scholarly journals Metabolic and Community Synergy of Oral Bacteria in Colorectal Cancer

mSphere ◽  
2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Kaitlin J. Flynn ◽  
Nielson T. Baxter ◽  
Patrick D. Schloss
Keyword(s):  
Colorectal Cancer ◽  
Fusobacterium Nucleatum ◽  
Oral Bacteria ◽  
Oral Microbiota ◽  
Community Members ◽  
Content Type ◽  
Bacterial Physiology ◽  
Oral Biofilms ◽  
Two Factors

ABSTRACT The oral periodontopathic bacterium Fusobacterium nucleatum has been repeatedly associated with colorectal tumors. Molecular analysis has identified specific virulence factors that promote tumorigenesis in the colon. However, other oral community members, such as members of the Porphyromonas spp., are also found with F. nucleatum on colonic tumors, and thus, narrow studies of individual pathogens do not take community-wide virulence properties into account. A broader view of oral bacterial physiology and pathogenesis identifies two factors that could promote colonization and persistence of oral bacterial communities in the colon. The polymicrobial nature of oral biofilms and the asaccharolytic metabolism of many of these species make them well suited to life in the microenvironment of colonic lesions. Consideration of these two factors offers a novel perspective on the role of oral microbiota in the initiation, development, and treatment of colorectal cancer.

scholarly journals Role of Oral Microbiota in Cancer Development

2019 ◽  
Vol 7 (1) ◽  
pp. 20 ◽  
Author(s):  
Tomasz Karpiński
Keyword(s):  
Cell Proliferation ◽  
Porphyromonas Gingivalis ◽  
Fusobacterium Nucleatum ◽  
Oral Bacteria ◽  
Cancer Development ◽  
Oral Microbiota ◽  
Cellular Apoptosis ◽  
Bacterial Stimulation ◽  
Specific Species

Nowadays cancer is the second main cause of death in the world. The most known bacterial carcinogen is Helicobacter pylori. Pathogens that can have an impact on cancer development in the gastrointestinal tract are also found in the oral cavity. Some specific species have been identified that correlate strongly with oral cancer, such as Streptococcus sp., Peptostreptococcus sp., Prevotella sp., Fusobacterium sp., Porphyromonas gingivalis, and Capnocytophaga gingivalis. Many works have also shown that the oral periopathogens Fusobacterium nucleatum and Porphyromonas gingivalis play an important role in the development of colorectal and pancreatic cancer. Three mechanisms of action have been suggested in regard to the role of oral microbiota in the pathogenesis of cancer. The first is bacterial stimulation of chronic inflammation. Inflammatory mediators produced in this process cause or facilitate cell proliferation, mutagenesis, oncogene activation, and angiogenesis. The second mechanism attributed to bacteria that may influence the pathogenesis of cancers by affecting cell proliferation is the activation of NF-κB and inhibition of cellular apoptosis. In the third mechanism, bacteria produce some substances that act in a carcinogenic manner. This review presents potentially oncogenic oral bacteria and possible mechanisms of their action on the carcinogenesis of human cells.

Fretibacterium fastidiosum gen. nov., sp. nov., isolated from the human oral cavity

2013 ◽  
Vol 63 (Pt_2) ◽  
pp. 458-463 ◽  
Author(s):  
Sonia R. Vartoukian ◽  
Julia Downes ◽  
Richard M. Palmer ◽  
William G. Wade
Keyword(s):  
New Genus ◽  
Novel Species ◽  
Fusobacterium Nucleatum ◽  
Oral Bacteria ◽  
Rrna Gene ◽  
Good Growth ◽  
Content Type ◽  
Cellular Fatty Acids ◽  
Link Type ◽  
Peptone Yeast Extract Glucose

SGP1T, a strain belonging to a lineage of the phylum Synergistetes with no previously cultivated representatives was subjected to a comprehensive range of phenotypic and genotypic tests. For good growth the strain was dependent on co-culture with, or extracts from, selected other oral bacteria. Cells of strain SGP1T were asaccharolytic and major amounts of acetic acid and moderate amounts of propionic acid were produced as end products of metabolism in peptone-yeast extract-glucose broth supplemented with a filtered cell sonicate of Fusobacterium nucleatum subsp. nucleatum ATCC 25586T (25 %, v/v). Hydrogen sulphide was produced and gelatin was weakly hydrolysed. The major cellular fatty acids were C14 : 0, C18 : 0 and C16 : 0. The DNA G+C content of strain SGP1T was 63 mol%. Phylogenetic analysis of the full-length 16S rRNA gene showed that strain SGP1T represented a novel group within the phylum Synergistetes . A novel species in a new genus, Fretibacterium fastidiosum gen. nov., sp. nov., is proposed. The type strain of Fretibacterium fastidiosum is SGP1T ( = DSM 25557T = JCM 16858T).

scholarly journals The role of Fusobacterium nucleatum in colorectal cancer: from carcinogenesis to clinical management

2019 ◽  
Vol 5 (3) ◽  
pp. 178-187 ◽  
Author(s):  
Chun-Hui Sun ◽  
Bin-Bin Li ◽  
Bo Wang ◽  
Jing Zhao ◽  
Xiao-Ying Zhang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Clinical Management ◽  
Fusobacterium Nucleatum

scholarly journals Protein Tyrosine and Serine/Threonine Phosphorylation in Oral Bacterial Dysbiosis and Bacteria-Host Interaction

2022 ◽  
Vol 11 ◽  
Author(s):  
Liang Ren ◽  
Daonan Shen ◽  
Chengcheng Liu ◽  
Yi Ding
Keyword(s):  
Community Development ◽  
Oral Bacteria ◽  
Bacterial Metabolism ◽  
Oral Microbiota ◽  
Bacterial Protein ◽  
Oral Diseases ◽  
Host Interactions ◽  
Host Interaction ◽  
Systemic Health

The human oral cavity harbors approximately 1,000 microbial species, and dysbiosis of the microflora and imbalanced microbiota-host interactions drive many oral diseases, such as dental caries and periodontal disease. Oral microbiota homeostasis is critical for systemic health. Over the last two decades, bacterial protein phosphorylation systems have been extensively studied, providing mounting evidence of the pivotal role of tyrosine and serine/threonine phosphorylation in oral bacterial dysbiosis and bacteria-host interactions. Ongoing investigations aim to discover novel kinases and phosphatases and to understand the mechanism by which these phosphorylation events regulate the pathogenicity of oral bacteria. Here, we summarize the structures of bacterial tyrosine and serine/threonine kinases and phosphatases and discuss the roles of tyrosine and serine/threonine phosphorylation systems in Porphyromonas gingivalis and Streptococcus mutans, emphasizing their involvement in bacterial metabolism and virulence, community development, and bacteria-host interactions.

EWOM firestorm: young consumers and online community

2019 ◽  
Vol 21 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Sasithorn Suwandee ◽  
Jiraporn Surachartkumtonkun ◽  
Aurathai Lertwannawit
Keyword(s):  
Social Media ◽  
Online Community ◽  
Community Members ◽  
Content Type ◽  
Service Failures ◽  
Young Consumers ◽  
Mixed Factorial Design ◽  
Information Characteristics ◽  
High Level

Purpose This study aims to examine the influence of homophily in an online community and the effect of electronic word of mouth (eWOM) consensus on young consumers’ attitudes. Design/methodology/approach This study implemented an experimental research design using a two (low/high homophily) × two (low/high eWOM consensus) mixed factorial design. This study explores young consumers’ changes in brand attitude after encountering negative eWOM. Findings The results indicate that a high consensus of negative eWOM among online community members leads to significant changes in attitude, while a low consensus of negative eWOM does not produce such an effect. Negative eWOM from either high or low homophilous sources produces significant changes in attitude. There are significant attitude changes when a strong consensus of negative eWOM is received from a source with a high level of homophily. Research limitations/implications Service failures in offline service settings lead to the dissemination of negative eWOM on social media. To handle and prevent social media crises, researchers should understand online crises antecedents relating to information characteristics i.e. eWOM consensus and characteristics of online community members to evaluate the crises impact. Brands should monitor tone and dialogue of online community member on social media to remedy and diminish any damage done to their brand image from negative eWOM. Originality/value This study contributes to the application of social network theory by understanding the role of nodes on negative eWOM effect in social media.

Culturally relevant constructionist design: exploring the role of community in identity development

2020 ◽  
Vol 121 (11/12) ◽  
pp. 847-867
Author(s):  
Sawaros Thanapornsangsuth ◽  
Nathan Holbert
Keyword(s):  
Identity Development ◽  
Low Income ◽  
Culturally Relevant ◽  
Performance Metrics ◽  
Community Members ◽  
Content Type ◽  
Maker Education ◽  
First Case ◽  
Cultural Connections

Purpose Many initiatives seek to engage children in maker education. However, there is a paucity of research examining children’s engagement in making in low-income formal school settings. Likewise, little work has been done to explore the transformative perspectives of both the children and the people around them. This study aims to explore a Culturally Relevant Constructionist Design framework that emphasizes making as a way of building connections to ones’ community. The participants’ shifting perspectives and receptivity in engaging in maker activities that involve making inventions for their community, inspired by the nation’s most beloved figure, King Bhumibol are evaluated. Design/methodology/approach This study investigates fourth-grade students, a teacher and community members around a public school in Thailand. Using qualitative research methods, data collection includes interviews, field notes observation, photos and videos of the sessions. This paper presents three case studies that represent the shifting perspectives and receptivity of teachers, community members and students through engaging in making experience. The first case illustrates the ways in which building for others supports the students’ formation of an identity of a creator. The two cases describe a teacher and a community member who developed new-found perceptions of students as valuable contributors to the community. Findings The findings highlight making inventions for the community as ways to connect teachers, community members and students together. The study also identifies key perceptions and experiences that empower students’ as contributors to their community. Through the process of making, the teacher and the community members also developed new-found positive perspectives of the students. Particularly, they viewed the students beyond traditional school performance metrics, and considered their other latent abilities. Practical implications This study discusses these findings in light of previous research on maker education especially in low-income communities. It also showcases the role of making for the betterment of the community as a tool for engendering change in schools and empowering students to design and make personally and socially meaningful projects. The study also highlights how design-based research carried out in the international context, particularly in Thai locality and classrooms. Originality/value This study argues against the deficit lens that assumes a low sense of expectation for what students from lower-income schools can do. Students hold unique worldviews that lead them to create innovations relevant to their local and cultural needs. The study addresses this gap by designing a framework that emphasizes making relevant cultural connections to students’ communities. The study also showcases maker-centered experiences that enable students to express their ideas, to cultivate relationships, to help others and to see themselves in new ways. The perspectives of the participants hold implications beyond the predominant focus of maker education initiatives.

Use of e-government services: the role of trust

2015 ◽  
Vol 10 (4) ◽  
pp. 622-633 ◽  
Author(s):  
Mercy Mpinganjira
Keyword(s):  
African Countries ◽  
Content Type ◽  
The Public ◽  
Government Services ◽  
Two Factors ◽  
Online Channel ◽  
Depth Interviews ◽  
Practical Implications ◽  
Structured Questionnaire

Purpose – The purpose of this paper is to investigate the role of trust in understanding usage of e-government services in South Africa. Of interest are services that involve two way interactions between citizens and government. Design/methodology/approach – Qualitative and quantitative data were collected from members of the public using in-depth interviews and a structured questionnaire, respectively. Findings – The findings show that trust in internet and in government as a provider of e-services are important factors that differentiates users and non-users of e-government services. The two factors are also significantly related to willingness to start using e-government services. Trust in e-service provider unlike trust in internet was however found to be a stronger differentiator of users and non-users and to have a stronger relationship with willingness to start using e-government services. Practical implications – Efforts aimed at promoting use of e-government services need to be based on a good understanding of factors that impact on citizens’ decisions in this regard. Such efforts need to include activities targeted at improving people’s trust in government’s ability to provide reliable and secure e-services. Originality/value – While provision of government services using the online channel is a growing phenomenon in most African countries, not much research has been done into what governments should focus on in order to entice more citizens to take up this channel. This study contributes to addressing this gap.

scholarly journals Central Role of the Early Colonizer Veillonella sp. in Establishing Multispecies Biofilm Communities with Initial, Middle, and Late Colonizers of Enamel

2010 ◽  
Vol 192 (12) ◽  
pp. 2965-2972 ◽  
Author(s):  
Saravanan Periasamy ◽  
Paul E. Kolenbrander
Keyword(s):  
Lactic Acid ◽  
Fluorescent Antibody ◽  
Fusobacterium Nucleatum ◽  
Single Species ◽  
Oral Bacteria ◽  
Flow Cells ◽  
Significant Growth ◽  
Dental Biofilm ◽  
Antibody Staining

ABSTRACT Human dental biofilm communities comprise several species, which can interact cooperatively or competitively. Bacterial interactions influence biofilm formation, metabolic changes, and physiological function of the community. Lactic acid, a common metabolite of oral bacteria, was measured in the flow cell effluent of one-, two- and three-species communities growing on saliva as the sole nutritional source. We investigated single-species and multispecies colonization by using known initial, early, middle, and late colonizers of enamel. Fluorescent-antibody staining and image analysis were used to quantify the biomass in saliva-fed flow cells. Of six species tested, only the initial colonizer Actinomyces oris exhibited significant growth. The initial colonizer Streptococcus oralis produced lactic acid but showed no significant growth. The early colonizer Veillonella sp. utilized lactic acid in two- and three-species biofilm communities. The biovolumes of all two-species biofilms increased when Veillonella sp. was present as one of the partners, indicating that this early colonizer promotes mutualistic community development. All three-species combinations exhibited enhanced growth except one, i.e., A. oris, Veillonella sp., and the middle colonizer Porphyromonas gingivalis, indicating specificity among three-species communities. Further specificity was seen when Fusobacterium nucleatum (a middle colonizer), Aggregatibacter actinomycetemcomitans (a late colonizer), and P. gingivalis did not grow with S. oralis in two-species biofilms, but inclusion of Veillonella sp. resulted in growth of all three-species combinations. We propose that commensal veillonellae use lactic acid for growth in saliva and that they communicate metabolically with initial, early, middle, and late colonizers to establish multispecies communities on enamel.

scholarly journals TGF-β1 Inhibits TLR-mediated Odontoblast Responses to Oral Bacteria

2009 ◽  
Vol 88 (4) ◽  
pp. 333-338 ◽  
Author(s):  
O.V. Horst ◽  
K.A. Tompkins ◽  
S.R. Coats ◽  
P.H. Braham ◽  
R.P. Darveau ◽  
...  
Keyword(s):  
Cell Surface ◽  
Tissue Repair ◽  
Lactobacillus Casei ◽  
Tooth Development ◽  
Fusobacterium Nucleatum ◽  
Poor Response ◽  
Oral Bacteria ◽  
Cellular Processes ◽  
Tgf Β1

TGF-β1 exerts diverse functions in tooth development and tissue repair, but its role in microbial defenses of the tooth is not well-understood. Odontoblasts extending their cellular processes into the dentin are the first cells to recognize signals from TGF-β1 and bacteria in carious dentin. This study aimed to determine the role of TGF-β1 in modulating odontoblast responses to oral bacteria. We show that these responses depend upon the expression levels of microbial recognition receptors TLR2 and TLR4 on the cell surface. Porphyromonas gingivalis, Prevotella intermedia, and Fusobacterium nucleatum activated both TLRs, but TLR4 played a greater role. Lack of cell-surface TLR2 was associated with poor response to Streptococcus mutans, Enterococcus faecalis, and Lactobacillus casei. TGF-β1 inhibited TLR2 and TLR4 expression and attenuated odontoblast responses. Our findings suggest that the balance between TLR-mediated inflammation and TGF-β1 anti-inflammatory activity plays an important role in pulpal inflammation.

scholarly journals Modulation of the Host Cell Transcriptome and Epigenome by Fusobacterium nucleatum

mBio ◽  
2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Cody A. Despins ◽  
Scott D. Brown ◽  
Avery V. Robinson ◽  
Andrew J. Mungall ◽  
Emma Allen-Vercoe ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Oral Cavity ◽  
Host Cell ◽  
Treatment Resistance ◽  
Fusobacterium Nucleatum ◽  
Content Type ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Cell Transcriptome ◽  
Cancer Settings

Fusobacterium nucleatum is a bacterium normally found in the healthy oral cavity but also has an emerging role in colorectal cancer and other cancer settings. The host-microbe interactions of F. nucleatum and its involvement in tumor initiation, progression, and treatment resistance are not fully understood.

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