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Journal of Medical Microbiology Oct 1993Fusobacteria are anaerobic gram-negative bacilli. Since the first reports in the late nineteenth century, various names have been applied to these organisms, sometimes... (Review)
Review
Fusobacteria are anaerobic gram-negative bacilli. Since the first reports in the late nineteenth century, various names have been applied to these organisms, sometimes with the same name being applied to different species. More recently, not only have there been changes to the nomenclature, but also attempts to differentiate between species which are believed to be either pathogenic or commensal or both. Because of their asaccharolytic nature, and a general paucity of positive results in routine biochemical tests, laboratory identification of the fusobacteria has been difficult. However, the application of novel molecular biological techniques to taxonomy has established a number of new species, together with the subspeciation of Fusobacterium necrophorum and F. nucleatum, and provided new methods for identification. The involvement of fusobacteria in a wide spectrum of human infections causing tissue necrosis and septicaemia has long been recognised, and, more recently, their importance in intra-amniotic infections, premature labour and tropical ulcers has been reported.
Topics: Animals; Anti-Bacterial Agents; Bacterial Typing Techniques; Drug Resistance, Microbial; Female; Fusobacterium; Fusobacterium Infections; Humans; Terminology as Topic
PubMed: 8411084
DOI: 10.1099/00222615-39-4-246 -
Journal of Bacteriology Dec 1960
Topics: Fusobacteria; Fusobacterium; Humans; Mouth
PubMed: 13730937
DOI: 10.1128/jb.80.6.737-740.1960 -
Journal of Advanced Research Feb 2024Metastasis is an important cause of high mortality and lethality of oral cancer. Fusobacterium nucleatum (Fn) can promote tumour metastasis. Outer membrane vesicles...
INTRODUCTION
Metastasis is an important cause of high mortality and lethality of oral cancer. Fusobacterium nucleatum (Fn) can promote tumour metastasis. Outer membrane vesicles (OMVs) are secreted by Fn. However, the effects of Fn-derived extracellular vesicles on oral cancer metastasis and the underlying mechanisms are unclear.
OBJECTIVES
We aimed to determine whether and how Fn OMVs mediate oral cancer metastasis.
METHODS
OMVs were isolated from brain heart infusion (BHI) broth supernatant of Fn by ultracentrifugation. Tumour-bearing mice were treated with Fn OMVs to evaluate the effect of OMVs on cancer metastasis. Transwell assays were performed to determine how Fn OMVs affect cancer cell migration and invasion. The differentially expressed genes in Fn OMV-treated/untreated cancer cells were identified by RNA-seq. Transmission electron microscopy, laser confocal microscopy, and lentiviral transduction were used to detect changes in autophagic flux in cancer cells stimulated with Fn OMVs. Western blotting assay was performed to determine changes in EMT-related marker protein levels in cancer cells. Fn OMVs' effects on migration after blocking autophagic flux by autophagy inhibitors were determined by in vitro and in vivo experiments.
RESULTS
Fn OMVs were structurally similar to vesicles. In the in vivo experiment, Fn OMVs promoted lung metastasis in tumour-bearing mice, while chloroquine (CHQ, an autophagy inhibitor) treatment reduced the number of pulmonary metastases resulting from the intratumoral Fn OMV injection. Fn OMVs promoted the migration and invasion of cancer cells in vivo, leading to altered expression levels of EMT-related proteins (E-cadherin downregulation; Vimentin/N-cadherin upregulation). RNA-seq showed that Fn OMVs activate intracellular autophagy pathways. Blocking autophagic flux with CHQ reduced in vitro and in vivo migration of cancer cells induced by Fn OMVs as well as reversed changes in EMT-related protein expression.
CONCLUSION
Fn OMVs not only induced cancer metastasis but also activated autophagic flux. Blocking autophagic flux weakened Fn OMV-stimulated cancer metastasis.
Topics: Animals; Mice; Fusobacterium nucleatum; Mouth Neoplasms; Autophagy
PubMed: 37059221
DOI: 10.1016/j.jare.2023.04.002 -
Australian Dental Journal Apr 1998The physiological and metabolic characteristics of representative isolates of the various subspecies of Fusobacterium nucleatum were investigated by growing them in... (Review)
Review
The physiological and metabolic characteristics of representative isolates of the various subspecies of Fusobacterium nucleatum were investigated by growing them in continuous culture in chemically-defined, media. Behaving almost identically, these organisms were found to obtain energy from the fermentation of simple carbohydrates such as glucose or fructose or from the fermentation of certain amino acids, free or in the form of small peptides. The latter can be attacked by aminopeptidase activity which was shown to be essential for the growth of the organism in an environment lacking fermentable carbohydrate and free amino acids but replete with small peptides. This metabolic versatility may explain the presence of F. nucleatum in both supra- and sub-gingival dental plaque and why it is often found together with organisms such as Porphyromonas gingivalis which display powerful endopeptidase activities. Using the technique of allozyme electrophoresis, the current subspeciation of F. nucleatum was shown to be of doubtful validity and evidence, based upon physiological and metabolic properties, for differences in pathogenicity between isolates was not detected. While this organism is a member of various bacterial consortia associated with periodontal diseases, its contribution to the disease process remains unclear.
Topics: Amino Acids; Aminopeptidases; Bacterial Typing Techniques; Culture Media; Dental Plaque; Electrophoresis; Endopeptidases; Fermentation; Fructose; Fusobacterium Infections; Fusobacterium nucleatum; Glucose; Humans; Peptides; Periodontal Diseases; Porphyromonas gingivalis; Reproducibility of Results; Symbiosis
PubMed: 9612984
DOI: 10.1111/j.1834-7819.1998.tb06098.x -
ELife Mar 2018The association between the bacterium and human colon cancer is more complicated than it first appeared.
The association between the bacterium and human colon cancer is more complicated than it first appeared.
Topics: Colonic Neoplasms; Colorectal Neoplasms; Fusobacteria; Fusobacterium; Fusobacterium Infections; Fusobacterium nucleatum; Humans
PubMed: 29533185
DOI: 10.7554/eLife.28434 -
Current Molecular Medicine Sep 2013Halitosis (bad breath) is estimated to influence more than half of the world's population with varying degree of intensity. More than 85% of halitosis originates from... (Review)
Review
Halitosis (bad breath) is estimated to influence more than half of the world's population with varying degree of intensity. More than 85% of halitosis originates from oral bacterial infections. Foul-smelling breath mainly results from bacterial production of volatile sulfur compounds (VSCs) such as hydrogen sulfide and methyl mercaptan. To date, major treatments for elimination of oral malodor include periodontal therapy combined with antibiotics or antimicrobial agents, and mechanical approaches including tooth and tongue cleaning. These treatments may transiently reduce VSCs but carry risks of generating toxicity, increasing resistant strains and misbalancing the resident human flora. Therefore, there is a need to develop alternative therapeutic modalities for halitosis. Plaque biofilms are the principal source for generating VSCs which are originally metabolized from amino acids during co-aggregation of oral bacteria. Blocking the bacterial coaggregation, therefore, may prevent various biofilm-associated oral diseases such as periodontitis and halitosis. Fusobacterium nucleatum (F. nucleatum), a Gram-negative anaerobe oral bacterium, is a main bacterial strain related to halitosis. Aggregation of F. nucleatum with other bacteria to form plaque biofilms in oral cavity causes bad breath. FomA, the major outer membrane protein of F. nucleatum, recruits other oral pathogenic bacteria such as Porphyromonas gingivalis (P. gingivalis) in the periodontal pockets. A halitosis vaccine targeting F. bacterium FomA significantly abrogates the enhancement of bacterial co-aggregation, biofilms, production of VSCs, and gum inflammation mediated by an inter-species interaction of F. nucleatum with P. gingivalis, which suggests FomA of F. nucleatum to be a potential target for development of vaccines or drugs against bacterial biofilm formation and its associated pathogenicities.
Topics: Bacterial Outer Membrane Proteins; Bacterial Vaccines; Biofilms; Fusobacterium nucleatum; Halitosis; Humans; Mouth; Sulfur Compounds
PubMed: 23865430
DOI: 10.2174/15665240113139990063 -
Nature Reviews. Microbiology Oct 2022
Topics: Biofilms; Fusobacterium; Fusobacterium nucleatum
PubMed: 35915254
DOI: 10.1038/s41579-022-00787-w -
Nature Microbiology Aug 2021Fusobacterium nucleatum, long known as a constituent of the oral microflora, has recently garnered renewed attention for its association with several different human...
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.
Topics: Bacterial Proteins; Fusobacterium Infections; Fusobacterium nucleatum; Humans; Neoplasms; Porins; RNA, Bacterial
PubMed: 34239075
DOI: 10.1038/s41564-021-00927-7 -
Journal of Pediatric Surgery Mar 2014Although luminal obstruction has traditionally been viewed as the underlying cause of appendicitis, recent evidence has suggested that the disease may result directly...
BACKGROUND
Although luminal obstruction has traditionally been viewed as the underlying cause of appendicitis, recent evidence has suggested that the disease may result directly from invasion by specific pathogens, e.g. Fusobacterium nucleatum. The purpose of this study was to survey microbial communities within pediatric appendectomy specimens using a culture-independent approach.
METHODS
We performed 16S ribosomal gene sequence analysis to profile the microbiota present within luminal fluid obtained from 22 pediatric appendectomy specimens. These included 10 simple appendicitis cases, 5 perforated appendicitis cases, 2 interval appendectomies, and 5 incidental appendectomies.
RESULTS
Samples could be divided into 2 distinct clusters based upon the composition of the appendiceal bacterial communities. Appendicitis samples contained an increased abundance of Fusobacterium spp. and a reduced abundance of Bacteroides spp. relative to non-appendicitis cases. Appendicitis samples also contained variable amounts of other oral taxa such as Porphyromonas, Parvimonas, and Gemella, whereas these taxa were generally absent from non-appendicitis samples.
CONCLUSIONS
Acute appendicitis is associated with an abundance of Fusobacterium spp. and other pathogens commonly found in the oral cavity. Further research is needed to determine whether these organisms directly cause appendicitis or rather proliferate in the appendix as a secondary consequence of inflammation.
Topics: Adolescent; Appendectomy; Appendicitis; Appendix; Bacteroides; Body Fluids; Child; Child, Preschool; DNA, Bacterial; DNA, Ribosomal; Fusobacterium; Humans; Infant; Microbiota; Mouth; Pilot Projects; Porphyromonas; Proteobacteria; RNA, Bacterial; RNA, Ribosomal, 16S; Ribotyping; Sequence Analysis, DNA
PubMed: 24650474
DOI: 10.1016/j.jpedsurg.2013.06.026 -
Transactions of the Royal Society of... 1968
Topics: Animals; Bites and Stings; Nigeria; Rat-Bite Fever; Sciuridae; Streptobacillus
PubMed: 5691463
DOI: 10.1016/0035-9203(68)90146-6