Publications by authors named "Yuetan Dou"

Introduction: Filifactor alocis is a newly appreciated member of the periodontal community with a strong periodontal disease correlation. Little is known about the survival mechanisms by which F. alocis copes with oxidative stress and establishes the infection within the local inflammatory microenvironment of the periodontal pocket.

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  • The PG1037 gene in Porphyromonas gingivalis is part of an operon involved in responding to oxidative stress and encodes a protein that has a zinc-finger motif and peroxidase motifs, but its exact function is still unknown.
  • Experimental methods included creating mutant versions of the PG1037 protein and conducting various assays to test their abilities to bind to and repair damaged DNA molecules.
  • Findings indicate that PG1037 plays a crucial role in recognizing and repairing DNA damage caused by oxidative stress, with specific motifs affecting its binding and activity.
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A dysbiotic microbial community whose members have specific/synergistic functions that are modulated by environmental conditions, can disturb homeostasis in the subgingival space leading to destructive inflammation, plays a role in the progression of periodontitis. Filifactor alocis, a gram-positive, anaerobic bacterium, is a newly recognized microbe that shows a strong correlation with periodontal disease. Our previous observations suggested F.

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Porphyromonas gingivalis, the causative agent of adult periodontitis, must gain resistance to frequent oxidative and nitric oxide (NO) stress attacks from immune cells in the periodontal pocket to survive. Previously, we found that, in the wild-type and under NO stress, the expression of PG1237 (CdhR), the gene encoding for a putative LuxR transcriptional regulator previously called community development and hemin regulator (CdhR), was upregulated 7.7-fold, and its adjacent gene PG1236 11.

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, a gram-negative anaerobe, is a leading etiological agent in periodontitis. This infectious pathogen can induce a dysbiotic, proinflammatory state within the oral cavity by disrupting commensal interactions between the host and oral microbiota. It is advantageous for to avoid complete host immunosuppression, as inflammation-induced tissue damage provides essential nutrients necessary for robust bacterial proliferation.

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The survival/adaptation of Porphyromonas gingivalis to the inflammatory environment of the periodontal pocket requires an ability to overcome oxidative stress. Several functional classes of genes, depending on the severity and duration of the exposure, were induced in P. gingivalis under HO-induced oxidative stress.

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  • The text discusses the link between environmental factors, oral bacteria, and periodontal disease, highlighting the role of Filifactor alocis in the disease process.
  • Filifactor alocis demonstrates the ability to withstand oxidative stress, which enhances its pathogenic potential and alters the oral microbial community.
  • Researchers have identified a specific protein, FA519, that aids in oxidative stress resistance, suggesting Filifactor alocis could serve as a potential diagnostic marker for periodontal disease, although further research is needed to understand its virulence.
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  • Anti-sigma factors, including PG1659, regulate sigma factor expression in response to environmental stress, with PG1659 being cotranscribed with the rpoE gene, which is crucial for oxidative stress resistance in P. gingivalis.
  • PG1659 is a hypothetical 130 amino acid transmembrane protein that has a calcium binding site and inhibits transcription initiation by the RpoE sigma factor.
  • Studies showed that PG1659 interacts with RpoE, and its absence leads to significant upregulation of the rpoE gene, indicating PG1659's role as an anti-sigma factor in the bacteria's regulatory network.
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  • The text indicates that there is a correction to a previously published article.
  • The article in question is identified by its Digital Object Identifier (DOI), which is 10.1371/journal.pone.0063367.
  • The correction likely addresses errors or inaccuracies found in the original manuscript.
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  • The study focuses on the proteases, specifically gingipains, produced by the bacteria associated with adult periodontitis, which play a key role in the disease's pathogenesis.
  • VimA is a protein that helps in the maturation of gingipains, but its exact functions and potential substitutes during stationary growth phases are not fully understood.
  • Researchers identified a related protein, PG1842, that may also be involved in activating gingipains when VimA is absent, suggesting potential pathways for targeting periodontal disease.
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Oral Biofilms are one of the most complex and diverse ecosystem developed by successive colonization of more than 600 bacterial taxa. Development starts with the attachment of early colonizers such as species and oral streptococci on the acquired pellicle and tooth enamel. These bacteria not only adhere to tooth surface but also interact with each other and lay foundation for attachment of bridging colonizer such as followed by late colonizers including the red complex species: and -the founders of periodontal disease.

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Filifactor alocis, a previously unrecognized Gram-positive anaerobic rod, is now considered a new emerging pathogen that may play a significant role in periodontal disease. F. alocis' unique characteristics and variations at the molecular level that may be responsible for the functional changes required to mediate the pathogenic process are discussed.

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The adaptation of Porphyromonas gingivalis to H2O2-induced stress while inducible is modulated by an unknown OxyR-independent mechanism. Previously, we reported that the PG_2212 gene was highly upregulated in P. gingivalis under conditions of prolonged oxidative stress.

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Changes in periodontal status are associated with shifts in the composition of the bacterial community in the periodontal pocket. The relative abundances of several newly recognized microbial species, including Filifactor alocis, as-yet-unculturable organisms, and other fastidious organisms have raised questions on their impact on disease development. We have previously reported that the virulence attributes of F.

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Previously, we have reported that gingipain activity in Porphyromonas gingivalis, the major causative agent in adult periodontitis, is post-translationally regulated by the unique Vim proteins including VimF, a putative glycosyltransferase. To further characterize VimF, an isogenic mutant defective in this gene in a different P. gingivalis genetic background was evaluated.

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Article Synopsis
  • Porphyromonas gingivalis, a bacteria linked to gum disease, can survive in environments with high levels of oxidative stress, such as hydrogen peroxide (H(2)O(2)).
  • Exposure to H(2)O(2) triggers an adaptive response in P. gingivalis, with certain genes being activated to manage DNA damage and protein stability, especially after short durations of stress.
  • The research found that a significant portion of genes in P. gingivalis changes its expression when exposed to oxidative stress, suggesting a complex resistance mechanism that helps the bacteria survive harsh conditions.
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A clear perception of gene essentiality in bacterial pathogens is pivotal for identifying drug targets to combat emergence of new pathogens and antibiotic-resistant bacteria, for synthetic biology, and for understanding the origins of life. We have constructed a comprehensive set of deletion mutants and systematically identified a clearly defined set of essential genes for Streptococcus sanguinis. Our results were confirmed by growing S.

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The Porphyromonas gingivalis recombinant VimA can interact with the gingipains and several other proteins, including a sialidase. Sialylation can be involved in protein maturation; however, its role in virulence regulation in P. gingivalis is unknown.

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Hydrogen peroxide (H(2)O(2)), an important substance produced by many members of the genus Streptococcus, plays important roles in virulence and antagonism within a microbial community such as oral biofilms. The spxB gene, which encodes pyruvate oxidase, is involved in H(2)O(2) production in many streptococcal species. However, knowledge about its regulation and relation with other genes putatively involved in the same pathway is limited.

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  • ECF sigma factors in bacteria, like Porphyromonas gingivalis, help them respond to environmental stresses and influence their ability to cause disease.
  • In a study, five ECF sigma factor genes were inactivated, resulting in mutants that formed black-pigmented colonies but showed increased sensitivity to hydrogen peroxide and reduced gingipain activity.
  • The findings suggest that ECF sigma factors play a key role in regulating virulence factors, with specific factors (PG0162 and PG1660) potentially affecting the post-transcriptional regulation of gingipains, vital for the bacteria's pathogenicity.
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  • The study investigates how ammonium affects nitrogen fixation gene expression in the bacterium Pseudomonas stutzeri A1501, revealing that 166 genes associated with nitrogen regulation are quickly downregulated after ammonium exposure.
  • A significant part of this research focuses on a newly characterized gene, pnfA, which is linked to the nif gene cluster and impacts nitrogenase activity and nitrate usage in a mutant strain.
  • The findings indicate that the transcriptional regulation of nif genes in A1501 is complex and highly sensitive to nitrogen availability, with rapid changes occurring under ammonium stress.
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The capacity to fix nitrogen is widely distributed in phyla of Bacteria and Archaea but has long been considered to be absent from the Pseudomonas genus. We report here the complete genome sequencing of nitrogen-fixing root-associated Pseudomonas stutzeri A1501. The genome consists of a single circular chromosome with 4,567,418 bp.

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An alkaline beta-mannanase was purified to homogeneity from a culture broth of alkaliphilic Bacillus sp. N16-5. The enzyme had optimum activity at pH 9.

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Based on the previous studies on numerical taxonomy and 16S rDNA PCR-RFLP analysis, the moderately halophilic bacteria isolated from Xinjiang Region constituted a new cluster, and the phylogenetic tree was constructed by comparing with the 16S rDNA sequences of the other moderately halophilic bacteria species. In the phylogenetic tree, most of the reference strains were clustered in a group, and the similarity values of 16S rDNA sequence were above 96%. However, AI-3, Alcanivorax borkumensis and Halobacillus litoralis were clustered in another group, and the similarity value of 16S rDNA sequences between AI-3 and Alcanivorax borkumensis was 96%, and that of 16S rDNA sequences between AI-3 and Halobacillus litoralis was 99%.

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