Project description:Anaerobic bacteria in the oral cavity can cause respiratory infections. However, their precise mechanisms of action remain elusive. Unexpectedly, bacterial flora analysis using 16s rRNA revealed ‘hidden’ mixed infections of anaerobic bacteria and commensal oral Streptococcus species in community-acquired pneumonia. The purpose of this study is to elucidate the mechanisms by which Prevotella intermedia exacerbates oral streptococcal pneumonia.
Project description:Oral lichen planus (OLP) is a common oral mucosal disease, of which the etiology and pathogenesis are still unclear. Microorganisms may play an essential role in the pathogenesis of OLP. Previous studies of our group found that the composition ratio of Prevotella melaninogenica (Pm) on the buccal mucosa surface of OLP patients increased significantly. In addition, Pm could invade the epithelium of OLP. As the first physical defense of the oral mucosa, oral keratinocytes may interact directly with Pm in OLP. Therefore, this study aimed to explore the impact of Pm on primary human oral keratinocytes' transcriptome.
Project description:Background: The oral anaerobe Prevotella melaninogenica is enriched in the lungs of people with cystic fibrosis (pwCF), yet its functional impact on respiratory tract homeostasis remains incompletely understood. Prior studies identified immune modulatory effects following lung exposure to Prevotella, but the relevance of these findings for CF infections is unknown. Methods: The impact of P. melaninogenica on infection with the CF pathogen Staphylococcus aureus was evaluated using a mouse lung infection model and human respiratory tract cystic fibrosis transmembrane conductance regulator (CFTR) mutant and isogenic wild-type (WT)-corrected CFBE41o- epithelial cells. RNA-sequencing was performed to compare Prevotella-induced signaling programs in WT-corrected versus CFTR mutant cells. Results: P. melaninogenica significantly reduced S. aureus lung infection, which was associated with elevated S. aureus killing by lung neutrophils and impaired S. aureus adherence to epithelial cells. Live or heat-killed Prevotella were sufficient to mediate these effects, which were dependent on the toll-like receptor TLR2. Prevotella impairment of S. aureus adherence also required CFTR function, as this effect was lost in CFTR mutant cells but restored by CFTR modulator therapy. RNA-sequencing identified several antibacterial defense pathways selectively upregulated by Prevotella in WT corrected epithelial cells, correlating with higher IL-8 and IL-6 cytokine production. Conclusions: P. melaninogenica enhanced neutrophil and epithelial defense against S. aureus, but these benefits were lost with CFTR dysfunction. CFTR modulator therapy rescued Prevotella responsiveness in respiratory epithelial cells, highlighting the potential for synergistic effects of host-microbiome interactions and CFTR targeted therapies.
Project description:We performed shotgun proteomics on the bacteria Prevotella brevis GA33 and Prevotella ruminicola 23. We did this for two types of samples (cell extract and cell membrane) and using two methods (data-dependent and data-independent acquisition).
Project description:The transcriptional responses of Prevotella ruminicola were determined during growth on 20 different carbohydrate sources including mono-, di- and tri- saccharides, oligosaccharides, polymeric xylan and complete plant material with the aim of obtaining a more complete understanding of the number of genes and metabolic networks associated with carbohydrate catabolism by this organism All microarray hybridizations and subsequent scanning was undertaken using a two colour system (Cy3 and Cy5): 34 samples
Project description:Prevotella bryantii B14 was cultivated with monensin. Growth was monitored over a period of 9h with a broad range of monensin concentrations.
Project description:Protein secretion into extracellular space is an important virulence mechanism both among Gram negative and Gram-positive bacteria. Prevotella intermedia, an important species associated with periodontitis, is known to be resistant to several antibiotics. Since P. intermedia is a part of normal oral microbiota, its complete elimination is not possible. Despite the remarkable clinical significance P. intermedia has, little is known about the molecular basis for its virulence. The aim of this study was to characterize the secretome of P. intermedia in biofilm and planktonic life mode. Proteins in the secretome preparations were identified by nanoLC-ESI-MS/MS. The biofilm secretome showed 109 proteins while the planktonic secretome showed 136 proteins. The biofilm and the planktonic secretomes contained 17 and 33 signal-peptide bearing proteins, 13 and 18 lipoproteins, respectively. Proteins with predicted virulence potential were 39 in biofilm and 44 in planktonic secretomes, respectively. Gene ontology analysis revealed that the biofilm secretome displayed a markedly higher percent proteins compared to planktonic secretome in terms of cellular amino acid metabolic process, nitrogen compound metabolic process, protein binding and methyltransferase and kinase activities. In conclusion, this study revealed differences in the protein profiles of P. intermedia biofilm and planktonic secretomes. This may set a basis for asking further questions into molecular mechanisms how this species exerts its virulence potential in the oral cavity.