Nicotine is a potent extracellular polysaccharide inducer in Fusobacterium nucleatum biofilms

The purpose of this in vitro study was to analyze the influence of nicotine on the extracellular polysaccharides in Fusobacterium nucleatum biofilm. Methods: F. nucleatum (ATCC 10953) biofilms supplemented with different concentrations of nicotine (0, 0.5, 1, 2, 4, and 8 mg/mL) were grown in two different BHI broth conditions [no sucrose and 1% sucrose]. Extracellular polysaccharides assay, pH measurements, and a spectrophotometric assay were performed. Data were submitted for ANOVA and Tukey honestly significant difference analyses (HSD) tests (α =.05). Results: Extracellular polysaccharides synthesis was influenced by an interaction between nicotine concentrations and growth medium solution containing sucrose (P<.05). The pH values declined in the sucrose-exposed biofilm were greater than in the group exposed only to nicotine (P<.05). The biofilm exposed to sucrose and nicotine had a higher total biofilm growth (P<.05) than the nicotine-treated biofilm without sucrose. Conclusions: Regardless of sucrose exposure, biofilms exposed to different nicotine concentrations influenced the amount of extracellular polysaccharides

Study of the inflammatory activating process in the early stage of Fusobacterium nucleatum infected PDLSCs / 国际口腔科学杂志·英文版

Fusobacterium nucleatum (F. nucleatum) is an early pathogenic colonizer in periodontitis, but the host response to infection with this pathogen remains unclear. In this study, we built an F. nucleatum infectious model with human periodontal ligament stem cells (PDLSCs) and showed that F. nucleatum could inhibit proliferation, and facilitate apoptosis, ferroptosis, and inflammatory cytokine production in a dose-dependent manner. The F. nucleatum adhesin FadA acted as a proinflammatory virulence factor and increased the expression of interleukin(IL)-1β, IL-6 and IL-8. Further study showed that FadA could bind with PEBP1 to activate the Raf1-MAPK and IKK-NF-κB signaling pathways. Time-course RNA-sequencing analyses showed the cascade of gene activation process in PDLSCs with increasing durations of F. nucleatum infection. NFκB1 and NFκB2 upregulated after 3 h of F. nucleatum-infection, and the inflammatory-related genes in the NF-κB signaling pathway were serially elevated with time. Using computational drug repositioning analysis, we predicted and validated that two potential drugs (piperlongumine and fisetin) could attenuate the negative effects of F. nucleatum-infection. Collectively, this study unveils the potential pathogenic mechanisms of F. nucleatum and the host inflammatory response at the early stage of F. nucleatum infection.

Expression, purification, and characterization of the histidine kinase CarS from Fusobacterium nucleatum / 生物工程学报

Fusobacterium nucleatum is an opportunistic pathogenic bacterium that can be enriched in colorectal cancer tissues, affecting multiple stages of colorectal cancer development. The two-component system plays an important role in the regulation and expression of genes related to pathogenic resistance and pathogenicity. In this paper, we focused on the CarRS two-component system of F. nucleatum, and the histidine kinase protein CarS was recombinantly expressed and characterized. Several online software such as SMART, CCTOP and AlphaFold2 were used to predict the secondary and tertiary structure of the CarS protein. The results showed that CarS is a membrane protein with two transmembrane helices and contains 9 α-helices and 12 β-folds. CarS protein is composed of two domains, one is the N-terminal transmembrane domain (amino acids 1-170), the other is the C-terminal intracellular domain. The latter is composed of a signal receiving domain (histidine kinases, adenylyl cyclases, methyl-accepting proteins, prokaryotic signaling proteins, HAMP), a phosphate receptor domain (histidine kinase domain, HisKA), and a histidine kinase catalytic domain (histidine kinase-like ATPase catalytic domain, HATPase_c). Since the full-length CarS protein could not be expressed in host cells, a fusion expression vector pET-28a(+)-MBP-TEV-CarScyto was constructed based on the characteristics of secondary and tertiary structures, and overexpressed in Escherichia coli BL21-Codonplus(DE3)RIL. CarScyto-MBP protein was purified by affinity chromatography, ion-exchange chromatography, and gel filtration chromatography with a final concentration of 20 mg/ml. CarScyto-MBP protein showed both protein kinase and phosphotransferase activities, and the MBP tag had no effect on the function of CarScyto protein. The above results provide a basis for in-depth analysis of the biological function of the CarRS two-component system in F. nucleatum.

Nivel de higiene y prevalencia de Porphyromona gingivalis y Fusobacterium nucleatum en pacientes recuperados de SARS-CoV-2 / Hygiene level and prevalence of Porphyromona gingivalis and Fusobacterium nucleatum in recovered SARS-CoV-2 patients

Introducción: El SARS-CoV-2 afecta el sistema respiratorio en diferentes grados. La cavidad oral es el lugar más colonizado por bacterias, por lo tanto, al no tener una adecuada higiene pueden presentarse diferentes enfermedades secundarias, lo que ha causado alerta en el gremio odontológico, ya que puede contribuir a complicaciones posteriores en los pacientes. Material y métodos: El estudio fue conformado por 47 pacientes voluntarios recuperados de SARS-CoV-2, residentes de Montemorelos, Nuevo León, México, donde fueron atendidos en Bucalia Dent, consultorio dental. Después del consentimiento informado de cada paciente, se realizó una historia clínica para conocer los síntomas, enfermedades sistémicas, ausencia de dientes y nivel de inflamación gingival de acuerdo al índice de Loe y Silness. A continuación, se tomó una muestra de biofilm microbiano (placa dentobacteriana), la cual se suspendió en una solución buffer de fosfato, posteriormente fue llevada al Centro de Investigación y Desarrollo en Ciencias de la Salud (CIDICS), Monterrey, N.L, México. Se extrajo DNA y se purificó, después se realizó PCR para detectar los patógenos orales; la PCR se visualizó en gel de agarosa (1.5%) por tinción de bromuro de etidio. Resultados: Se detectó 80.85% Porphyromona gingivalis y 68.09% Fusobacterium nucleatum en pacientes recuperados de SARS-CoV-2; 23.4% presentaron inflamación leve de acuerdo al índice de Loe y Silness, 54.5% fueron masculinos y 45.5% femeninos. Por otro lado, 36.4% de los pacientes con inflamación leve tenían de cuatro a seis dientes ausentes. En estos pacientes se detectó 18.18% únicamente con Fusobacterium nucleatum y 27.27% sólo con Porphyromona gingivalis; el sexo masculino tuvo predisposición en 66.6% y el femenino en 33.33%. Se observó infección con los dos patógenos presentes en 45.45%; y 60% de estos pacientes fueron masculinos. Conclusiones: Los pacientes recuperados de SARSCoV- 2 analizados en esta investigación mostraron mala higiene oral y alta prevalencia de los patógenos mencionados altamente relacionados a inflamación gingival o enfermedad periodontal, lo que nos indica que es indispensable la intervención del odontólogo al finalizar el periodo de infección de cada paciente (AU)

Introduction: SARS-CoV-2 affects the respiratory system to different degrees. The oral cavity is a colonized place by bacterias, therefore, by not having good hygiene, different secondary diseases can occur; this has caused an alert in the dental industry, since it can contribute to later complications in patients. Material and methods: The study was conducted in 47 SARS-CoV-2 recovered volunteers from the Montemorelos city of the Nuevo León state, Mexico, who were attended at the Bucalia Dent dental clinic. An informed consent was obtained from each of the patients, then their clinical history was documented in order to know the symptoms, previous systemic diseases, absence of teeth and degree of gingival inflammation, as suggested by Loe and Silness. Subsequently, a dental plaque sample was taken from all patients, which was suspended in a phosphate buffered solution and shipped to The Center for Research and Development in Health Sciences (CIDICS), Monterrey, NL, Mexico for storage. DNA extraction and purification was performed and PCR was carried out for the oral pathogens detection. All PCR products were visualized on 1.5% agarose gel by ethidium bromide staining. Results: Porphyromona gingivalis and Fusobacterium nucleatum were detected in 80.85% and 68.09% of SARS-CoV-2 recovered patients, respectively. 23.4% showed mild inflammation based on the Loe and Silness criteria, 54.5% were male and 45.5% female. On the other hand, 36.4% of patients with mild inflammation had between 4 to 6 missing teeth. A single infection by Fusobacterium nucleatum was detected in 18.18% and by Porphyromona gingivalis in 27.27%; the male sex had a predisposition with 66.66% and 33.33% female; coinfection of both pathogens was observed in 45.45% where 60% were male. Conclusions: SARS-CoV-2 recovered patients show poor oral hygiene and a high prevalence of oral pathogens related to the development of inflammatory gingival or periodontal disease, this suggests the need for an odontological clinical intervention at the end of the course of infection or disease caused by SARS-CoV-2 (AU)

Identification of Proteins Associated with the Formation of Oral Biofilms

ABSTRACT Objective: To identify proteins associated with the formation of Streptococcus gordonii and Fusobacterium nucleatum biofilms. Material and Methods: Biofilms composed of two bacterial species, S. gordonii and F. nucleatum, were cultured for 1, 4, 7, and 10 days. The presence of both species was confirmed via amplification of the srtA and radD genes using real-time PCR. The concentrations of proteins associated with the biofilms and individual species were quantified using Western blotting. Results: The protein profiles of S. gordonii and F. nucleatum from individual cultures determined using one-dimensional electrophoresis revealed proteins found in S. gordonii and in F. nucleatum. Ct and reciprocal Ct values were determined for the exposed S. gordonii and F. nucleatum biofilms. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) protein was detected in biofilms and F. nucleatum, whereas HSP40 protein was present only in biofilms after 7 and 10 days of formation. Conclusion: HSP40 was detected only in the formed biofilms; thus, HSP40 is an essential proteins for adhesion.

In vitro homeostasis of rat oral epithelial cell cultures following withdrawal of periodontal pathogens

Abstract Inflammation of periodontal tissues is the consequence of interaction between periodontal pathogens and immune system. This is associated with increased expression of inflammatory cytokines, which may exert destructive effect to the periodontal tissues when released over long period. The aim of this study was to chronologically track the homeostasis of oral keratinocytes following removal of periodontal pathogens. This was done by investigating expression of selected inflammatory markers and integrity of epithelial monolayers in vitro. Rat oral keratinocytes were stimulated with heat-killed Fusobacterium nucleatum and Porphyromonas gingivalis over 7-days then bacteria were washed away and epithelial cells re-cultured for 3-days. Expression of IL-1β, IL-6, and IL-8 was measured by ELISA while transcription of tissue inhibitor of metalloproteinase-1 (TIMP-1) and matrix metalloproteinase -8 (MMP-8) was measured by polymerase chain reaction before and after removal of bacteria. Integrity of epithelial sheet was investigated by using transepithelial electrical resistance. Data showed general downregulation of IL-1b, IL-6, and IL-8 associated with restoring transcription of TIMP-1 and MMP-8 to normal level following removal of bacteria from epithelial cultures. However, expression of IL-8 and MMP-8 remained significantly higher than unstimulated epithelial cells despite withdrawal of F. nucleatum and P. gingivalis respectively from oral keratinocytes cultures. In addition, integrity of epithelial barrier function remained compromised even after removal of P. gingivalis. Results suggest that even after three days following removal of periodontal pathogens, oral keratinocytes sustained persistent upregulation of certain inflammatory markers that could compromise integrity of epithelial barrier function.

Resumo A inflamação dos tecidos periodontais é a consequência da interação entre patógenos periodontais e o sistema imunológico. Isso está associado ao aumento da expressão de citocinas inflamatórias, que podem exercer efeito destrutivo nos tecidos periodontais quando liberadas por um longo período. O objetivo deste estudo foi rastrear cronologicamente a homeostase dos queratinócitos orais após a remoção dos patógenos periodontais. Isto foi feito através da investigação da expressão de marcadores inflamatórios selecionados e da integridade de monocamadas epiteliais in vitro. Os queratinócitos orais de rato foram estimulados com Fusobacterium nucleatum e Porphyromonas gingivalis destruídas pelo calor por 7 dias, depois as bactérias foram lavadas e as células epiteliais foram cultivadas novamente por 3 dias. A expressão de IL-1b, IL-6 e IL-8 foi medida por ELISA, enquanto a transcrição do inibidor tecidual de metaloproteinase-1 (TIMP-1) e matriz metalopeptidase-8 (MMP-8) foi medida por reação em cadeia da polimerase antes e após a remoção de bactérias. A integridade da folha epitelial foi investigada usando resistência elétrica transepitelial. Os dados mostraram uma regulação negativa geral de IL-1b, IL-6 e IL-8 associada à restauração da transcrição de TIMP-1 e MMP-8 para o nível normal após a remoção de bactérias de culturas epiteliais. No entanto, a expressão de IL-8 e MMP-8 permaneceu significativamente maior que as células epiteliais não estimuladas, apesar da retirada de F. nucleatum e P. gingivalis, respectivamente, das culturas de queratinócitos orais. Além disso, a integridade da função da barreira epitelial permaneceu comprometida mesmo após a remoção de P. gingivalis. Os resultados sugerem que, mesmo após três dias após a remoção dos patógenos periodontais, os queratinócitos orais sustentaram uma regulação positiva persistente de certos marcadores inflamatórios que poderiam comprometer a integridade da função da barreira epitelial.

Efeito de análogos de curcumina, irradiados ou não por LED, como agentes antimicrobianos e indutores de proliferação e migração celular / Effect of curcumin analogues, irradiated or not by LED, as antimicrobial agents and inducers of cell proliferation and migration

O tratamento endodôntico de dentes permanentes jovens com infecções pulpares/periapicais antes de completar a rizogênese ainda é um desafio para a Endodontia e a Odontopediatria. Relatos científicos têm mostrado que a curcumina (CUR), um fitoquímico polifenólico, apresenta diversas propriedades terapêuticas, entre as quais, amplo espectro de ação antimicrobiana e a capacidade de induzir a proliferação e migração celular. Além disso, devido à sua capacidade excitatória na presença de luz, a CUR também tem sido utilizada como fotossensibilizante em terapia fotodinâmica associada ao LED (light emitting diode), promovendo aumento dos seus efeitos biológicos. Uma forma de aumentar seu potencial terapêutico e reduzir algumas limitações do uso da CUR é a síntese de análogos a partir de pequenas modificações químicas na estrutura original, entretanto, mantendo sua capacidade fotossensibilizante. O objetivo desse estudo foi avaliar a ação antimicrobiana e antibiofilme de análogos de curcumina sob a influência ou não do LED sobre microrganismos de interesse endodôntico e sua influência sobre a viabilidade, proliferação e migração de fibroblastos da linhagem L-929. Uma série de compostos análogos de CUR (PCR-4 H, PCR-3 OH, PCR-4 OH, PCR-3 OCH3, PCR-4 OCH3, PCR-3 acetil, PCR-4 acetil) foram sintetizados pela metodologia de Pabon. A atividade antimicrobiana da CUR e seus análogos foi determinada pelo ensaio de Concentração Inibitória Mínima (CIM) e Concentração Bactericida Mínima (CBM) sobre Streptococcus mutans, Lactobacillus casei, Actinomyces israelii, Enterococcus faecalis e Fusobacterium nucleatum, sob a ação ou não do LED InGaN (nitreto de gálio e índio, com potência de saída de 100 mW/cm², ponta do LED com área de 0,78 cm², 60 s). A curcumina e seu análogo com melhor efeito antimicrobiano (PCR-3 OH) foi avaliado sobre o biofilme inicial (72h) e maduro (1 semana) dessas espécies em microplacas e sobre biofilmes multiespécies formados em túbulos dentinários por contagem das UFC/mL e por microscopia confocal, respectivamente, sob ação ou não do LED. Também foram avaliados quanto à citotoxicidade e a capacidade de induzir proliferação e migração em fibroblastos, por meio de ensaios de metiltetrazólio, azul de tripan e azul de Coomassie, respectivamente. Os dados foram avaliados estatisticamente (p<0,05). Dos 7 análogos de curcumina sintetizados, PCR-3 OH foi o único composto que apresentou atividade bactericida quando testado sobre as bactérias de interesse endodôntico selecionadas. Seu efeito foi potencializado na presença do LED, variando entre as espécies bacterianas. A curcumina teve efeito bactericida para as espécies S. mutans, A. israelii, L. casei e F. nucleatum, e em algumas delas, foi independente do LED. Ambos os compostos reduziram o crescimento dos biofilmes iniciais ou maduros, independente do LED. Entretanto, quando irradiados, o efeito dos compostos variou de acordo com a espécie bacteriana, sendo que A. israelii e S. mutans foram os mais afetados. Ambos os compostos reduziram significativamente os biofilmes multiespécies quando comparados ao controle sem tratamento, sendo que melhor efeito foi observado para PCR-3 OH. A curcumina foi considerada citocompatível a partir de 0,039µg/mL e PCR-3 OH a partir de 0,019 µg/mL. Houve redução significativa na viabilidade celular quando os compostos foram irradiados com LED nas concentrações 0,039 e 0,019 µg/mL. O LED, dentro dos parâmetros testados, reduziu significativamente a viabilidade, a proliferação e a migração celular, independente do composto ou tempo de exposição. Conclui-se que PCR-3 OH apresentou atividade bactericida e sobre biofilmes simples e multiespécies de bactérias de interesse endodôntico superior à CUR, principalmente sob ação do LED. Entretanto, sua citocompatiblidade foi inferior à da CUR. A presença do LED afetou a viabilidade, proliferação e migração dos fibroblastos, mostrando que os parâmetros utilizados para fins antimicrobianos não foram adequados para aplicação em células eucarióticas(AU)

Endodontic treatment of young permanent teeth with pulp / periapical infections before completing rhizogenesis is still a challenge for Endodontics and Pediatric Dentistry. Scientific reports have shown that curcumin (CUR), a polyphenolic phytochemical, has several therapeutic properties, including a broad spectrum of antimicrobial action and the ability to induce cell proliferation and migration. In addition, due to its excitatory capacity in the presence of light, CUR has also been used as a photosensitizer in photodynamic therapy associated with LED (light emitting diode), promoting an increase in its biological effects. One way to increase its therapeutic potential and reduce some limitations of the use of CUR is the synthesis of analogues from small chemical modifications in the original structure, however, maintaining its photosensitizing capacity. The aim of this study was to evaluate the antimicrobial and antibiofilm action of curcumin analogues under the influence or not of LED on microorganisms of endodontic interest and their influence on the viability, proliferation and migration of L-929 fibroblasts. A series of CUR analog compounds (PCR-4 H, PCR-3 OH, PCR-4 OH, PCR-3 OCH3, PCR-4 OCH3, PCR-3 acetyl, PCR-4 acetyl) were synthesized by Pabon's methodology. The antimicrobial activity of CUR and its analogs was determined by the Minimum Concentration Inhibitory (CIM) and Minimum Bactericidal Concentration (CBM) assay on Streptococcus mutans, Lactobacillus casei, Actinomyces israelii, Enterococcus faecalis and Fusobacterium nucleatum, with or without the InGaN LED (gallium and indium nitride, with output power of 100 mW / cm², LED tip with an area of 0.78 cm², 60 sec). Curcumin and its analog with the best antimicrobial effect (PCR-3 OH) were evaluated on the initial (72h) and mature (1 week) biofilm of these species in microplates and on multispecies biofilms formed in dentinal tubules by counting CFU / mL and by confocal microscopy, respectively, under the action or not of the LED. They were also evaluated for cytotoxicity and the ability to induce proliferation and migration in fibroblasts, using methyltetrazolium, trypan blue and Coomassie blue assays, respectively. The data were evaluated statistically (p <0.05). Of the 7 curcumin analogues synthesized, PCR-3 OH was the only compound that showed bactericidal activity when tested on selected bacteria of endodontic interest. Its effect was enhanced in the presence of LED, varying between bacterial species. Curcumin had a bactericidal effect for the species S. mutans, A. israelii, L. casei and F. nucleatum, and in some of them, it was independent of the LED. Both compounds reduced the growth of the initial or mature biofilms, regardless of the LED. However, when irradiated, the effect of the compounds varied according to the bacterial species, with A. israelii and S. mutans being the most affected. Both compounds significantly reduced multispecies biofilms when compared to the untreated control, with the best effect being observed for PCR-3 OH. Curcumin was considered cytocompatible from 0.039 µg / mL and PCR-3 OH from 0.019 µg / mL. There was a significant reduction in cell viability when the compounds were irradiated with LED at concentrations of 0.039 and 0.019 µg / mL. The LED, within the parameters tested, significantly reduced cell viability, proliferation and migration, regardless of the compound or time of exposure. It is concluded that PCR-3 OH showed bactericidal activity and on simple and multispecies biofilms of bacteria of endodontic interest superior to CUR, mainly under the action of LED. However, its cytocompatibility was lower than that of the CUR. The presence of the LED affected the viability, proliferation and migration of fibroblasts, showing that the parameters used for antimicrobial purposes were not suitable for application in eukariotic cells(AU)

Chemical Composition and Antibacterial Effect of Plantago Major Extract on Periodontal Pathogens

Abstract Objective: To determine the in vitro antibacterial effect of different concentrations of the ethanol extract of Plantago major (plantain) on Porphyromonas gingivalis and Fusobacterium nucleatum. Material and Methods: Bacterial susceptibility tests were used in conjunction with the agar diffusion test and the minimum inhibitory concentration (MIC) test using the broth macrodilution technique. Results: Different concentrations of ethanol extract (25%, 50%, 75% and 100%) dissolved in 70% ethanol were used, with a positive control (0.12% chlorhexidine + 0.05% cetyl-pyridinium chloride) and a negative control (70% alcohol). The extracts at 75% and 100% showed inhibition halos against both strains studied. With 0.12% chlorhexidine + 0.05% cetyl-pyridinium chloride, inhibition halos averaged 14.9 mm, in contrast to 70º alcohol, where no bacterial inhibition was observed. The MIC was 50% for both species. Conclusion: The ethanol extract of Plantago major presents an in vitro antibacterial effect on Porphyromonas gingivalis, they may have potential applications in food and pharmaceutical products.

Essential Oil from Psidium cattleianum Sabine (Myrtaceae) Fresh Leaves: Chemical Characterization and in vitro Antibacterial Activity Against Endodontic Pathogens

Abstract Endodontic infections result from oral pathogenic bacteria which reach and infect dental pulp, as well as surrounding tissues, through cracks, unrepaired caries and failed caries restorations. This study aims to determine the chemical composition of essential oil from Psidium cattleianum leaves (PC-EO) and to assess its antibacterial activity against endodontic bacteria. Antibacterial activity of PC-EO was evaluated in terms of its minimum inhibitory concentration (MIC) values by the broth microdilution method on 96-well microplates. Bacteria Porphyromonas gingivalis (MIC = 20 µg/mL), Prevotella nigrescens (MIC = 62.5 µg/mL), Fusobacterium nucleatum (MIC = 12.5 µg/mL), Actinomyces naeslundii (MIC = 50 µg/mL), Bacteroides fragilis (MIC = 12.5 µg/mL), Aggregatibacter actinomycetemcomitans (MIC = 6.25 µg/mL) and Peptostreptococcus anaerobius (MIC = 62.5 µg/mL) were evaluated and compared to chlorhexidine dihydrochloride (CDH), the positive control. PC-EO was obtained by hydrodistillation with the use of a Clevenger-type apparatus whereas its chemical composition was analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Viridiflorol (17.9%), β-caryophyllene (11.8%), 1,8-cineole (10.8%) and β-selinene (8.6%) were the major constituents found in PC-EO, which exhibited high antibacterial activity against all endodontic pathogens under investigation. Therefore, PC-EO, a promising source of bioactive compounds, may provide therapeutic solutions for the field of endodontics.

Comparison of 16S Ribosomal RNA Targeted Sequencing and Culture for Bacterial Identification in Normally Sterile Body Fluid Samples: Report of a 10-Year Clinical Laboratory Review

As 16S ribosomal RNA (rRNA)-targeted sequencing can detect DNA from non-viable bacteria, it can be used to identify pathogens from clinical samples even in patients pretreated with antibiotics. We compared the results of 16S rRNA-targeted sequencing and culture for identifying bacterial species in normally sterile body fluid (NSBF): cerebrospinal, pericardial, peritoneal and pleural fluids. Over a 10-year period, a total of 312 NSBF samples were evaluated simultaneously using 16S rRNA-targeted sequencing and culture. Results were concordant in 287/312 (92.0%) samples, including 277 (88.8%) negative and 10 (3.2%) positive samples. Of the 16 sequencing-positive, culture-negative samples, eight showed clinically relevant isolates that included Fusobacterium nucleatum subsp. nucleatum, Streptococcus pneumoniae, and Staphylococcus spp. All these samples were obtained from the patients pretreated with antibiotics. The diagnostic yield of 16S rRNA-targeted sequencing combined with culture was 11.2%, while that of culture alone was 6.1%. 16S rRNA-targeted sequencing in conjunction with culture could be useful for identifying bacteria in NSBF samples, especially when patients have been pretreated with antibiotics and when anaerobic infection is suspected.

Research progress of correlation between periodontal pathogens and systemic diseases / 南方医科大学学报

Periodontal pathogens are the main pathogenic factor of periodontitis. Periodontal pathogens have a large variety of virulence factors such as lipopolysaccharide, fimbriae and proteases, which enables the pathogens to infect periodontal tissues and stimulate the secretion of inflammatory cytokines, causing chronic systemic inflammation. Periodontal pathogens may invade multiple systems such as the circulatory system, immune system, respiratory system and digestive system to cause systematic diseases. Recent studies have shown that periodontal pathogens may have close relations with systemic diseases such as cardiovascular disease, diabetes, rheumatoid arthritis, and cancer. Among the periodontal pathogens, can be found in atherosclerotic plaques to impairing the function of the vascular endothelium; may also increase the level of inflammatory factors such as TNF-α to promote insulin resistance and diabetes. Many of the periodontal pathogens such as , and can be detected in the synovial fluid of rheumatoid arthritis patients, suggesting their involvement in the pathogenesis of rheumatoid arthritis. may cause alterations in the intestinal microbiome in mice and promote the occurrence of intestinal tumors. Herein we review the recent progresses in the relationship between periodontal pathogens and systemic diseases.

Desbridamiento artroscópico de osteomielitis de rodilla por Fusobacterium Nucleatum en niño de 4 años. Reporte de caso con 8 años de seguimiento / Arthroscopic debridement in knee osteomyelitis by Fusobacterium Nucleatum in a 4 years-old child

La infección osteoarticular por microorganismos anaerobios es infrecuente, siendo la infección por fusobacterium nucleatum en niños muy rara. Se presenta el caso de un varón de 4 años que consulta por dolor, limitación funcional, y signos inflamatorios locales en la rodilla derecha de 1 mes de evolución, con ausencia de fiebre y sin antecedente traumático previo. Las pruebas de imagen objetivan una lesión lítica en cóndilo femoral externo con una colección en el espacio articular. Con el diagnóstico de osteomielitis en cóndilo femoral externo y artritis séptica de rodilla, se realizaron dos artroscopias consecutivas para desbridamiento articular y curetaje de la lesión. Se instauró terapia antibiótica intravenosa empírica y posteriormente específica tras el aislamiento de fusobacterium nucleatum. Fue necesario la identificación microbiológica mediante PCR universal 16S r ARN, ante la negatividad repetida de los cultivos.Tras 8 años de seguimiento el niño no presenta signos de infección local, las imágenes radiológicas del defecto osteocondral han mejorado y a la exploración muestra una correcta movilidad realizando una vida normal, incluso actividad deportiva. Tipo de Trabajo: Reporte de Caso. Nivel Evidencia: V

Osteoarticular infection by anaerobic microorganisms is infrequent in children, specially caused by Fusobacterium Nucleatum.A 4-year-old male patient that consults for pain, functional limitation and local inflammatory signs on the right knee, without fever for a 1-month, and no history of trauma. The radiological images showed a lytic lesion in the external femoral condyle with a collection in the joint space. After the diagnosis of osteomyelitis in external femoral condyle and septic arthritis of the knee, two consecutive arthroscopies were carried out for joint debridement and curettage of the lesion.Previously the isolation of fusobacterium nucleatum an empirical intravenous antibiotic therapy was instituted. Microbiological identification by 16S rRNA universal PCR was necessary in view of the repeated negativity of the cultures. Once the diagnosis is carried out, a more specific antibiotic treatment could be administered. After 8 years of follow-up, the child showed no signs of local infection, the radiological images of the osteochondral defect had improved. On physical examination the child presented a correct mobility leading a normal life and even doing sport. Type of Study: Case report. Level of Evidence: V

Perillyl alcohol has antibacterial effects and reduces ROS production in macrophages

Abstract Natural products have emerged as a rich source of bioactive compounds for adjunctive treatments of many infectious and inflammatory conditions, including periodontitis. Among the monoterpenes with significant biological properties, there is the perillyl alcohol (POH), which can be found in several essential oils and has shown immunomodulatory properties in recent studies, which may be interesting in the treatment of non-neoplastic inflammatory disorders. Objective To determine the antibacterial and immune modulatory activities of the POH. Methodology The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the POH for two significant Gram-negative periodontal pathogens were determined by macrodilution and subculture, respectively. Cell proliferation and cytotoxicity in RAW 264.7 macrophages were determined by Trypan Blue and mitochondrial enzymatic activity assay. The modulation of reactive oxygen species (ROS) was analyzed by flow cytometry and expression of TNF and arginase-1 by real-time PCR. Results The POH was effective against P. gingivalis (ATCC 33277) and F. nucleatum (ATCC 25586) with MIC= MBC=1600 μM. No cytotoxicity up to 100 µM was observed on macrophages. The cell proliferation was inhibited from 48 hours at 100 μM (p<0.05) and 250 μM (p<0.01). The POH increased ROS production at both 10 μM and 100 μM (p<0.05) in unstimulated cells. The PMA-induced ROS production was not affected by POH, whereas 100 μM significantly reduced lipopolysaccharide-induced (LPS-induced) ROS. The expression of TNF was not affected by POH in unstimulated cells or in cells polarized to M1 phenotype, whereas both concentrations of POH reduced (p<0.05) the expression of arginase-1 in M2-polarized macrophages. Conclusion The POH has antibacterial activity against periodontal pathogens and reduced proliferation of murine macrophages without significant cytotoxicity at concentrations up to 100 μM. In addition, the POH reduced the LPS-induced ROS and the expression of arginase-1 in M2-polarized macrophages.

Comparación del efecto antibacteriano de un extracto etanólico de propóleo a dos concentraciones y del paramonoclorofenol alcanforado frente a Enterococcus faecalis y Fusobacterium nucleatum / Comparison between the antibacterial effects of two concentrations of an ethanolic extract of propolis and camphorated paramonochlorophenol versus Enterococcus Faecalis and Fusobacterium Nucleatum

Objetivo: Comparar el efecto antibacteriano in vitro de un extracto etanólico de propóleo a dos concentraciones frente a Enterococcus faecalis ATCC: 29212 y Fusobacterium nucleatum ATCC: 25586 con el paramonoclorofenol alcanforado (PMCFA). Materiales y método: Se incluyeron dos grupos de 15 placas Petri con cepas activadas de Enterococcus faecalis y Fusobacterium nucleatum. Se elaboró un extracto etanólico a partir de propóleo (EEP), proveniente de la provincia de Oxapampa (Perú), y se diluyó a concentraciones del 20% y el 30%. Se comparó su efecto antibacteriano frente al PMCFA, usando clorhexidina al 2% como control positivo y agua destilada como control negativo; mediante el método de Kirby-Bauer, en un periodo de 7 días para Fusobacterium nucleatum y 24 y 48 horas para Enterococcus faecalis. Se realizó el análisis estadístico mediante el programa SPSS versión 21. Resultados: Frente a Enterococcus faecalis se obtuvieron halos de 10,32 mm, 14,23 mm y 9,10 mm a las 24 horas y halos de 11 mm, 14,96 mm y 8,94 mm a las 48 horas, para las concentraciones de EEP al 20%, el 30% y el PMCFA, respectivamente. Por su parte, frente a Fusobacterium nucleatum, halos de 18,89 mm, 23,17 mm y 13,50 mm para las concentraciones al 20%, el 30% y el PMCFA, respectivamente. Conclusiones: El extracto etanólico elaborado a partir de propóleo de Oxapampa mostró efecto antibacteriano a una concentración del 20% y el 30%, que fue significativamente mayor al del PMCFA, frente a cepas activadas de Enterococcus faecalis y Fusobacterium nucleatum. (AU)

Objective: To compare the antibacterial effect of two concentrations of an ethanolic extract of propolis (EEP) with that of camphorated paramonochlorophenol (CPMC) in Enterococcus faecalis ATCC: 29212 and Fusobacterium nucleatum ATCC: 25586. Material and methods:Two groups of 15 petri plates each, containing activated strains of Enterococcus faecalis and Fusobacterium nucleatum were included in the study. The EEP was prepared using Peruvian propolis from the province of Oxapampa diluted to 20% and 30% of the original concentration. The antibacterial effect of both extracts was compared to CPMC using the Kirby-Bauer disk diffusion method of 07 days for Fusobacterium nucleatum and 24 and 48 hours for Enterococcus faecalis.Statistical analysis was performed using the SPSS program version 21. Results: Inhibitory diameters of 10.32 mm for 20% EEP, 14.23 mm for 30% EEP and 9.10 mm for CPMC were obtained for Enterococcus faecalis at 24 hours, being 11 mm for 20% EEP, 14.96 mm for 30% EEP and 8.94 mm for CPMC at 48 hours. For Fusobacterium nucleatum, the inhibitory diameters were 18.89 mm for 20% EEP, 23.17 mm for 30% EEP and 13.50 mm for CPMC at 7 days. Conclusions: The EEP elaborated from Oxapampa Propolis showed antibacterial effects at concentrations of 20% and 30%, which were significantly higher than those of CPMC in activated strains of Enterococcus faecalis and Fusobacterium nucleatum. (AU)

Regulation of ghrelin receptor by microbial and inflammatory signals in human osteoblasts

Abstract: Recently, it has been suggested that the anti-inflammatory hormone ghrelin (GHRL) and its receptor GHS-R may play a pivotal role in periodontal health and diseases. However, their exact regulation and effects in periodontitis are not known. The aim of this in-vitro study was to investigate the effect of microbial and inflammatory insults on the GHS-R1a expression in human osteoblast-like cells. MG-63 cells were exposed to interleukin (IL)-1β and Fusobacterium nucleatum in the presence and absence of GHRL for up to 2 d. Subsequently, gene expressions of GHS-R1a, inflammatory mediators and matrix metalloproteinase were analyzed by real-time PCR. GHS-R protein synthesis and NF-κB p65 nuclear translocation were assessed by immunocytochemistry and immunofluorescence microscopy, respectively. IL-1β and F. nucleatum caused a significant upregulation of GHS-R1a expression and an increase in GHS-R1a protein. Pre-incubation with a MEK1/2 inhibitor diminished the IL-1β-induced GHS-R1a upregulation. IL-1β and F. nucleatum also enhanced the expressions of cyclooxygenase 2, CC-chemokine ligand 2, IL-6, IL-8, and matrix metalloproteinase 1, but these stimulatory effects were counteracted by GHRL. By contrast, the stimulatory actions of IL-1β and F. nucleatum on the GHS-R1a expression were further enhanced by GHRL. Our study provides original evidence that IL-1β and F. nucleatum regulate the GHS-R/GHRL system in osteoblast-like cells. Furthermore, we demonstrate for the first time that the proinflammatory and proteolytic actions of IL-1β and F. nucleatum on osteoblast-like cells are inhibited by GHRL. Our study suggests that microbial and inflammatory insults upregulate GHS-R1a, which may represent a protective negative feedback mechanism in human bone.

Relationship of Oral Bacterial Load Over One Year of Smoking Cessation / 치위생과학회지

BACKGROUND: Smoking exerts an adverse effect on the periodontal tissue by reorganizing the ecosystem of oral microorganisms and is considered to be an important factor in the development of periodontal disease. Although cross-sectional studies on smokers and non-smokers have been attempted to investigate the microbial differences in periodontal oral cavity, only few studies have been conducted to investigate the changes in oral microorganisms during smoking cessation. The purpose of this study was to investigate the changes of bacteria in saliva and gingival crevicular fluid (GCF) over a period of one year among 11 smokers trying to quit smoking.METHODS: Eleven smokers trying to quit smoking visited the clinic at baseline, two weeks, two months, four months, six months, and 12 months to give saliva and GCF samples. The amounts of 16S rRNA, Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum subsp. nucleatum, Streptococcus mutans, and Streptococcus sobrinus in saliva and GCF were quantified using real-time polymerase chain reaction TaqMan probe assay. The results were analyzed by nonparametric statistical analysis using Friedman test and Spearman correlation coefficient.RESULTS: After cessation of smoking, the amounts of 16S rRNA corresponding to P. gingivalis, F. nucleatum, P. intermedia, and T. denticola in saliva decreased and then again increased significantly. The amount of F. nucleatum 16S rRNA in GCF decreased significantly after smoking cessation. Positive correlations were observed between 16S rRNA and F. nucleatum and between F. nucleatum and T. denticola in saliva and GCF.CONCLUSION: Even if the number of subjects in this study was small, we suggest that smoking cessation may reduce the total bacterial amount and F. nucleatum in GCF. However, the results regarding changes in the microbial ecosystem due to smoking or smoking cessation were inconsistent. Therefore, further in-depth studies need to be carried out.

Antimicrobial effect of toothbrush with light emitting diode on dental biofilm attached to zirconia surface: an in vitro study

PURPOSE: The purpose of this study was to evaluate the antimicrobial effects of a toothbrush with light-emitting diodes (LEDs) on periodontitis-associated dental biofilm attached to a zirconia surface by static and dynamic methods. MATERIALS AND METHODS: Zirconia disks (12 mm diameter, 2.5 mm thickness) were inserted into a 24-well plate (static method) or inside a Center for Disease Control and Prevention (CDC) biofilm reactor (dynamic method) to form dental biofilms using Streptococcus gordonii and Fusobacterium nucleatum. The disks with biofilm were subdivided into five treatment groups-control, commercial photodynamic therapy (PDT), toothbrush alone (B), brush with LED (BL), and brush with LED+erythrosine (BLE). After treatment, the disks were agitated to detach the bacteria, and the resulting solutions were spread directly on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy (SEM) was performed to visualize alterations in bacterial morphology. RESULTS: No significant difference in biofilm formation was observed between dynamic and static methods. A significant difference was observed in the number of viable bacteria between the control and all experimental groups (P < 0.05). The percentage of bacterial reduction in the BLE group was significantly higher than in the other treated groups (P < 0.05). SEM revealed damaged bacterial cell walls in the PDT, BL, and BLE groups, but intact cell walls in the control and B groups. CONCLUSION: The findings suggest that an LED toothbrush with erythrosine is more effective than other treatments in reducing the viability of periodontitis-associated bacteria attached to zirconia in vitro.

Prognostic Impact of Fusobacterium nucleatum Depends on Combined Tumor Location and Microsatellite Instability Status in Stage II/III Colorectal Cancers Treated with Adjuvant Chemotherapy

BACKGROUND: This study aimed to investigate the prognostic impact of intratumoral Fusobacterium nucleatum in colorectal cancer (CRC) treated with adjuvant chemotherapy. METHODS: F. nucleatum DNA was quantitatively measured in a total of 593 CRC tissues retrospectively collected from surgically resected specimens of stage III or high-risk stage II CRC patients who had received curative surgery and subsequent oxaliplatin-based adjuvant chemotherapy (either FOLFOXor CAPOX). Each case was classified into one of the three categories: F. nucleatum–high, –low, or –negative. RESULTS: No significant differences in survival were observed between the F.nucleatum–high and –low/negative groups in the 593 CRCs (p = .671). Subgroup analyses according to tumor location demonstrated that disease-free survival was significantly better in F.nucleatum–high than in –low/negative patients with non-sigmoid colon cancer (including cecal, ascending, transverse, and descending colon cancers; n = 219; log-rank p = .026). In multivariate analysis, F. nucleatum was determined to be an independent prognostic factor in non-sigmoid colon cancers (hazard ratio, 0.42; 95% confidence interval, 0.18 to 0.97; p = .043). Furthermore, the favorable prognostic effect of F. nucleatum–high was observed only in a non-microsatellite instability-high (non-MSI-high) subset of non-sigmoid colon cancers (log-rank p = 0.014), but not in a MSI-high subset (log-rank p = 0.844), suggesting that the combined status of tumor location and MSI may be a critical factor for different prognostic impacts of F. nucleatum in CRCs treated with adjuvant chemotherapy. CONCLUSIONS: Intratumoral F. nucleatum load is a potential prognostic factor in a non-MSI-high/non-sigmoid/non-rectal cancer subset of stage II/III CRCs treated with oxaliplatin-based adjuvant chemotherapy.

Diagnóstico molecular de microorganismos periodontopatógenos en pacientes alcohó-licos - fumadores con periodontitis crónica de la ciudad de Loja, Ecuador / Diagnóstico molecular de microrganismos periodontopatogênicos em pacientes taba-gistas com periodontite crônica na cidade de Loja, Equador / Molecular diagnosis of microorganisms periodontopathogens in alcoholic - smoking patients with chronic periodontitis of the city of Loja, Ecuador

Los pacientes alcohólicos y fumadores presentan mayor predisposición de desarrollar enfermedad periodontal. Objetivo: Determinar la presencia de los microorganismos periodontopatógenos: Porphyromona gingivalis, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum y Aggregatibacter actinomycetemcomitans mediante la Reacción en Ca-dena de la Polimerasa (PCR), en pacientes alcohólicos fumadores con periodontitis crónica. Materiales y métodos: El universo fue de 31 pacientes de 18 y 62 años de edad de sexo masculino alcohólicos y/o fumadores en los cuales fueron excluidos aquellos que consumían algún tipo de droga, dando una muestra de 23 pacientes con bolsas periodontales ≥ 6mm del Centro de Rehabilitación de la ciudad de Loja, Ecuador. Se realizó un examen periodontal completo y la toma de muestras en dos de los sitios más profundos de cada paciente. Las variables analizadas fueron: presencia de biofilm dental, sangrado al sondaje, profundidad al sondaje y nivel de inserción clínica. Los datos fueron analizados con la prueba de Kruskal Wallis con un nivel de significancia del 5%. Resultados: La periodontitis crónica estuvo en el 52,1% de los pacientes de 18 a 30 años, siendo más susceptibles los alcohólicos de riesgo y fumadores leves. El 91,04 % de alcohóli-cos y fumadores se encuentran asociados con la presencia de biofilm dental (p = 0,028) y en el diagnóstico molecular el 41,18% de los pacientes presentan más de 3 microorganismos (p = 0,039). Conclusión: Se evidenció la presencia de los periodontopatógenos estudiados en pacientes alcohólicos fumadores con periodontitis crónica.

Alcoholic and smoking patients have a greater predisposition to develop periodontal disease. Objective: To determine the presence of microorganisms periodontopathogens: Porphyromona gingivalis, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans by Polymerase Chain Reaction (PCR), in alcoho-lic-smoking patients with chronic periodontitis. Materials and methods: The group was composed of 31 patients between the ages of 18 to 62-year-old, male alcoholics and/or smokers in which were excluded those who take some kind of drug, giving a sample of 23 patients with periodontal pockets ≥ 6mm from the Center of Rehabilitation of the city of Loja, Ecuador. A full periodontal examination and the sample taking were in two of the most profound sites of each patient. The variables analyzed were: the presence of dental biofilm, bleeding on probing, probing depth and clinical attachment level. The data were analyzed with the Kruskal Wallis Test with a significance level of 5%. Results: The chronic periodontitis was in the 52.1% of the patients between the ages of 18 to 30 years old, is more susceptible in risky alcoholics-smokers and low smokers. The 91.04 % of alcoholics and smokers are associated with the presence of dental biofilm (p = 0.028) and in the molecular diagnosis the 41.18% of patients exhibit more than 3 microorganisms (p = 0.039). Conclusion: That observed presence of the periodontopathogens in alcoholic-smoking patients with chronic periodontitis.

Os pacientes alcoólicos e fumantes apresentam uma possibilidade maior de desenvolver doença peridental. Objetivo: Determinar a presença do periodontopatógenos de microorganismos Porphyromona gingivalis, Treponema denticola, Fusobacterium nucleatum e Aggregatibacter actinomycetemcomitans por meio da Reação em Cadeia de Polimerasa (PCR),em pacientes alcoólicos e fumantes com periodontite crônico. Materiais e métodos: O universo pertenceu a 31 pacientes de 18 e 62 anos de idade de sexo masculino alcoólicos e/ou fumantes nos quais foram excluídos aqueles que consumiram algum tipo de droga, tendo uma amostra de 23 pacientes com bolsas peridentais. 6mm do Centro de Reabilitação da cidade de Loja, Equador. Um exame periodontal completo e a amostragem foram realizados em dois locais profundamente localizados de cada paciente. As variáveis analisadas eram: presença de biofilm dental, sangrou ao sondaje, profundidade ao sondaje e nível de suplemento clínico. Os dados foram analisados com o teste de Kruskal Wallis com um nível de significancia de 5%. Resultados: O periodontite crônico estava em 52,1% dos pacientes de 18 para 30 anos, enquanto sendo mais suscetível os alcoólicos de risco e fumantes ligeiros. 91,04% de alcoólicos e fumantes são associados com a presença de biofilm dental (p = 0028) e na diagnose 41,18% molecular dos pacientes apresenta mais de 3 microorganismos (p = 0039). Conclusões: A presença do periodontopatógenos foi comprovada nos pacientes alcoólicos e fumantes com periodontite crônico.

Real-time PCR quantification of 9 periodontal pathogens in saliva samples from periodontally healthy Korean young adults

PURPOSE: Few studies have examined periodontal pathogens from saliva samples in periodontally healthy young adults. The purposes of this study were to determine the prevalence of periodontopathic bacteria and to quantify periodontal pathogens in saliva samples using real-time polymerase chain reaction (PCR) assays in periodontally healthy Korean young adults under 35 years of age. METHODS: Nine major periodontal pathogens were analyzed by real-time PCR in saliva from 94 periodontally healthy young adults. Quantification of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Peptostreptococcus anaerobius, and Eikenella corrodens was performed by DNA copy number measurement. RESULTS: F. nucleatum and E. corrodens were detected in all subjects; the numbers of positive samples were 87 (92.6%), 91 (96.8%), and 90 (95.7%) for P. gingivalis, P. anaerobius, and C. rectus, respectively. Other pathogens were also detected in periodontally healthy subjects. Analysis of DNA copy numbers revealed that the most abundant periodontal pathogen was F. nucleatum, which was significantly more prevalent than all other bacteria (P < 0.001), followed by P. anaerobius, P. gingivalis, E. corrodens, C. rectus, and T. denticola. There was no significant difference in the prevalence of each bacterium between men and women. The DNA copy number of total bacteria was significantly higher in men than in women. CONCLUSIONS: Major periodontal pathogens were prevalent in the saliva of periodontally healthy Korean young adults. Therefore, we suggest that the development of periodontal disease should not be overlooked in periodontally healthy young people, as it can arise due to periodontal pathogen imbalance and host susceptibility.