RESUMEN

Fusobacteria have been associated to different diseases, including colorectal cancer (CRC), but knowledge of which taxonomic groups contribute to specific conditions is incomplete. We analyzed the genetic diversity and relationships within the Fusobacterium genus. We report recent and ancestral recombination in core genes, indicating that fusobacteria have mosaic genomes and emphasizing that taxonomic demarcation should not rely on single genes/gene regions. Across databases, we found ample evidence of species miss-classification and of undescribed species, which are both expected to complicate disease association. By focusing on a lineage that includes F. periodonticum/pseudoperiodonticum and F. nucleatum, we show that genomes belong to four modern populations, but most known species/subspecies emerged from individual ancestral populations. Of these, the F. periodonticum/pseudoperiodonticum population experienced the lowest drift and displays the highest genetic diversity, in line with the less specialized distribution of these bacteria in oral sites. A highly drifted ancestral population instead contributed genetic ancestry to a new species, which includes genomes classified within the F. nucleatum animalis diversity in a recent CRC study. Thus, evidence herein calls for a re-analysis of F. nucleatum animalis features associated to CRC. More generally, our data inform future molecular profiling approaches to investigate the epidemiology of Fusobacterium-associated diseases.

Asunto(s)

Fusobacterium , Genoma Bacteriano , Genómica , Filogenia , Fusobacterium/genética , Fusobacterium/clasificación , Genómica/métodos , Variación Genética , Humanos , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/genética

RESUMEN

Fusobacterium nucleatum (F. nucleatum), an anaerobic resident of the oral cavity, is increasingly recognized as a contributing factor to ulcerative colitis (UC). The adhesive properties of F. nucleatum are mediated by its key virulence protein, FadA adhesin. However, further investigations are needed to understand the pathogenic mechanisms of this oral pathogen in UC. The present study aimed to explore the role of the FadA adhesin in the colonization and invasion of oral F. nucleatum in dextran sulphate sodium (DSS)-induced colitis mice via molecular techniques. In this study, we found that oral inoculation of F. nucleatum strain carrying the FadA adhesin further exacerbated DSS-induced colitis, leading to elevated alveolar bone loss, disease severity, and mortality. Additionally, CDH1 gene knockout mice treated with DSS presented increases in body weight and alveolar bone density, as well as a reduction in disease severity. Furthermore, FadA adhesin adhered to its mucosal receptor E-cadherin, leading to the phosphorylation of ß-catenin and the degradation of IκBα, the activation of the NF-κB signalling pathway and the upregulation of downstream cytokines. In conclusion, this research revealed that oral inoculation with F. nucleatum facilitates experimental colitis via the secretion of the virulence adhesin FadA. Targeting the oral pathogen F. nucleatum and its virulence factor FadA may represent a promising therapeutic approach for a portion of UC patients.

Asunto(s)

Adhesinas Bacterianas , Colitis Ulcerosa , Infecciones por Fusobacterium , Fusobacterium nucleatum , Animales , Humanos , Ratones , Adhesinas Bacterianas/metabolismo , Adhesinas Bacterianas/genética , Adhesión Bacteriana , Cadherinas/metabolismo , Colitis Ulcerosa/microbiología , Sulfato de Dextran , Modelos Animales de Enfermedad , Infecciones por Fusobacterium/microbiología , Fusobacterium nucleatum/patogenicidad , Ratones Endogámicos C57BL , Ratones Noqueados , Virulencia , Factores de Virulencia/genética , Factores de Virulencia/metabolismo

RESUMEN

Fusobacterium nucleatum can bind to host cells and potentiate intestinal tumorigenesis. Here we used a genome-wide screen to identify an adhesin, RadD, which facilitates the attachment of F. nucleatum to colorectal cancer (CRC) cells in vitro. RadD directly binds to CD147, a receptor overexpressed on CRC cell surfaces, which initiated a PI3K-AKT-NF-κB-MMP9 cascade, subsequently enhancing tumorigenesis in mice. Clinical specimen analysis showed that elevated radD gene levels in CRC tissues correlated positively with activated oncogenic signalling and poor patient outcomes. Finally, blockade of the interaction between RadD and CD147 in mice effectively impaired F. nucleatum attachment and attenuated F. nucleatum-induced oncogenic response. Together, our study provides insights into an oncogenic mechanism driven by F. nucleatum RadD and suggests that the RadD-CD147 interaction could be a potential therapeutic target for CRC.

Asunto(s)

Adhesinas Bacterianas , Adhesión Bacteriana , Basigina , Carcinogénesis , Neoplasias Colorrectales , Fusobacterium nucleatum , Fusobacterium nucleatum/patogenicidad , Fusobacterium nucleatum/genética , Fusobacterium nucleatum/fisiología , Neoplasias Colorrectales/microbiología , Neoplasias Colorrectales/patología , Animales , Humanos , Ratones , Basigina/metabolismo , Basigina/genética , Adhesinas Bacterianas/metabolismo , Adhesinas Bacterianas/genética , Carcinogénesis/genética , Línea Celular Tumoral , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/complicaciones , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/genética , Transducción de Señal , FN-kappa B/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfatidilinositol 3-Quinasas/genética , Femenino

RESUMEN

Intestinal dysbiosis is a major contributor to colorectal cancer (CRC) development, leading to bacterial translocation into the bloodstream. This study aimed to evaluate the presence of circulated bacterial DNA (cbDNA) in CRC patients (n = 75) and healthy individuals (n = 25). DNA extracted from peripheral blood was analyzed using PCR, with specific primers targeting 16S rRNA, Escherichia coli (E. coli), and Fusobacterium nucleatum (F. nucleatum). High 16S rRNA and E. coli detections were observed in all patients and controls. Only the detection of F. nucleatum was significantly higher in metastatic non-excised CRC, compared to controls (p < 0.001), non-metastatic excised CRC (p = 0.023), and metastatic excised CRC (p = 0.023). This effect was mainly attributed to the presence of the primary tumor (p = 0.006) but not the presence of distant metastases (p = 0.217). The association of cbDNA with other clinical parameters or co-morbidities was also evaluated, revealing a higher detection of E. coli in CRC patients with diabetes (p = 0.004). These results highlighted the importance of bacterial translocation in CRC patients and the potential role of F. nucleatum as an intratumoral oncomicrobe in CRC.

Asunto(s)

Neoplasias Colorrectales , ADN Bacteriano , Escherichia coli , Fusobacterium nucleatum , ARN Ribosómico 16S , Humanos , Fusobacterium nucleatum/genética , Fusobacterium nucleatum/aislamiento & purificación , Neoplasias Colorrectales/microbiología , Neoplasias Colorrectales/sangre , Neoplasias Colorrectales/patología , Masculino , Femenino , Persona de Mediana Edad , ADN Bacteriano/genética , ADN Bacteriano/sangre , Anciano , Escherichia coli/genética , ARN Ribosómico 16S/genética , Disbiosis/microbiología , Adulto , Estudios de Casos y Controles , Traslocación Bacteriana , Anciano de 80 o más Años , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/sangre , Infecciones por Fusobacterium/complicaciones

RESUMEN

Fusobacterium necrophorum is a Gram-negative anaerobic bacterium responsible for localized infections of the oropharynx that can evolve into bacteremia and/or septic thrombophlebitis of the jugular vein or peritonsillar vein, called Lemierre's syndrome. To identify microbial genetic determinants associated with the severity of this life-threatening disease, 70 F. necrophorum strains were collected and grouped into two categories according to the clinical presentation: (i) localized infection, (ii) bacteremia with/without Lemierre's syndrome. Comparative genomic analyses revealed two clades with distinct genetic content, one clade being significantly enriched with isolates from subjects with bacteremia. To identify genetic determinants contributing to F. necrophorum pathogenicity, genomic islands and virulence factor orthogroups (OVFs) were predicted. The presence/absence profiles of OVFs did not group isolates according to their clinical category, but rather according to their phylogeny. However, a variant of lktA, a key virulence factor, with a frameshift deletion that results in two open reading frames, was associated with bacteremia. Moreover, a genome-wide association study identified three orthogroups associated with bacteremic strains: (i) cas8a1, (ii) a sodium/solute symporter, and (iii) a POP1 domain-containing protein. Further studies must be performed to assess the functional impact of lktA mutation and of these orthogroups on the physiopathological mechanisms of F. necrophorum infections.

Asunto(s)

Bacteriemia , Fusobacterium necrophorum , Síndrome de Lemierre , Factores de Virulencia , Fusobacterium necrophorum/genética , Fusobacterium necrophorum/aislamiento & purificación , Humanos , Síndrome de Lemierre/microbiología , Bacteriemia/microbiología , Factores de Virulencia/genética , Masculino , Femenino , Filogenia , Adulto , Estudio de Asociación del Genoma Completo , Persona de Mediana Edad , Proteínas Bacterianas/genética , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/complicaciones , Anciano , Islas Genómicas/genética , Proteínas Hemolisinas

RESUMEN

F. nucleatum, involved in carcinogenesis of colon carcinomas, has been described as part of the commensal flora of the female upper reproductive tract. Although its contribution to destructive inflammatory processes is well described, its role as commensal uterine bacteria has not been thoroughly investigated. Since carcinogenesis shares similar mechanisms with early pregnancy development (including proliferation, invasion, blood supply and the induction of tolerance), these mechanisms induced by F. nucleatum could play a role in early pregnancy. Additionally, implantation and placentation require a well-balanced immune activation, which might be suitably managed by the presence of a limited amount of bacteria or bacterial residues. We assessed the effect of inactivated F. nucleatum on macrophage-trophoblast interactions. Monocytic cells (THP-1) were polarized into M1, M2a or M2c macrophages by IFN-γ, IL-4 or TGF-ß, respectively, and subsequently treated with inactivated fusobacteria (bacteria:macrophage ratio of 0.1 and 1). Direct effects on macrophages were assessed by viability assay, flow cytometry (antigen presentation molecules and cytokines), qPCR (cytokine expression), in-cell Western (HIF and P-NF-κB) and ELISA (VEGF secretion). The function of first trimester extravillous trophoblast cells (HTR-8/SVneo) in response to macrophage-conditioned medium was microscopically assessed by migration (scratch assay), invasion (sprouting assay) and tube formation. Underlying molecular changes were investigated by ELISA (VEGF secretion) and qPCR (matrix-degrading factors and regulators). Inflammation-primed macrophages (M1) as well as high bacterial amounts increased pro-inflammatory NF-κB expression and inflammatory responses. Subsequently, trophoblast functions were impaired. In contrast, low bacterial stimulation caused an increased HIF activation and subsequent VEGF-A secretion in M2c macrophages. Accordingly, there was an increase of trophoblast tube formation. Our results suggest that a low-mass endometrial/decidual microbiome can be tolerated and while it supports implantation and further pregnancy processes.

Asunto(s)

Fusobacterium nucleatum , Macrófagos , Trofoblastos , Humanos , Trofoblastos/inmunología , Trofoblastos/microbiología , Trofoblastos/metabolismo , Fusobacterium nucleatum/inmunología , Fusobacterium nucleatum/fisiología , Macrófagos/inmunología , Macrófagos/microbiología , Macrófagos/metabolismo , Femenino , Embarazo , Citocinas/metabolismo , Células THP-1 , FN-kappa B/metabolismo , Infecciones por Fusobacterium/inmunología , Infecciones por Fusobacterium/microbiología , Factor A de Crecimiento Endotelial Vascular/metabolismo

RESUMEN

BACKGROUND: Fusobacterium nucleatum inhabits the oral cavity and affects the progression of gastrointestinal cancer. Our prior findings link F. nucleatum to poor prognosis in oesophageal squamous cell carcinoma via NF-κB pathway. However, its role in oesophagogastric junction and gastric adenocarcinoma remains unexplored. We investigated whether F. nucleatum influences these cancers, highlighting its potential impact. METHODS: Two cohorts of EGJ and gastric adenocarcinoma patients (438 from Japan, 380 from the USA) were studied. F. nucleatum presence was confirmed by qPCR, FISH, and staining. Patient overall survival (OS) was assessed based on F. nucleatum positivity. EGJ and gastric adenocarcinoma cell lines were exposed to F. nucleatum to study molecular and phenotypic effects, validated in xenograft mouse model. RESULTS: In both cohorts, F. nucleatum-positive EGJ or gastric adenocarcinoma patients had notably shorter OS. F. nucleatum positivity decreased in more acidic tumour environments. Cancer cell lines with F. nucleatum showed enhanced proliferation and NF-κB activation. The xenograft model indicated increased tumour growth and NF-κB activation in F. nucleatum-treated cells. Interestingly, co-occurrence of F. nucleatum and Helicobacter pylori, a known risk factor, was rare. CONCLUSIONS: F. nucleatum can induce the NF-κB pathway in EGJ and gastric adenocarcinomas, leading to tumour progression and poor prognosis.

Asunto(s)

Adenocarcinoma , Neoplasias Esofágicas , Unión Esofagogástrica , Infecciones por Fusobacterium , Fusobacterium nucleatum , FN-kappa B , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/microbiología , Neoplasias Gástricas/patología , Neoplasias Gástricas/mortalidad , Animales , Neoplasias Esofágicas/microbiología , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/mortalidad , Ratones , Unión Esofagogástrica/patología , Unión Esofagogástrica/microbiología , Masculino , Femenino , Adenocarcinoma/microbiología , Adenocarcinoma/patología , Adenocarcinoma/mortalidad , FN-kappa B/metabolismo , Línea Celular Tumoral , Infecciones por Fusobacterium/complicaciones , Infecciones por Fusobacterium/microbiología , Anciano , Persona de Mediana Edad , Pronóstico , Proliferación Celular , Microambiente Tumoral , Ensayos Antitumor por Modelo de Xenoinjerto

Asunto(s)

Neoplasias de Cabeza y Cuello , Carcinoma de Células Escamosas de Cabeza y Cuello , Humanos , Neoplasias de Cabeza y Cuello/microbiología , Pronóstico , Carcinoma de Células Escamosas de Cabeza y Cuello/microbiología , Fusobacterium/aislamiento & purificación , Carcinoma de Células Escamosas , Infecciones por Fusobacterium/complicaciones , Infecciones por Fusobacterium/microbiología , Masculino , Femenino

RESUMEN

Pleural empyema can lead to significant morbidity and mortality despite chest drainage and antibiotic treatment, necessitating novel and minimally invasive interventions. Fusobacterium nucleatum is an obligate anaerobe found in the human oral and gut microbiota. Advances in sequencing and puncture techniques have made it common to detect anaerobic bacteria in empyema cases. In this report, we describe the case of a 65-year-old man with hypertension who presented with a left-sided encapsulated pleural effusion. Initial fluid analysis using metagenomic next-generation sequencing (mNGS) revealed the presence of Fusobacterium nucleatum and Aspergillus chevalieri. Unfortunately, the patient experienced worsening pleural effusion despite drainage and antimicrobial therapy. Ultimately, successful treatment was achieved through intrapleural metronidazole therapy in conjunction with systemic antibiotics. The present case showed that intrapleural antibiotic therapy is a promising measure for pleural empyema.

Asunto(s)

Antibacterianos , Empiema Pleural , Fusobacterium nucleatum , Terapia Recuperativa , Humanos , Masculino , Anciano , Empiema Pleural/tratamiento farmacológico , Empiema Pleural/microbiología , Antibacterianos/administración & dosificación , Antibacterianos/uso terapéutico , Fusobacterium nucleatum/efectos de los fármacos , Fusobacterium nucleatum/aislamiento & purificación , Fusobacterium nucleatum/genética , Infecciones por Fusobacterium/tratamiento farmacológico , Infecciones por Fusobacterium/complicaciones , Infecciones por Fusobacterium/microbiología , Metronidazol/uso terapéutico , Metronidazol/administración & dosificación , Secuenciación de Nucleótidos de Alto Rendimiento , Resultado del Tratamiento

RESUMEN

Zebu cattle (Bos indicus) is reported to be more resistant towards harmful environmental factors than taurine cattle (Bos taurus). A few hundred zebu cattle are kept in Switzerland and in contrast to the Swiss indigenous breeds, infectious hoof disease in zebu is not observed. Therefore, we compared the prevalence of three ruminant hoof pathogens in zebu and taurine cattle. These included Treponema spp., Fusobacterium necrophorum and Dichelobacter nodosus which are associated with bovine digital dermatitis (BDD), different bovine hoof diseases and ovine footrot, respectively. Interdigital swabs and punch biopsies from hind feet of slaughter animals were tested for the three pathogens by PCR. Sixty zebu from eight farms were compared to a convenience sample of 20 taurine cattle from 17 farms. Treponema spp. associated with BDD were not detected in zebu while 23 % of animals and 50 % of farms were positive for benign D. nodosus, with results indicating environmental contamination rather than colonization. Taurine cattle showed 35 % of animals and 41 % of farms positive for T. phagedenis while 90 % of animals and 94 % of farms were colonized by D. nodosus as indicated by a 500-fold higher bacterial load than in zebu. The difference in prevalence of the two pathogens between zebu and taurine cattle was highly significant. F. necrophorum was as well only detected in taurine cattle with values of 15 % of animals and 17.7 % of farms, being significantly different at the animal level. Furthermore, genetic analysis of Swiss zebu indicates high genomic diversity and clear separation from taurine cattle. This is the first evidence that zebu show resistance towards colonization by bacterial hoof pathogens in contrast to taurine cattle.

Asunto(s)

Enfermedades de los Bovinos , Dichelobacter nodosus , Fusobacterium necrophorum , Pezuñas y Garras , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Suiza/epidemiología , Pezuñas y Garras/microbiología , Dichelobacter nodosus/genética , Dichelobacter nodosus/patogenicidad , Fusobacterium necrophorum/genética , Fusobacterium necrophorum/patogenicidad , Fusobacterium necrophorum/aislamiento & purificación , Treponema/genética , Treponema/aislamiento & purificación , Treponema/clasificación , Enfermedades del Pie/veterinaria , Enfermedades del Pie/microbiología , Prevalencia , Resistencia a la Enfermedad , Infecciones por Fusobacterium/veterinaria , Infecciones por Fusobacterium/microbiología

RESUMEN

BACKGROUND: Epidemiological studies have demonstrated that periodontitis is an independent risk factor for chronic obstructive pulmonary disease (COPD). However, the mechanism underlying the association between these two diseases remains unclear. The lung microbiota shares similarities with the oral microbiota, and there is growing evidence to suggest that the lung microbiome could play a role in the pathogenesis of COPD. This study aimed to investigate whether periodontal pathogens could contribute to the pathogenesis of COPD in a mouse model. METHODS: We established mouse models with oral infection by typical periodontal pathogens, porphyromonas gingivalis (Pg group) or fusobacterium nucleatum (Fn group), over a three-month period. Mice that did not receive oral infection were set as the control group (C group). We assessed the level of alveolar bone resorption, lung function, and histological changes in the lungs of the mice. Additionally, we measured the levels of inflammatory factors and tissue damage associated factors in the lung tissues. RESULTS: Lung function indices, including airway resistance, peak inspiratory/expiratory flow and expiratory flow-50%, were significantly reduced in the Fn group compared to the C group. Additionally, histological examination revealed an increased number of inflammatory cells and bullae formation in the lung tissue sections of the Fn group. Meanwhile, levels of inflammatory factors such as IL-1ß, IL-6, IFN-γ, and TNF-α, as well as tissue damage associated factors like matrix metalloproteinase-8 and neutrophil elastase, were significantly elevated in the lung tissue of the Fn group in comparison to the C group. The Pg group also showed similar but milder lung changes compared to the Fn group. Pg or Fn could be detected in the lungs of both oral infected groups. CONCLUSION: The results indicated that oral periodontal pathogens infection could induce COPD-like lung changes in mice, and they may play a biological role in the association between periodontitis and COPD.

Asunto(s)

Modelos Animales de Enfermedad , Fusobacterium nucleatum , Porphyromonas gingivalis , Enfermedad Pulmonar Obstructiva Crónica , Animales , Enfermedad Pulmonar Obstructiva Crónica/microbiología , Enfermedad Pulmonar Obstructiva Crónica/patología , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Ratones , Pérdida de Hueso Alveolar/microbiología , Pérdida de Hueso Alveolar/patología , Pulmón/patología , Pulmón/microbiología , Periodontitis/microbiología , Periodontitis/patología , Periodontitis/complicaciones , Masculino , Infecciones por Bacteroidaceae/complicaciones , Infecciones por Bacteroidaceae/microbiología , Infecciones por Bacteroidaceae/patología , Infecciones por Fusobacterium/complicaciones , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/patología , Ratones Endogámicos C57BL

RESUMEN

BACKGROUND: Colorectal cancer (CRC) is a significant global health concern, and understanding the role of specific bacterial infections in its development and progression is of increasing interest. This cross-sectional study investigated the associations between Bacteroides fragilis (B. fragilis) and Fusobacterium nucleatum (F. nucleatum) infections and Vietnamese CRC patients. METHODS: 192 patients with either polyps or CRC at varying stages were recruited from May 2017 to December 2020. Real-time PCR assessed infection rates and bacterial loads in CRC tissues. RESULTS: B. fragilis infection was notably higher in CRC tissues (51.6 %) than polyps (9.4 %), with a fivefold higher relative load. Positive associations were found in stages II and III, indicating a fivefold increase in CRC progression risk. F. nucleatum infection rates were significantly higher in CRC tissues (55.2 %) than in polyps (10.5 %). In stage II, the infection rate exceeded that in adjacent tissues. The relative load of F. nucleatum was higher in stage III than in stages I and II. Positive F. nucleatum patients had a 3.2 times higher risk of CRC progression. CONCLUSION: These findings suggest associations between loading of F. nucleatum or/and B. fragilis with the advanced stages of CRC.

Asunto(s)

Infecciones por Bacteroides , Bacteroides fragilis , Neoplasias Colorrectales , Infecciones por Fusobacterium , Fusobacterium nucleatum , Humanos , Neoplasias Colorrectales/microbiología , Bacteroides fragilis/aislamiento & purificación , Bacteroides fragilis/genética , Fusobacterium nucleatum/aislamiento & purificación , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/epidemiología , Infecciones por Fusobacterium/complicaciones , Masculino , Femenino , Vietnam/epidemiología , Persona de Mediana Edad , Estudios Transversales , Infecciones por Bacteroides/microbiología , Infecciones por Bacteroides/epidemiología , Anciano , Adulto , Carga Bacteriana , Pueblos del Sudeste Asiático

RESUMEN

BACKGROUND: Legionella pneumonia is one of the most severe types of atypical pneumonia, impairing multiple organ systems, posing a threat to life. Diagnosing Legionella pneumonia is challenging due to difficulties in culturing the bacteria and limitations in immunoassay sensitivity and specificity. CASE PRESENTATION: This paper reports a rare case of sepsis caused by combined infection with Legionella pneumophila and Fusobacterium necrophorum, leading to respiratory failure, acute kidney injury, acute liver injury, myocardial damage, and electrolyte disorders. In addition, we systematically reviewed literature on patients with combined Legionella infections, analyzing their clinical features, laboratory results and diagnosis. CONCLUSIONS: For pathogens that require prolonged incubation periods and are less sensitive to conventional culturing methods, metagenomic next-generation sequencing (mNGS) can be a powerful supplement to pathogen screening and plays a significant role in the auxiliary diagnosis of complex infectious diseases.

Asunto(s)

Coinfección , Infecciones por Fusobacterium , Fusobacterium necrophorum , Secuenciación de Nucleótidos de Alto Rendimiento , Legionella pneumophila , Enfermedad de los Legionarios , Humanos , Legionella pneumophila/genética , Legionella pneumophila/aislamiento & purificación , Enfermedad de los Legionarios/diagnóstico , Enfermedad de los Legionarios/microbiología , Infecciones por Fusobacterium/diagnóstico , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/complicaciones , Fusobacterium necrophorum/aislamiento & purificación , Fusobacterium necrophorum/genética , Coinfección/diagnóstico , Coinfección/microbiología , Metagenómica/métodos , Masculino , Persona de Mediana Edad , Neumonía Bacteriana/microbiología , Neumonía Bacteriana/diagnóstico

RESUMEN

The study aimed to develop a quantitative colorimetric loop-mediated isothermal amplification technique using the phenol red indicator (QLAMP-PhR) for detecting Fusobacterium nucleatum (Fn) levels in colorectal cancer (CRC) patients and healthy individuals. QLAMP-PhR assays were conducted on 251 stool samples specific for the Fn FadA gene. Six primers were synthesized and utilized with master mix reagents, and a phenol red indicator was employed to enhance the QLAMP-PhR technique. A standard quantitative analysis curve was generated using a logarithmic function (absorbance vs. concentration) by serially diluting the copy number of genomic DNA templates (Fn ATCC25586). The CRC group exhibited a significantly higher abundance of Fn compared to the healthy control group (P < 0.001). These findings suggest that the QLAMP-PhR technique effectively identifies Fn specifically by its gene for the key virulence factor FadA. Additionally, ideas for developing a real-time QLAMP-PhR test were presented. Compared to the traditional polymerase chain reaction (PCR) technique, QLAMP-PhR offers several advantages including rapidity, simplicity, specificity, sensitivity, and cost-effectiveness method that can quantitatively screen for Fn presence in normal populations. The QLAMP-PhR method represents a sensitive and specific amplification assay for the rapid detection of the Fn pathogen. To the best of our knowledge, this study is the first to report the application of QLAMP-PhR for detecting FadA in Fn.

Asunto(s)

Neoplasias Colorrectales , Colorimetría , Heces , Fusobacterium nucleatum , Técnicas de Amplificación de Ácido Nucleico , Humanos , Neoplasias Colorrectales/microbiología , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/genética , Fusobacterium nucleatum/genética , Fusobacterium nucleatum/aislamiento & purificación , Heces/microbiología , Técnicas de Amplificación de Ácido Nucleico/métodos , Colorimetría/métodos , Masculino , Femenino , Fenolsulfonftaleína , Técnicas de Diagnóstico Molecular/métodos , Persona de Mediana Edad , Anciano , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/diagnóstico , Sensibilidad y Especificidad , Adulto

RESUMEN

OBJECTIVES: Several studies have reported the effects of Fusobacterium nucleatum stimulation on oral cancer cells. However, given that these studies typically span a stimulation period of three days to eight days, the in vitro studies conducted to date may not fully mimic the oral cancer environment, which involves constant exposure to oral commensal bacteria. This study aimed to elucidate the effects of prolonged and persistent Fusobacterium nucleatum infection on oral cancer cells. METHODS: Human tongue squamous cell carcinoma (SCC) cells were continuously stimulated with Fusobacterium nucleatum for two or four weeks, then experimentally evaluated. RESULTS: Prolonged, persistent Fusobacterium nucleatum stimulation increased the cells' proliferative, invasive, and migratory capacities, decreased their expression of epithelial markers, and increased their expression of mesenchymal markers progressively with time. The cells also adopted a spindle-shaped morphology and cell-to-cell contact dependence was progressively lost, suggesting time-dependent occurrence of epithelial-mesenchymal transition. Furthermore, mRNA levels of CD44, a cancer stem cell marker, were time-dependently upregulated. When SCC cells were stimulated with Fusobacterium nucleatum for four weeks in the presence of dexamethasone, Fusobacterium nucleatum induced epithelial-mesenchymal transition was inhibited. CONCLUSIONS: Epithelial-mesenchymal transition in human tongue SCC cells was time-dependently induced by prolonged, persistent Fusobacterium nucleatum stimulation and inhibited by dexamethasone. Routine decontamination of the oral cavity may be crucial for controlling tumor invasion and metastasis.

Asunto(s)

Carcinoma de Células Escamosas , Transición Epitelial-Mesenquimal , Fusobacterium nucleatum , Transición Epitelial-Mesenquimal/efectos de los fármacos , Humanos , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/microbiología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Neoplasias de la Boca/patología , Neoplasias de la Boca/microbiología , Neoplasias de la Lengua/patología , Neoplasias de la Lengua/microbiología , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/patología , Dexametasona/farmacología , Receptores de Hialuranos/metabolismo , Invasividad Neoplásica

RESUMEN

Periodontitis is linked to the onset and progression of oral squamous cell carcinoma (OSCC), an epidemiologically frequent and clinically aggressive malignancy. In this context, Fusobacterium (F.) nucleatum and Porphyromonas (P.) gingivalis, two bacteria that cause periodontitis, are found in OSCC tissues as well as in oral premalignant lesions, where they exert pro-tumorigenic activities. Since the two bacteria are present also in endodontic diseases, playing a role in their pathogenesis, here we analyze the literature searching for information on the impact that endodontic infection by P. gingivalis or F. nucleatum could have on cellular and molecular events involved in oral carcinogenesis. Results from the reviewed papers indicate that infection by P. gingivalis and/or F. nucleatum triggers the production of inflammatory cytokines and growth factors in dental pulp cells or periodontal cells, affecting the survival, proliferation, invasion, and differentiation of OSCC cells. In addition, the two bacteria and the cytokines they induce halt the differentiation and stimulate the proliferation and invasion of stem cells populating the dental pulp or the periodontium. Although most of the literature confutes the possibility that bacteria-induced endodontic inflammatory diseases could impact on oral carcinogenesis, the papers we have analyzed and discussed herein recommend further investigations on this topic.

Asunto(s)

Infecciones por Fusobacterium , Fusobacterium nucleatum , Neoplasias de la Boca , Porphyromonas gingivalis , Humanos , Porphyromonas gingivalis/patogenicidad , Fusobacterium nucleatum/patogenicidad , Neoplasias de la Boca/microbiología , Neoplasias de la Boca/patología , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/complicaciones , Carcinogénesis , Infecciones por Bacteroidaceae/microbiología , Infecciones por Bacteroidaceae/complicaciones , Carcinoma de Células Escamosas/microbiología , Carcinoma de Células Escamosas/etiología , Carcinoma de Células Escamosas/patología , Periodontitis/microbiología , Animales , Citocinas/metabolismo

RESUMEN

Fusobacterium nucleatum (F. nucleatum) is closely correlated with tumorigenesis in colorectal cancer (CRC). We aimed to investigate the effects of host norepinephrine on the carcinogenicity of F. nucleatum in CRC and reveal the underlying mechanism. The results revealed that both norepinephrine and bacterial quorum sensing (QS) molecule auto-inducer-2 (AI-2) were positively associated with the progression of F. nucleatum related CRC (p < 0.01). In vitro studies, norepinephrine induced upregulation of QS-associated genes and promoted the virulence and proliferation of F. nucleatum. Moreover, chronic stress significantly increased the colon tumour burden of ApcMin/+ mice infected with F. nucleatum (p < 0.01), which was decreased by a catecholamine inhibitor (p < 0.001). Our findings suggest that stress-induced norepinephrine may promote the progression of F. nucleatum related CRC via bacterial QS signalling. These preliminary data provide a novel strategy for the management of pathogenic bacteria by targeting host hormones-bacterial QS inter-kingdom signalling.

Asunto(s)

Neoplasias Colorrectales , Fusobacterium nucleatum , Norepinefrina , Percepción de Quorum , Transducción de Señal , Percepción de Quorum/efectos de los fármacos , Fusobacterium nucleatum/patogenicidad , Fusobacterium nucleatum/efectos de los fármacos , Fusobacterium nucleatum/fisiología , Animales , Neoplasias Colorrectales/microbiología , Norepinefrina/farmacología , Ratones , Humanos , Progresión de la Enfermedad , Infecciones por Fusobacterium/microbiología , Virulencia , Homoserina/análogos & derivados , Homoserina/metabolismo , Ratones Endogámicos C57BL , Masculino , Lactonas

RESUMEN

Fusobacterium nucleatum, a gram-negative oral bacterium, has been consistently validated as a strong contributor to the progression of several types of cancer, including colorectal (CRC) and pancreatic cancer. While previous in vitro studies have shown that intracellular F. nucleatum enhances malignant phenotypes such as cell migration, the dependence of this regulation on features of the tumor microenvironment (TME) such as oxygen levels are wholly uncharacterized. Here we examine the influence of hypoxia in facilitating F. nucleatum invasion and its effects on host responses focusing on changes in the global epigenome and transcriptome. Using a multiomic approach, we analyze epigenomic alterations of H3K27ac and global transcriptomic alterations sustained within a hypoxia and normoxia conditioned CRC cell line HCT116 at 24 h following initial infection with F. nucleatum. Our findings reveal that intracellular F. nucleatum activates signaling pathways and biological processes in host cells similar to those induced upon hypoxia conditioning in the absence of infection. Furthermore, we show that a hypoxic TME favors F. nucleatum invasion and persistence and therefore infection under hypoxia may amplify malignant transformation by exacerbating the effects induced by hypoxia alone. These results motivate future studies to investigate host-microbe interactions in tumor tissue relevant conditions that more accurately define parameters for targeted cancer therapies.

Asunto(s)

Neoplasias Colorrectales , Epigenoma , Infecciones por Fusobacterium , Fusobacterium nucleatum , Oxígeno , Transcriptoma , Humanos , Fusobacterium nucleatum/genética , Fusobacterium nucleatum/fisiología , Fusobacterium nucleatum/patogenicidad , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/microbiología , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Células HCT116 , Infecciones por Fusobacterium/genética , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/metabolismo , Oxígeno/metabolismo , Microambiente Tumoral/genética , Regulación Neoplásica de la Expresión Génica

RESUMEN

BACKGROUND AND PURPOSE: Fusobacterium necrophorum (F necrophorum) is an anaerobic bacteria that causes invasive head and neck infections in children. Several studies have demonstrated an increasing prevalence of F necrophorum as the causative agent in acute mastoiditis in children, with associated high rates of intracranial complications such as epidural abscess and sinus venous thrombosis, to name a few. F necrophorum requires a treatment protocol that differs from the empiric treatment that is tailored to more common pathogens (eg, group A streptococci, Streptococcus pneumonia), and hence expediting the diagnosis is important. For evaluating complicated acute mastoiditis in children, cranial CT venography remains the imaging study of choice in most medical centers due to its availability in emergency situations. Based on our clinical experience, our hypothesis is that children with F necrophorum-associated complicated acute mastoiditis can be differentiated from those with other etiologies using CT venography. MATERIALS AND METHODS: CT venography studies of 76 children hospitalized and treated for complicated acute mastoiditis were retrospectively reviewed. Retrieved imaging data included intracranial complications (epidural abscess, sinus venous thrombosis), cranial bone-related complications, and extracranial complications (subperiosteal abscess, temporomandibular joint abscess, and soft-tissue inflammation). The cohort was divided into children with F necrophorum-related disease (study group) and those with non-F necrophorum-related disease (control group). RESULTS: Thirty-seven children (49%) comprised the study group, and 39 children in whom the causative agents were other bacteria comprised the control group. There were significantly higher rates of complications in the study group: sinus venous thrombosis (P < .001), perisigmoid epidural abscess (P = .036), and extramastoid osteomyelitis (P < .001). Thrombosis in venous sites beyond the sigmoid sinus and jugular foramen (a pattern consistent with an otogenic variant of Lemierre syndrome) and emphysematous osteomyelitis were found only among children in the F necrophorum-related study group (32% and 22% accordingly). CONCLUSIONS: In children with complicated acute mastoiditis, CT venography findings of emphysematous osteomyelitis and/or thrombosis in venous sites beyond the sigmoid sinus and jugular foramen (a pattern consistent with the otogenic variant of Lemierre syndrome) should lead the radiologist to suggest F necrophorum-related mastoiditis.

Asunto(s)

Infecciones por Fusobacterium , Fusobacterium necrophorum , Mastoiditis , Humanos , Mastoiditis/diagnóstico por imagen , Mastoiditis/complicaciones , Mastoiditis/microbiología , Masculino , Niño , Femenino , Preescolar , Infecciones por Fusobacterium/diagnóstico por imagen , Infecciones por Fusobacterium/complicaciones , Infecciones por Fusobacterium/microbiología , Estudios Retrospectivos , Adolescente , Lactante , Enfermedad Aguda , Tomografía Computarizada por Rayos X/métodos , Flebografía/métodos , Trombosis de los Senos Intracraneales/diagnóstico por imagen

RESUMEN

Fusobacterium nucleatum, a pathobiont inhabiting the oral cavity, contributes to opportunistic diseases, such as periodontal diseases and gastrointestinal cancers, which involve microbiota imbalance. Broad-spectrum antimicrobial agents, while effective against F. nucleatum infections, can exacerbate dysbiosis. This necessitates the discovery of more targeted narrow-spectrum antimicrobial agents. We therefore investigated the potential for the fusobacterial enoyl-ACP reductase II (ENR II) isoenzyme FnFabK (C4N14_ 04250) as a narrow-spectrum drug target. ENRs catalyze the rate-limiting step in the bacterial fatty acid synthesis pathway. Bioinformatics revealed that of the four distinct bacterial ENR isoforms, F. nucleatum specifically encodes FnFabK. Genetic studies revealed that fabK was indispensable for F. nucleatum growth, as the gene could not be deleted, and silencing of its mRNA inhibited growth under the test conditions. Remarkably, exogenous fatty acids failed to rescue growth inhibition caused by the silencing of fabK. Screening of synthetic phenylimidazole analogues of a known FabK inhibitor identified an inhibitor (i.e., 681) of FnFabK enzymatic activity and F. nucleatum growth, with an IC50 of 2.1 µM (1.0 µg/mL) and a MIC of 0.4 µg/mL, respectively. Exogenous fatty acids did not attenuate the activity of 681 against F. nucleatum. Furthermore, FnFabK was confirmed as the intracellular target of 681 based on the overexpression of FnFabK shifting MICs and 681-resistant mutants having amino acid substitutions in FnFabK or mutations in other genetic loci affecting fatty acid biosynthesis. 681 had minimal activity against a range of commensal flora, and it was less active against streptococci in physiologic fatty acids. Taken together, FnFabK is an essential enzyme that is amenable to drug targeting for the discovery and development of narrow-spectrum antimicrobial agents.

Asunto(s)

Antibacterianos , Fusobacterium nucleatum , Fusobacterium nucleatum/enzimología , Fusobacterium nucleatum/efectos de los fármacos , Fusobacterium nucleatum/genética , Antibacterianos/farmacología , Antibacterianos/química , Humanos , Enoil-ACP Reductasa (NADH)/genética , Enoil-ACP Reductasa (NADH)/antagonistas & inhibidores , Enoil-ACP Reductasa (NADH)/metabolismo , Pruebas de Sensibilidad Microbiana , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/antagonistas & inhibidores , Ácidos Grasos/química , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/tratamiento farmacológico , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/química