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Microorganisms May 2020Oral bacteria possess the ability to form biofilms on solid surfaces. After the penetration of oral bacteria into the pulp, the contact between biofilms and pulp tissue...
Oral bacteria possess the ability to form biofilms on solid surfaces. After the penetration of oral bacteria into the pulp, the contact between biofilms and pulp tissue may result in pulpitis, pulp necrosis and/or periapical lesion. Depending on the environmental conditions and the availability of nutrients in the pulp chamber and root canals, mainly Gram-negative anaerobic microorganisms predominate and form the intracanal endodontic biofilm. The objective of the present study was to investigate the role of different substrates on biofilm formation as well as the separate and collective incorporation of six endodontic pathogens, namely and into a nine-species "basic biofilm". This biofilm was formed in vitro as a standard subgingival biofilm, comprising and The resulting endodontic-like biofilms were grown 64 h under the same conditions on hydroxyapatite and dentin discs. After harvesting the endodontic-like biofilms, the bacterial growth was determined using quantitative real-time PCR, were labeled using fluorescence in situ hybridization (FISH) and analyzed by confocal laser scanning microscopy (CLSM). The addition of six endodontic pathogens to the "basic biofilm" induced a decrease in the cell number of the "basic" species. Interestingly, counts increased in biofilms containing and respectively, both on hydroxyapatite and on dentin discs, whereas counts increased only on dentin discs by addition of . The growth of on hydroxyapatite discs and of and on dentin discs were significantly higher in the biofilm containing all species than in the "basic biofilm". Contrarily, the counts of , and on hydroxyapatite discs as well as counts of and on dentin discs decreased in the all-species biofilm. Overall, all bacterial species associated with endodontic infections were successfully incorporated into the standard multispecies biofilm model both on hydroxyapatite and dentin discs. Thus, future investigations on endodontic infections can rely on this newly established endodontic-like multispecies biofilm model.
PubMed: 32384777
DOI: 10.3390/microorganisms8050674 -
Cellular Microbiology Aug 2020The host-microbe relationship is pivotal for oral health as well as for peri-implant diseases. Peri-implant mucosa and commensal biofilm play important roles in the...
The host-microbe relationship is pivotal for oral health as well as for peri-implant diseases. Peri-implant mucosa and commensal biofilm play important roles in the maintenance of host-microbe homeostasis, but little is known about how they interact. We have therefore investigated the early host-microbe interaction between commensal multispecies biofilm (Streptococcus oralis, Actinomyces naeslundii, Veillonella dispar, Porphyromonas gingivalis) and organotypic peri-implant mucosa using our three-dimensional model. After 24 hr, biofilms induced weak inflammatory reaction in the peri-implant mucosa by upregulation of five genes related to immune response and increased secretion of IL-6 and CCL20. Biofilm volume was reduced which might be explained by secretion of β-Defensins-1, -2, and CCL20. The specific tissue reaction without intrinsic overreaction might contribute to intact mucosa. Thus, a relationship similar to homeostasis and oral health was established within the first 24 hr. In contrast, the mucosa was damaged and the bacterial distribution was altered after 48 hr. These were accompanied by an enhanced immune response with upregulation of additional inflammatory-related genes and increased cytokine secretion. Thus, the homeostasis-like relationship was disrupted. Such profound knowledge of the host-microbe interaction at the peri-implant site may provide the basis to improve strategies for prevention and therapy of peri-implant diseases.
Topics: Actinomyces; Biofilms; Cytokines; Fibroblasts; Host Microbial Interactions; Humans; Models, Anatomic; Mouth Mucosa; Porphyromonas gingivalis; Veillonella
PubMed: 32329166
DOI: 10.1111/cmi.13209 -
GigaScience Apr 2020Changes to human respiratory tract microbiome may contribute significantly to the progression of respiratory diseases. However, there are few studies examining the...
BACKGROUND
Changes to human respiratory tract microbiome may contribute significantly to the progression of respiratory diseases. However, there are few studies examining the relative abundance of microbial communities at the species level along the human respiratory tract.
FINDINGS
Bronchoalveolar lavage, throat swab, mouth rinse, and nasal swab samples were collected from 5 participants. Bacterial ribosomal operons were sequenced using the Oxford Nanopore MinION to determine the relative abundance of bacterial species in 4 compartments along the respiratory tract. More than 1.8 million raw operon reads were obtained from the participants with ∼600,000 rRNA reads passing quality assurance/quality control (70-95% identify; >1,200 bp alignment) by Discontiguous MegaBLAST against the EZ BioCloud 16S rRNA gene database. Nearly 3,600 bacterial species were detected overall (>750 bacterial species within the 5 dominant phyla: Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Fusobacteria. The relative abundance of bacterial species along the respiratory tract indicated that most microbes (95%) were being passively transported from outside into the lung. However, a small percentage (<5%) of bacterial species were at higher abundance within the lavage samples. The most abundant lung-enriched bacterial species were Veillonella dispar and Veillonella atypica while the most abundant mouth-associated bacterial species were Streptococcus infantis and Streptococcus mitis.
CONCLUSIONS
Most bacteria detected in lower respiratory samples do not seem to colonize the lung. However, >100 bacterial species were found to be enriched in bronchoalveolar lavage samples (compared to mouth/nose) and may play a substantial role in lung health.
Topics: Bacteria; Bronchoalveolar Lavage Fluid; Humans; Lung; Microbiota; RNA, Ribosomal, 16S
PubMed: 32298431
DOI: 10.1093/gigascience/giaa038 -
NPJ Biofilms and Microbiomes Mar 2020Cigarette smoking affects the oral microbiome, which is related to various systemic diseases. While studies that investigated the relationship between smoking and the...
Cigarette smoking affects the oral microbiome, which is related to various systemic diseases. While studies that investigated the relationship between smoking and the oral microbiome by 16S rRNA amplicon sequencing have been performed, investigations involving metagenomic sequences are rare. We investigated the bacterial species composition in the tongue microbiome, as well as single-nucleotide variant (SNV) profiles and gene content of these species, in never and current smokers by utilizing metagenomic sequences. Among 234 never smokers and 52 current smokers, beta diversity, as assessed by weighted UniFrac measure, differed between never and current smokers (pseudo-F = 8.44, R = 0.028, p = 0.001). Among the 26 species that had sufficient coverage, the SNV profiles of Actinomyces graevenitzii, Megasphaera micronuciformis, Rothia mucilaginosa, Veillonella dispar, and one Veillonella sp. were significantly different between never and current smokers. Analysis of gene and pathway content revealed that genes related to the lipopolysaccharide biosynthesis pathway in Veillonella dispar were present more frequently in current smokers. We found that species-level tongue microbiome differed between never and current smokers, and 5 species from never and current smokers likely harbor different strains, as suggested by the difference in SNV frequency.
Topics: Adult; Aged; Bacteria; Case-Control Studies; Cigarette Smoking; DNA, Bacterial; DNA, Ribosomal; Female; High-Throughput Nucleotide Sequencing; Humans; Male; Metagenomics; Middle Aged; Phylogeny; Polymorphism, Single Nucleotide; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Tongue
PubMed: 32170059
DOI: 10.1038/s41522-020-0121-6 -
Journal of Dental Research Jun 2020Severe early childhood caries (S-ECC) is a multifactorial disease that can lead to suffering and reduced oral health-related quality of life in young children. The...
Severe early childhood caries (S-ECC) is a multifactorial disease that can lead to suffering and reduced oral health-related quality of life in young children. The bacterial and fungal composition of dental plaque and how children's sex is associated with S-ECC are largely unknown. In this study, V4-16S rRNA and ITS1 rRNA gene amplicon sequencing was used to compare the plaque bacteriome and mycobiome of children <72 mo of age: 40 with S-ECC (15 males, 25 females) and 40 caries-free (19 males, 21 females). Health- and nutrition-related questionnaire data were also investigated. This study aimed to analyze potential sex-based differences in the supragingival plaque microbiota of young children with S-ECC and those caries-free. Behavioral and nutritional habit differences were observed between children with S-ECC and those caries-free and between male and female children. Overall, higher levels of , and other bacterial species were found in the S-ECC group as compared with caries-free controls ( < 0.05). A significant difference in the abundance of was observed between males and females with S-ECC ( < .05). Fungal taxonomic analysis showed significantly higher levels of in the plaque of children with S-ECC as compared with those caries-free ( < 0.05), but no differences were observed with ( > 0.05). Significant differences in the relative abundance of , and fungal species were also observed between the caries-free and S-ECC groups ( < 0.05). Machine learning analysis revealed the most important bacterial and fungal species for classifying S-ECC versus caries-free. Different patterns of crosstalk between microbial species were observed between male and female children. Our work demonstrates that plaque microbiota and sex may be important determinants for S-ECC and could be factors to consider for inclusion in caries risk assessment tools.
Topics: Candida; Child; Child, Preschool; Dental Caries; Dental Plaque; Female; Humans; Male; Microbiota; Quality of Life; RNA, Ribosomal, 16S; Streptococcus mutans; Veillonella
PubMed: 32109360
DOI: 10.1177/0022034520908595 -
Frontiers in Oncology 2019Nasopharyngeal carcinoma (NPC) is a malignant nasopharyngeal disease with a complicated etiology that occurs mostly in southern China. Intestinal flora imbalance is...
Nasopharyngeal carcinoma (NPC) is a malignant nasopharyngeal disease with a complicated etiology that occurs mostly in southern China. Intestinal flora imbalance is believed to be associated with a variety of organ malignancies. Current studies revealed that the destruction of intestinal flora is associated with NPC, and many studies have shown that intestinal flora can be used as a biomarker for many cancers and to predict cancer. To compare the differences in intestinal flora compositions and biological functions among 8 patients with familial NPC (NPC_F), 24 patients with sporadic NPC (NPC_S), and 27 healthy controls (NOR), we compared the intestinal flora DNA sequencing and hematological testing results between every two groups using bioinformatic methods. Compared to the NOR group, the intestinal flora structures of the patients in the NPC_F and NPC_S groups showed significant changes. In NPC_F, spp., spp., and spp. were significantly increased, and and spp. were significantly reduced. In NPC_S, , and spp. were significantly increased, and was significantly reduced. A beta diversity analysis showed significant difference compared NPC_F with NOR based on Bray Curtis ( = 0.012) and Unweighted UniFrac ( = 0.0045) index, respectively. The areas under the ROC curves plotted were all 1. Additionally, the concentrations of 5-hydroxytryptamine (5-HT) in NPC_F and NPC_S were significantly higher than those of NOR. was positively correlated with 5-HT (rcm: 0.85, < 0.001). A functional analysis of the intestinal flora showed that NPC_F was associated with Neurodegenerative Diseases ( = 0.023) and that NPC_S was associated with Neurodegenerative Diseases ( = 0.045) as well. We found that NPC was associated with structural imbalances in the intestinal flora, with that promoted the elevation of 5-HT and opportunistic pathogens being significantly increased, while probiotics significantly decreased. can be used as a novel biomarker and disease prediction models should be established for NPC. The new biomarkers and disease prediction models may be used for disease risk prediction and the screening of high-risk populations, as well as for the early noninvasive diagnosis of NPC.
PubMed: 31867274
DOI: 10.3389/fonc.2019.01346 -
Archives of Microbiology May 2020The highest number (35.1% of global incident cases) of new oropharyngeal (OP) and hypopharyngeal (HP) cancer cases was reported in South-Central Asia. The highest... (Comparative Study)
Comparative Study
The highest number (35.1% of global incident cases) of new oropharyngeal (OP) and hypopharyngeal (HP) cancer cases was reported in South-Central Asia. The highest incidence of HP cancer in India was reported in East Khasi Hills District of Meghalaya, Aizawl District of Mizoram, and Kamrup Urban District of Assam. HP and OP cancer showed the highest mortality rate, worst prognoses and the highest rate of nodal metastases and distant metastases. Thus, research is required to detect specific biomarkers for early prevention and diagnosis for these cancers. Oral microbiome signatures in saliva are considered as a potential diagnostic biomarker for OP and HP cancer. Bacterial profile alterations in OP and HP cancer have not been reported in India population, to establish the association of oral bacteria in the progression of OP and HP cancer; we studied bacterial communities in saliva of eight OP and seven HP cancer patients as compared to healthy controls using 16S rRNA V3-V4 region sequencing. The higher abundance of Haemophilus parainfluenzae, Haemophilus influenzae and Prevotella copri and lower abundance of Rothia mucilaginosa, Aggregatibacter segnis, Veillonella dispar, Prevotella nanceiensis, Rothia aeria, Capnocytophaga ochracea, Neisseria bacilliformis, Prevotella nigrescens and Selenomonas noxia in saliva of OP and HP cancer patients may be considered as a non-invasive diagnostic biomarker for OP and HP cancer patients. Streptococcus anginosus may be considered as a non-invasive diagnostic biomarker for OP cancer patients only. Therefore, evaluation of salivary microbial biomarkers may be informative to understand the pathobiology and carcinogenesis of OP and HP cancer.
Topics: Bacteria; Biodiversity; Carcinoma, Squamous Cell; Case-Control Studies; Female; Humans; Hypopharyngeal Neoplasms; India; Male; Microbiota; Oropharyngeal Neoplasms; RNA, Ribosomal, 16S; Saliva
PubMed: 31832691
DOI: 10.1007/s00203-019-01790-1 -
BMC Oral Health Nov 2019The extent to which the composition and diversity of the oral microbiome varies with age is not clearly understood.
BACKGROUND
The extent to which the composition and diversity of the oral microbiome varies with age is not clearly understood.
METHODS
The 16S rRNA gene of subgingival plaque in 1219 women, aged 53-81 years, was sequenced and its taxonomy annotated against the Human Oral Microbiome Database (v.14.5). Composition of the subgingival microbiome was described in terms of centered log(2)-ratio (CLR) transformed OTU values, relative abundance, and prevalence. Correlations between microbiota abundance and age were evelauted using Pearson Product Moment correlations. P-values were corrected for multiple testing using the Bonferroni method.
RESULTS
Of the 267 species identified overall, Veillonella dispar was the most abundant bacteria when described by CLR OTU (mean 8.3) or relative abundance (mean 8.9%); whereas Streptococcus oralis, Veillonella dispar and Veillonella parvula were most prevalent (100%, all) when described as being present at any amount. Linear correlations between age and several CLR OTUs (Pearson r = - 0.18 to 0.18), of which 82 (31%) achieved statistical significance (P < 0.05). The correlations lost significance following Bonferroni correction. Twelve species that differed across age groups (each corrected P < 0.05); 5 (42%) were higher in women ages 50-59 compared to ≥70 (corrected P < 0.05), and 7 (48%) were higher in women 70 years and older.
CONCLUSIONS
We identified associations between several bacterial species and age across the age range of postmenopausal women studied. Understanding the functions of these bacteria could identify intervention targets to enhance oral health in later life.
Topics: Aged; Aged, 80 and over; Bacteria; Dental Plaque; Female; Humans; Microbiota; Middle Aged; Postmenopause; RNA, Ribosomal, 16S
PubMed: 31722703
DOI: 10.1186/s12903-019-0906-2 -
Frontiers in Microbiology 2019Fusobacteria are common obligately anaerobic Gram-negative bacteria of the oral cavity that may act as a bridge between early and late colonizing bacteria in dental...
Fusobacteria are common obligately anaerobic Gram-negative bacteria of the oral cavity that may act as a bridge between early and late colonizing bacteria in dental plaque and have a role in oral and extra-oral infections. has a crucial role in oral biofilm structure and ecology, as revealed in experimental and clinical biofilm models. The aim of this study was to investigate the impact of various species on biofilm formation and structure in three different oral biofilm models namely a supragingival, a supragingival "feeding", and a subgingival biofilm model. The standard six-species supragingival and "feeding" biofilm models employed contained , , , , , and sp. The subgingival biofilm model contained 10 species (, , ssp. , , , , , , , and ). Six different species or subspecies, respectively, were tested namely ssp. , ssp. , ssp. , ssp. , , and ). Biofilms were grown anaerobically on hydroxyapatite disks in 24-well culture dishes. After 64 h, biofilms were either harvested and quantified by culture analysis or proceeded to fluorescent hybridization (FISH) and confocal laser scanning microscopy (CLSM). All species tested established well in the biofilms, with CFUs ranging from 1.4E+04 ( ssp. ) to 5.6E+06 ( ssp. ). The presence of specific sp./ssp. induced a significant decrease in levels in the supragingival model and in levels in the "feeding" supragingival model. In the subgingival model, the counts of , , , , and significantly decreased in the presence of specific sp./ssp. Collectively, this study showed variations in the growing capacities of different fusobacteria within biofilms, affecting the growth of surrounding species and potentially the biofilm architecture. Hence, clinical or experimental studies need to differentiate between sp./ssp., as their biological properties may well vary.
PubMed: 31417514
DOI: 10.3389/fmicb.2019.01716 -
Journal of Gastrointestinal Surgery :... Aug 2020Recently, the link between obesity and gut microbiota has become a focus for research. This study shed some light on the modification of postoperative gut microbial...
BACKGROUND
Recently, the link between obesity and gut microbiota has become a focus for research. This study shed some light on the modification of postoperative gut microbial composition after bariatric surgery.
METHODS
A prospective longitudinal study on healthy lean subjects and patients who underwent bariatric surgery (Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy) was carried out. Anthropometric and metabolic data, smoking, food preferences data, and stool samples were collected from lean subjects and from obese patients before and 3 and 6 months after surgery (T0, T3, and T6, respectively).
RESULTS
We collected stool samples from 25 obese patients before surgery and 3 and 6 months thereafter and from 25 normal weight patients. After Roux-en-Y gastric bypass, Yokenella regensburgei (p < 0.05), Fusobacterium varium (p < 0.05), Veillonella dispar/atypica (p < 0.05), and Streptococcus australis/gordonii (p < 0.05) were transiently identified in the gut at T3. Roux-en-Y gastric bypass patients had a permanent increase in Akkermansia muciniphila (p < 0.05), which is associated with healthy metabolism, both at T3 and T6. There were no significant changes in gut microbiota in laparoscopic sleeve gastrectomy patients.
CONCLUSIONS
In our study, Roux-en-Y gastric bypass induced major microbial differences and greater weight loss compared with laparoscopic sleeve gastrectomy. Analyzing the microbiota composition, a proliferation of potential pathogens and the onset of beneficial bacteria was observed. The effects of these bacteria on human health are still far from clear. Understanding the mechanisms of action of these bacteria could be the keystone in developing new therapeutic strategies for obesity.
Topics: Bariatric Surgery; Enterobacteriaceae; Fusobacterium; Gastrectomy; Gastric Bypass; Gastrointestinal Microbiome; Humans; Laparoscopy; Longitudinal Studies; Obesity, Morbid; Prospective Studies; Streptococcus; Veillonella
PubMed: 31388884
DOI: 10.1007/s11605-019-04321-x