scholarly journals Diversity and Morphology of Members of the Phylum “Synergistetes” in Periodontal Health and Disease

2009 ◽  
Vol 75 (11) ◽  
pp. 3777-3786 ◽  
Author(s):  
S. R. Vartoukian ◽  
R. M. Palmer ◽  
W. G. Wade

ABSTRACT Members of the phylum “Synergistetes” have frequently been detected in the human oral cavity at sites of dental disease, but they have rarely been detected in studies of oral health. Only two oral “Synergistetes” taxa are cultivable. The aims of this study were to investigate the diversity of “Synergistetes” in the oral cavity, to establish whether “Synergistetes” taxa are more strongly associated with periodontitis than with oral health, and to visualize unculturable “Synergistetes” in situ. Sixty samples (saliva, dental plaque, and mucosal swabs) were collected from five subjects with periodontitis and five periodontally healthy controls. Using phylum-specific 16S rRNA gene primers, “Synergistetes” were identified by PCR, cloning, and sequencing of 48 clones per PCR-positive sample. Subgingival plaque samples were labeled with probes targeting rRNA of unculturable oral “Synergistetes” using fluorescent in situ hybridization (FISH). Analysis of 1,664 clones revealed 12 “Synergistetes” operational taxonomic units (OTUs) at the 99% sequence identity level, 5 of which were novel. “Synergistetes” OTU 4.2 was found in significantly more subjects with periodontitis than controls (P = 0.048) and was more abundant in subgingival plaque at diseased sites than at healthy sites in subjects with periodontitis (P = 0.019) or controls (P = 0.019). FISH analysis revealed that unculturable oral “Synergistetes” cells were large curved bacilli. The human oral cavity harbors a diverse population of “Synergistetes.” “Synergistetes” OTU 4.2 is associated with periodontitis and may have a pathogenic role.

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
V. K. Chava ◽  
K. Sirisha

This paper attempts to summarise the findings accumulated within the last few years concerning the hormone of darkness “melatonin.” Based on its origin, from the pineal gland until recently it was portrayed exclusively as a hormone. Due to its lipophilic nature, it is accessible to every cell. Thus, in the classic sense it is a cell protector rather than a hormone. Recent studies, by Claustrat et al. (2005), detected few extrapineal sources of melatonin like retina, gastrointestinal tract, and salivary glands. Due to these sources, research by Cutando et al. (2007), is trying to explore the implications of melatonin in the oral cavity, in addition to its physiologic anti-oxidant, immunomodulatory and oncostatic functions at systemic level that may be receptor dependent or independent. Recently, certain in vivo studies by Shimozuma et al. (2011), detected the secretion of melatonin from salivary glands further emphasising its local activity. Thus, within our confines the effects of melatonin in the mouth are reviewed, adding a note on therapeutic potentials of melatonin both systemically and orally.


2018 ◽  
Author(s):  
Jeffrey S. McLean ◽  
Batbileg Bor ◽  
Thao T. To ◽  
Quanhui Liu ◽  
Kristopher A. Kerns ◽  
...  

ABSTRACTRecently, we discovered that a member of the Saccharibacteria/TM7 phylum (strain TM7x) isolated from the human oral cavity, has an ultra-small cell size (200-300nm), a highly reduced genome (705 Kbp) with limited de novo biosynthetic capabilities, and a very novel lifestyle as an obligate epibiont on the surface of another bacterium 1. There has been considerable interest in uncultivated phyla, particularly those that are now classified as the proposed candidate phyla radiation (CPR) reported to include 35 or more phyla and are estimated to make up nearly 15% of the domain Bacteria. Most members of the larger CPR group share genomic properties with Saccharibacteria including reduced genomes (<1Mbp) and lack of biosynthetic capabilities, yet to date, strain TM7x represents the only member of the CPR that has been cultivated and is one of only three CPR routinely detected in the human body. Through small subunit ribosomal RNA (SSU rRNA) gene surveys, members of the Saccharibacteria phylum are reported in many environments as well as within a diversity of host species and have been shown to increase dramatically in human oral and gut diseases. With a single copy of the 16S rRNA gene resolved on a few limited genomes, their absolute abundance is most often underestimated and their potential role in disease pathogenesis is therefore underappreciated. Despite being an obligate parasite dependent on other bacteria, six groups (G1-G6) are recognized using SSU rRNA gene phylogeny in the oral cavity alone. At present, only genomes from the G1 group, which includes related and remarkably syntenic environmental and human oral associated representatives1, have been uncovered to date. In this study we systematically captured the spectrum of known diversity in this phylum by reconstructing completely novel Class level genomes belonging to groups G3, G6 and G5 through cultivation enrichment and/or metagenomic binning from humans and mammalian rumen. Additional genomes for representatives of G1 were also obtained from modern oral plaque and ancient dental calculus. Comparative analysis revealed remarkable divergence in the host-associated members across this phylum. Within the human oral cavity alone, variation in as much as 70% of the genes from nearest oral clade (AAI 50%) as well as wide GC content variation is evident in these newly captured divergent members (G3, G5 and G6) with no environmental relatives. Comparative analyses suggest independent episodes of transmission of these TM7 groups into humans and convergent evolution of several key functions during adaptation within hosts. In addition, we provide evidence from in vivo collected samples that each of these major groups are ultra-small in size and are found attached to larger cells.


2006 ◽  
Vol 72 (1) ◽  
pp. 793-801 ◽  
Author(s):  
Alexandra J Scupham ◽  
Laura L. Presley ◽  
Bo Wei ◽  
Elizabeth Bent ◽  
Natasha Griffith ◽  
...  

ABSTRACT Enteric microbiota play a variety of roles in intestinal health and disease. While bacteria in the intestine have been broadly characterized, little is known about the abundance or diversity of enteric fungi. This study utilized a culture-independent method termed oligonucleotide fingerprinting of rRNA genes (OFRG) to describe the compositions of fungal and bacterial rRNA genes from small and large intestines (tissue and luminal contents) of restricted-flora and specific-pathogen-free mice. OFRG analysis identified rRNA genes from all four major fungal phyla: Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota. The largest assemblages of fungal rRNA sequences were related to the genera Acremonium, Monilinia, Fusarium, Cryptococcus/Filobasidium, Scleroderma, Catenomyces, Spizellomyces, Neocallimastix, Powellomyces, Entophlyctis, Mortierella, and Smittium and the order Mucorales. The majority of bacterial rRNA gene clones were affiliated with the taxa Bacteroidetes, Firmicutes, Acinetobacter, and Lactobacillus. Sequence-selective PCR analyses also detected several of these bacterial and fungal rRNA genes in the mouse chow. Fluorescence in situ hybridization analysis with a fungal small-subunit rRNA probe revealed morphologically diverse microorganisms resident in the mucus biofilm adjacent to the cecal and proximal colonic epithelium. Hybridizing organisms comprised about 2% of the DAPI (4′,6-diamidino-2-phenylindole, dihydrochloride)-positive organisms in the mucus biofilm, but their abundance in fecal material may be much lower. These data indicate that diverse fungal taxa are present in the intestinal microbial community. Their abundance suggests that they may play significant roles in enteric microbial functions.


2013 ◽  
Vol 63 (Pt_4) ◽  
pp. 1214-1218 ◽  
Author(s):  
Julia Downes ◽  
Floyd E. Dewhirst ◽  
Anne C. R. Tanner ◽  
William G. Wade

Five strains of anaerobic, Gram-negative bacilli isolated from the human oral cavity were subjected to a comprehensive range of phenotypic and genotypic tests and were found to comprise a homogeneous group. Phylogenetic analysis of full-length 16S rRNA gene sequences showed that these strains represented a novel group within the family Prevotellaceae , and the most closely related species was Prevotella tannerae . P. tannerae and the novel taxon are deeply branched from the genus Prevotella , with sequence identities to the type strain of the type species of Prevotella , Prevotella melaninogenica , of 82.2 and 85.6 %, respectively. The novel genus Alloprevotella gen. nov. is proposed to accommodate the novel species Alloprevotella rava gen. nov., sp. nov. and the previously named Prevotella tannerae Moore et al. 1994 as Alloprevotella tannerae gen. nov., comb. nov. The type species is Alloprevotella tannerae. The type strain of Alloprevotella rava is 81/4-12T ( = DSM 22548T  = CCUG 58091T) and the type strain of Alloprevotella tannerae is ATCC 51259T  = CCUG 34292T  = CIP 104476T  = NCTC 13073T. Alloprevotella rava is weakly to moderately saccharolytic and produces moderate amounts of acetic acid and major amounts of succinic acid as end products of fermentation. Strains are sensitive to 20 % bile and hydrolyse gelatin. The principal cellular long-chain fatty acids are anteiso-C15 : 0, iso-C15 : 0, C16 : 0, iso-C17 : 0 and iso-C17 : 0 3-OH. The G+C content of the DNA of the type strain is 47 mol%.


Author(s):  
Julia Downes ◽  
Maria Mantzourani ◽  
David Beighton ◽  
Samuel Hooper ◽  
Melanie J. Wilson ◽  
...  

Six strains of anaerobic, pleomorphic Gram-positive bacilli, isolated from the human oral cavity and an infected arm wound, were subjected to a comprehensive range of phenotypic and genotypic tests and were found to comprise a homogeneous group. 16S rRNA gene sequence analysis revealed that the isolates were most closely related to Scardovia inopinata CCUG 35729T (94.8–94.9 % 16S rRNA gene sequence similarity). The isolates were saccharolytic and produced acetic and lactic acids as end products of fermentation. The major fatty acids were C16 : 0 (49.8 %) and C18 : 1 ω9c (35.8 %). Polar lipid analysis revealed a variety of glycolipids, diphosphatidylglycerol, an unidentified phospholipid and an unidentified phosphoglycolipid. No respiratory quinones were detected. The peptidoglycan was of the type A4α l-Lys–Thr–Glu, with l-lysine partially replaced by l-ornithine. The DNA G+C content of one of the strains, C1A_55T , was 55 mol%. A novel species, Scardovia wiggsiae sp. nov., is proposed to accommodate the six isolates, with the type strain C1A_55T (=DSM 22547T=CCUG 58090T).


Genome ◽  
2011 ◽  
Vol 54 (9) ◽  
pp. 710-717 ◽  
Author(s):  
B. Kolano ◽  
B.W. Gardunia ◽  
M. Michalska ◽  
A. Bonifacio ◽  
D. Fairbanks ◽  
...  

The chromosomal organization of two novel repetitive DNA sequences isolated from the Chenopodium quinoa Willd. genome was analyzed across the genomes of selected Chenopodium species. Fluorescence in situ hybridization (FISH) analysis with the repetitive DNA clone 18–24J in the closely related allotetraploids C. quinoa and Chenopodium berlandieri Moq. (2n = 4x = 36) evidenced hybridization signals that were mainly present on 18 chromosomes; however, in the allohexaploid Chenopodium album L. (2n = 6x = 54), cross-hybridization was observed on all of the chromosomes. In situ hybridization with rRNA gene probes indicated that during the evolution of polyploidy, the chenopods lost some of their rDNA loci. Reprobing with rDNA indicated that in the subgenome labeled with 18–24J, one 35S rRNA locus and at least half of the 5S rDNA loci were present. A second analyzed sequence, 12–13P, localized exclusively in pericentromeric regions of each chromosome of C. quinoa and related species. The intensity of the FISH signals differed considerably among chromosomes. The pattern observed on C. quinoa chromosomes after FISH with 12–13P was very similar to GISH results, suggesting that the 12–13P sequence constitutes a major part of the repetitive DNA of C. quinoa.


2021 ◽  
Author(s):  
Anthony R. McLean ◽  
Julian Torres-Morales ◽  
Gary G. Borisy ◽  
Jessica L. Mark Welch

Patterns of microbial distribution are determined by as-yet poorly understood rules governing where microbes can grow and thrive. Therefore, a detailed understanding of where bacteria localize is necessary to advance microbial ecology and microbiome-based therapeutics. The site-specialist hypothesis predicts that most microbes in the human oral cavity have a primary habitat within the mouth where they are most abundant. We asked whether this hypothesis accurately describes the distribution of the members of the genus Streptococcus, a clinically relevant taxon that dominates most oral sites. Prior analysis of 16S rRNA gene sequencing data indicated that some oral Streptococcus clades are site-specialists while others may be generalists. However, within complex microbial populations composed of numerous closely-related species and strains, such as the oral streptococci, genome-scale analysis is necessary to provide the resolution to discriminate closely related taxa with distinct functional roles. Here we assess whether individual species within this genus are generalists using publicly available genomic sequence data that provides species-level resolution. We chose a set of high-quality representative genomes for Streptococcus species from the human oral microbiome. Onto these genomes, we mapped short-read metagenomic sequences from supragingival plaque, tongue dorsum, and other sites in the oral cavity. We found that every reliably detectable Streptococcus species in the human oral cavity was a site-specialist and that even closely related species such as S. mitis, S. oralis, and S. infantis specialized in different sites. These findings indicate that closely related bacteria can have distinct habitat distributions in the absence of dispersal limitation and under similar environmental conditions and immune regimes. These three species also share substantially the same species-specific core genes indicating that neither taxonomy nor gene content are clear predictors of site-specialization. Site-specificity may instead be influenced by subtle characteristics such as nucleotide-level divergences within conserved genes.


2017 ◽  
Vol 142 (4) ◽  
pp. 298-305 ◽  
Author(s):  
Guangxin Liu ◽  
Xiaoling Zhang ◽  
Yue Lan ◽  
Haoyang Xin ◽  
Fengrong Hu ◽  
...  

Karyotype comparison and fluorescence in situ hybridization (FISH) were conducted to analyze the wild Lilium species distributed in China. The karyotype results revealed that all species except Lilium lancifolium (2n = 3X = 36) were diploid and had two pairs of metacentric or submetacentric chromosomes. The karyotypes of all species are similar. FISH analysis revealed that there are 5–12 45S rRNA gene loci dispersed on the chromosomes of the 14 diploid species, and 15 45S rRNA gene loci were detected in the triploid species L. lancifolium. Most of the FISH signals were detected on the long arms and the centromeric regions. Three samples of L. brownii [Hubei, China (lat. 31°28′N, long. 110°23′E); Liaoning, China (lat. 40°07′N, long. 124°19′E); and Guangxi, China (lat. 25°06′N, long. 107°27′E)] showed very similar chromosome patterns in both the karyotype and the FISH analyses, further demonstrating that these samples belonged to the same species. L. brownii is widely distributed in China from latitude 25°06′N to 40°07′N, indicating that it is highly adaptable to the environment.


2018 ◽  
Author(s):  
Qianqian Liu ◽  
Feizhou Zhu ◽  
Liyu Chen ◽  
Meihua Xu ◽  
Jianwei Chen ◽  
...  

The microbiota in the human gut is not only a complicated microecological system but also plays important roles in both health and disease. In order to understand the roles of these gut bacteria, we determined the distribution of microbiota in different regions of the gut by sequencing the 16S rRNA gene V4 region of the bacteria in the saliva, gastric juice, and stool of healthy individuals. The 16S rRNA gene V3-V5 region sequences of saliva and stool microbiota were obtained from Human Microbiome Project (HMP) and the V4 sequence was obtained from the V3-V5 sequences by a program designed by Perl language. We found that the microbiota of the gastric juice is more similar to those in the saliva rather than that in the stool. The frequency of some taxa was significantly different among the three groups with the Streptococcus, Veillonella, Oribacterium, Selenomonas, Actinomyces, and Granulicatella most abundant in the saliva; the Prevotella, Neisseria, Actinobacillus, Treponema, and Helicobacter most abundant in the gastric juice; and the Bacteroides, Parabacteroides, Faecalibacterium, Sutterella, Ruminococcus, Oscillospira and Phascolarctobacterium most abundant in the stool. In addition, results from PICRUSt analyses suggest that the functions of microbiota in the gastric juice are more similar as those in the saliva than in the stool. Moreover, we also found that the membrane transport of the microbiota in the saliva is higher than that in the stool and gastric juice. To our knowledge, this is the first comprehensive comparison of microbiota in the human oral cavity, stomach, and intestine.


2021 ◽  
Author(s):  
Sabrina Naud ◽  
Issam Hasni ◽  
Sara Bellali ◽  
Hoang Thong Kieu ◽  
Cheikh Ibrahima Lo ◽  
...  

Abstract Phenotypic, phylogenetic and genomic studies were carried out on three unidentified Gram-stain positive, facultative anaerobic, and cocci-shaped bacteria isolated from the human oral cavity. The 16S rRNA gene of strains Marseille-P5794 T , Marseille-P6264 T and Marseille-P7376 T exhibited a sequence identity of 99,41%, 99.67% and 97.88%, respectively with Streptococcus cristatus, their closest phylogenetic relative with standing in nomenclature. Moreover, the rpoB gene sequence of strains Marseille-P5794 T and Marseille-P6264 T shared a similarity level with 96.1%, and 95.9% with Streptococcus cristatus whereas strain Marseille-P7376 T shared a 93.98% identity with Streptococcus sanguinis. Whole genome comparison of strains Marseille-P5794 T , Marseille-P6264 T and Marseille-P7376 T with their phylogenetic neighbours were under the threshold values set to define new species using digital DNA-DNA hybridization and Orthologous Average Nucleotide Identity. The taxonogenomics analysis thus allowed the classification of these strains as new species within the Streptococcus genus named Streptoccocus resistens sp. nov. Strain Marseille-P5794 T (=CSUR P5794 = CECT9902), Streptococcus buccae sp. nov. Strain Marseille-P6264 T (=CSUR P6264 = CECT9910) and Streptococcus mediterraneus sp. nov. Strain Marseille-P7376 (=CSUR P7376 = CECT30035).


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