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Crowley C, Selvaraj A, Hariharan A, Healy CM, Moran GP. Fusobacterium nucleatum subsp. polymorphum recovered from malignant and potentially malignant oral disease exhibit heterogeneity in adhesion phenotypes and adhesin gene copy number, shaped by inter-subspecies horizontal gene transfer and recombination-derived mosaicism. Microb Genom 2024; 10:001217. [PMID: 38529905 PMCID: PMC10995627 DOI: 10.1099/mgen.0.001217] [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: 01/05/2024] [Accepted: 02/29/2024] [Indexed: 03/27/2024] Open
Abstract
Fusobacterium nucleatum is an anaerobic commensal of the oral cavity associated with periodontitis and extra-oral diseases, including colorectal cancer. Previous studies have shown an increased relative abundance of this bacterium associated with oral dysplasia or within oral tumours. Using direct culture, we found that 75 % of Fusobacterium species isolated from malignant or potentially malignant oral mucosa were F. nucleatum subsp. polymorphum. Whole genome sequencing and pangenome analysis with Panaroo was carried out on 76 F. nucleatum subsp. polymorphum genomes. F. nucleatum subsp. polymorphum was shown to possesses a relatively small core genome of 1604 genes in a pangenome of 7363 genes. Phylogenetic analysis based on the core genome shows the isolates can be separated into three main clades with no obvious genotypic associations with disease. Isolates recovered from healthy and diseased sites in the same patient are generally highly related. A large repertoire of adhesins belonging to the type V secretion system (TVSS) could be identified with major variation in repertoire and copy number between strains. Analysis of intergenic recombination using fastGEAR showed that adhesin complement is shaped by horizontal gene transfer and recombination. Recombination events at TVSS adhesin genes were not only common between lineages of subspecies polymorphum, but also between different subspecies of F. nucleatum. Strains of subspecies polymorphum with low copy numbers of TVSS adhesin encoding genes tended to have the weakest adhesion to oral keratinocytes. This study highlights the genetic heterogeneity of F. nucleatum subsp. polymorphum and provides a new framework for defining virulence in this organism.
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Affiliation(s)
- Claire Crowley
- Division of Oral Biosciences, Dublin Dental University Hospital and School of Dental Science, Trinity College Dublin, Dublin, Ireland
| | - Ajith Selvaraj
- Division of Oral Biosciences, Dublin Dental University Hospital and School of Dental Science, Trinity College Dublin, Dublin, Ireland
| | - Arvind Hariharan
- Division of Oral Biosciences, Dublin Dental University Hospital and School of Dental Science, Trinity College Dublin, Dublin, Ireland
| | - Claire M. Healy
- Division of Oral and Maxillofacial Surgery, Oral Medicine and Oral Pathology, Dublin Dental University Hospital and School of Dental Science, Trinity College Dublin, Dublin, Ireland
| | - Gary P. Moran
- Division of Oral Biosciences, Dublin Dental University Hospital and School of Dental Science, Trinity College Dublin, Dublin, Ireland
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Abstract
The importance of the microbiota in the development of colorectal cancer (CRC) is increasingly evident, but identifying specific microbial features that influence CRC initiation and progression remains a central task for investigators. Studies determining the microbial mechanisms that directly contribute to CRC development or progression are revealing bacterial factors such as toxins that contribute to colorectal carcinogenesis. However, even when investigators have identified bacteria that express toxins, questions remain about the host determinants of a toxin's cancer-potentiating effects. For other cancer-correlating bacteria that lack toxins, the challenge is to define cancer-relevant virulence factors. Herein, we evaluate three CRC-correlating bacteria, colibactin-producing Escherichia coli, enterotoxigenic Bacteroides fragilis, and Fusobacterium nucleatum, for their virulence features relevant to CRC. We also consider the beneficial bioactivity of gut microbes by highlighting a microbial metabolite that may enhance CRC antitumor immunity. In doing so, we aim to elucidate unique and shared mechanisms underlying the microbiota's contributions to CRC and to accelerate investigation from target validation to CRC therapeutic discovery.
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Affiliation(s)
- Slater L. Clay
- Department of Immunology and Infectious Diseases and Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
- Harvard T.H. Chan Microbiome in Public Health Center, Boston, Massachusetts, USA
| | - Diogo Fonseca-Pereira
- Department of Immunology and Infectious Diseases and Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
- Harvard T.H. Chan Microbiome in Public Health Center, Boston, Massachusetts, USA
| | - Wendy S. Garrett
- Department of Immunology and Infectious Diseases and Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
- Harvard T.H. Chan Microbiome in Public Health Center, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
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Chu S, Cheng Z, Yin Z, Xu J, Wu F, Jin Y, Yang G. Airway Fusobacterium is Associated with Poor Response to Immunotherapy in Lung Cancer. Onco Targets Ther 2022; 15:201-213. [PMID: 35250279 PMCID: PMC8896836 DOI: 10.2147/ott.s348382] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/15/2022] [Indexed: 12/11/2022] Open
Abstract
Purpose There is a major limitation in the immunotherapy for solid cancer is that it only benefited a minority of cancer patients. This study aims to investigate whether the differential composition of the lung microbiome could affect the sustained clinical responses in lung cancers treated with immunotherapy. Methods Twenty-seven non-responders and 19 responders treated with anti-PD-1 therapy were included in the discovery set. Bacterial load in bronchoalveolar lavage from lung cancer patients was examined by quantitative PCR of 16S rRNA copies. Bacterial 16S rDNA was sequenced using the Illumina HiSeq on the 16S rDNA V3-V4 variable region. Operational taxonomic unit (OTU) analysis was performed using VSEARCH v2. The α-diversity and β-diversity were calculated using QIIME software. Results The mean copy number of bacterial 16S DNA levels significantly decreased after anti-PD-1 treatment (after: 1.8 ± 0.6×104 copies per milliliter vs prior to treatment: 3.3 ± 1.1x104, p = 0.0036). In addition, longitudinal analysis revealed that microbial diversity was reduced taxonomically after treatment compared to those prior to the treatment (Shannon values: before: 3.291 ± 0.067 vs after: 2.668 ± 0.168, p < 0.01). Further, we observed a reduction of Fusobacterium nucleatum, including phylum Fusobacteria (p < 0.01), class Fusobacteria (p < 0.01), order Fusobacteria (p < 0.01), family Fusobacteria (p < 0.01), genus Fusobacteria (p = 0.025) in the responders post anti-PD-1 treatment. However, there was no significant difference of Fusobacterium in non-responders. An independent cohort was used to validate the levels of Fusobacterium, demonstrating that patients with higher abundance of Fusobacterium prior to treatment were significantly more likely to have poor response to anti-PD-1 therapy (p < 0.001). Conclusion Airway enriched Fusobacterium prior to anti-PD-1 therapy is associated with poor response in lung cancer, which indicated that potential resistance to immunotherapy can be attributed to lung microbiome.
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Affiliation(s)
- Shujuan Chu
- Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China
| | - Zaixing Cheng
- Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China
| | - Zhongyuan Yin
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China
| | - Juanjuan Xu
- Department of Respiratory Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China
| | - Feng Wu
- Department of Respiratory Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China
| | - Yang Jin
- Department of Respiratory Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China
| | - Guanghai Yang
- Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China
- Correspondence: Guanghai Yang, Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China, Tel +86 27 85351615, Email
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Ponath F, Tawk C, Zhu Y, Barquist L, Faber F, Vogel J. RNA landscape of the emerging cancer-associated microbe Fusobacterium nucleatum. Nat Microbiol 2021; 6:1007-1020. [PMID: 34239075 DOI: 10.1038/s41564-021-00927-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 05/24/2021] [Indexed: 12/14/2022]
Abstract
Fusobacterium nucleatum, long known as a constituent of the oral microflora, has recently garnered renewed attention for its association with several different human cancers. The growing interest in this emerging cancer-associated bacterium contrasts with a paucity of knowledge about its basic gene expression features and physiological responses. As fusobacteria lack all established small RNA-associated proteins, post-transcriptional networks in these bacteria are also unknown. In the present study, using differential RNA-sequencing, we generate high-resolution global RNA maps for five clinically relevant fusobacterial strains-F. nucleatum subspecies nucleatum, animalis, polymorphum and vincentii, as well as F. periodonticum-for early, mid-exponential growth and early stationary phase. These data are made available in an online browser, and we use these to uncover fundamental aspects of fusobacterial gene expression architecture and a suite of non-coding RNAs. Developing a vector for functional analysis of fusobacterial genes, we discover a conserved fusobacterial oxygen-induced small RNA, FoxI, which serves as a post-transcriptional repressor of the major outer membrane porin FomA. Our findings provide a crucial step towards delineating the regulatory networks enabling F. nucleatum adaptation to different environments, which may elucidate how these bacteria colonize different compartments of the human body.
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Affiliation(s)
- Falk Ponath
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, Würzburg, Germany
| | - Caroline Tawk
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Yan Zhu
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, Würzburg, Germany.,Faculty of Medicine, University of Würzburg, Würzburg, Germany
| | - Franziska Faber
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Jörg Vogel
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, Würzburg, Germany. .,Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany. .,Faculty of Medicine, University of Würzburg, Würzburg, Germany.
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Brennan CA, Garrett WS. Fusobacterium nucleatum - symbiont, opportunist and oncobacterium. Nat Rev Microbiol 2020; 17:156-166. [PMID: 30546113 DOI: 10.1038/s41579-018-0129-6] [Citation(s) in RCA: 565] [Impact Index Per Article: 141.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Fusobacterium nucleatum has long been found to cause opportunistic infections and has recently been implicated in colorectal cancer; however, it is a common member of the oral microbiota and can have a symbiotic relationship with its hosts. To address this dissonance, we explore the diversity and niches of fusobacteria and reconsider historic fusobacterial taxonomy in the context of current technology. We also undertake a critical reappraisal of fusobacteria with a focus on F. nucleatum as a mutualist, infectious agent and oncogenic microorganism. In this Review, we delve into recent insights and future directions for fusobacterial research, including the current genetic toolkit, our evolving understanding of its mechanistic role in promoting colorectal cancer and the challenges of developing diagnostics and therapeutics for F. nucleatum.
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Affiliation(s)
| | - Wendy S Garrett
- Harvard T. H. Chan School of Public Health, Boston, MA, USA.
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Utilizing Whole Fusobacterium Genomes To Identify, Correct, and Characterize Potential Virulence Protein Families. J Bacteriol 2019; 201:JB.00273-19. [PMID: 31501282 DOI: 10.1128/jb.00273-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 09/03/2019] [Indexed: 12/20/2022] Open
Abstract
Fusobacterium spp. are Gram-negative, anaerobic, opportunistic pathogens involved in multiple diseases, including a link between the oral pathogen Fusobacterium nucleatum and the progression and severity of colorectal cancer. The identification and characterization of virulence factors in the genus Fusobacterium has been greatly hindered by a lack of properly assembled and annotated genomes. Using newly completed genomes from nine strains and seven species of Fusobacterium, we report the identification and corrected annotation of verified and potential virulence factors from the type 5 secreted autotransporter, FadA, and MORN2 protein families, with a focus on the genetically tractable strain F. nucleatum subsp. nucleatum ATCC 23726 and type strain F. nucleatum subsp. nucleatum ATCC 25586. Within the autotransporters, we used sequence similarity networks to identify protein subsets and show a clear differentiation between the prediction of outer membrane adhesins, serine proteases, and proteins with unknown function. These data have identified unique subsets of type 5a autotransporters, which are key proteins associated with virulence in F. nucleatum However, we coupled our bioinformatic data with bacterial binding assays to show that a predicted weakly invasive strain of F. necrophorum that lacks a Fap2 autotransporter adhesin strongly binds human colonocytes. These analyses confirm a gap in our understanding of how autotransporters, MORN2 domain proteins, and FadA adhesins contribute to host interactions and invasion. In summary, we identify candidate virulence genes in Fusobacterium, and caution that experimental validation of host-microbe interactions should complement bioinformatic predictions to increase our understanding of virulence protein contributions in Fusobacterium infections and disease.IMPORTANCE Fusobacterium spp. are emerging pathogens that contribute to mammalian and human diseases, including colorectal cancer. Despite a validated connection with disease, few proteins have been characterized that define a direct molecular mechanism for Fusobacterium pathogenesis. We report a comprehensive examination of virulence-associated protein families in multiple Fusobacterium species and show that complete genomes facilitate the correction and identification of multiple, large type 5a secreted autotransporter genes in previously misannotated or fragmented genomes. In addition, we use protein sequence similarity networks and human cell interaction experiments to show that previously predicted noninvasive strains can indeed bind to and potentially invade human cells and that this could be due to the expansion of specific virulence proteins that drive Fusobacterium infections and disease.
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Complete Genome Sequence of Fusobacterium necrophorum subsp. necrophorum ATCC 25286. Microbiol Resour Announc 2019; 8:MRA00025-19. [PMID: 30834361 PMCID: PMC6386562 DOI: 10.1128/mra.00025-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 01/25/2019] [Indexed: 01/30/2023] Open
Abstract
Fusobacterium necrophorum is a pathogenic Gram-negative, anaerobic bacterium. In this study, we present the first complete genome sequence of Fusobacterium necrophorum subsp. Fusobacterium necrophorum is a pathogenic Gram-negative, anaerobic bacterium. In this study, we present the first complete genome sequence of Fusobacterium necrophorum subsp. necrophorum ATCC 25286. These data provide a critical advancement in our understanding of virulence factors that could contribute to F. necrophorum pathogenesis in both human and livestock infections.
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Abstract
Fusobacterium spp. are Gram-negative, oral bacteria that are increasingly associated with human pathologies as diverse as periodontitis, preterm birth, and colorectal cancer. While a recent surge in F. nucleatum research has increased our understanding of this human pathogen, a lack of complete genomes has hindered the identification and characterization of associated host-pathogen virulence factors. Here we report the first eight complete Fusobacterium genomes sequenced using an Oxford Nanopore MinION and Illumina sequencing pipeline and assembled using the open-source program Unicycler. These genomes are highly accurate, and seven of the genomes represent the first complete sequences for each strain. In summary, the FusoPortal resource provides a publicly available resource that will guide future genetic, bioinformatic, and biochemical experiments to characterize this genus of emerging human pathogens. Understanding the virulence mechanisms of human pathogens from the genus Fusobacterium has been hindered by a lack of properly assembled and annotated genomes. Here we report the first complete genomes for seven Fusobacterium strains, as well as resequencing of the reference strain Fusobacterium nucleatum subsp. nucleatum ATCC 25586 (total of seven species; total of eight genomes). A highly efficient and cost-effective sequencing pipeline was achieved using sample multiplexing for short-read Illumina (150 bp) and long-read Oxford Nanopore MinION (>80 kbp) platforms, coupled with genome assembly using the open-source software Unicycler. Compared to currently available draft assemblies (previously 24 to 67 contigs), these genomes are highly accurate and consist of only one complete chromosome. We present the complete genome sequence of F. nucleatum subsp. nucleatum ATCC 23726, a genetically tractable and biomedically important strain and, in addition, reveal that the previous F. nucleatum subsp. nucleatum ATCC 25586 genome assembly contains a 452-kb genomic inversion that has been corrected using our sequencing and assembly pipeline. To enable genomic analyses by the scientific community, we concurrently used these genomes to launch FusoPortal, a repository of interactive and downloadable genomic data, genome maps, gene annotations, and protein functional analyses and classifications. In summary, this report provides detailed methods for accurately sequencing, assembling, and annotating Fusobacterium genomes, while focusing on using open-source software to foster the availability of reproducible and open data. This resource will enhance efforts to properly identify virulence proteins that may contribute to a repertoire of diseases that includes periodontitis, preterm birth, and colorectal cancer. IMPORTANCEFusobacterium spp. are Gram-negative, oral bacteria that are increasingly associated with human pathologies as diverse as periodontitis, preterm birth, and colorectal cancer. While a recent surge in F. nucleatum research has increased our understanding of this human pathogen, a lack of complete genomes has hindered the identification and characterization of associated host-pathogen virulence factors. Here we report the first eight complete Fusobacterium genomes sequenced using an Oxford Nanopore MinION and Illumina sequencing pipeline and assembled using the open-source program Unicycler. These genomes are highly accurate, and seven of the genomes represent the first complete sequences for each strain. In summary, the FusoPortal resource provides a publicly available resource that will guide future genetic, bioinformatic, and biochemical experiments to characterize this genus of emerging human pathogens.
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