Tetramic Acids Mutanocyclin and Reutericyclin A, Produced by Streptococcus mutans Strain B04Sm5 Modulate the Ecology of an in vitro Oral Biofilm

The human oral microbiome consists of diverse microbes actively communicating and interacting through a variety of biochemical mechanisms. Dental caries is a major public health issue caused by fermentable carbohydrate consumption that leads to dysbiosis of the oral microbiome. Streptococcus mutans is a known major contributor to caries pathogenesis, due to its exceptional ability to form biofilms in the presence of sucrose, as well as to its acidophilic lifestyle. S. mutans can also kill competing bacteria, which are typically health associated, through the production of bacteriocins and other small molecules. A subset of S. mutans strains encode the muc biosynthetic gene cluster (BGC), which was recently shown to produce the tetramic acids, mutanocyclin and reutericyclins A, B, and C. Reutericyclin A displayed strong antimicrobial activity and mutanocyclin appeared to be anti-inflammatory; however the effect of these compounds, and the carriage of muc by S. mutans, on the ecology of the oral microbiota is not known, and was examined here using a previously developed in vitro biofilm model derived from human saliva. While reutericyclin significantly inhibited in vitro biofilm formation and acid production at sub-nanomolar concentrations, mutanocyclin did not present any activity until the high micromolar range. 16S rRNA gene sequencing revealed that reutericyclin drastically altered the biofilm community composition, while mutanocyclin showed a more specific effect, reducing the relative abundance of cariogenic Limosilactobacillus fermentum. Mutanocyclin or reutericyclin produced by the S. mutans strains amended to the community did not appear to affect the community in the same way as the purified compounds, although the results were somewhat confounded by the differing growth rates of the S. mutans strains. Regardless of the strain added, the addition of S. mutans to the in vitro community significantly increased the abundance of S. mutans and Veillonella infantium, only. Overall, this study illustrates that reutericyclin A and mutanocyclin do impact the ecology of a complex in vitro oral biofilm; however, further research is needed to determine the extent to which the production of these compounds affects the virulence of S. mutans.

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Impact of Oropharyngeal Administration of Colostrum in Preterm Newborns’ Oral Microbiome

Nutrients ◽

10.3390/nu13124224 ◽

2021 ◽

Vol 13 (12) ◽

pp. 4224

Author(s):

Ramon V. Cortez ◽

Andrea Fernandes ◽

Luiz Gustavo Sparvoli ◽

Marina Padilha ◽

Rubens Feferbaum ◽

...

Keyword(s):

Preterm Infants ◽

16S Rrna Gene Sequencing ◽

Oral Microbiome ◽

Rrna Gene ◽

Oral Microbiota ◽

Alpha And Beta Diversity ◽

Longitudinal Observational Study ◽

Key Factor ◽

Rrna Gene Sequencing ◽

Preterm Newborns

The initial colonization of the human microbiota is of paramount importance. In this context, the oropharyngeal administration of colostrum is a safe, viable, and well-tolerated practice even by the smallest preterm infants. Therefore, this study evaluated the effects of oropharyngeal administration of colostrum on the establishment of preterm infants’ oral microbiota. A longitudinal observational study was carried out with 20 premature neonates, divided into two groups: one receiving the protocol (Oropharyngeal Administration of Colostrum; OAC) and the other one receiving Standard Caare (SC). Saliva samples were collected from the newborns weekly during the study period (from the day of birth until the 21st day of life) for analysis of oral microbiota through 16S rRNA gene sequencing. We observed that the colonization of the oral microbiota of preterm newborns preseanted a higher relative abundance of Staphylococcus on the 7th day of life, mainly in the OAC group. Additionally, an increased abundance of Bifidobacterium and Bacteroides was observed in the OAC group at the first week of life. Regarding alpha and beta diversity, time was a key factor in the oral modulation of both groups, showing how dynamic this environment is in early life.

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Variations of Oral Microbiome in Chronic Insomnia Patients with Different Tongue Features

The American Journal of Chinese Medicine ◽

10.1142/s0192415x20500445 ◽

2020 ◽

Vol 48 (04) ◽

pp. 923-944 ◽

Cited By ~ 2

Author(s):

Meng Liu ◽

Xiting Wang ◽

Fengzhi Wu ◽

Ning Dai ◽

Mindan Chen ◽

...

Keyword(s):

Relative Abundance ◽

16S Rrna Gene Sequencing ◽

Oral Bacteria ◽

Oral Microbiome ◽

Chronic Insomnia ◽

Rrna Gene ◽

Oral Microbiota ◽

Healthy Individuals ◽

Tongue Diagnosis ◽

Therapeutic Decision Making

Chronic insomnia is a disease which brings intense mental pain and disturbing complications to patients worldwide. The oral microbiome exhibits a mechanistic influence on human health. Therefore, it is crucial to understand the oral microbial diversity in insomnia. Tongue diagnosis has been considered a critical basic procedure in insomnia therapeutic decision-making in Traditional Chinese Medicine (TCM). Hence, it is significant to elucidate the various oral microbiome differences in chronic insomnia patients with different tongue features. In this paper, we used 16S rRNA gene sequencing and bioinformatics analysis to investigate dynamic changes in oral bacterial profile and correlations between chronic insomnia patients and healthy individuals, as well as in patients with different tongue coatings. Moreover, the relationship between the severity of insomnia and oral microbiota was explored. Our findings showed that chronic insomnia patients harbored a significantly higher diversity of oral bacteria when compared to healthy controls. More importantly, the results revealed that the diversity and relative abundance of the bacterial community was significantly altered among different tongue coatings in patients but not in healthy individuals. Oral bacteria with a relative abundance [Formula: see text]1% and [Formula: see text] among different tongue groups were considered remarkable bacteria, which included three phyla Proteobacteria, Bacteroidetes, Gracilibacteria, and four genera, Streptococcus, Prevotella_7, Rothia, and Neisseria. Our findings indicate that changes in oral microbiome correlate with tongue coatings in patients with chronic insomnia. Thus, the remarkable microbiome may provide inspiration for further studies on the correlation between tongue diagnosis and oral microbiome in chronic insomnia patients.

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Streptococcus species enriched in the oral cavity of patients with RA are a source of peptidoglycan-polysaccharide polymers that can induce arthritis in mice

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2020-219009 ◽

2021 ◽

pp. annrheumdis-2020-219009

Author(s):

Rabia Moentadj ◽

Yiwen Wang ◽

Kate Bowerman ◽

Linda Rehaume ◽

Hendrik Nel ◽

...

Keyword(s):

Operational Taxonomic Unit ◽

16S Rrna Gene Sequencing ◽

Chronic Arthritis ◽

Rrna Gene ◽

Oral Microbiota ◽

Potential Contribution ◽

Barrier Dysfunction ◽

Microbial Dysbiosis ◽

Periodontal Inflammation

ObjectivesAnalysis of oral dysbiosis in individuals sharing genetic and environmental risk factors with rheumatoid arthritis (RA) patients may illuminate how microbiota contribute to disease susceptibility. We studied the oral microbiota in a prospective cohort of patients with RA, first-degree relatives (FDR) and healthy controls (HC), then genomically and functionally characterised streptococcal species from each group to understand their potential contribution to RA development.MethodsAfter DNA extraction from tongue swabs, targeted 16S rRNA gene sequencing and statistical analysis, we defined a microbial dysbiosis score based on an operational taxonomic unit signature of disease. After selective culture from swabs, we identified streptococci by sequencing. We examined the ability of streptococcal cell walls (SCW) from isolates to induce cytokines from splenocytes and arthritis in ZAP-70-mutant SKG mice.ResultsRA and FDR were more likely to have periodontitis symptoms. An oral microbial dysbiosis score discriminated RA and HC subjects and predicted similarity of FDR to RA. Streptococcaceae were major contributors to the score. We identified 10 out of 15 streptococcal isolates as S. parasalivarius sp. nov., a distinct sister species to S. salivarius. Tumour necrosis factor and interleukin 6 production in vitro differed in response to individual S. parasalivarius isolates, suggesting strain specific effects on innate immunity. Cytokine secretion was associated with the presence of proteins potentially involved in S. parasalivarius SCW synthesis. Systemic administration of SCW from RA and HC-associated S. parasalivarius strains induced similar chronic arthritis.ConclusionsDysbiosis-associated periodontal inflammation and barrier dysfunction may permit arthritogenic insoluble pro-inflammatory pathogen-associated molecules, like SCW, to reach synovial tissue.

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Gender Variations in the Oral Microbiomes of Elderly Patients with Initial Periodontitis

Journal of Immunology Research ◽

10.1155/2021/7403042 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Jie Zhao ◽

Ying-Hui Zhou ◽

Ya-Qiong Zhao ◽

Yao Feng ◽

Fei Yan ◽

...

Keyword(s):

Immune System ◽

Elderly Patients ◽

16S Rrna Gene Sequencing ◽

Oral Microbiome ◽

Rrna Gene ◽

Oral Microbiota ◽

Microbial Composition ◽

Linear Discriminant ◽

Immune System Diseases ◽

Analytical Approaches

Periodontitis is a globally prevalent disease that imposes a functional and aesthetic burden on patients. The oral microbiome influences human health. The aim of this study was at assessing gender variation in the subgingival bacterial microbiome of elderly patients with initial periodontitis and to determine the causes of this variation. Twelve males and twenty females (range 50–68 years old) with initial periodontitis provided subgingival plaque samples. 16S rRNA gene sequencing, QIIME-based data processing, and statistical analyses were carried out using several different analytical approaches to detect differences in the oral microbiome between the two groups. Males had higher Chao1 index, observed species, and phylogenetic diversity whole tree values than females. Analysis of β-diversity indicated that the samples were reasonably divided by the gender. The linear discriminant analysis effect size showed that the most representative biomarkers were the genus Haemophilus in males, whereas the dominant bacteria in females were Campylobacter. Kyoto Encyclopedia of Genes and Genomes analysis showed that predicting changes in the female oral microbiota may be related to the immune system and immune system diseases are the main factor in males. These data suggest that gender may be a differentiating factor in the microbial composition of subgingival plaques in elderly patients with initial periodontitis. These results could deepen our understanding of the role of gender in the oral microbiota present during initial periodontitis.

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Development and characterization of an oral microbiome transplant among Australians for the treatment of dental caries and periodontal disease: A study protocol

PLoS ONE ◽

10.1371/journal.pone.0260433 ◽

2021 ◽

Vol 16 (11) ◽

pp. e0260433

Author(s):

Sonia Nath ◽

Peter Zilm ◽

Lisa Jamieson ◽

Kostas Kapellas ◽

Nirmal Goswami ◽

...

Keyword(s):

Dental Caries ◽

Cell Model ◽

Artificial Saliva ◽

Interdisciplinary Approach ◽

Oral Microbiome ◽

Rrna Gene ◽

Oral Microbiota ◽

Host Immune System ◽

Oral Diseases

Background Oral microbiome transplantation (OMT) is a novel concept of introducing health-associated oral microbiota into the oral cavity of a diseased patient. The premise is to reverse the state of oral dysbiosis, and restore the ecological balance to maintain a stable homeostasis with the host immune system. This study will assess the effectiveness, feasibility, and safety of OMT using an interdisciplinary approach. Methods/Design To find donors suitable for microbial transplantation, supragingival plaque samples will be collected from 600 healthy participants. Each sample (200μL) will subsequently be examined in two ways: 1) 100μL of the sample will undergo high-throughput 16S rRNA gene amplicon sequencing and shotgun sequencing to identify the composition and characterisation of a healthy supragingival microbiome, 2) the remaining 100μL of the plaque sample will be mixed with 25% artificial saliva medium and inoculated into a specialised in-vitro flow cell model containing a hydroxyapatite disk. To obtain sufficient donor plaque, the samples would be grown for 14 days and further analysed microscopically and sequenced to examine and confirm the growth and survival of the microbiota. Samples with the healthiest microbiota would then be incorporated in a hydrogel delivery vehicle to enable transplantation of the donor oral microbiota. The third step would be to test the effectiveness of OMT in caries and periodontitis animal models for efficacy and safety for the treatment of oral diseases. Discussion If OMTs are found to be successful, it can form a new treatment method for common oral diseases such as dental caries and periodontitis. OMTs may have the potential to modulate the oral microbiota and shift the ecological imbalances to a healthier state.

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Salivary microbiome profiling reveals a dysbiotic schizophrenia-associated microbiota

npj Schizophrenia ◽

10.1038/s41537-021-00180-1 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Ying Qing ◽

Lihua Xu ◽

Gaoping Cui ◽

Liya Sun ◽

Xiaowen Hu ◽

...

Keyword(s):

16S Rrna Gene Sequencing ◽

Oral Microbiome ◽

Disease Stage ◽

First Episode ◽

Rrna Gene ◽

Oral Microbiota ◽

Β Diversity ◽

Metabolic Functions ◽

Α Diversity ◽

Rrna Gene Sequencing

AbstractSchizophrenia is a debilitating mental disorder and often has a prodromal period, referred to as clinical high risk (CHR) for psychosis, prior to the first episode. The etiology and pathogenesis of schizophrenia remain unclear. Despite the human gut microbiome being associated with schizophrenia, the role of the oral microbiome, which is a vital player in the mouth–body connection, is not well understood. To address this, we performed 16S rRNA gene sequencing to investigate the salivary microbiome in 85 patients with drug-naïve first-episode schizophrenia (FES), 43 individuals at CHR, and 80 healthy controls (HCs). The salivary microbiome of FES patients was characterized by higher α-diversity and lower β-diversity heterogeneity than those of CHR subjects and HCs. Proteobacteria, the predominant phylum, was depleted, while Firmicutes and the Firmicutes/Proteobacteria ratio was enriched, in a stepwise manner from HC to CHR to FES. H2S-producing bacteria exhibited disease-stage-specific enrichment and could be potential diagnostic biomarkers for FES and CHR. Certain salivary microbiota exhibited disease-specific correlation patterns with symptomatic severities, peripheral pro-inflammatory cytokines, thioredoxin, and S100B in FES. Furthermore, the metabolic functions from inferred metagenomes of the salivary microbiome were disrupted in FES, especially amino acid metabolism, carbohydrate metabolism, and xenobiotic degradation. This study has established a link between salivary microbiome alterations and disease initiation and provided the hypothesis of how the oral microbiota could influence schizophrenia.

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Oral Microbiota Identifies Patients in Early Onset Rheumatoid Arthritis

Microorganisms ◽

10.3390/microorganisms9081657 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1657

Author(s):

Anders Esberg ◽

Linda Johansson ◽

Ingegerd Johansson ◽

Solbritt Rantapää Dahlqvist

Keyword(s):

Rheumatoid Arthritis ◽

Early Onset ◽

Amplicon Sequencing ◽

Oral Bacteria ◽

Oral Microbiome ◽

Rrna Gene ◽

Oral Microbiota ◽

Disease Manifestation ◽

Periodontal Status ◽

Quality Register

Rheumatoid arthritis (RA) is the most common autoimmune inflammatory disease, and single periodontitis-associated bacteria have been suggested in disease manifestation. Here, the oral microbiota was characterized in relation to the early onset of RA (eRA) taking periodontal status into consideration. 16S rRNA gene amplicon sequencing of saliva bacterial DNA from 61 eRA patients without disease-modifying anti-rheumatic drugs and 59 matched controls was performed. Taxonomic classification at 98.5% was conducted against the Human Oral Microbiome Database, microbiota functions were predicted using PICRUSt, and periodontal status linked from the Swedish quality register for clinically assessed caries and periodontitis. The participants were classified into three distinct microbiota-based cluster groups with cluster allocation differences by eRA status. Independently of periodontal status, eRA patients had enriched levels of Prevotella pleuritidis, Treponema denticola, Porphyromonas endodontalis and Filifactor alocis species and in the Porphyromonas and Fusobacterium genera and functions linked to ornithine metabolism, glucosylceramidase, beta-lactamase resistance, biphenyl degradation, fatty acid metabolism and 17-beta-estradiol-17-dehydrogenase metabolism. The results support a deviating oral microbiota composition already in eRA patients compared with healthy controls and highlight a panel of oral bacteria that may be useful in eRA risk assessment in both periodontally healthy and diseased persons.

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The growth response of rice (Oryza sativa L. var. FARO 44) in vitro after inoculation with bacterial isolates from a typical ferruginous ultisol

Bulletin of the National Research Centre ◽

10.1186/s42269-021-00528-8 ◽

2021 ◽

Vol 45 (1) ◽

Author(s):

Musa Saheed Ibrahim ◽

Beckley Ikhajiagbe

Keyword(s):

16S Rrna ◽

Bacillus Cereus ◽

Proteus Mirabilis ◽

Growth Response ◽

Gene Sequencing ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Rice Seedlings ◽

Rrna Gene Sequencing

Abstract Background Rice forms a significant portion of food consumed in most household worldwide. Rice production has been hampered by soil factors such as ferruginousity which has limited phosphorus availability; an important mineral component for the growth and yield of rice. The presence of phosphate-solubilizing bacteria (PSB) in soils has been reported to enhance phosphate availability. In view of this, the present study employed three bacteria species (BCAC2, EMBF2 and BCAF1) that were previously isolated and proved P solubilization capacities as inocula to investigate the growth response of rice germinants in an in vitro setup. The bacteria isolates were first identified using 16S rRNA gene sequencing and then applied as inoculum. The inolula were prepared in three concentrations (10, 7.5 and 5.0 ml) following McFarland standard. Viable rice (var. FARO 44) seeds were sown in petri dishes and then inoculated with the three inocula at the different concentrations. The setup was studied for 28 days. Results 16S rRNA gene sequencing identified the isolates as: isolate BCAC2= Bacillus cereus strain GGBSU-1, isolate BCAF1= Proteus mirabilis strain TL14-1 and isolate EMBF2= Klebsiella variicola strain AUH-KAM-9. Significant improvement in rice germination, morphology, physiology and biomass parameters in the bacteria-inoculated setups was observed compared to the control. Germination percentage after 4 days was 100 % in the inoculated rice germinants compared to 65% in the control (NiS). Similarly, inoculation with the test isolates enhanced water-use efficiency by over 40%. The rice seedlings inoculated with Bacillus cereus strain GGBSU-1 (BiS) showed no signs of chlorosis and necrosis throughout the study period as against those inoculated with Proteus mirabilis strain TL14-1 (PiS) and Klebsiella variicola strain AUH-KAM-9 (KiS). Significant increase in chlorophyll-a, chlorophyll-b and alpha amylase was observed in the rice seedlings inoculated with BiS as against the NiS. Conclusion Inoculating rice seeds with Bacillus cereus strain GGBSU-1, Proteus mirabilis strain TL14-1 and Klebsiella variicola strain AUH-KAM-9 in an in vitro media significantly improved growth parameters of the test plant. Bacillus cereus strain GGBSU-1 showed higher efficiency due to a more improved growth properties observed.

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Bacterial endosymbiont inhabiting Leucaena leucocephala leaves and their antioxidant and antidiabetic potential

Journal of Complementary and Integrative Medicine ◽

10.1515/jcim-2020-0203 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Sridevi Chigurupati ◽

Shantini Vijayabalan ◽

Kesavanarayanan Krishnan Selvarajan ◽

Ahmad Alhowail ◽

Fatema Kauser

Keyword(s):

Free Radical ◽

Crude Extract ◽

Leucaena Leucocephala ◽

Endophytic Bacteria ◽

Radical Scavenging ◽

16S Rrna Gene Sequencing ◽

Free Radical Scavenging ◽

Rrna Gene ◽

Standard Drug

AbstractObjectivesResearch on endosymbionts is emerging globally and is considered as a potential source of bioactive phytochemicals. The present study examines the antioxidant and antidiabetic of the endophytic crude extract isolated from Leucaena leucocephala leaves.MethodsEndophytic bacteria were isolated from the leaves of L. leucocephala and 16S rRNA gene sequencing was used to establish their identity. The in vitro antioxidant effect of endophytic crude extract (LL) was evaluated using 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) free radical scavenging methods. The in vitro antidiabetic properties of LL were evaluated using α-amylase and α-glucosidase enzyme inhibition assay.ResultsThe isolated endophytic bacteria were identified as Cronobacter sakazakii. LL displayed potent free radical scavenging effect against ABTS and DPPH radicals with an inhibitory concentration 50% (IC50) value of 17.49 ± 0.06 and 11.3 ± 0.1 μg/mL respectively. LL exhibited α-amylase and α-glucosidase inhibition with an IC50 value of 23.3 ± 0.08 and 23.4 ± 0.1 μg/mL respectively compared to the standard drug (acarbose). Both glucose loaded normoglycemic rats and STZ induced diabetic rats treated with LL (200 mg/kg) exhibited a considerable reduction in blood glucose levels p<0.01 after 8 h of treatment when compared to normal and diabetic control rats respectively.ConclusionsThus, the study shows that LL has a wellspring of natural source of antioxidants, and antidiabetic agents and phytoconstituents present in endophytes could be the rich source for bioactive compounds.

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Live Bacillus subtilis natto Promotes Rumen Fermentation by Modulating Rumen Microbiota In Vitro

Animals ◽

10.3390/ani11061519 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1519

Author(s):

Meinan Chang ◽

Fengtao Ma ◽

Jingya Wei ◽

Junhao Liu ◽

Xuemei Nan ◽

...

Keyword(s):

Bacillus Subtilis ◽

16S Rrna ◽

Rumen Fluid ◽

Gene Sequencing ◽

16S Rrna Gene Sequencing ◽

Rumen Fermentation ◽

Rrna Gene ◽

Bacillus Subtilis Natto ◽

Rrna Gene Sequencing

Previous studies have shown that Bacillus subtilis natto affects rumen fermentation and rumen microbial community structure, which are limited to detect a few microbial abundances using traditional methods. However, the regulation of B. subtilis natto on rumen microorganisms and the mechanisms of microbiota that affect rumen fermentation is still unclear. This study explored the effects of live and autoclaved B. subtilis natto on ruminal microbial composition and diversity in vitro using 16S rRNA gene sequencing and the underlying mechanisms. Rumen fluid was collected, allocated to thirty-six bottles, and divided into three treatments: CTR, blank control group without B. subtilis natto; LBS, CTR with 109 cfu of live B. subtilis natto; and ABS, CTR with 109 cfu of autoclaved B. subtilis natto. The rumen fluid was collected after 0, 6, 12, and 24 h of fermentation, and pH, ammonia nitrogen (NH3-N), microbial protein (MCP), and volatile fatty acids (VFAs) were determined. The diversity and composition of rumen microbiota were assessed by 16S rRNA gene sequencing. The results revealed LBS affected the concentrations of NH3-N, MCP, and VFAs (p < 0.05), especially after 12 h, which might be attributed to changes in 18 genera. Whereas ABS only enhanced pH and NH3-N concentration compared with the CTR group (p < 0.05), which might be associated with changes in six genera. Supplementation with live B. subtilis natto improved ruminal NH3-N and propionate concentrations, indicating that live bacteria were better than autoclaved ones. This study advances our understanding of B. subtilis natto in promoting ruminal fermentation, providing a new perspective for the precise utilization of B. subtilis natto in dairy rations.

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