MA02142
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA02115
| | - Shuai Le
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing400038, China
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Dong PT, Tian J, Kobayashi-Kirschvink KJ, Cen L, McLean JS, Bor B, Shi W, He X. Episymbiotic Saccharibacteria induce intracellular lipid droplet production in their host bacteria. THE ISME JOURNAL 2024; 18:wrad034. [PMID: 38366018 PMCID: PMC10939385 DOI: 10.1093/ismejo/wrad034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/07/2023] [Accepted: 12/20/2023] [Indexed: 02/18/2024]
Abstract
Saccharibacteria (formerly TM7) are a group of widespread and genetically diverse ultrasmall bacteria with highly reduced genomes that belong to Candidate Phyla Radiation, a large monophyletic lineage with poorly understood biology. Nanosynbacter lyticus type strain TM7x is the first Saccharibacteria member isolated from the human oral microbiome. With restrained metabolic capacities, TM7x lives on the surface of, and forms an obligate episymbiotic relationship with its bacterial host, Schaalia odontolytica strain XH001. The symbiosis allows TM7x to propagate but presents a burden to host bacteria by inducing stress response. Here, we employed super-resolution fluorescence imaging to investigate the physical association between TM7x and XH001. We showed that the binding with TM7x led to a substantial alteration in the membrane fluidity of XH001. We also revealed the formation of intracellular lipid droplets in XH001 when forming episymbiosis with TM7x, a feature that has not been reported in oral bacteria. The TM7x-induced lipid droplets accumulation in XH001 was confirmed by label-free Raman spectroscopy, which also unveiled additional phenotypical features when XH001 cells are physically associated with TM7x. Further exploration through culturing XH001 under various stress conditions showed that lipid droplets accumulation was a general response to stress. A survival assay demonstrated that the presence of lipid droplets plays a protective role in XH001, enhancing its survival under adverse conditions. In conclusion, our study sheds new light on the intricate interaction between Saccharibacteria and their host bacteria, highlighting the potential benefit conferred by TM7x to its host and further emphasizing the context-dependent nature of symbiotic relationships.
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Affiliation(s)
- Pu-Ting Dong
- Department of Microbiology, The ADA Forsyth Institute, Boston, MA 02142, United States
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, United States
| | - Jing Tian
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China
| | - Koseki J Kobayashi-Kirschvink
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, United States
- Laser Biomedical Research Center, G. R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Lujia Cen
- Department of Microbiology, The ADA Forsyth Institute, Boston, MA 02142, United States
| | - Jeffrey S McLean
- Department of Periodontics, University of Washington, Seattle, WA 98195, United States
| | - Batbileg Bor
- Department of Microbiology, The ADA Forsyth Institute, Boston, MA 02142, United States
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, United States
| | - Wenyuan Shi
- Department of Microbiology, The ADA Forsyth Institute, Boston, MA 02142, United States
| | - Xuesong He
- Department of Microbiology, The ADA Forsyth Institute, Boston, MA 02142, United States
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, United States
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Hendrickson EL, Bor B, Kerns KA, Cen L, Shi W, He X, McLean JS. Ultrasmall epibiont Nanosynbacter lyticus strain TM7x and host bacteria transcriptional activity after initial host parasitism. J Oral Microbiol 2023; 16:2287349. [PMID: 38188073 PMCID: PMC10768705 DOI: 10.1080/20002297.2023.2287349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/20/2023] [Indexed: 01/09/2024] Open
Abstract
Background Oral Saccharibacteria Nanosynbacter lyticus strain TM7× lives as an ultrasmall epibiont on the surface of its host, Schaalia odontolytica strain XH001. Establishing this interaction is a poorly understood multi-step process. The recovery phase marks a shift in the TM7×/host interaction, switching from the early killing phase, with extensive host cell death, to a stable symbiosis phase where the host and epibiont can grow together. Results Transcriptomes of TM7× and host, XH001, were captured during the recovery phase and compared to uninfected host and the early host/epibiont interaction (initial encounter). XH001 showed increased expression for rhamnose cell wall components and for the precursor to peptidoglycan while TM7× showed increases in the peptidoglycan pathway. Transporter expression was generally increased for both organisms during recovery compared to the initial encounter, though, XH001 showed lower amino acid transporter expression. Consistent with host parasitism, XH001 showed increased expression of various stress-related genes during recovery while TM7× showed reduced stress. TM7× displayed higher expression of type IV pili, consistent with increased attachment to new hosts. Conclusion As TM7× is a member of the broadly distributed Candidate Phyla Radiation with small genomes lacking numerous biosynthetic pathways, this study provides further insights into how these epibionts interact and modulate their host bacteria.
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Affiliation(s)
| | - Batbileg Bor
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | | | - Lujia Cen
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
| | - Wenyuan Shi
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
| | - Xuesong He
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Jeffrey S McLean
- Department of Periodontics, University of Washington, Seattle, WA, USA
- Department of Oral Health Sciences, University of Washington, Seattle, WA, USA
- Department of Microbiology, University of Washington, Seattle, WA, USA
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Dong PT, Tian J, Kobayashi-Kirschvink KJ, Cen L, McLean JS, Bor B, Shi W, He X. Episymbiotic bacterium induces intracellular lipid droplet production in its host bacteria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.06.556576. [PMID: 37732248 PMCID: PMC10508740 DOI: 10.1101/2023.09.06.556576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Saccharibacteria (formerly TM7) Nanosynbacter lyticus type strain TM7x exhibits a remarkably compact genome and an extraordinarily small cell size. This obligate epibiotic parasite forms a symbiotic relationship with its bacterial host, Schaalia odontolytica, strain XH001 (formerly Actinomyces odontolyticus strain XH001). Due to its limited genome size, TM7x possesses restrained metabolic capacities, predominantly living on the surface of its bacterial host to sustain this symbiotic lifestyle. To comprehend this intriguing, yet understudied interspecies interaction, a thorough understanding of the physical interaction between TM7x and XH001 is imperative. In this study, we employed super-resolution fluorescence imaging to investigate the physical association between TM7x and XH001. We found that the binding with TM7x led to a substantial alteration in the membrane fluidity of the host bacterium XH001. Unexpectedly, we revealed the formation of intracellular lipid droplets in XH001 when forming episymbiosis with TM7x, a feature not commonly observed in oral bacteria cells. The TM7x-induced LD accumulation in XH001 was further confirmed by label-free non-invasive Raman spectroscopy, which also unveiled additional phenotypical features when XH001 cells are physically associated with TM7x. Further exploration through culturing host bacterium XH001 alone under various stress conditions showed that LD accumulation was a general response to stress. Intriguingly, a survival assay demonstrated that the presence of LDs likely plays a protective role in XH001, enhancing its overall survival under adverse conditions. In conclusion, our study sheds new light on the intricate interaction between Saccharibacteria and its host bacterium, highlighting the potential benefit conferred by TM7x to its host, and further emphasizing the context-dependent nature of symbiotic relationships.
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Affiliation(s)
- Pu-Ting Dong
- Department of Microbiology, the Forsyth Institute, Boston, MA 02142, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Jing Tian
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China
| | - Koseki J. Kobayashi-Kirschvink
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Laser Biomedical Research Center, G. R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Lujia Cen
- Department of Microbiology, the Forsyth Institute, Boston, MA 02142, USA
| | - Jeffrey S. McLean
- Department of Periodontics, University of Washington, Seattle, WA 98195, USA
| | - Batbileg Bor
- Department of Microbiology, the Forsyth Institute, Boston, MA 02142, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Wenyuan Shi
- Department of Microbiology, the Forsyth Institute, Boston, MA 02142, USA
| | - Xuesong He
- Department of Microbiology, the Forsyth Institute, Boston, MA 02142, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA
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Naud S, Valles C, Abdillah A, Abou Chacra L, Mekhalif FZ, Ibrahim A, Caputo A, Baudoin JP, Gouriet F, Bittar F, Lagier JC, Ranque S, Fenollar F, Tidjani Alou M, Raoult D. Preliminary landscape of Candidatus Saccharibacteria in the human microbiome. Front Cell Infect Microbiol 2023; 13:1195679. [PMID: 37577371 PMCID: PMC10414567 DOI: 10.3389/fcimb.2023.1195679] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 07/11/2023] [Indexed: 08/15/2023] Open
Abstract
Introduction Candidate Phyla Radiation (CPR) and more specifically Candidatus Saccharibacteria (TM7) have now been established as ubiquitous members of the human oral microbiota. Additionally, CPR have been reported in the gastrointestinal and urogenital tracts. However, the exploration of new human niches has been limited to date. Methods In this study, we performed a prospective and retrospective screening of TM7 in human samples using standard PCR, real-time PCR, scanning electron microscopy (SEM) and shotgun metagenomics. Results Using Real-time PCR and standard PCR, oral samples presented the highest TM7 prevalence followed by fecal samples, breast milk samples, vaginal samples and urine samples. Surprisingly, TM7 were also detected in infectious samples, namely cardiac valves and blood cultures at a low prevalence (under 3%). Moreover, we observed CPR-like structures using SEM in all sample types except cardiac valves. The reconstruction of TM7 genomes in oral and fecal samples from shotgun metagenomics reads further confirmed their high prevalence in some samples. Conclusion This study confirmed, through their detection in multiple human samples, that TM7 are human commensals that can also be found in clinical settings. Their detection in clinical samples warrants further studies to explore their role in a pathological setting.
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Affiliation(s)
- Sabrina Naud
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Camille Valles
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Abdourahim Abdillah
- Aix Marseille Université, IRD, AP-HM, SSA, VITROME, IHU Méditerranée InfectionMarseille, France
| | - Linda Abou Chacra
- Aix Marseille Université, IRD, AP-HM, SSA, VITROME, IHU Méditerranée InfectionMarseille, France
| | - Fatima Zouina Mekhalif
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Ahmad Ibrahim
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Aurelia Caputo
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Jean-Pierre Baudoin
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Frédérique Gouriet
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Fadi Bittar
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Jean-Christophe Lagier
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Stéphane Ranque
- Aix Marseille Université, IRD, AP-HM, SSA, VITROME, IHU Méditerranée InfectionMarseille, France
| | - Florence Fenollar
- Aix Marseille Université, IRD, AP-HM, SSA, VITROME, IHU Méditerranée InfectionMarseille, France
| | - Maryam Tidjani Alou
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Didier Raoult
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France
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Lee HW, Yoon SR, Dang YM, Kang M, Lee K, Ha JH, Bae JW. Presence of an ultra-small microbiome in fermented cabbages. PeerJ 2023; 11:e15680. [PMID: 37483986 PMCID: PMC10358336 DOI: 10.7717/peerj.15680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 06/13/2023] [Indexed: 07/25/2023] Open
Abstract
Background Ultramicrobacteria (UMB), also known as ultra-small bacteria, are tiny bacteria with a size less than 0.1 µm3. They have a high surface-to-volume ratio and are found in various ecosystems, including the human body. UMB can be classified into two types: one formed through cell contraction and the other that maintains a small size. The ultra-small microbiome (USM), which may contain UMB, includes all bacteria less than 0.2 µm in size and is difficult to detect with current methods. However, it poses a potential threat to food hygiene, as it can pass through sterilization filters and exist in a viable but non-culturable (VBNC) state. The data on the USM of foods is limited. Some bacteria, including pathogenic species, are capable of forming UMB under harsh conditions, making it difficult to detect them through conventional culture techniques. Methods The study described above focused on exploring the diversity of USM in fermented cabbage samples from three different countries (South Korea, China, and Germany). The samples of fermented cabbage (kimchi, suancai, and sauerkraut) were purchased and stored in chilled conditions at approximately 4 °C until filtration. The filtration process involved two steps of tangential flow filtration (TFF) using TFF cartridges with different pore sizes (0.2 µm and 100 kDa) to separate normal size bacteria (NM) and USM. The USM and NM isolated via TFF were stored in a refrigerator at 4 °C until DNA extraction. The extracted DNA was then amplified using PCR and the full-length 16S rRNA gene was sequenced using single-molecule-real-time (SMRT) sequencing. The transmission electron microscope (TEM) was used to confirm the presence of microorganisms in the USM of fermented cabbage samples. Results To the best of our knowledge, this is the first study to identify the differences between USM and NM in fermented cabbages. Although the size of the USM (average 2,171,621 bp) was smaller than that of the NM (average 15,727,282 bp), diversity in USM (average H' = 1.32) was not lower than that in NM (average H' = 1.22). In addition, some members in USM probably underwent cell shrinkage due to unfavorable environments, while others maintained their size. Major pathogens were not detected in the USM in fermented cabbages. Nevertheless, several potentially suspicious strains (genera Cellulomonas and Ralstonia) were detected. Our method can be used to screen food materials for the presence of USM undetectable via conventional methods. USM and NM were efficiently separated using tangential flow filtration and analyzed via single-molecule real-time sequencing. The USM of fermented vegetables exhibited differences in size, diversity, and composition compared with the conventional microbiome. This study could provide new insights into the ultra-small ecosystem in fermented foods, including fermented cabbages.
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Affiliation(s)
- Hae-Won Lee
- Hygienic Safety ⋅ Materials Research Group, World Institute of Kimchi, Gwangju, Republic of Korea
- Department of Biology and Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul, Republic of Korea
| | - So-Ra Yoon
- Hygienic Safety ⋅ Materials Research Group, World Institute of Kimchi, Gwangju, Republic of Korea
| | - Yun-Mi Dang
- Hygienic Safety ⋅ Materials Research Group, World Institute of Kimchi, Gwangju, Republic of Korea
| | - Miran Kang
- Practical Technology Research Group, World Institute of Kimchi, Gwangju, Republic of Korea
| | - Kwangho Lee
- Center for Research Facilities, Chonnam National University, Gwangju, Republic of Korea
| | - Ji-Hyung Ha
- Hygienic Safety ⋅ Materials Research Group, World Institute of Kimchi, Gwangju, Republic of Korea
| | - Jin-Woo Bae
- Department of Biology and Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul, Republic of Korea
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Kamada S, Wakabayashi R, Naganuma T. Phylogenetic Revisit to a Review on Predatory Bacteria. Microorganisms 2023; 11:1673. [PMID: 37512846 PMCID: PMC10385382 DOI: 10.3390/microorganisms11071673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
Predatory bacteria, along with the biology of their predatory behavior, have attracted interest in terms of their ecological significance and industrial applications, a trend that has been even more pronounced since the comprehensive review in 2016. This mini-review does not cover research trends, such as the role of outer membrane vesicles in myxobacterial predation, but provides an overview of the classification and newly described taxa of predatory bacteria since 2016, particularly with regard to phylogenetic aspects. Among them, it is noteworthy that in 2020 there was a major phylogenetic reorganization that the taxa hosting Bdellovibrio and Myxococcus, formerly classified as Deltaproteobacteria, were proposed as the new phyla Bdellovibrionota and Myxococcota, respectively. Predatory bacteria have been reported from other phyla, especially from the candidate divisions. Predatory bacteria that prey on cyanobacteria and predatory cyanobacteria that prey on Chlorella have also been found. These are also covered in this mini-review, and trans-phylum phylogenetic trees are presented.
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Affiliation(s)
- Saki Kamada
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashihiroshima 739-8528, Japan
| | - Ryoka Wakabayashi
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashihiroshima 739-8528, Japan
| | - Takeshi Naganuma
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashihiroshima 739-8528, Japan
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Bonal M, Goetghebuer L, Joseph C, Gonze D, Faust K, George IF. Deciphering Interactions Within a 4-Strain Riverine Bacterial Community. Curr Microbiol 2023; 80:238. [PMID: 37294449 DOI: 10.1007/s00284-023-03342-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 05/23/2023] [Indexed: 06/10/2023]
Abstract
The dynamics of a community of four planktonic bacterial strains isolated from river water was followed in R2 broth for 72 h in batch experiments. These strains were identified as Janthinobacterium sp., Brevundimonas sp., Flavobacterium sp. and Variovorax sp. 16S rRNA gene sequencing and flow cytometry analyses were combined to monitor the change in abundance of each individual strain in bi-cultures and quadri-culture. Two interaction networks were constructed that summarize the impact of the strains on each other's growth rate in exponential phase and carrying capacity in stationary phase. The networks agree on the absence of positive interactions but also show differences, implying that ecological interactions can be specific to particular growth phases. Janthinobacterium sp. was the fastest growing strain and dominated the co-cultures. However, its growth rate was negatively affected by the presence of other strains 10 to 100 times less abundant than Janthinobacterium sp. In general, we saw a positive correlation between growth rate and carrying capacity in this system. In addition, growth rate in monoculture was predictive of carrying capacity in co-culture. Taken together, our results highlight the necessity to take growth phases into account when measuring interactions within a microbial community. In addition, evidence that a minor strain can greatly influence the dynamics of a dominant one underlines the necessity to choose population models that do not assume a linear dependency of interaction strength to abundance of other species for accurate parameterization from such empirical data.
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Affiliation(s)
- Mathias Bonal
- Laboratory of Ecology of Aquatic Systems, Brussels Bioengineering School, Université Libre de Bruxelles, 1050, Brussels, Belgium
- Laboratory of Molecular Bacteriology (Rega Institute), Department of Microbiology, Immunology and Transplantation, KU Leuven, 3000, Louvain, Belgium
| | - Lise Goetghebuer
- Laboratory of Ecology of Aquatic Systems, Brussels Bioengineering School, Université Libre de Bruxelles, 1050, Brussels, Belgium
| | - Clémence Joseph
- Laboratory of Molecular Bacteriology (Rega Institute), Department of Microbiology, Immunology and Transplantation, KU Leuven, 3000, Louvain, Belgium
| | - Didier Gonze
- Unit of Theoretical Chronobiology, Faculty of Sciences, Université Libre de Bruxelles, 1050, Brussels, Belgium
| | - Karoline Faust
- Laboratory of Molecular Bacteriology (Rega Institute), Department of Microbiology, Immunology and Transplantation, KU Leuven, 3000, Louvain, Belgium
| | - Isabelle F George
- Laboratory of Ecology of Aquatic Systems, Brussels Bioengineering School, Université Libre de Bruxelles, 1050, Brussels, Belgium.
- Laboratory of Marine Biology, Department of Biology, Université Libre de Bruxelles, 1050, Brussels, Belgium.
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Wang Y, Zhang Y, Hu Y, Liu L, Liu SJ, Zhang T. Genome-centric metagenomics reveals the host-driven dynamics and ecological role of CPR bacteria in an activated sludge system. MICROBIOME 2023; 11:56. [PMID: 36945052 PMCID: PMC10031880 DOI: 10.1186/s40168-023-01494-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 02/14/2023] [Indexed: 06/16/2023]
Abstract
BACKGROUND Candidate phyla radiation (CPR) constitutes highly diverse bacteria with small cell sizes and are likely obligate intracellular symbionts. Given their distribution and complex associations with bacterial hosts, genetic and biological features of CPR bacteria in low-nutrient environments have received increasing attention. However, CPR bacteria in wastewater treatment systems remain poorly understood. We utilized genome-centric metagenomics to answer how CPR communities shift over 11 years and what kind of ecological roles they act in an activated sludge system. RESULTS We found that approximately 9% (135) of the 1,526 non-redundant bacterial and archaeal metagenome-assembled genomes were affiliated with CPR. CPR bacteria were consistently abundant with a relative abundance of up to 7.5% in the studied activated sludge system. The observed striking fluctuations in CPR community compositions and the limited metabolic and biosynthetic capabilities in CPR bacteria collectively revealed the nature that CPR dynamics may be directly determined by the available hosts. Similarity-based network analysis further confirmed the broad bacterial hosts of CPR lineages. The proteome contents of activated sludge-associated CPR had a higher similarity to those of environmental-associated CPR than to those of human-associated ones. Comparative genomic analysis observed significant enrichment of genes for oxygen stress resistance in activated sludge-associated CPR bacteria. Furthermore, genes for carbon cycling and horizontal gene transfer were extensively identified in activated sludge-associated CPR genomes. CONCLUSIONS These findings highlight the presence of specific host interactions among CPR lineages in activated sludge systems. Despite the lack of key metabolic pathways, these small, yet abundant bacteria may have significant involvements in biogeochemical cycling and bacterial evolution in activated sludge systems. Video Abstract.
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Affiliation(s)
- Yulin Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266000 People’s Republic of China
- Environmental Microbiome Engineering and Biotechnology Laboratory, The University of Hong Kong, Hong Kong, People’s Republic of China
| | - Yulin Zhang
- Environmental Microbiome Engineering and Biotechnology Laboratory, The University of Hong Kong, Hong Kong, People’s Republic of China
| | - Yu Hu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266000 People’s Republic of China
| | - Lei Liu
- Environmental Microbiome Engineering and Biotechnology Laboratory, The University of Hong Kong, Hong Kong, People’s Republic of China
| | - Shuang-Jiang Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266000 People’s Republic of China
| | - Tong Zhang
- Environmental Microbiome Engineering and Biotechnology Laboratory, The University of Hong Kong, Hong Kong, People’s Republic of China
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11
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Type IV pili trigger episymbiotic association of Saccharibacteria with its bacterial host. Proc Natl Acad Sci U S A 2022; 119:e2215990119. [PMID: 36454763 PMCID: PMC9894109 DOI: 10.1073/pnas.2215990119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Recent characterization of the obligate episymbiont Saccharibacteria (TM7) belonging to the candidate phyla radiation (CPR) has expanded the extent of microbial diversity. However, the episymbiotic lifestyle of TM7 is still underexploited due to the deficiency of cultivated representatives. Here, we describe gene-targeted TM7 cultivation guided by repurposing epicPCR (emulsion, paired isolation, and concatenation PCR) to capture in situ TM7‒host associations. Using this method, we obtained a novel Saccharibacteria isolate TM7i and its host Leucobacter aridicollis J1 from Cicadae Periostracum, the castoff shell of cicada. Genomic analyses and microscopic characterizations revealed that TM7i could bind to J1 through twitching-like motility mediated by type IV pili (T4P). We further showed that the inhibition of T4P extrusion suppressed the motility and host adherence of TM7i, resulting in its reduced growth. However, the inactivation of T4P had little effect on the growth of TM7i that had already adhered to J1, suggesting the essential role of T4P in host recognition by TM7i. By capturing CPR‒host association and elaborating the T4P-dependent episymbiotic association mechanism, our studies shed light on the distinct yet widespread lifestyle of CPR bacteria.
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12
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Hendrickson EL, Bor B, Kerns KA, Lamont EI, Chang Y, Liu J, Cen L, Schulte F, Hardt M, Shi W, He X, McLean JS. Transcriptome of Epibiont Saccharibacteria Nanosynbacter lyticus Strain TM7x During the Establishment of Symbiosis. J Bacteriol 2022; 204:e0011222. [PMID: 35975994 PMCID: PMC9487520 DOI: 10.1128/jb.00112-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 07/25/2022] [Indexed: 11/20/2022] Open
Abstract
Saccharibacteria Nanosynbacter lyticus strain TM7x is a member of the broadly distributed candidate phylum radiation. These bacteria have ultrasmall cell sizes, have reduced genomes, and live as epibionts on the surfaces of other bacteria. The mechanisms by which they establish and maintain this relationship are not yet fully understood. The transcriptomes of the epibiont TM7x and its host bacteria Schaalia odontolytica strain XH001 were captured across the establishment of symbiosis during both the initial interaction and stable symbiosis. The results showed a dynamic interaction with large shifts in gene expression for both species between the initial encounter and stable symbiosis, notably in transporter genes. During stable symbiosis, the host XH001 showed higher gene expression for peptidoglycan biosynthesis, mannosylation, cell cycle and stress-related genes, whereas it showed lower expression of chromosomal partitioning genes. This was consistent with the elongated cell shape seen in XH001 infected with TM7x and our discovery that infection resulted in thickened cell walls. Within TM7x, increased pili, type IV effector genes, and arginine catabolism/biosynthesis gene expression during stable symbiosis implied a key role for these functions in the interaction. Consistent with its survival and persistence in the human microbiome as an obligate epibiont with reduced de novo biosynthetic capacities, TM7x also showed higher levels of energy production and peptidoglycan biosynthesis, but lower expression of stress-related genes, during stable symbiosis. These results imply that TM7x and its host bacteria keep a delicate balance in order to sustain an episymbiotic lifestyle. IMPORTANCE Nanosynbacter lyticus type strain TM7x is the first cultivated member of the Saccharibacteria and the candidate phyla radiation (CPR). It was discovered to be ultrasmall in cell size with a highly reduced genome that establishes an obligate epibiotic relationship with its host bacterium. The CPR is a large, monophyletic radiation of bacteria with reduced genomes that includes Saccharibacteria. The vast majority of the CPR have yet to be cultivated, and our insights into these unique organisms to date have been derived from only a few Saccharibacteria species. Being obligate parasites, it is unknown how these ultrasmall Saccharibacteria, which are missing many de novo biosynthetic pathways, are maintained at a high prevalence within the human microbiome as well as in the environment.
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Affiliation(s)
- Erik L. Hendrickson
- Department of Periodontics, University of Washington, Seattle, Washington, USA
| | - Batbileg Bor
- Department of Microbiology, The Forsyth Institute, Cambridge, Massachusetts, USA
| | - Kristopher A. Kerns
- Department of Periodontics, University of Washington, Seattle, Washington, USA
| | - Eleanor I. Lamont
- Department of Periodontics, University of Washington, Seattle, Washington, USA
| | - Yunjie Chang
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, USA
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jun Liu
- School of Medicine, Yale University, New Haven, Connecticut, USA
| | - Lujia Cen
- Department of Microbiology, The Forsyth Institute, Cambridge, Massachusetts, USA
| | - Fabian Schulte
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, USA
| | - Markus Hardt
- Center for Salivary Diagnostics, The Forsyth Institute, Cambridge, Massachusetts, USA
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts, USA
| | - Wenyuan Shi
- Department of Microbiology, The Forsyth Institute, Cambridge, Massachusetts, USA
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA
| | - Xuesong He
- Department of Microbiology, The Forsyth Institute, Cambridge, Massachusetts, USA
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA
| | - Jeffrey S. McLean
- Department of Periodontics, University of Washington, Seattle, Washington, USA
- Department of Oral Health Sciences, University of Washington, Seattle, Washington, USA
- Department of Microbiology, University of Washington, Seattle, Washington, USA
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13
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Candidate Phyla Radiation, an Underappreciated Division of the Human Microbiome, and Its Impact on Health and Disease. Clin Microbiol Rev 2022; 35:e0014021. [PMID: 35658516 DOI: 10.1128/cmr.00140-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Candidate phyla radiation (CPR) is an emerging division of the bacterial domain within the human microbiota. Still poorly known, these microorganisms were first described in the environment in 1981 as "ultramicrobacteria" with a cell volume under 0.1 μm3 and were first associated with the human oral microbiota in 2007. The evolution of technology has been paramount for the study of CPR within the human microbiota. In fact, since these ultramicrobacteria have yet to be axenically cultured despite ongoing efforts, progress in imaging technology has allowed their observation and morphological description. Although their genomic abilities and taxonomy are still being studied, great strides have been made regarding their taxonomic classification, as well as their lifestyle. In addition, advancements in next-generation sequencing and the continued development of bioinformatics tools have allowed their detection as commensals in different human habitats, including the oral cavity and gastrointestinal and genital tracts, thus highlighting CPR as a nonnegligible part of the human microbiota with an impact on physiological settings. Conversely, several pathologies present dysbiosis affecting CPR levels, including inflammatory, mucosal, and infectious diseases. In this exhaustive review of the literature, we provide a historical perspective on the study of CPR, an overview of the methods available to study these organisms and a description of their taxonomy and lifestyle. In addition, their distribution in the human microbiome is presented in both homeostatic and dysbiotic settings. Future efforts should focus on developing cocultures and, if possible, axenic cultures to obtain isolates and therefore genomes that would provide a better understanding of these ultramicrobacteria, the importance of which in the human microbiome is undeniable.
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14
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Dataset for Genome Sequencing and De Novo Assembly of the Candidate Phyla Radiation in Supragingival Plaque. THE CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY = JOURNAL CANADIEN DES MALADIES INFECTIEUSES ET DE LA MICROBIOLOGIE MEDICALE 2022; 2022:4899824. [PMID: 35345870 PMCID: PMC8957474 DOI: 10.1155/2022/4899824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 01/26/2022] [Indexed: 11/17/2022]
Abstract
The Candidate Phyla Radiation (CPR), as a newly discovered and difficult-to-culture bacterium, accounts for the majority of the bacterial domain, which may be related to various oral diseases, including dental caries. Restricted by laboratory culture conditions, there is limited knowledge about oral CPR. Advances in metagenomics provide a new way to study CPR through molecular biology. Here, we used metagenomic assembly and binning to reconstruct more and higher quality metagenome-assembled genomes (MAGs) of CPR from oral dental plaque. These MAGs represent novel CPR species, which differed from all known CPR organisms. Relative abundance of different CPR MAGs in the caries and caries-free group was estimated by mapping metagenomic reads to newly constructed MAGs. The relative abundance of two CPR MAGs was significantly increased in the caries group, indicating that there might be a relationship with caries activity. The detection of a large number of unclassified CPR MAGs in the dataset implies that the phylogenetic diversity of CPR is enormous. The results provide a reference value for exploring the ecological distribution and function of uncultured or difficult-to-culture microorganisms.
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Abstract
Saccharibacteria (TM7), which are obligate episymbionts growing on the surface of host bacteria, may play an important role in oral disease, such as periodontitis (1, 2). As TM7 is a newly cultured lineage of bacteria, its research is limited by the small number of isolated representatives relative to the number of TM7 genomes assembled from culture-independent studies (3–5). A comprehensive view of both TM7 taxa and TM7 strain-level variations remains opaque. In this study, we expanded our previously developed TM7 baiting method into using many host bacteria in parallel, which allowed us to obtain 37 TM7 strains from the human oral cavity. These strains were further classified into low-enrichment (LE, n = 24) and high-enrichment (HE, n = 13) groups based on their proficiency at propagating on host bacteria. Of the 13 HE strains, 10 belong to “Candidatus Nanosynbacter sp.” strain HMT-352 (human microbial taxon) (6), enabling us to explore both the phenotypic and genomic strain variations within a single TM7 species. We show that TM7 HMT-352 strains exhibit a diverse host range and varied growth dynamics during the establishment of their episymbiotic relationship with host bacteria. Furthermore, despite HMT-352 strains sharing a majority of their genes, we identified several gene clusters that may play a pivotal role in host affinity. More importantly, our comparative analyses also provide TM7 gene candidates associated with strain-level phenotypic variation that may be important for episymbiotic interactions with host bacteria. IMPORTANCE Candidate phylum radiation (CPR) bacteria comprise a poorly understood phylum that is estimated to encompass ∼26% of all diversity of domain bacteria. Among CPR bacteria, the Saccharibacteria lineage (TM7) is of particular interest, as it is found in high abundance in the mammal microbiome and has been associated with oral disease. While many CPR genomes, TM7 included, have been acquired through culture-independent methods, only a small number of representatives have been isolated. Such isolated representatives, however, shed light on the physiology, pathogenesis, and episymbiotic interactions of TM7. Combined with genomic analyses, experiments involving isolated representatives can distinguish phylogenetic to phenotypic discrepancies and better identify genes of importance. In this study, we utilized multiple host bacteria in parallel to isolate TM7 bacteria and examined strain-level variation in TM7 to reveal key genes that may drive TM7-host interactions. Our findings accentuate that broad phylogenetic characterization of CPR is the next step in understanding these bacteria.
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16
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Jiang QL, Lu Y, Zhang MJ, Cui ZY, Pei ZM, Li WH, Lu LG, Wang JJ, Lu YY. Mucosal bacterial dysbiosis in patients with nodular lymphoid hyperplasia in the terminal ileum. World J Gastroenterol 2022; 28:811-824. [PMID: 35317097 PMCID: PMC8900573 DOI: 10.3748/wjg.v28.i8.811] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/19/2021] [Accepted: 01/14/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Nodular lymphoid hyperplasia (NLH) in the small intestine is a rare benign lesion characterized by multiple small nodules on the intestinal surface. Patients with terminal ileal NLH may experience long-term abdominal pain, diarrhea, and abdominal distension, among other symptoms. Supplementation with probiotics could mitigate these symptoms. NLH is linked to the immune system, and it may result from accumulation of plasma-cell precursors due to a maturational defect during the development of B lymphocytes. The intestinal microbiome plays an essential role in the immune system. Thus, we speculate that the gut flora plays a key role in terminal ileal NLH.
AIM To explore the correlation between intestinal flora and terminal ileal NLH.
METHODS We collected mucosal biopsy samples that were obtained via colonoscopy from 15 patients with terminal ileal NLH (the test group) and 15 normal subjects (the control group). We subsequently performed 16S-rRNA gene amplicon sequencing of these samples, and the results were evaluated using alpha diversity, beta diversity and microbial composition analyses. The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States was used to predict the metabolic pathways and orthologous groups according to the Kyoto Encyclopedia of Genes and Genomes database.
RESULTS Compared with the control group, the terminal ileal NLH group showed an increased alpha diversity (P < 0.05). The overall intestinal microbiota in the NLH group was significantly different from that of the control group (P < 0.05), implying that there was the dysbiosis in the terminal ileal NLH patients. The relative abundance of phylum Bacteroidetes was significantly lower in the NLH group, while that of Patescibacteria and Campilobacterota was significantly higher. The genus Bacteroides was the dominant gut microbiota in both groups, but its abundance was significantly lower in the test group than it was in the control group. Conversely, the relative abundances of Haemophilus, Streptococcus, Pseudomonas, Actinomyces, TM7X, Fusobacterium nucleatum, Parvimonas, Granulicatella, Helicobacter, and the [Eubacterium] nodatum group were significantly higher in the test group than they were in the control group. In addition, several altered metabolic pathways, orthologous groups, and modules were found. For example, the Peptidoglycan biosynthesis and Aminoacyl tRNA biosynthesis were both increased in the test group.
CONCLUSION Maintaining the microbial balance and supplementing targeted protective bacteria could improve symptoms and potentially reduce the risk of lymphoma transformation in patients with terminal ileal NLH.
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Affiliation(s)
- Qiao-Li Jiang
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - You Lu
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - Meng-Jie Zhang
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - Zhen-Yu Cui
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - Zhong-Mei Pei
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - Wen-Hua Li
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - Lun-Gen Lu
- Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China
| | - Jing-Jing Wang
- Shanghai Key Laboratory of Pancreatic Diseases, Institute of Translational Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China
| | - Ying-Ying Lu
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
- Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China
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17
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Acquisition of the arginine deiminase system benefits epiparasitic Saccharibacteria and their host bacteria in a mammalian niche environment. Proc Natl Acad Sci U S A 2022; 119:2114909119. [PMID: 34992141 PMCID: PMC8764695 DOI: 10.1073/pnas.2114909119] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/19/2021] [Indexed: 01/10/2023] Open
Abstract
The Candidate Phyla Radiation (CPR) is a large monophyletic lineage with poorly understood biology. Saccharibacteria are ultrasmall parasitic CPR bacteria with highly reduced genomes that have made the transition from an environmental origin to mammals. We tested the function and impact of the arginine deiminase system (ADS), an arginine catabolism pathway likely acquired by mammal-associated Saccharibacteria during their environment-to-mammal niche transition. We showed that the acquired ADS not only helped facilitate Saccharibacterial adaptation to mammals but also contributed to the establishment of cooperative episymbiotic interaction with their bacterial hosts within mammalian microbiomes. Our study provides experimental evidence demonstrating the importance of function acquired by Saccharibacteria during niche transition in facilitating their adaptation from the environment to a mammalian niche. Saccharibacteria are a group of widespread and genetically diverse ultrasmall bacteria with highly reduced genomes that belong to the Candidate Phyla Radiation. Comparative genomic analyses suggest convergent evolution of key functions enabling the adaptation of environmental Saccharibacteria to mammalian microbiomes. Currently, our understanding of this environment-to-mammal niche transition within Saccharibacteria and their obligate episymbiotic association with host bacteria is limited. Here, we identified a complete arginine deiminase system (ADS), found in further genome streamlined mammal-associated Saccharibacteria but missing in their environmental counterparts, suggesting acquisition during environment-to-mammal niche transition. Using TM7x, the first cultured Saccharibacteria strain from the human oral microbiome and its host bacterium Actinomyces odontolyticus, we experimentally tested the function and impact of the ADS. We demonstrated that by catabolizing arginine and generating adenosine triphosphate, the ADS allows metabolically restrained TM7x to maintain higher viability and infectivity when disassociated from the host bacterium. Furthermore, the ADS protects TM7x and its host bacterium from acid stress, a condition frequently encountered within the human oral cavity due to bacterial metabolism of dietary carbohydrates. Intriguingly, with a restricted host range, TM7x forms obligate associations with Actinomyces spp. lacking the ADS but not those carrying the ADS, suggesting the acquired ADS may also contribute to partner selection for cooperative episymbiosis within a mammalian microbiome. These data present experimental characterization of a mutualistic interaction between TM7x and their host bacteria, and illustrate the benefits of acquiring a novel pathway in the transition of Saccharibacteria to mammalian microbiomes.
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18
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Pozzi C, Levi R, Braga D, Carli F, Darwich A, Spadoni I, Oresta B, Dioguardi CC, Peano C, Ubaldi L, Angelotti G, Bottazzi B, Garlanda C, Desai A, Voza A, Azzolini E, Cecconi M, Mantovani A, Penna G, Barbieri R, Politi LS, Rescigno M. A 'Multiomic' Approach of Saliva Metabolomics, Microbiota, and Serum Biomarkers to Assess the Need of Hospitalization in Coronavirus Disease 2019. GASTRO HEP ADVANCES 2022; 1:194-209. [PMID: 35174369 PMCID: PMC8818445 DOI: 10.1016/j.gastha.2021.12.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 12/06/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS The SARS-CoV-2 pandemic has overwhelmed the treatment capacity of the health care systems during the highest viral diffusion rate. Patients reaching the emergency department had to be either hospitalized (inpatients) or discharged (outpatients). Still, the decision was taken based on the individual assessment of the actual clinical condition, without specific biomarkers to predict future improvement or deterioration, and discharged patients often returned to the hospital for aggravation of their condition. Here, we have developed a new combined approach of omics to identify factors that could distinguish coronavirus disease 19 (COVID-19) inpatients from outpatients. METHODS Saliva and blood samples were collected over the course of two observational cohort studies. By using machine learning approaches, we compared salivary metabolome of 50 COVID-19 patients with that of 270 healthy individuals having previously been exposed or not to SARS-CoV-2. We then correlated the salivary metabolites that allowed separating COVID-19 inpatients from outpatients with serum biomarkers and salivary microbiota taxa differentially represented in the two groups of patients. RESULTS We identified nine salivary metabolites that allowed assessing the need of hospitalization. When combined with serum biomarkers, just two salivary metabolites (myo-inositol and 2-pyrrolidineacetic acid) and one serum protein, chitinase 3-like-1 (CHI3L1), were sufficient to separate inpatients from outpatients completely and correlated with modulated microbiota taxa. In particular, we found Corynebacterium 1 to be overrepresented in inpatients, whereas Actinomycetaceae F0332, Candidatus Saccharimonas, and Haemophilus were all underrepresented in the hospitalized population. CONCLUSION This is a proof of concept that a combined omic analysis can be used to stratify patients independently from COVID-19.
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Key Words
- AUC, area under the curve
- CHI3L1
- CHI3L1, chitinase 3-like-1
- CI, confidence interval
- COVID-19
- COVID-19, coronavirus disease 19
- DT, decision tree
- ELISA, enzyme-linked immunosorbent assay
- ESI, electrospray ionization
- FDR, false discovery rate
- IgG, immunoglobulin G
- LR, logistic regression
- Metabolome
- Microbiota
- PCA, principal component analysis
- PTX3, pentraxin 3
- RFE, recursive feature elimination
- SVM, support vector machine
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Affiliation(s)
- Chiara Pozzi
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy
| | - Riccardo Levi
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - Daniele Braga
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy
| | - Francesco Carli
- Department of Informatics, Università degli Studi di Torino, Torino, Piemonte, Italy
| | - Abbass Darwich
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - Ilaria Spadoni
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - Bianca Oresta
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy
| | - Carola Conca Dioguardi
- Institute of Genetic and Biomedical Research, UoS of Milan, National Research Council, Rozzano, Milan, Italy
| | - Clelia Peano
- Institute of Genetic and Biomedical Research, UoS of Milan, National Research Council, Rozzano, Milan, Italy
| | - Leonardo Ubaldi
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | | | | | - Cecilia Garlanda
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy,Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - Antonio Desai
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy,Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - Antonio Voza
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy,Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - Elena Azzolini
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy,Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - Maurizio Cecconi
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy,Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | | | - Alberto Mantovani
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy,Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy,The William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Giuseppe Penna
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy
| | - Riccardo Barbieri
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Letterio S. Politi
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy,Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - Maria Rescigno
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy,Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy,Correspondence: Address correspondence to: Prof. Maria Rescigno, PhD, Humanitas University Pieve Emanuele, Milan, Italy
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19
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de Lima AMDL, de Lima Rosa G, Müller Guzzo EF, Padilha RB, Costa da Silva R, Silveira AK, de Lima Morales D, Conci de Araujo M, Fonseca Moreira JC, Barth AL, Coitinho AS, Van Der Sand ST. Gut microbiota modulation by prednisolone in a rat kindling model of pentylenetetrazol (PTZ)-induced seizure. Microb Pathog 2021; 163:105376. [PMID: 34974121 DOI: 10.1016/j.micpath.2021.105376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/02/2021] [Accepted: 12/28/2021] [Indexed: 11/26/2022]
Abstract
The gut microbiota is a complex community composed by several microorganisms that interact in the maintenance of homeostasis and contribute to physiological processes, including brain function. The relationship of the taxonomic composition of the gut microbiota with neurological diseases such as autism, Parkinson's, Alzheimer's, anxiety, and depression is widely recognized. The immune system is an important intermediary between the gut microbiota and the central nervous system, being one of the communication routes of the gut-brain axis. Although the complexity of the relationship between inflammation and epilepsy has not yet been elucidated, inflammatory processes are similar in many ways to the consequences of dysbiosis and contribute to disease progression. This study aimed to analyze the taxonomic composition of the gut microbiota of rats treated with prednisolone in a kindling model of epilepsy. Male Wistar rats (90 days, n = 24) divided into four experimental groups: sodium chloride solution 0.9 g%, diazepam 2 mg/kg, prednisolone 1 mg/kg, and prednisolone 5 mg/kg administered intraperitoneally (i.p.) for 14 days. The kindling model was induced by pentylenetetrazole (PTZ) 25 mg/kg i.p. on alternate days. The taxonomic profile was established by applying metagenomic DNA sequencing. There was no change in alpha diversity, and the composition of the gut microbiota between prednisolone and diazepam was similar. The significant increase in Verrucomicrobia, Saccharibacteria, and Actinobacteria may be related to the protective activity against seizures and inflammatory processes that cause some cases of epilepsy. Further studies are needed to investigate the functional influence that these species have on epilepsy and the inflammatory processes that trigger it.
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Affiliation(s)
- Amanda Muliterno Domingues Lourenço de Lima
- Programa de Pós-Graduação em Microbiologia Agrícola e do Ambiente, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil
| | - Gabriel de Lima Rosa
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil
| | - Edson Fernando Müller Guzzo
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil
| | - Rafael Bremm Padilha
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil
| | - Rodrigo Costa da Silva
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil
| | - Alexandre Kleber Silveira
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Ramiro Barcelos 2.600 - Annex, Porto Alegre, RS, Brazil
| | - Daiana de Lima Morales
- Laboratório de Pesquisa em Resistência Bacteriana, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2.350, Porto Alegre, RS, Brazil
| | - Milena Conci de Araujo
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil
| | - José Claudio Fonseca Moreira
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Ramiro Barcelos 2.600 - Annex, Porto Alegre, RS, Brazil
| | - Afonso Luís Barth
- Laboratório de Pesquisa em Resistência Bacteriana, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2.350, Porto Alegre, RS, Brazil
| | - Adriana Simon Coitinho
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil; Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Farmacologia e Terapêutica, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil.
| | - Sueli Teresinha Van Der Sand
- Programa de Pós-Graduação em Microbiologia Agrícola e do Ambiente, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil; Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil
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20
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Complete Genome Sequence of Arachnia rubra Strain DSM 100122 T, a Cultured Member of the Human Oral Microbiome. Microbiol Resour Announc 2021; 10:e0095921. [PMID: 34854708 PMCID: PMC8638593 DOI: 10.1128/mra.00959-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We report the complete genome of Arachnia rubra strain DSM 100122T. The genome is 3.32 Mb, with a GC content of 64.2%. The genome contains 3,005 predicted genes, including 2,923 predicted protein-coding genes.
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21
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Episymbiotic Saccharibacteria suppresses gingival inflammation and bone loss in mice through host bacterial modulation. Cell Host Microbe 2021; 29:1649-1662.e7. [PMID: 34637779 DOI: 10.1016/j.chom.2021.09.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/23/2021] [Accepted: 09/16/2021] [Indexed: 12/14/2022]
Abstract
Saccharibacteria (TM7) are obligate epibionts living on the surface of their host bacteria and are strongly correlated with dysbiotic microbiomes during periodontitis and other inflammatory diseases, suggesting they are putative pathogens. However, due to the recalcitrance of TM7 cultivation, causal research to investigate their role in inflammatory diseases is lacking. Here, we isolated multiple TM7 species on their host bacteria from periodontitis patients. These TM7 species reduce inflammation and consequential bone loss by modulating host bacterial pathogenicity in a mouse ligature-induced periodontitis model. Two host bacterial functions involved in collagen binding and utilization of eukaryotic sialic acid are required for inducing bone loss and are altered by TM7 association. This TM7-mediated downregulation of host bacterial pathogenicity is shown for multiple TM7/host bacteria pairs, suggesting that, in contrast to their suspected pathogenic role, TM7 could protect mammalian hosts from inflammatory damage induced by their host bacteria.
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22
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Complete Genome Sequence of Human Oral Actinomyces sp. HMT175 Strain ORNL0102, a Host of the Saccharibacterium (TM7) HMT957. Microbiol Resour Announc 2021; 10:e0041221. [PMID: 34110241 PMCID: PMC8354542 DOI: 10.1128/mra.00412-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Actinomyces sp. HMT175 strain ORNL0102 was isolated from a human saliva sample and can serve as a host for the ectobiont saccharibacterium (TM7) HMT957. Its 3.3-Mbp circular chromosome was completely sequenced using PacBio long reads, and it encodes 2,408 proteins and 63 RNAs.
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23
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McLean JS, Bor B, Kerns KA, Liu Q, To TT, Solden L, Hendrickson EL, Wrighton K, Shi W, He X. Acquisition and Adaptation of Ultra-small Parasitic Reduced Genome Bacteria to Mammalian Hosts. Cell Rep 2021; 32:107939. [PMID: 32698001 PMCID: PMC7427843 DOI: 10.1016/j.celrep.2020.107939] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 06/20/2020] [Accepted: 06/30/2020] [Indexed: 12/31/2022] Open
Abstract
The first cultivated representative of the enigmatic phylum Saccharibacteria (formerly TM7) was isolated from humans and revealed an ultra-small cell size (200-300 nm), a reduced genome with limited biosynthetic capabilities, and a unique parasitic lifestyle. TM7x was the only cultivated member of the candidate phyla radiation (CPR), estimated to encompass 26% of the domain Bacteria. Here we report on divergent genomes from major lineages across the Saccharibacteria phylum in humans and mammals, as well as from ancient dental calculus. These lineages are present at high prevalence within hosts. Direct imaging reveals that all groups are ultra-small in size, likely feeding off commensal bacteria. Analyses suggest that multiple acquisition events in the past led to the current wide diversity, with convergent evolution of key functions allowing Saccharibacteria from the environment to adapt to mammals. Ultra-small, parasitic CPR bacteria represent a relatively unexplored paradigm of prokaryotic interactions within mammalian microbiomes.
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Affiliation(s)
- Jeffrey S McLean
- Department of Periodontics, University of Washington, Seattle, WA 98195, USA; Department of Microbiology, University of Washington, Seattle, WA 98195, USA.
| | - Batbileg Bor
- Department of Microbiology, The Forsyth Institute, Cambridge, MA 02142, USA; Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Kristopher A Kerns
- Department of Periodontics, University of Washington, Seattle, WA 98195, USA
| | - Quanhui Liu
- Department of Periodontics, University of Washington, Seattle, WA 98195, USA
| | - Thao T To
- Department of Periodontics, University of Washington, Seattle, WA 98195, USA
| | - Lindsey Solden
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Erik L Hendrickson
- Department of Periodontics, University of Washington, Seattle, WA 98195, USA
| | - Kelly Wrighton
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Wenyuan Shi
- Department of Microbiology, The Forsyth Institute, Cambridge, MA 02142, USA
| | - Xuesong He
- Department of Microbiology, The Forsyth Institute, Cambridge, MA 02142, USA; Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA
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24
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Complete Genome Sequence of Human Oral Actinomyces sp. HMT897 Strain ORNL0104, a Host of the Saccharibacterium (TM7) HMT351. Microbiol Resour Announc 2021; 10:10/14/e00040-21. [PMID: 33833021 PMCID: PMC8032463 DOI: 10.1128/mra.00040-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Actinomyces sp. HMT897 strain ORNL0104 was isolated from a human saliva sample and can serve as a host for the ectobiont Saccharibacteria/TM7 HMT351. Its 3.3-Mb chromosome was completely sequenced using PacBio long reads, and it encodes 2,407 proteins and 63 RNAs. Actinomyces sp. HMT897 strain ORNL0104 was isolated from a human saliva sample and can serve as a host for the ectobiont Saccharibacteria (TM7) HMT351. Its 3.3-Mb chromosome was completely sequenced using PacBio long reads, and it encodes 2,407 proteins and 63 RNAs.
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25
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Abstract
The human mouth harbors a complex microbiota, the composition of which is potentially influenced by a wide range of factors, including the intake of food and drink, the availability of endogenous nutrients, the host immune system, drug treatments, and systemic diseases. Despite these possible influences, the oral microbiota is remarkably resilient, particularly in comparison with the microbiota of the large intestine. Diet, with the exception of excessive and/or frequent consumption of fermentable carbohydrate or supplementation with nitrate, has minimal impact on the composition of the oral bacterial community. The common oral diseases dental caries and the periodontal diseases is associated with modification of the oral microbiota primarily as a result of the ecological changes induced by excessive acid production and inflammation, respectively. Systemically-administered antimicrobials have only a small effect on the composition of the oral bacterial community, and while locally delivered antimicrobials can have some clinical benefits, the biofilm lifestyle of oral bacteria lends them substantial resistance to the agents used. Saliva plays an important role in oral microbial ecology, by supplying nutrients and providing protection against colonization by nonoral organisms. Dry mouth is one condition that has a major effect on the microbiota, resulting in increased colonization by opportunistic pathogens. Some systemic diseases do affect the oral microbiome, notably diabetes, in which raised levels of glucose in saliva and tissue impact on bacterial nutrition.
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Affiliation(s)
- William G Wade
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London, UK.,Department of Microbiology, Forsyth Institute, Cambridge, MA, USA
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26
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Utter DR, He X, Cavanaugh CM, McLean JS, Bor B. The saccharibacterium TM7x elicits differential responses across its host range. THE ISME JOURNAL 2020; 14:3054-3067. [PMID: 32839546 PMCID: PMC7784981 DOI: 10.1038/s41396-020-00736-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 07/01/2020] [Accepted: 08/03/2020] [Indexed: 12/28/2022]
Abstract
Host range is a fundamental component of symbiotic interactions, yet it remains poorly characterized for the prevalent yet enigmatic subcategory of bacteria/bacteria symbioses. The recently characterized obligate bacterial epibiont Candidatus Nanosynbacter lyticus TM7x with its bacterial host Actinomyces odontolyticus XH001 offers an ideal system to study such a novel relationship. In this study, the host range of TM7x was investigated by coculturing TM7x with various related Actinomyces strains and characterizing their growth dynamics from initial infection through subsequent co-passages. Of the twenty-seven tested Actinomyces, thirteen strains, including XH001, could host TM7x, and further classified into "permissive" and "nonpermissive" based on their varying initial responses to TM7x. Ten permissive strains exhibited growth/crash/recovery phases following TM7x infection, with crash timing and extent dependent on initial TM7x dosage. Meanwhile, three nonpermissive strains hosted TM7x without a growth-crash phase despite high TM7x dosage. The physical association of TM7x with all hosts, including nonpermissive strains, was confirmed by microscopy. Comparative genomic analyses revealed distinguishing genomic features between permissive and nonpermissive hosts. Our results expand the concept of host range beyond a binary to a wider spectrum, and the varying susceptibility of Actinomyces strains to TM7x underscores how small genetic differences between hosts can underly divergent selective trajectories.
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Affiliation(s)
- Daniel R Utter
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Xuesong He
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, 02142, USA
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, 02115, USA
| | - Colleen M Cavanaugh
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Jeffrey S McLean
- Department of Periodontics, University of Washington, Seattle, WA, 98119, USA
| | - Batbileg Bor
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, 02142, USA.
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, 02115, USA.
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27
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Murugkar PP, Collins AJ, Chen T, Dewhirst FE. Isolation and cultivation of candidate phyla radiation Saccharibacteria (TM7) bacteria in coculture with bacterial hosts. J Oral Microbiol 2020; 12:1814666. [PMID: 33209205 PMCID: PMC7651992 DOI: 10.1080/20002297.2020.1814666] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Background The vast majority of bacteria on earth have not yet been cultivated. There are many bacterial phyla with no cultivated examples including most members of the Candidate Phylum Radiation with the exception of human oral isolates from the phylum Saccharibacteria. Aims The aims of this research were to develop reproducible methods and validate approaches for the cultivation of human oral Saccharibacteria and to identify the conceptual pitfalls that delayed isolation of these bacteria for 20 years after their discovery. Methods Oral samples were dispersed and passed through 0.2 µm membrane filters. The ultrasmall saccharibacterial cells in the filtrate were pelleted, inoculated into broth cultures of potential bacterial host cells and passaged into fresh medium every 2–3 days. Results Thirty-two isolates representing four species of Saccharibacteria were isolated in stable coculture with three species of host bacteria from the phylum Actinobacteria. Complete genome sequences were obtained for 16 isolates. Conclusions Human oral Saccharibacteria are obligate bacterial parasites that can be stably passaged in coculture with specific species of host bacteria. Isolating these important members of the human oral microbiome, and many natural environments, requires abandoning many of Koch’s concepts and methods and embracing novel microbiological approaches.
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Affiliation(s)
- Pallavi P Murugkar
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA.,Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Andrew J Collins
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA.,Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Tsute Chen
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA.,Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Floyd E Dewhirst
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA.,Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
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28
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Complete Genome Sequence of Strain BB001, a Novel Epibiont Bacterium from the Candidate Phylum Saccharibacteria (TM7). Microbiol Resour Announc 2020; 9:9/34/e00810-20. [PMID: 32816985 PMCID: PMC7441243 DOI: 10.1128/mra.00810-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Strain BB001 is cultivated from the human oral cavity on its basibiont bacterial host Actinomyces sp. It is an ultrasmall bacterium with a reduced genome that grows obligately on its bacterial host. BB001 is the first member of human microbiome taxon 957. Strain BB001 is cultivated from the human oral cavity on its basibiont bacterial host Actinomyces sp. It is an ultrasmall bacterium with a reduced genome that grows obligately on its bacterial host. BB001 is the first member of human microbiome taxon 957.
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29
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Bor B, Collins A, Murugkar P, Balasubramanian S, To T, Hendrickson E, Bedree J, Bidlack F, Johnston C, Shi W, McLean J, He X, Dewhirst F. Insights Obtained by Culturing Saccharibacteria With Their Bacterial Hosts. J Dent Res 2020; 99:685-694. [PMID: 32075512 PMCID: PMC7243422 DOI: 10.1177/0022034520905792] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Oral microbiome research has moved from asking "Who's there?" to "What are they doing?" Understanding what microbes "do" involves multiple approaches, including obtaining genomic information and examining the interspecies interactions. Recently we isolated a human oral Saccharibacteria (TM7) bacterium, HMT-952, strain TM7x, which is an ultrasmall parasite of the oral bacterium Actinomyces odontolyticus. The host-parasite interactions, such as phage-bacterium or Saccharibacteria-host bacterium, are understudied areas with large potential for insight. The Saccharibacteria phylum is a member of Candidate Phyla Radiation, a large lineage previously devoid of cultivated members. However, expanding our understanding of Saccharibacteria-host interactions requires examining multiple phylogenetically distinct Saccharibacteria-host pairs. Here we report the isolation of 3 additional Saccharibacteria species from the human oral cavity in binary coculture with their bacterial hosts. They were obtained by filtering ultrasmall Saccharibacteria cells free of other larger bacteria and inoculating them into cultures of potential host bacteria. The binary cocultures obtained could be stably passaged and studied. Complete closed genomes were obtained and allowed full genome analyses. All have small genomes (<1 Mb) characteristic of parasitic species and dramatically limited de novo synthetic pathway capabilities but include either restriction modification or CRISPR-Cas systems as part of an innate defense against foreign DNA. High levels of gene synteny exist among Saccharibacteria species. Having isolates growing in coculture with their hosts allowed time course studies of growth and parasite-host interactions by phase contrast, fluorescence in situ hybridization, and scanning electron microscopy. The cells of the 4 oral Saccharibacteria species are ultrasmall and could be seen attached to their larger Actinobacteria hosts. Parasite attachment appears to lead to host cell death and lysis. The successful cultivation of Saccharibacteria species has significantly expanded our understanding of these ultrasmall Candidate Phyla Radiation bacteria.
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Affiliation(s)
- B. Bor
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - A.J. Collins
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
- Covaris, Inc., Woburn, MA, USA
| | - P.P. Murugkar
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
- Stanford Microbiome Therapeutics Initiative, Stanford University, Palo Alto, CA, USA
| | - S. Balasubramanian
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
- Emulate, Inc., Boston, MA, USA
| | - T.T. To
- Department of Periodontics, University of Washington, Seattle, WA, USA
| | - E.L. Hendrickson
- Department of Periodontics, University of Washington, Seattle, WA, USA
| | - J.K. Bedree
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
- Section of Oral Biology, Division of Oral Biology and Medicine, School of Dentistry, University of California Los Angeles, Los Angeles, CA, USA
| | - F.B. Bidlack
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - C.D. Johnston
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - W. Shi
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
| | - J.S. McLean
- Department of Periodontics, University of Washington, Seattle, WA, USA
| | - X. He
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
| | - F.E. Dewhirst
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
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30
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Zhang B, Yue J, Guo Y, Liu T, Zhou M, Yang Y, Wu J, Zeng Y, Ning X. Effects of bioporous carriers on the performance and microbial community structure in side-stream anaerobic membrane bioreactors. Can J Microbiol 2020; 66:475-489. [PMID: 32223723 DOI: 10.1139/cjm-2019-0632] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to investigate the effects of a volcanic rock porous carrier (VRPC) on sludge reduction, pollutant removal, and microbial community structure in an anaerobic side-stream reactor (ASSR). Three lab-scale membrane bioreactors (MBRs), including an anoxic-oxic MBR, which served as the control (C-MBR), an ASSR-coupled MBR (A-MBR), and an A-MBR filled with VRPC (FA-MBR) were stably and simultaneously operated for 120 days. The effect of the three reactors on the removal of chemical oxygen demand (COD) was almost negligible (all greater than 95%), but the average removal efficiency of ammonium nitrogen, total nitrogen, and total phosphorus was significantly improved by the insertion of an ASSR, especially when the ASSR was filled with VRPC. Finally, A-MBR and FA-MBR achieved 16.2% and 26.4% sludge reduction rates, with observed sludge yields of 0.124 and 0.109 g mixed liquid suspended solids/g COD, respectively. Illumina MiSeq sequencing revealed that microbial diversity and richness were highest in the VRPC, indicating that a large number of microorganisms formed on the carrier surface in the form of a biofilm. Abundant denitrifying bacteria (Azospira, Comamonadaceae_unclassified, and Flavobacterium) were immobilized on the carrier biofilm, which contributed to increased nitrogen removal. The addition of a VRPC to the ASSR successfully immobilized abundant hydrolytic, fermentative, and slow-growing microorganisms, which all contributed to reductions in sludge yield.
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Affiliation(s)
- Bin Zhang
- School of Civil Engineering and Construction and Environment, Xihua University, Chengdu 610039, P.R. China.,School of Food and Biotechnology, Xihua University, Chengdu 610039, P.R. China
| | - Jiao Yue
- School of Civil Engineering and Construction and Environment, Xihua University, Chengdu 610039, P.R. China
| | - Yu Guo
- School of Civil Engineering, Sichuan University of Science & Engineering, Zigong 643000, P.R. China
| | - Taixin Liu
- School of Civil Engineering, Sichuan University of Science & Engineering, Zigong 643000, P.R. China
| | - Min Zhou
- School of Civil Engineering, Sichuan University of Science & Engineering, Zigong 643000, P.R. China
| | - Ying Yang
- School of Civil Engineering, Sichuan University of Science & Engineering, Zigong 643000, P.R. China
| | - Jiaxu Wu
- School of Civil Engineering, Sichuan University of Science & Engineering, Zigong 643000, P.R. China
| | - Yang Zeng
- School of Civil Engineering, Sichuan University of Science & Engineering, Zigong 643000, P.R. China
| | - Xinqiang Ning
- School of Civil Engineering, Sichuan University of Science & Engineering, Zigong 643000, P.R. China
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31
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Armitage GC. A brief history of periodontics in the United States of America: Pioneers and thought-leaders of the past, and current challenges. Periodontol 2000 2019; 82:12-25. [PMID: 31850629 DOI: 10.1111/prd.12303] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This paper summarizes historical events in periodontology in the United States over the past 200 years. The contributions of some of the key thought-leaders of the past are highlighted. Throughout the 20th century, the evolution of thought, leading to the views currently held regarding the pathogenesis and treatment of periodontal diseases, was significantly influenced by: (1) major changes in health-care education; (2) the emergence of periodontics as a specialty of dentistry; (3) the publication of peer-reviewed journals with an emphasis on periodontology; (4) formation of the National Institute of Dental and Craniofacial Research (NIDCR); and (5) expansion of periodontal research programs by the NIDCR. The two major future challenges facing periodontal research are development of a better understanding of the ecological complexities of host-microbial interactions in periodontal health and disease, and identification of the relevant mechanisms involved in the predictable regeneration of damaged periodontal tissues.
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Affiliation(s)
- Gary C Armitage
- Division of Periodontology, Department of Orofacial Sciences, University of California San Francisco, San Francisco, California, USA
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32
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Complete Genome Sequence of Strain PM004, a Novel Cultured Member of the Human Oral Microbiome from the Candidate Phylum Saccharibacteria (TM7). Microbiol Resour Announc 2019; 8:8/42/e01159-19. [PMID: 31624157 PMCID: PMC6797546 DOI: 10.1128/mra.01159-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Strain PM004 is a cultured representative of human microbial taxon 955, a bacterium from the phylum Saccharibacteria It is an obligate parasite with a genome of <0.9 Mb and can be grown in coculture with its host, Pseudopropionibacterium propionicum The complete genome sequence is presented here.
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33
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Complete Genome Sequence of Strain AC001, a Novel Cultured Member of the Human Oral Microbiome from the Candidate Phylum Saccharibacteria (TM7). Microbiol Resour Announc 2019; 8:8/42/e01158-19. [PMID: 31624156 PMCID: PMC6797545 DOI: 10.1128/mra.01158-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Strain AC001 is a cultured representative of human microbial taxon 488, a bacterium from the candidate phylum Saccharibacteria It is an obligate parasite with a genome of <0.9 Mb and grows in coculture with its host, Pseudopropionibacterium propionicum The complete genome sequence is presented here.
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34
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Cross KL, Campbell JH, Balachandran M, Campbell AG, Cooper SJ, Griffen A, Heaton M, Joshi S, Klingeman D, Leys E, Yang Z, Parks JM, Podar M. Targeted isolation and cultivation of uncultivated bacteria by reverse genomics. Nat Biotechnol 2019; 37:1314-1321. [PMID: 31570900 PMCID: PMC6858544 DOI: 10.1038/s41587-019-0260-6] [Citation(s) in RCA: 164] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Accepted: 08/15/2019] [Indexed: 12/16/2022]
Abstract
Most microorganisms from all taxonomic levels are uncultured. Single-cell
genomes and metagenomes continue to increase the known diversity of
Bacteria and Archaea, but while
‘omics can be used to infer physiological or ecological roles for species
in a community, most of those hypothetical roles remain unvalidated. Here we
report an approach to capture specific microorganisms from complex communities
into pure cultures using genome-informed antibody engineering. We apply our
reverse genomics approach to isolate and sequence single cells and to cultivate
three different species-level lineages of human oral Saccharibacteria/TM7. Using
our pure cultures we show that all three saccharibacteria species are epibionts
of diverse Actinobacteria. We also isolate and cultivate human
oral SR1 bacteria, which are members of a lineage of previously uncultured
bacteria. Reverse-genomics-enabled cultivation of microorganisms can be applied
to any species from any environment and has the potential to unlock the
isolation, cultivation and characterization of species from as-yet-uncultured
branches of the microbial tree of life.
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Affiliation(s)
- Karissa L Cross
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.,Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - James H Campbell
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.,Department of Natural Sciences, Northwest Missouri State University, Maryville, MO, USA
| | | | - Alisha G Campbell
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.,Genome Science and Technology Program, University of Tennessee, Knoxville, TN, USA.,Department of Natural Sciences, Northwest Missouri State University, Maryville, MO, USA
| | - Sarah J Cooper
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.,Genome Science and Technology Program, University of Tennessee, Knoxville, TN, USA
| | - Ann Griffen
- College of Dentistry, The Ohio State University, Columbus, OH, USA
| | | | - Snehal Joshi
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Dawn Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Eugene Leys
- College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Zamin Yang
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Jerry M Parks
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.,Genome Science and Technology Program, University of Tennessee, Knoxville, TN, USA
| | - Mircea Podar
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA. .,Department of Microbiology, University of Tennessee, Knoxville, TN, USA. .,Genome Science and Technology Program, University of Tennessee, Knoxville, TN, USA.
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35
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Bernstein DB, Dewhirst FE, Segrè D. Metabolic network percolation quantifies biosynthetic capabilities across the human oral microbiome. eLife 2019; 8:39733. [PMID: 31194675 PMCID: PMC6609349 DOI: 10.7554/elife.39733] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 06/13/2019] [Indexed: 12/18/2022] Open
Abstract
The biosynthetic capabilities of microbes underlie their growth and interactions, playing a prominent role in microbial community structure. For large, diverse microbial communities, prediction of these capabilities is limited by uncertainty about metabolic functions and environmental conditions. To address this challenge, we propose a probabilistic method, inspired by percolation theory, to computationally quantify how robustly a genome-derived metabolic network produces a given set of metabolites under an ensemble of variable environments. We used this method to compile an atlas of predicted biosynthetic capabilities for 97 metabolites across 456 human oral microbes. This atlas captures taxonomically-related trends in biomass composition, and makes it possible to estimate inter-microbial metabolic distances that correlate with microbial co-occurrences. We also found a distinct cluster of fastidious/uncultivated taxa, including several Saccharibacteria (TM7) species, characterized by their abundant metabolic deficiencies. By embracing uncertainty, our approach can be broadly applied to understanding metabolic interactions in complex microbial ecosystems.
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Affiliation(s)
- David B Bernstein
- Department of Biomedical Engineering, Boston University, Boston, United States.,Biological Design Center, Boston University, Boston, United States
| | - Floyd E Dewhirst
- The Forsyth Institute, Cambridge, United States.,Harvard School of Dental Medicine, Boston, United States
| | - Daniel Segrè
- Department of Biomedical Engineering, Boston University, Boston, United States.,Biological Design Center, Boston University, Boston, United States.,Bioinformatics Program, Boston University, Boston, United States.,Department of Biology, Boston University, Boston, United States.,Department of Physics, Boston University, Boston, United States
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36
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Bor B, Bedree JK, Shi W, McLean JS, He X. Saccharibacteria (TM7) in the Human Oral Microbiome. J Dent Res 2019; 98:500-509. [PMID: 30894042 DOI: 10.1177/0022034519831671] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bacteria from the Saccharibacteria phylum (formerly known as TM7) are ubiquitous members of the human oral microbiome and are part of the Candidate Phyla Radiation. Recent studies have revealed remarkable 16S rRNA diversity in environmental and mammalian host-associated members across this phylum, and their association with oral mucosal infectious diseases has been reported. However, due to their recalcitrance to conventional cultivation, TM7's physiology, lifestyle, and role in health and diseases remain elusive. The recent cultivation and characterization of Nanosynbacter lyticus type strain TM7x (HMT_952)-the first Saccharibacteria strain coisolated as an ultrasmall obligate parasite with its bacterial host from the human oral cavity-provide a rare glimpse into the novel symbiotic lifestyle of these enigmatic human-associated bacteria. TM7x is unique among all bacteria: it has an ultrasmall size and lives on the surface of its host bacterium. With a highly reduced genome, it lacks the ability to synthesize any of its own amino acids, vitamins, or cell wall precursors and must parasitize other oral bacteria. TM7x displays a highly dynamic interaction with its bacterial hosts, as reflected by the reciprocal morphologic and physiologic changes in both partners. Furthermore, depending on environmental conditions, TM7x can exhibit virulent killing of its host bacterium. Thus, Saccharibacteria potentially affect oral microbial ecology by modulating the oral microbiome structure hierarchy and functionality through affecting the bacterial host's physiology, inhibiting the host's growth dynamics, or affecting the relative abundance of the host via direct killing. At this time, several other uncharacterized members of this phylum have been detected in various human body sites at high prevalence. In the oral cavity alone, at least 6 distinct groups vary widely in relative abundance across anatomic sites. Here, we review the current knowledge on the diversity and unique biology of this recently uncovered group of ultrasmall bacteria.
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Affiliation(s)
- B Bor
- 1 The Forsyth Institute, Cambridge, MA, USA.,2 Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - J K Bedree
- 1 The Forsyth Institute, Cambridge, MA, USA.,3 Section of Oral Biology, Division of Oral Biology and Medicine, School of Dentistry, University of California-Los Angeles, Los Angeles, CA, USA
| | - W Shi
- 1 The Forsyth Institute, Cambridge, MA, USA
| | - J S McLean
- 4 Department of Periodontics, University of Washington, Seattle, WA, USA
| | - X He
- 1 The Forsyth Institute, Cambridge, MA, USA
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37
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Yao Q, Yang H, Wang X, Wang H. Effects of hexavalent chromium on intestinal histology and microbiota in Bufo gargarizans tadpoles. CHEMOSPHERE 2019; 216:313-323. [PMID: 30384300 DOI: 10.1016/j.chemosphere.2018.10.147] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/19/2018] [Accepted: 10/20/2018] [Indexed: 06/08/2023]
Abstract
Chromium is detrimental heavy metal pollutants and can enter and affect aquatic organisms. In our experiment, B. gargarizans embryos were chronically exposed in different concentrations of Cr (VI) (0, 13, 104, and 416 μg Cr6+ L-1) until reached Gosner stage 38. We measured morphological parameters of the body and intestine of B. gargarizans tadpoles, and examined alteration of intestinal tissue. Furthermore, we analyzed the intestinal microbial community of B. gargarizans tadpoles using 16S rRNA gene amplicon sequencing. Our research demonstrated that Cr (VI) exposure caused alteration of intestinal tissue structure in 416 μg Cr6+ L-1 treatment groups. Total body length, body wet weight, intestinal length and wet weight of B. gargarizans tadpoles were significantly declined at 416 μg Cr6+ L-1. In addition, 16S rRNA gene sequencing revealed that Cr (VI) exposure significantly altered the intestinal microbiota diversity and composition, and perturbed the community structure of the microbiota. As for the intestinal microbiota, at the phylum level, Fusobacteria significantly changed in all Cr (VI) treated groups. Saccharibacteria and TM6_Dependentiae were detected only in the high dose exposure groups. At the genus level, Aeromonas was significantly decreased in Cr (VI) treated groups. According to the results of functional prediction, Cr (VI) exposure affected metabolism and increased risk of disease by inducing the alterations of intestinal microbiota structure. Taken together, the present study provide a new framework elucidating the toxic effects Cr (VI) exposure on B. gargarizans tadpoles associated with intestinal histology and microbiota.
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Affiliation(s)
- Qiong Yao
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Hongyu Yang
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Xianchan Wang
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Hongyuan Wang
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China.
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38
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Ishaq SL, Page CM, Yeoman CJ, Murphy TW, Van Emon ML, Stewart WC. Zinc AA supplementation alters yearling ram rumen bacterial communities but zinc sulfate supplementation does not. J Anim Sci 2019; 97:687-697. [PMID: 30508094 PMCID: PMC6358250 DOI: 10.1093/jas/sky456] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 11/29/2018] [Indexed: 12/15/2022] Open
Abstract
Despite the body of research into Zn for human and animal health and productivity, very little work has been done to discern whether this benefit is exerted solely on the host organism, or whether there is some effect of dietary Zn upon the gastrointestinal microbiota, particularly in ruminants. We hypothesized that (i) supplementation with Zn would alter the rumen bacterial community in yearling rams, but that (ii) supplementation with either inorganically sourced ZnSO4, or a chelated Zn AA complex, which was more bioavailable, would affect the rumen bacterial community differently. Sixteen purebred Targhee yearling rams were utilized in an 84-d completely randomized design, and allocated to one of three pelleted dietary treatments: control diet without fortified Zn (~1 × NRC), a diet fortified with a Zn AA complex (~2 × NRC), and a diet fortified with ZnSO4 (~2 × NRC). Rumen bacterial community was assessed using Illumina MiSeq of the V4 to V6 region of the 16S rRNA gene. One hundred and eleven OTUs were found with > 1% abundance across all samples. The genera Prevotella, Solobacterium, Ruminococcus, Butyrivibrio, Olsenella, Atopobium, and the candidate genus Saccharimonas were abundant in all samples. Total rumen bacterial evenness and diversity in rams were reduced by supplementation with a Zn AA complex, but not in rams supplemented with an equal concentration of ZnSO4, likely due to differences in bioavailability between organic and inorganically sourced supplement formulations. A number of bacterial genera were altered by Zn supplementation, but only the phylum Tenericutes was significantly reduced by ZnSO4 supplementation, suggesting that either Zn supplementation formulation could be utilized without causing a high-level shift in the rumen bacterial community which could have negative consequences for digestion and animal health.
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Affiliation(s)
| | - Chad M Page
- Montana State University, Department of Animal and Range Sciences, Bozeman
| | - Carl J Yeoman
- Montana State University, Department of Animal and Range Sciences, Bozeman
| | - Thomas W Murphy
- Montana State University, Department of Animal and Range Sciences, Bozeman
| | - Megan L Van Emon
- Montana State University, Department of Animal and Range Sciences, Bozeman
| | - Whit C Stewart
- Montana State University, Department of Animal and Range Sciences, Bozeman
- University of Wyoming, Department of Animal Science, Laramie
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39
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Bor B, McLean JS, Foster KR, Cen L, To TT, Serrato-Guillen A, Dewhirst FE, Shi W, He X. Rapid evolution of decreased host susceptibility drives a stable relationship between ultrasmall parasite TM7x and its bacterial host. Proc Natl Acad Sci U S A 2018; 115:12277-12282. [PMID: 30442671 PMCID: PMC6275545 DOI: 10.1073/pnas.1810625115] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Around one-quarter of bacterial diversity comprises a single radiation with reduced genomes, known collectively as the Candidate Phyla Radiation. Recently, we coisolated TM7x, an ultrasmall strain of the Candidate Phyla Radiation phylum Saccharibacteria, with its bacterial host Actinomyces odontolyticus strain XH001 from human oral cavity and stably maintained as a coculture. Our current work demonstrates that within the coculture, TM7x cells establish a long-term parasitic association with host cells by infecting only a subset of the population, which stay viable yet exhibit severely inhibited cell division. In contrast, exposure of a naïve A. odontolyticus isolate, XH001n, to TM7x cells leads to high numbers of TM7x cells binding to each host cell, massive host cell death, and a host population crash. However, further passaging reveals that XH001n becomes less susceptible to TM7x over time and enters a long-term stable relationship similar to that of XH001. We show that this reduced susceptibility is driven by rapid host evolution that, in contrast to many forms of phage resistance, offers only partial protection. The result is a stalemate where infected hosts cannot shed their parasites; nevertheless, parasite load is sufficiently low that the host population persists. Finally, we show that TM7x can infect and form stable long-term relationships with other species in a single clade of Actinomyces, displaying a narrow host range. This system serves as a model to understand how parasitic bacteria with reduced genomes such as those of the Candidate Phyla Radiation have persisted with their hosts and ultimately expanded in their diversity.
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Affiliation(s)
- Batbileg Bor
- Department of Microbiology, The Forsyth Institute, Cambridge, MA 02142;
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02115
| | - Jeffrey S McLean
- Department of Periodontics, University of Washington, Seattle, WA 98119
| | - Kevin R Foster
- Department of Zoology, University of Oxford, OX1 3PS Oxford, United Kingdom
| | - Lujia Cen
- Department of Microbiology, The Forsyth Institute, Cambridge, MA 02142
| | - Thao T To
- Department of Periodontics, University of Washington, Seattle, WA 98119
| | - Alejandro Serrato-Guillen
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA 90095
| | - Floyd E Dewhirst
- Department of Microbiology, The Forsyth Institute, Cambridge, MA 02142
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02115
| | - Wenyuan Shi
- Department of Microbiology, The Forsyth Institute, Cambridge, MA 02142
| | - Xuesong He
- Department of Microbiology, The Forsyth Institute, Cambridge, MA 02142;
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40
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Bedree JK, Bor B, Cen L, Edlund A, Lux R, McLean JS, Shi W, He X. Quorum Sensing Modulates the Epibiotic-Parasitic Relationship Between Actinomyces odontolyticus and Its Saccharibacteria epibiont, a Nanosynbacter lyticus Strain, TM7x. Front Microbiol 2018; 9:2049. [PMID: 30319555 PMCID: PMC6166536 DOI: 10.3389/fmicb.2018.02049] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 08/13/2018] [Indexed: 11/13/2022] Open
Abstract
The ultra-small, obligate parasitic epibiont, TM7x, the first and only current member of the long-elusive Saccharibacteria (formerly the TM7 phylum) phylum to be cultivated, was isolated in co-culture with its bacterial host, Actinomyces odontolyticus subspecies actinosynbacter, XH001. Initial phenotypic characterization of the TM7x-associated XH001 co-culture revealed enhanced biofilm formation in the presence of TM7x compared to XH001 as monoculture. Genomic analysis and previously published transcriptomic profiling of XH001 also revealed the presence of a putative AI-2 quorum sensing (QS) operon, which was highly upregulated upon association of TM7x with XH001. This analysis revealed that the most highly induced gene in XH001 was an lsrB ortholog, which encodes a putative periplasmic binding protein for the auto inducer (AI)-2 QS signaling molecule. Further genomic analyses suggested the lsrB operon in XH001 is a putative hybrid AI-2/ribose transport operon as well as the existence of a luxS ortholog, which encodes the AI-2 synthase. In this study, the potential role of AI-2 QS in the epibiotic-parasitic relationship between XH001 and TM7x in the context of biofilm formation was investigated. A genetic system for XH001 was developed to generate lsrB and luxS gene deletion mutants in XH001. Phenotypic characterization demonstrated that deletion mutations in either lsrB or luxS did not affect XH001's growth dynamic, mono-species biofilm formation capability, nor its ability to associate with TM7x. TM7x association with XH001 induced lsrB gene expression in a luxS-dependent manner. Intriguingly, unlike wild type XH001, which displayed significantly increased biofilm formation upon establishing the epibiotic-parasitic relationship with TM7x, XH001ΔlsrB, and XH001ΔluxS mutants failed to achieve enhanced biofilm formation when associated with TM7x. In conclusion, we demonstrated a significant role for AI-2 QS in modulating dual-species biofilm formation when XH001 and TM7x establish their epibiotic-parasitic relationship.
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Affiliation(s)
- Joseph K Bedree
- Section of Oral Biology, Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Microbiology, The Forsyth Institute, Cambridge, MA, United States
| | - Batbileg Bor
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, United States
| | - Lujia Cen
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, United States
| | - Anna Edlund
- Department of Genomic Medicine, J. Craig Venter Institute, La Jolla, CA, United States
| | - Renate Lux
- Section of Periodontics, Division of Constitutive and Regenerative Sciences, School of Dentistry, University of California, Los Angeles, Los Angeles, CA, United States
| | - Jeffrey S McLean
- Department of Periodontics, School of Dentistry, University of Washington, Seattle, WA, United States
| | - Wenyuan Shi
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, United States
| | - Xuesong He
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, United States
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41
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Takenaka R, Aoi Y, Ozaki N, Ohashi A, Kindaichi T. Specificities and Efficiencies of Primers Targeting Candidatus Phylum Saccharibacteria in Activated Sludge. MATERIALS 2018; 11:ma11071129. [PMID: 29970836 PMCID: PMC6073563 DOI: 10.3390/ma11071129] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/28/2018] [Accepted: 07/02/2018] [Indexed: 11/16/2022]
Abstract
Candidatus Saccharibacteria is a well-described candidate phylum that has not been successfully isolated. Nevertheless, its presence was suggested by 16S rRNA gene sequencing data, and it is frequently detected in natural environments and activated sludge. Because pure culture representatives of Candidatus Saccharibacteria are lacking, the specificity of primers for the determination of their abundance and diversity should be carefully evaluated. In this study, eight Candidatus Saccharibacteria-specific primers were selected from previous studies and evaluated for their coverage against a public database, annealing temperature of the combined primer sets, as well as their utilization to determine the detection frequencies and phylogenetic diversity by cloning analysis, and in quantification by quantitative polymerase chain reaction (PCR). Among the eight primers, four primers (TM7314F, TM7580F, TM7-910R, and TM7-1177R) showed high coverage. Cloning analysis showed that four primer sets (TM7314F and TM7-910R, TM7314F and TM7-1177R, TM7580F and TM7-910R, and TM7580F and TM7-1177R) yielded high detection frequencies for Candidatus Saccharibacteria in activated sludge from a wastewater treatment plant in Higashihiroshima City, Japan. Quantitative PCR results indicated that the primer set containing TM7314F and TM7-910R was superior for the specific detection of Candidatus Saccharibacteria in activated sludge.
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Affiliation(s)
- Ryota Takenaka
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima 739-8527, Japan.
| | - Yoshiteru Aoi
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8530, Japan.
| | - Noriatsu Ozaki
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima 739-8527, Japan.
| | - Akiyoshi Ohashi
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima 739-8527, Japan.
| | - Tomonori Kindaichi
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima 739-8527, Japan.
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42
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Starr EP, Shi S, Blazewicz SJ, Probst AJ, Herman DJ, Firestone MK, Banfield JF. Stable isotope informed genome-resolved metagenomics reveals that Saccharibacteria utilize microbially-processed plant-derived carbon. MICROBIOME 2018; 6:122. [PMID: 29970182 PMCID: PMC6031116 DOI: 10.1186/s40168-018-0499-z] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 06/11/2018] [Indexed: 05/18/2023]
Abstract
BACKGROUND The transformation of plant photosynthate into soil organic carbon and its recycling to CO2 by soil microorganisms is one of the central components of the terrestrial carbon cycle. There are currently large knowledge gaps related to which soil-associated microorganisms take up plant carbon in the rhizosphere and the fate of that carbon. RESULTS We conducted an experiment in which common wild oats (Avena fatua) were grown in a 13CO2 atmosphere and the rhizosphere and non-rhizosphere soil was sampled for genomic analyses. Density gradient centrifugation of DNA extracted from soil samples enabled distinction of microbes that did and did not incorporate the 13C into their DNA. A 1.45-Mbp genome of a Saccharibacteria (TM7) was identified and, despite the microbial complexity of rhizosphere soil, curated to completion. The genome lacks many biosynthetic pathways, including genes required to synthesize DNA de novo. Rather, it requires externally derived nucleotides for DNA and RNA synthesis. Given this, we conclude that rhizosphere-associated Saccharibacteria recycle DNA from bacteria that live off plant exudates and/or phage that acquired 13C because they preyed upon these bacteria and/or directly from the labeled plant DNA. Isotopic labeling indicates that the population was replicating during the 6-week period of plant growth. Interestingly, the genome is ~ 30% larger than other complete Saccharibacteria genomes from non-soil environments, largely due to more genes for complex carbon utilization and amino acid metabolism. Given the ability to degrade cellulose, hemicellulose, pectin, starch, and 1,3-β-glucan, we predict that this Saccharibacteria generates energy by fermentation of soil necromass and plant root exudates to acetate and lactate. The genome also encodes a linear electron transport chain featuring a terminal oxidase, suggesting that this Saccharibacteria may respire aerobically. The genome encodes a hydrolase that could breakdown salicylic acid, a plant defense signaling molecule, and genes to interconvert a variety of isoprenoids, including the plant hormone zeatin. CONCLUSIONS Rhizosphere Saccharibacteria likely depend on other bacteria for basic cellular building blocks. We propose that isotopically labeled CO2 is incorporated into plant-derived carbon and then into the DNA of rhizosphere organisms capable of nucleotide synthesis, and the nucleotides are recycled into Saccharibacterial genomes.
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Affiliation(s)
- Evan P. Starr
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
| | - Shengjing Shi
- Lincoln Science Centre, AgResearch Ltd, Christchurch, 8140 New Zealand
| | - Steven J. Blazewicz
- Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, 94550 USA
| | | | - Donald J. Herman
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720 USA
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94704 USA
| | - Mary K. Firestone
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720 USA
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94704 USA
| | - Jillian F. Banfield
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720 USA
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94704 USA
- Department of Earth and Planetary Science, University of California Berkeley, Berkeley, CA 94720 USA
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43
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Villmones HC, Haug ES, Ulvestad E, Grude N, Stenstad T, Halland A, Kommedal Ø. Species Level Description of the Human Ileal Bacterial Microbiota. Sci Rep 2018; 8:4736. [PMID: 29549283 PMCID: PMC5856834 DOI: 10.1038/s41598-018-23198-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 03/06/2018] [Indexed: 02/07/2023] Open
Abstract
The small bowel is responsible for most of the body’s nutritional uptake and for the development of intestinal and systemic tolerance towards microbes. Nevertheless, the human small bowel microbiota has remained poorly characterized, mainly owing to sampling difficulties. Sample collection directly from the distal ileum was performed during radical cystectomy with urinary diversion. Material from the ileal mucosa were analysed using massive parallel sequencing of the 16S rRNA gene. Samples from 27 Caucasian patients were included. In total 280 unique Operational Taxonomic Units were identified, whereof 229 could be assigned to a species or a species group. The most frequently detected bacteria belonged to the genera Streptococcus, Granulicatella, Actinomyces, Solobacterium, Rothia, Gemella and TM7(G-1). Among these, the most abundant species were typically streptococci within the mitis and sanguinis groups, Streptococcus salivarius, Rothia mucilaginosa and Actinomyces from the A. meyeri/odontolyticus group. The amounts of Proteobacteria and strict anaerobes were low. The microbiota of the distal part of the human ileum is oral-like and strikingly different from the colonic microbiota. Although our patient population is elderly and hospitalized with a high prevalence of chronic conditions, our results provide new and valuable insights into a lesser explored part of the human intestinal ecosystem.
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Affiliation(s)
| | | | - Elling Ulvestad
- Department of Microbiology, Haukeland University Hospital, 5021, Bergen, Norway.,Department of Clinical Science, University of Bergen, 5021, Bergen, Norway
| | - Nils Grude
- Department of Microbiology, Vestfold Hospital Trust, 3103, Tønsberg, Norway
| | - Tore Stenstad
- Department of Infectious Medicine, Vestfold Hospital Trust, 3103, Tønsberg, Norway
| | - Adrian Halland
- Department of Urology, Vestfold Hospital Trust, 3103, Tønsberg, Norway
| | - Øyvind Kommedal
- Department of Microbiology, Haukeland University Hospital, 5021, Bergen, Norway
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44
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Cheng C, Zhou Z, Niu T, An Y, Shen X, Pan W, Chen Z, Liu J. Effects of side-stream ratio on sludge reduction and microbial structures of anaerobic side-stream reactor coupled membrane bioreactors. BIORESOURCE TECHNOLOGY 2017; 234:380-388. [PMID: 28343057 DOI: 10.1016/j.biortech.2017.03.077] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 03/09/2017] [Accepted: 03/11/2017] [Indexed: 06/06/2023]
Abstract
An anoxic/oxic membrane bioreactor (AO-MBR) and three anaerobic side-stream reactor (ASSR) coupled MBRs (ASSR-MBR) were operated to investigate effects of side-stream ratio (SR) on sludge reduction and microbial community structure of ASSR-MBRs. The ASSR-MBR achieved efficient COD and ammonium nitrogen removal. SR increased from 0.2 to 1.0 favored nitrogen removal, and increased sludge reduction from 6.0% to 49.7%. The total released COD in the ASSR increased with the rising SR and was inversely proportional to sludge yield of ASSR-MBR. Pyrosequencing analysis showed that phyla Chloroflexi and Armatimonadetes surviving in anaerobic conditions were enriched in the ASSR, while Nitrospirae was dominant in the MBR. Comparison at the genus level revealed that higher SR favored the growth of slow growers, while lower SR enriched hydrolytic and predatory bacteria. The results suggested that SR has a profound effect on nitrogen removal, sludge reduction and microbial community structure in the ASSR-MBR.
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Affiliation(s)
- Cheng Cheng
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Zhen Zhou
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China.
| | - Tianhao Niu
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Ying An
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Xuelian Shen
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Wei Pan
- Shanghai Municipal Sewerage Co., Ltd, Shanghai 200233, China
| | - Zhihui Chen
- Shanghai Municipal Sewerage Co., Ltd, Shanghai 200233, China
| | - Jin Liu
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
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Kantor RS, Huddy RJ, Iyer R, Thomas BC, Brown CT, Anantharaman K, Tringe S, Hettich RL, Harrison STL, Banfield JF. Genome-Resolved Meta-Omics Ties Microbial Dynamics to Process Performance in Biotechnology for Thiocyanate Degradation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:2944-2953. [PMID: 28139919 DOI: 10.1021/acs.est.6b04477] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Remediation of industrial wastewater is important for preventing environmental contamination and enabling water reuse. Biological treatment for one industrial contaminant, thiocyanate (SCN-), relies upon microbial hydrolysis, but this process is sensitive to high loadings. To examine the activity and stability of a microbial community over increasing SCN- loadings, we established and operated a continuous-flow bioreactor fed increasing loadings of SCN-. A second reactor was fed ammonium sulfate to mimic breakdown products of SCN-. Biomass was sampled from both reactors for metagenomics and metaproteomics, yielding a set of genomes for 144 bacteria and one rotifer that constituted the abundant community in both reactors. We analyzed the metabolic potential and temporal dynamics of these organisms across the increasing loadings. In the SCN- reactor, Thiobacillus strains capable of SCN- degradation were highly abundant, whereas the ammonium sulfate reactor contained nitrifiers and heterotrophs capable of nitrate reduction. Key organisms in the SCN- reactor expressed proteins involved in SCN- degradation, sulfur oxidation, carbon fixation, and nitrogen removal. Lower performance at higher loadings was linked to changes in microbial community composition. This work provides an example of how meta-omics can increase our understanding of industrial wastewater treatment and inform iterative process design and development.
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Affiliation(s)
- Rose S Kantor
- Department of Plant and Microbial Biology, University of California , Berkeley, California 94720, United States
| | - Robert J Huddy
- Centre for Bioprocess Engineering Research, Department of Chemical Engineering, University of Cape Town , Rondebosch, 7701, South Africa
| | - Ramsunder Iyer
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Graduate School of Genome Science and Technology, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Brian C Thomas
- Department of Earth and Planetary Sciences, University of California , Berkeley, California 94720, United States
| | - Christopher T Brown
- Department of Plant and Microbial Biology, University of California , Berkeley, California 94720, United States
| | - Karthik Anantharaman
- Department of Earth and Planetary Sciences, University of California , Berkeley, California 94720, United States
| | - Susannah Tringe
- Joint Genome Institute , Walnut Creek, California 94598, United States
| | - Robert L Hettich
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Susan T L Harrison
- Centre for Bioprocess Engineering Research, Department of Chemical Engineering, University of Cape Town , Rondebosch, 7701, South Africa
| | - Jillian F Banfield
- Department of Earth and Planetary Sciences, University of California , Berkeley, California 94720, United States
- Department of Environmental Science, Policy, and Management, University of California , Berkeley, California 94720, United States
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Ecology of the Oral Microbiome: Beyond Bacteria. Trends Microbiol 2017; 25:362-374. [PMID: 28089325 DOI: 10.1016/j.tim.2016.12.012] [Citation(s) in RCA: 182] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 12/13/2016] [Accepted: 12/16/2016] [Indexed: 01/08/2023]
Abstract
Although great strides have been made in understanding the complex bacterial community inhabiting the human oral cavity, for a variety of (mainly technical) reasons the ecological contributions of oral fungi, viruses, phages, and the candidate phyla radiation (CPR) group of ultrasmall bacteria have remained understudied. Several recent reports have illustrated the diversity and importance of these organisms in the oral cavity, while TM7x and Candida albicans have served as crucial paradigms for CPR species and oral fungi, respectively. A comprehensive understanding of the oral microbiota and its influence on host health and disease will require a holistic view that emphasizes interactions among different residents within the oral community, as well as their interaction with the host.
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Abstract
BACKGROUND The majority of environmental bacteria and around a third of oral bacteria remain uncultivated. Furthermore, several bacterial phyla have no cultivable members and are recognised only by detection of their DNA by molecular methods. Possible explanations for the resistance of certain bacteria to cultivation in purity in vitro include: unmet fastidious growth requirements; inhibition by environmental conditions or chemical factors produced by neighbouring bacteria in mixed cultures; or conversely, dependence on interactions with other bacteria in the natural environment, without which they cannot survive in isolation. Auxotrophic bacteria, with small genomes lacking in the necessary genetic material to encode for essential nutrients, frequently rely on close symbiotic relationships with other bacteria for survival, and may therefore be recalcitrant to cultivation in purity. HIGHLIGHT Since in-vitro culture is essential for the comprehensive characterisation of bacteria, particularly with regard to virulence and antimicrobial resistance, the cultivation of uncultivated organisms has been a primary focus of several research laboratories. Many targeted and open-ended strategies have been devised and successfully used. Examples include: the targeted detection of specific bacteria in mixed plate cultures using colony hybridisation; growth in simulated natural environments or in co-culture with 'helper' strains; and modified media preparation techniques or development of customised media eg. supplementation of media with potential growth-stimulatory factors such as siderophores. CONCLUSION Despite significant advances in recent years in methodologies for the cultivation of previously uncultivated bacteria, a substantial proportion remain to be cultured and efforts to devise high-throughput strategies should be a high priority.
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Affiliation(s)
- Sonia R Vartoukian
- Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK
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Draft Genome Sequence of Actinomyces odontolyticus subsp. actinosynbacter Strain XH001, the Basibiont of an Oral TM7 Epibiont. GENOME ANNOUNCEMENTS 2016; 4:4/1/e01685-15. [PMID: 26847892 PMCID: PMC4742689 DOI: 10.1128/genomea.01685-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Here, we present the draft genome sequence of Actinomyces odontolyticus subsp. actinosynbacter strain XH001, isolated from the human oral cavity. Uniquely, it was discovered as a host bacterium to the ultrasmall epibiont TM7x, which is the first cultivated member of “Candidatus Saccharibacteria” (formerly candidate phylum TM7).
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