-
ACS Chemical Biology Dec 2021is an early colonizer of the oral microbiome with documented bactericidal activity against the oral pathogen . has been observed to possess the typical competence...
is an early colonizer of the oral microbiome with documented bactericidal activity against the oral pathogen . has been observed to possess the typical competence regulon found within most oral streptococci; however, the competence-stimulating peptide (CSP) responsible for QS activation and the regulatory role of the competence regulon is yet to be explored. Herein, we have both confirmed the identity of the CSP and utilized a wide range of phenotypic assays to characterize its regulatory role in competence, biofilm formation, and hydrogen peroxide formation. To determine the importance of each amino acid residue in CSP/ComD binding, we performed systematic replacement of amino acid residues within the CSP and developed a luciferase-based reporter system to assess the ability of these mutated analogues to modulate the competence regulon. Additionally, we performed CD analysis on mutated CSP analogues to determine the correlation between the peptide secondary structure and QS activation. To further explore ' potential as a biotherapeutic against infection, lead QS activators and inhibitors were used in interspecies competition assays to assess the effect of QS modulation on interactions between these two species. Lastly, we have documented a lack of -induced cytotoxicity, highlighting the potential of this native flora as a biotherapeutic with minimal health risks.
Topics: Bacterial Proteins; Biofilms; Hydrogen Peroxide; Peptides; Protein Binding; Regulon; Streptococcus; Streptococcus mutans; Structure-Activity Relationship
PubMed: 34860484
DOI: 10.1021/acschembio.1c00746 -
Microorganisms Sep 2019Adolescence is closely associated with a high risk of caries. The identification of specific bacteria in an oral microniche, the interdental space of the molars,...
Adolescence is closely associated with a high risk of caries. The identification of specific bacteria in an oral microniche, the interdental space of the molars, according to carious risk can facilitate the prediction of future caries and the anticipation of the progression or stabilization of caries in adolescents. A cross-sectional clinical study according to the bacteriological criteria of interdental healthy adolescents and carious risk factors-low and high-using a real-time polymerase chain reaction technique was conducted. The presence of 26 oral pathogens from the interdental microbiota of 50 adolescents aged 15 to 17 years were qualitatively and quantitatively analyzed. Bacteria known to be cariogenic (, spp., , , , , , and ) did not present differences in abundance according to carious risk. Periodontal bacteria from the red complex are positively correlated with carious risk. However, only 3 bacteria-, and -presented a significant increase in the highest group. Estimating the risk of caries associated with bacterial factors in interdental sites of molars in adolescents contributes to the better definition of carious risk status, periodicity and intensity of diagnostic, prevention and restorative services.
PubMed: 31491909
DOI: 10.3390/microorganisms7090319 -
Microbiology Spectrum Oct 2021When encountering oxidative stress, organisms selectively upregulate antioxidant genes and simultaneously suppress the translation of most other proteins. Eukaryotes...
When encountering oxidative stress, organisms selectively upregulate antioxidant genes and simultaneously suppress the translation of most other proteins. Eukaryotes employ multiple strategies to adjust translation at both the initiation and elongation stages; however, how prokaryotes modulate translation under oxidative stress remains unclear. Here, we report that upon hydrogen peroxide (HO) challenge, Streptococcus oligofermentans reduced translation via RNase Z (So-RNaseZ) oxidative degradation, thus hindering tRNA maturation. S. oligofermentans encodes all CCA-less tRNAs that require So-RNaseZ for 3' end maturation. A combination of nonreducing SDS-PAGE and liquid chromatography/tandem mass spectrometry (LC/MS-MS) assays demonstrated that HO oxidation induced Cys38-Cys149 disulfide linkages in recombinant So-RNaseZ protein, and serine substitution of Cys38 or Cys149 abolished these disulfide linkages. Consistently, redox Western blotting also determined intramolecular disulfide-linked So-RNaseZ in HO-treated cells. The disulfide-linked So-RNaseZ and monomer were both subject to proteolysis, whereas C149S mutation alleviated oxidative degradation of So-RNaseZ, suggesting that HO-mediated disulfide linkages substantially contributed to So-RNaseZ degradation. Accordingly, Northern blotting determined that tRNA precursor accumulation and mature tRNA species decrease in HO-treated . Moreover, reduced overall protein synthesis, as indicated by puromycin incorporation, and retarded growth of occurred in an HO concentration-dependent manner. Overexpression of So-RNaseZ not only elevated tRNA precursor processing and protein synthesis but also partly rescued HO-suppressed growth. Moreover, So-RNaseZ oxidative degradation-mediated translation repression elevated survival under high HO stress. Therefore, this work found that So-RNaseZ oxidative degradation-impeded tRNA maturation contributes to streptococcal translation repression and provides the oxidative stress adaptability for . Translation regulation is a common strategy used by organisms to reduce oxidative damage. Catalase-negative streptococci produce as well as tolerate high levels of HO. This work reports a novel translation regulation mechanism employed by Streptococcus oligofermentans in response to HO challenge, in which the key tRNA endonuclease So-RNaseZ is oxidized to form Cys38-Cys149 disulfide linkages and both the disulfide-linked So-RNaseZ and monomers are subject to proteolysis; thus, tRNA maturation, protein translation, and growth are all suppressed. Notably, So-RNaseZ oxidative degradation-mediated translation repression offers oxidative adaptability to and enhances its survival against high HO challenge. So-RNaseZ orthologs and HO-sensitive cysteines (Cys38 and Cys149) are widely distributed in and species genomes, which also encode all CCA-less tRNAs and lack catalase. Therefore, RNase Z oxidative degradation-based translation regulation could be widely employed by these lactic acid bacteria, including pathogenic streptococci, to cope with HO.
Topics: Antioxidants; Disulfides; Endoribonucleases; Gene Expression Regulation, Bacterial; Hydrogen Peroxide; Oxidative Stress; Protein Biosynthesis; RNA, Transfer; Streptococcus
PubMed: 34704809
DOI: 10.1128/Spectrum.01167-21 -
Genome Biology and Evolution Oct 2014Streptococcus sinensis is a recently discovered human pathogen isolated from blood cultures of patients with infective endocarditis. Its phylogenetic position, as well...
Streptococcus sinensis is a recently discovered human pathogen isolated from blood cultures of patients with infective endocarditis. Its phylogenetic position, as well as those of its closely related species, remains inconclusive when single genes were used for phylogenetic analysis. For example, S. sinensis branched out from members of the anginosus, mitis, and sanguinis groups in the 16S ribosomal RNA gene phylogenetic tree, but it was clustered with members of the anginosus and sanguinis groups when groEL gene sequences used for analysis. In this study, we sequenced the draft genome of S. sinensis and used a polyphasic approach, including concatenated genes, whole genomes, and matrix-assisted laser desorption ionization-time of flight mass spectrometry to analyze the phylogeny of S. sinensis. The size of the S. sinensis draft genome is 2.06 Mb, with GC content of 42.2%. Phylogenetic analysis using 50 concatenated genes or whole genomes revealed that S. sinensis formed a distinct cluster with Streptococcus oligofermentans and Streptococcus cristatus, and these three streptococci were clustered with the "sanguinis group." As for phylogenetic analysis using hierarchical cluster analysis of the mass spectra of streptococci, S. sinensis also formed a distinct cluster with S. oligofermentans and S. cristatus, but these three streptococci were clustered with the "mitis group." On the basis of the findings, we propose a novel group, named "sinensis group," to include S. sinensis, S. oligofermentans, and S. cristatus, in the Streptococcus genus. Our study also illustrates the power of phylogenomic analyses for resolving ambiguities in bacterial taxonomy.
Topics: Base Composition; DNA, Bacterial; Phylogeny; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Streptococcus
PubMed: 25331233
DOI: 10.1093/gbe/evu232 -
Scientific Reports Nov 2017Periodontitis is a global health problem and the 6 most common infectious disease worldwide. Porphyromonas gingivalis is considered a keystone pathogen in the disease...
Periodontitis is a global health problem and the 6 most common infectious disease worldwide. Porphyromonas gingivalis is considered a keystone pathogen in the disease and is capable of elevating the virulence potential of the periodontal microbial community. Strategies that interfere with P. gingivalis colonization and expression of virulence factor are therefore attractive approaches for preventing and treating periodontitis. We have previously reported that an 11-mer peptide (SAPP) derived from Streptococcus cristatus arginine deiminase (ArcA) was able to repress the expression and production of several well-known P. gingivalis virulence factors including fimbrial proteins and gingipains. Herein we expand and develop these studies to ascertain the impact of this peptide on phenotypic properties of P. gingivalis related to virulence potential. We found that growth rate was not altered by exposure of P. gingivalis to SAPP, while monospecies and heterotypic biofilm formation, and invasion of oral epithelial cells were inhibited. Additionally, SAPP was able to impinge the ability of P. gingivalis to dysregulate innate immunity by repressing gingipain-associated degradation of interleukin-8 (IL8). Hence, SAPP has characteristics that could be exploited for the manipulation of P. gingivalis levels in oral communities and preventing realization of virulence potential.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Biofilms; Peptides; Porphyromonas gingivalis; Streptococcus
PubMed: 29176569
DOI: 10.1038/s41598-017-16522-y -
Journal of B.U.ON. : Official Journal... 2021The characteristics of pathogenic microbes are useful for understanding the microbe-driven tumorigenesis. There is a lack of studies on the lung microecology for lung...
PURPOSE
The characteristics of pathogenic microbes are useful for understanding the microbe-driven tumorigenesis. There is a lack of studies on the lung microecology for lung cancer (LC) patients without any respiratory infection. In this work, we aimed to describe the profiles of pathogenic microbes in lung microenvironment of non-small cell lung cancer (NSCLC) patients using pathogen targeted sequencing and 16S rDNA sequencing.
METHODS
A total of 22 NSCLC patients (13 adenocarcinomas and 9 squamous cell carcinomas) without any pulmonary infection were enrolled. Among them, we collected 15 pieces of tumor tissues, 5 pieces of peritumoral tissues, 6 blood serum samples, and 5 broncho-alveolar lavage fluid (BALF) samples. Pathogen targeted sequencingand16S rDNA sequencing was performed for microbial classification.
RESULTS
The pathogen targeted sequencing results showed that 33, 14, 11, and 27 pathogenic microorganisms were detected in tumor tissues, peritumoral tissues, blood samples, and BALF, respectively. No common microorganisms were shared by four sample types. However, some common elements were shared by three sets: Streptococcus cristatus, Enterococcus, Staphylococcus haemolyticus, Corynebacterium pseudodiphtheria, Acinetobacter jungii, Haemophilus haemolyticus and Haemophilus parainfluenzae. Based on the 16S rDNA sequencing of two BALF samples, there were 104 OTUs found in one BALF sample and 127 OTUs in the other BALF sample; among them, there were 82 common ones, such as OTU1, OTU10, OTU101, OTU105, OTU106, and so on. Based on the above microbial classification and abundance, there might be enriched function in COG terms like COG1132, COG0438 and COG0745, and KEGG terms like K06147, K02029, and K09687.
CONCLUSION
This study emphasizes the role of the microbiome in LC patients without respiratory infection. These potential biomarkers of LC based on the taxonomic composition of pathogenic microorganisms might have clinical application.
Topics: Adenocarcinoma; Aged; Aged, 80 and over; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Female; Humans; Lung Neoplasms; Male; Middle Aged; Respiratory Tract Infections; Tumor Microenvironment
PubMed: 34761593
DOI: No ID Found -
BMC Nephrology Jan 2020Diagnosis and treatment of either ANCA disease or silent infection-related glomerulonephritis is complicated and is a huge treatment challenge when overlapping clinical... (Review)
Review
Diagnostic and treatment challenge of unrecognized subacute bacterial endocarditis associated with ANCA-PR3 positive immunocomplex glomerulonephritis: a case report and literature review.
BACKGROUND
Diagnosis and treatment of either ANCA disease or silent infection-related glomerulonephritis is complicated and is a huge treatment challenge when overlapping clinical manifestations occur. We report a case of ANCA-PR3 glomerulonephritis, nervous system involvement, hepatosplenomegaly and clinically silent subacute infectious endocarditis.
CASE PRESENTATION
A 57-year-old man with known mitral valve prolaps was admitted for unexplained renal failure with signs of nephritic syndrome, hepatosplenomegaly, sudden unilateral hearing loss, vertigo, malaise, new onset hemolytic anemia and thrombocytopenia. Immunoserology revealed positive c-anti-neutrophil cytoplasm antibody (ANCA)/anti-proteinase 3 (anti-PR3), mixed type crioglobulinemia and lowered complement fraction C3. Head MRI showed many microscopic hemorrhages. Common site of infection, as well as solid malignoma were ruled out. In accordance with clinical and laboratory findings, systemic vasculitis was assumed, although the etiology remained uncertain (ANCA-associated, cryoglobulinemic or related to unrecognized infection). After kidney biopsy, clinical signs of sepsis appeared. Blood cultures revealed Streptococcus cristatus. Echocardiography showed mitral valve endocarditis. Kidney biopsy revealed proliferative, necrotizing immunocomplex glomerulonephritis. Half a year later, following intravenous immunoglobulins, glucocorticoids, antibiotic therapy and surgical valve repair, the creatinine level decreased and c-ANCA and cryoglobulins disappeared. A second kidney biopsy revealed no residual kidney disease. Four years after treatment, the patient is stable with no symptoms or signs of vasculitis recurrence.
CONCLUSIONS
Here we describe the diagnostic and treatment challenge in a patient with unrecognized subacute bacterial endocarditis associated with ANCA-PR3 immunocomplex proliferative and crescentic glomerulonephritis. In patients with ANCA-PR3 immunocomplex glomerulonephritis and other overlapping manifestations suggesting systemic disease, it is important to recognize and aggressively treat any possible coexisting bacterial endocarditis, This is the most important step for a favorable patient outcome, including complete clinical and pathohistological resolution of the glomerulonephritis.
Topics: Anti-Bacterial Agents; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Asymptomatic Diseases; Cryoglobulinemia; Endocarditis, Bacterial; Glomerulonephritis; Glucocorticoids; Humans; Immunoglobulins, Intravenous; Immunologic Factors; Male; Middle Aged; Mitral Valve Prolapse; Myeloblastin
PubMed: 32005179
DOI: 10.1186/s12882-020-1694-2 -
The ISME Journal Sep 2018Information on how the oral microbiome develops during early childhood and how external factors influence this ecological process is scarce. We used high-throughput...
Information on how the oral microbiome develops during early childhood and how external factors influence this ecological process is scarce. We used high-throughput sequencing to characterize bacterial composition in saliva samples collected at 3, 6, 12, 24 months and 7 years of age in 90 longitudinally followed children, for whom clinical, dietary and health data were collected. Bacterial composition patterns changed through time, starting with "early colonizers", including Streptococcus and Veillonella; other bacterial genera such as Neisseria settled after 1 or 2 years of age. Dental caries development was associated with diverging microbial composition through time. Streptococcus cristatus appeared to be associated with increased risk of developing tooth decay and its role as potential biomarker of the disease should be studied with species-specific probes. Infants born by C-section had initially skewed bacterial content compared with vaginally delivered infants, but this was recovered with age. Shorter breastfeeding habits and antibiotic treatment during the first 2 years of age were associated with a distinct bacterial composition at later age. The findings presented describe oral microbiota development as an ecological succession where altered colonization pattern during the first year of life may have long-term consequences for child´s oral and systemic health.
Topics: Anti-Bacterial Agents; Bacteria; Breast Feeding; Child; Child, Preschool; Delivery, Obstetric; Dental Caries; Ecological and Environmental Phenomena; Humans; Infant; Longitudinal Studies; Microbiota; Mouth; Saliva; Streptococcus
PubMed: 29899505
DOI: 10.1038/s41396-018-0204-z -
Frontiers in Pediatrics 2020Molecular assays for infectious diseases have emerged as important clinical decision-making tools. Unbiased, metagenomic next-generation sequencing is a novel approach...
Molecular assays for infectious diseases have emerged as important clinical decision-making tools. Unbiased, metagenomic next-generation sequencing is a novel approach holding promise to detect pathogens missed by conventional modalities and to deconvolute admixed nucleic acid sequences from polymicrobial infections in order to identify constituent pathogens. Recent studies have raised concerns about the clinical impact of metagenomics assays and whether their expense is justified. Here, we report a case of polyclonal endocarditis in a 14-year-old woman with a history of Tetralogy of Fallot. Three sets of admission blood cultures and a commercial plasma metagenomics assay were negative for pathogens, despite persistent vegetations observed on the valve during a later procedure. Multiple strains of were identified from the explanted valve by amplicon-based 16S rRNA sequencing, confirming the patient had received appropriate antibiotic therapy. This case highlights limitations in the use and interpretation of clinical metagenomics for infectious disease diagnosis and indicates that the clinical yield of these tools may depend upon infection type and anatomic location.
PubMed: 33489996
DOI: 10.3389/fped.2020.575674 -
Applied and Environmental Microbiology Jun 2020The human oral cavity is a complex ecosystem, and the alterations in salivary microbial communities are associated with both oral and nonoral diseases. The Mediterranean...
The human oral cavity is a complex ecosystem, and the alterations in salivary microbial communities are associated with both oral and nonoral diseases. The Mediterranean diet (MD) is a healthy dietary pattern useful for both prevention and treatment of several diseases. To further explore the effects of the MD on human health, in this study, we investigated the changes in the salivary microbial communities in overweight/obese subjects after an individually tailored MD-based nutritional intervention. Healthy overweight and obese subjects were randomized between two intervention groups. The MD group (Med-D group) increased their MD adherence during 8 weeks of intervention while the control diet (control-D) group did not change their dietary habits. The salivary microbiota was assessed at baseline and after 4 and 8 weeks of intervention. Despite no observed changes in the overall salivary microbiota composition, we found a significant decrease in the relative abundances of species-level operational taxonomic units annotated as , , and in the Med-D group compared to that in the control-D group after 8 weeks of intervention, which are known to be associated with periodontal disease. Such variations were significantly linked to dietary variables such as MD adherence rates and intakes of animal versus vegetable proteins. In addition, increased levels of were observed in the Med-D group, which has been reported as an antagonistic taxon inhibiting gene expression. Our findings suggest that an MD-based nutritional intervention may be implicated in reducing periodontal bacteria, and an MD may be a dietary strategy supportive of oral homeostasis. Changes in dietary behavior with increased adherence to a Mediterranean diet can determine a reduction of periodontopathogenic bacterial abundances in the saliva of overweight subjects with cardiometabolic risk due to an unhealthy lifestyle, without any change in individual energy intake, nutrient intake, and physical activity.
Topics: Adult; Bacterial Physiological Phenomena; Diet, Mediterranean; Female; Humans; Male; Middle Aged; Obesity; Overweight; Periodontal Diseases; Random Allocation; Saliva; Young Adult
PubMed: 32276980
DOI: 10.1128/AEM.00777-20