Genus Porphyromonas Research Articles

Przeciwbakteryjna aktywność olejku tatarakowego (Oleum Calami) wobec bakterii beztlenowych

Introduction. The plants have been used for many thousands of years in medicine ancient Roma and Egypt. Among usage a herb was calamus. It was importation to Poland probably in XIII age. Calamus to grown on lowlands, on pond and lakes shares. Acorus calamus belongs to the family Araceae. The herb having rhizome with many nodes, elongated leaves with intensive smelling. In etheric oil are components as: α- and β-azarone, cyperenone, cyperole, acorine, acorytine, caryophylene, isoasarone, saflor, eugenol, camphor, geranyl acetate, cyperdone, spathulenol, borneol, linalool and linolenic acid. The oil has various pharmacological and antimicrobial activities. Aim. The goal of the investigation was to test activity calamus oil against anaerobic bacteria. Material and methods. The anaerobic bacteria were isolated from oral cavity and upper respiratory tract. The strains of following genera were tested: Bacteroides, Parabacteroides, Prevotella, Porphyromonas, Tannerella, Fusobacterium, Finegoldia, Parvimonas, Peptostreptococcus, Actinomyces, Bifidobacterium, Propionibacterium. The data volume 9 reference strains. The concentration the calamus oil (Semifarm) were: 2.0, 1.0, 0.5, 0.25, 0.12 and 0.06 mg/ml. The investigations was carried out using plate dilution technique method in Brucella agar supplemented with 5% defibrynated sheep blood, menadione and hemin. Inoculum containing 106 CFU per 1 ml was seeded with Steers replicator upon the agar with oil or without the oil (strains growth control). The agar plates was incubated in anaerobic condition in anaerobic jar in mixed of gases (10% C02 , 10% H2 i 80% N2) with palladium catalyst and anaerobiosis indicator, in 37°C for 48 hrs. The MIC was recorded by reading the lowest concentration the inhibited growth of anaerobic bacteria. Results. The results showed, that the most susceptible from genus of Bacteroides were the rods of Bacteroides uniformis (MIC ≤ 0.06-0.25 mg/ml). The strain Bacteroides ureolyticus and Bacteroides vulgatus were susceptible to 0.5 mg/ml, and Bacteroides fragilis to ≥ 20.0 mg/ml. The growth rods from genus Porphyromonas was inhibited by concentrations ≤ 0.06-0.25 mg/ml. The calamus oil was active against Gram-positive rods in range 0.25-0.5 mg/ml. The growth of Actinomyces, Bifidobacterium and Propionibacterium was inhibited by oil concentration 0.25-0.5 mg/ml. The Gram-positive cocci was susceptible to concentrations with ranges from ≤ 0.06 to 1.0 mg/ml. The most susceptible from the cocci was the strains Parvimonas micra (MIC < 0.06 mg/ml). The results other authors to confirm that Gram-positive rods are more susceptible to calamus oil than Gram-negative anaerobic bacteria. Conclusions. The calamus oil was high activity towards tested anaerobic bacteria. The most susceptible among Gram-negative rods was Bacteroides ureolyticus, Porphyromonas asaccharolytica and Porphyromonas levii. Gram-positive cocci were more susceptible on calamus oil than Gram-positive rods. The tested oil demonstrated the more activity towards Gram-positive bacteria than Gram-negative anaerobic rods.

Działanie in vitro olejku cyprysowego (Oleum Cupressi) na bakterie beztlenowe

Introduction. Cypress (Cupressus sempervirens L.) belongs to the family Cupressaceae. It is evergreen, and grows in Mediterranean region. The Cypress leaves and young branches are utilized to produce the essential oil. Cypress oil contain a number of components, in it α-pinene, Δ3-carene, α-terpinyl acetate, cedrol, α-terpinolene, β-myrcene, limonene, α-terpineolene, terpinen-4-ol, β-pinene, δ-cadinene and sabinene. The oil is used in therapy different diseases. It to have antimicrobial activity. Aim. The aim of the date was evaluation the susceptibility of anaerobic bacteria to Cypress oil. Material and methods. The anaerobic bacteria were isolated from patients. The 62 microorganisms, in it 36 strains of Gram-negative rods, 14 Gram-positive cocci and 12 Gram-positive rods, and 7 reference strains were tested. Susceptibility (MIC) was determined by means of plate dilution technique in Brucella agar supplemented with 5% defibrynated sheep blood, menadione and hemin. The Cypress oil was dissolved in DMSO and distilled water to obtain final following concentrations: 2.5, 5.0, 7.5, 10.0, 15.0 and 20.0 mg/ml. Inoculum containing 106 CFU per 1 ml was seeded with Steers replicator upon the agar with oil or without the oil (strains growth control). The agar plates was incubated in anaerobic condition in anaerobic jar in 37°C for 48 hrs. The MIC was interpreted as the lowest concentration of Cypress oil inhibiting the growth of tested bacteria. Results. The results indicated that from among Gram-negative rods the most susceptible to Cypress oil was the strains from genus Tannerella forsythia (MIC < 2.5-5.0 mg/ml), Bacteroides uniformis (MIC = 5.0 mg/ml), Bacteroides vulgatus and Porphyromonas asaccharolytica (MIC 5.0-7.5 mg/ml) and Porphyromonas levii (MIC = 7.5 mg/ml). The strains from genera Fusobacterium and of Bacteroides fragilis were the susceptible to 2.5-≥ 20.0 mg/ml. The Cypress oil was least active towards Prevotella and Parabacteroides strains (MIC ≥ 20.0 mg/ml).The tested Gram-positive cocci were more susceptible. The growth of the strains were inhibited by concentrations in ranges ≤ 2.5-7.5 mg/ml. The oil was minor active towards Gram-positive rods (MIC ≤ 2.5-20.0 mg/ml). Among the strains the genus of Actinomyces odontolyticus (MIC = 5.0 mg/ml) and Actinomyces viscosus (MIC ≤ 2.5-7.5 mg/ml) were the most susceptible. The growth of rods of Bifidobacterium breve was inhibited by concentrations 10.0 mg/ml. The data indicates that the Gram-negative rods were the less susceptible than Gram-positive bacteria to cypress oil. Conclusions. Among Gram-negative rods the most susceptible were the strains Tannerella forsythia, Bacteroides uniformis, Bacteroides vulgatus, Porphyromonas asaccharolytica and Porphyromonas levii. The oil was more active against Gram-positive cocci. Gram-positive anaerobic bacteria demonstrate the more susceptible to Cypress oil then Gram-positive rods.

Oral microbial dysbiosis in patients with Kostmann syndrome.

The oral microbiome is maintained by host- and microbe-derived factors. A shift in microbial composition, as a result of diseases related to the immune system, is the most important step in the development of oral and dental diseases. The aim of this study was to investigate the oral microbial composition of patients with Kostmann syndrome, who have severe neutropenia, compared with healthy children. A group of nine Kostmann syndrome patients and a group of nine healthy controls participated. After clinical investigation, DNA from stimulated saliva specimens was examined by high-throughput sequencing of the V3-V4 hypervariable region of the 16S rRNA gene using Illumina sequencing. The QIIME software package was used for 16 S rRNA amplicon analysis, while the Greengenes database was used for taxonomic classification. The periodontal pocket depths, plaque indices and bleeding-on-probing percentages and caries status on the deciduous teeth of the patients with Kostmann syndrome were statistically higher than those for the healthy controls. Patients with Kostmann syndrome had significantly lower bacterial diversity as compared to the controls. The presence of Firmicutes was statistically higher in patients with Kostmann syndrome, while that for Proteobacteria was higher in samples from the healthy controls (P<0.05). Streptococcus, Rothia, Granulicatella, Actinomyces, and genera from the family Gemellaceae were present as the core microbiome (abundance >1 % in at least 75 % of samples) in all groups, whereas the genus Porphyromonas was only detected as a member of the core microbiome in Kostmann patients. The evidence of lower bacterial diversity and differences in microbial profile for patients with Kostmann syndrome not only shows the impact of immune system-related diseases on oral microbiota, but also endorses the ecological plaque hypothesis proposed for the aetiology of oral diseases such as dental caries and periodontitis.

Composition Analysis and Feature Selection of the Oral Microbiota Associated with Periodontal Disease.

Periodontitis is an inflammatory disease involving complex interactions between oral microorganisms and the host immune response. Understanding the structure of the microbiota community associated with periodontitis is essential for improving classifications and diagnoses of various types of periodontal diseases and will facilitate clinical decision-making. In this study, we used a 16S rRNA metagenomics approach to investigate and compare the compositions of the microbiota communities from 76 subgingival plagues samples, including 26 from healthy individuals and 50 from patients with periodontitis. Furthermore, we propose a novel feature selection algorithm for selecting features with more information from many variables with a combination of these features and machine learning methods were used to construct prediction models for predicting the health status of patients with periodontal disease. We identified a total of 12 phyla, 124 genera, and 355 species and observed differences between health- and periodontitis-associated bacterial communities at all phylogenetic levels. We discovered that the genera Porphyromonas, Treponema, Tannerella, Filifactor, and Aggregatibacter were more abundant in patients with periodontal disease, whereas Streptococcus, Haemophilus, Capnocytophaga, Gemella, Campylobacter, and Granulicatella were found at higher levels in healthy controls. Using our feature selection algorithm, random forests performed better in terms of predictive power than other methods and consumed the least amount of computational time.

Polysaccharides extracted from Phellinus linteus ameliorate high-fat high-fructose diet induced insulin resistance in mice

Phellinus linteus polysaccharide (PLP) has hypoglycemic effects, but mechanisms remain unclear. Male C57BL/6 J mice were either fed a normal diet (CON) or a high-fat high-fructose diet (HFD) for 16 weeks, and starting from week 12, HFD-fed animals in PLP group were orally given PLP. PLP administration significantly reduced fasting blood glucose level and ameliorated glucose intolerance. Differentially expressed genes involved in FOXO signaling pathway and in vitamin B12 (VB12) transport were identified between HFD and PLP group. HFD decreased the phosphatidylcholine (PC) to phosphatidylethanolamine (PE) ratio and S-adenosyl methionine to S-adenosyl homocysteine ratio, which were recovered by PLP treatment. Plasma VB12 levels in HFD group was lower than CON or PLP group, and PLP stimulated the proliferation of gut bacteria in genus Porphyromonas with capability of VB12 synthesis. In conclusion, PLP administration improved insulin resistance via modifying hepatic phospholipids metabolism and rescuing insulin signaling transduction.

Wrażliwość bakterii beztlenowych na olejek anyżowy (Oleum anisi)

Introduction. Anise (Pimpinella anisum L.) belong to Apiaceae family. The plant is distributed in China, Iran, Indie and America. The fruits green' lanceoled leaves, white flowers and green-yellow seeds. The fruits are used to produce an essential oils. The anise oil is widely used in folk medicine, food, cosmetic and pharmaceutical industries. The fruits consists of 6-30% volatile oil. Its the major components are trans-anethole, estragol, eugenol, linalool, α-terpineol, cis-anethole, anisaldehyde, coumarins, methylchavikol, scopoletin, umbelliferone, estrols and polyacetylenes. Aim. The aim of this study was to determine the antimicrobial activity of anise oil against anaerobic bacteria isolated from oral cavity and upper respiratory tract. Material and methods. A total 54 strains of anaerobic bacteria and 8 standards strains from genera Porphyromonas, Prevotella, Bacteroides, Parabacteroides, Fusobacterium, Tannerella, Finegoldia, Peptostreptococcus, Actinomyces, Propionibacterium, Bifidobacterium and 8 standards strains Bacteroides fragilis ATCC 25285, Porphyromonas asaccharolytica ATCC 29743, Peptostreptococcus anaerobius ATCC 27337, Fusobacterium nucleatum ATCC 25586, Finegoldia magna ATCC 29328, Parabacteroides distasonis ATCC 8503, Propionibacterium acnes ATCC 11827 and Actinomyces odontolyticus ATCC 17929 were investigated. The susceptibility (MIC) was determined by the two-fold of plate dilution method in Brucella agar supplemented with 5% defibrinated sheep blood, menadione and hemin. The inoculum containing 106 CFU/spot was seeded with Steers replicator upon the surface of agar containing testing oil and free oil (the strains growth control). Incubation the plates was performed in anaerobic conditions in anaerobic jars with 10% CO2 , 10% H2 and 80% N2 . The MIC was considered to be the last dilution that did not bacterial colonial growth. Results. The results showed, that the most susceptible to oils from Gram-negative anaerobes were the strains of Tannerella forsythia (MIC 0.5-&lt; 0.12 mg/ml), Fusobacterium necrophorum, Bacteroides vulgatus and Bacteroides uniformis (MIC = 25 mg/ml). The strains from genus of Prevotella bivia and Parabacteroides distasonis were the lowest sensitive. The growth of the strains was inhibited by concentration &gt; 2.0 mg/ml. The anise oil was more active against Gram-positive rods and cocci then Gram-negative anaerobic bacteria. Conclusions. The anise oil was very active against all bacterial strains tested. The most susceptible to oil was the strains from genus Tannerella forsythia, Fusobacteria necrophorum, Bacteroides vulgatus and Bacteroides uniformis. The Gram-positive-rods and cocci was more susceptible to anise oil then anaerobic Gram-negative rods.

Post-translational regulation of a Porphyromonas gingivalis regulator

ABSTRACT Background: Bacteria use two-component signal transduction systems (among others) to perceive and respond to environmental changes. Within the genus Porphyromonas, we observed degeneration of these systems, as exemplified by the loss of RprX, the sensor kinase partner of the RprY. Objective: The purpose of this study was to investigate modulation of RprY function by acetylation. Design: The transcriptional activity of the rprY-pat genes were measured by RT-PCR and 5ʹ-RACE. The acetylation of RprY were detected by western blotting. Electromobility shift and in vitro ChIP assays were used to measure the DNA binding activity of RprY. The expression of RprY target genes was measured by qRT-PCR. Effects of acetylation on phosphorylation of RprY were measured by Phos-tag gels. Results: The rprY gene is cotranscribed with pat. RprY is acetylated in vivo, and autoacetylated in vitro in a reaction that is enhanced by Pat; the CobB sirtuin deacetylates RprY. Acetylation reduced the DNA binding of RprY. Induced oxidative stress decreased production of RprY in vivo, increased its acetylation and increased expression of nqrA. Conclusions: We propose that to compensate for the loss of RprX, P. gingivalis has evolved a novel mechanism to inactivate RprY through acetylation.

Investigation of potential targets of Porphyromonas CRISPRs among the genomes of Porphyromonas species.

The oral bacterial species Porphyromonas gingivalis, a periodontal pathogen, has plastic genomes that may be driven by homologous recombination with exogenous deoxyribonucleic acid (DNA) that is incorporated by natural transformation and conjugation. However, bacteriophages and plasmids, both of which are main resources of exogenous DNA, do not exist in the known P. gingivalis genomes. This could be associated with an adaptive immunity system conferred by clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated (cas) genes in P. gingivalis as well as innate immune systems such as a restriction-modification system. In a previous study, few immune targets were predicted for P. gingivalis CRISPR/Cas. In this paper, we analyzed 51 P. gingivalis genomes, which were newly sequenced, and publicly available genomes of 13 P. gingivalis and 46 other Porphyromonas species. We detected 6 CRISPR/Cas types (classified by sequence similarity of repeat) in P. gingivalis and 12 other types in the remaining species. The Porphyromonas CRISPR spacers with potential targets in the genus Porphyromonas were approximately 23 times more abundant than those with potential targets in other genus taxa (1,720/6,896 spacers vs. 74/6,896 spacers). Porphyromonas CRISPR/Cas may be involved in genome plasticity by exhibiting selective interference against intra- and interspecies nucleic acids.

First report on sepsis caused by Porphyromonas pogonae

We report on a 62 year old patient who developed sepsis due to an infection caused by Porphyromonas pogonae, a recently described species of the bacterial genus Porphyromonas. This is the first case of an invasive infection with this pathogen.

Subgingival Microbiome of Gingivitis in Chinese Undergraduates.

To analyse the microbiome composition of health and gingivitis in Chinese undergraduates with high-throughput sequencing. Sequencing of 16S rRNA gene amplicons was performed with the MiSeq system to compare subgingival bacterial communities from 54 subjects with gingivitis and 12 periodontally healthy controls. A total of 1,967,372 sequences representing 14 phyla, 104 genera, and 96 species were detected. Analysis of similarities (Anosim) test and Principal Component Analysis (PCA) showed significantly different community profiles between the health control and the subjects with gingivitis. Alpha-diversity metrics were significantly higher in the subgingival plaque of the subjects with gingivitis compared with that of the healthy control. Overall, the relative abundance of 35 genera and 46 species were significantly different between the two groups, among them 28 genera and 45 species showed higher relative abundance in the subjects with gingivitis, whereas seven genera and one species showed a higher relative abundance in the healthy control. The genera Porphyromonas, Treponema, and Tannerella showed higher relative abundance in the subjects with gingivitis, while the genera Capnocytophaga showed higher proportions in health controls. Porphyromonas gingivalis, Prevotella intermedia and Porphyromonas endodontalis had higher relative abundance in gingivitis. Among them, Porphyromonas gingivalis was most abundant. Our results revealed significantly different microbial community composition and structures of subgingival plaque between subjects with gingivitis and healthy controls. Subjects with gingivitis showed greater taxonomic diversity compared with periodontally healthy subjects. The proportion of Porphyromonas, especially Porphyromonas gingivalis, may be associated with gingivitis subjects aged between 18 and 21 years old in China. Adults with gingivitis in this age group may have a higher risk of developing periodontitis.

バクテロイデーテス門細菌のIX型分泌機構およびV型線毛の研究

Many bacteria symbiotic and parasitic in humans are included in the genera Bacteroides, Prevotella, Porphyromonas and others, which belong to the phylum Bacteroidetes. We have been studying gingipain, a major secretory protease of Porphyromonas gingivalis which is a periodontopathogenic bacterium belonging to the genus Porphyromonas, and pili which contribute to host colonization in the bacterium. In the process, it was found that gingipain was secreted by a system not reported previously. Furthermore, this secretion system was found to exist widely in the Bacteroidetes phylum bacteria and closely related to the gliding motility of bacteroidete bacteria, and it was named the Por secretion system (later renamed the type IX secretion system). Regarding P. gingivalis pili, it was found that the pilus protein is transported as a lipoprotein to the cell surface, and the pilus formation occurs due to degradation by arginine-gingipain. Pili with this novel formation mechanism was found to be widely present in bacteria belonging to the class Bacteroidia in the phylum Bacteroidetes and was named the type V pili.

Exploration of bacterial species associated with the salivary microbiome of individuals with a low susceptibility to dental caries.

Dental caries is caused by acidogenic plaque microbiota formed on saliva-bathed tooth surfaces, in which multiple organisms act collectively to initiate and expand a cavity. We explored bacterial species associated with the salivary microbiome of individuals with low susceptibility to dental caries. The bacterial composition of saliva from 19 young adults was analyzed using barcoded pyrosequencing of the 16S rRNA gene; we compared 10 caries-experienced (CE) and nine caries-free (CF) individuals.Aquantitative PCR assay of salivafrom 139 orally healthy adults aged 40-59years was carried outto confirm the result obtained by pyrosequencing analysis. The microbiomes of CF individuals showed more diverse communities with a significantly greater proportion of the genus Porphyromonas. Among operational taxonomic units (OTUs) corresponding to the genus Porphyromonas, the OTU corresponding to P. pasteri was the most predominant and its relative abundance in CF individuals was significantly greater than in CE individuals (P<0.001, Wilcoxon rank sum test). A quantitative PCR assay of saliva confirmed that the amounts of P. pasteri were significantly higher in individuals with lower caries experience (filled teeth <15, n=67) than in those with higher caries experience (filled teeth ≥15, n=72) (P<0.001, Student's t test). These results revealed an association between a greater abundance of P. pasteri and lower susceptibility to dental caries. P. pasteri may be a bacterial species that could potentially be used as a marker for maintaining a healthy oral microbiome against dental caries.

Porphyromonas loveana sp. nov., isolated from the oral cavity of Australian marsupials.

An obligatory anaerobic, Gram-stain-negative coccobacillus with black-pigmented colonies was isolated from the oral cavity of selected Australian marsupial species. Phenotypic and molecular criteria showed that this bacterium was a distinct species within the genus Porphyromonas, and was closely related to Porphyromonas gingivalis and Porphyromonas gulae. This putative novel species and P. gulae could be differentiated from P. gingivalis by catalase activity. Further characterization by multi-locus enzyme electrophoresis of glutamate dehydrogenase and malate dehydrogenase enzyme mobility and matrix-assisted laser desorption ionization time-of-flight MS showed that this putative novel species could be differentiated phenotypically from P. gingivalis and P. gulae. Definitive identification by 16S rRNA gene sequencing showed that this bacterium belonged to a unique monophyletic lineage, phylogenetically distinct from P. gingivalis (94.9 % similarity) and P. gulae (95.5 %). This also was supported by 16S-23S rRNA intergenic spacer region and glutamate dehydrogenase gene sequencing. A new species epithet, Porphyromonas loveana sp. nov., is proposed for this bacterium, with DSM 28520T (=NCTC 13658T=UQD444T=MRK101T), isolated from a musky rat kangaroo, as the type strain.

Porphyromonas pasteri sp. nov., isolated from human saliva.

A bacterial strain, designated KUFDS01T, isolated from human saliva was characterized using a polyphasic taxonomic approach that included analysis of physiological and biochemical features, cellular fatty acid profiles and phylogenetic position based on 16S rRNA gene sequence analysis. Cells of the strain were obligately anaerobic, non-pigmented, non-spore-forming, non-motile, Gram-stain-negative rods. Growth of the strain was inhibited on medium containing 20% bile. The 16S rRNA gene sequence analysis showed that the strain was a member of the genus Porphyromonas. Strain KUFDS01T was closely related to Porphyromonas catoniae JCM 13863T (96.6% sequence similarity). An hsp60 gene sequence analysis indicated that strain KUFDS01T was different from P. catoniae JCM 13863T, with a sequence similarity value of 87.8%. The major cellular fatty acids of strain KUFDS01T were C16 : 0, iso-C15 : 0, anteiso-C15 : 0, C18 : 2ω6, 9c and C18 : 1ω9c. The DNA G+C content of strain KUFDS01T was 57.7 ± 0.66 mol%. On the basis of these data, strain KUFDS01T represents a novel species of the genus Porphyromonas, for which the name Porphyromonas pasteri sp. nov. is proposed. The type strain of P. pasteri is KUFDS01T ( = JCM 30531T = CCUG 66735T).

Porphyromonas pogonae sp. nov., an anaerobic but low concentration oxygen adapted coccobacillus isolated from lizards (Pogona vitticeps) or human clinical specimens, and emended description of the genus Porphyromonas Shah and Collins 1988

During the process of identifying a Gram-negative coccobacillus isolated from a human clinical specimen, we found that the isolate's 16S rRNA gene had very close sequence identity with that of a variant Porphyromonas isolated from polymicrobial infections in the central bearded dragon, a species of lizard [2]. The 16S rRNA gene sequences of the human isolate and of six isolates from lizards were nearly identical (99.9–100%). Phylogenetic analysis placed all of these isolates in a single phylogenetic cluster well separated from other species in the genus Porphyromonas. The closest species was Porphyromonas catoniae with 90.7–90.9% sequence identity, although there was less than 6% DNA similarity between the P. catoniae type strain and our representative isolates from lizards (PAGU 1787T) and human (PAGU 1776). These isolates could grow under anaerobic or microaerobic conditions (6% O2 atmosphere). The isolates were positive for catalase and very strong β-hemolytic activity, but did not show black or brown pigmentation. Biochemically, the isolates could be differentiated from closely related species by pyroglutamic acid arylamidase and glycine arylamidase activity, and some others. The fermentation products mainly included succinic acid and propionic acid. The major fatty acids detected in cells of the isolates were iso-C15:0, anteiso-C15:0, and 3OH-iso-C17:0. The G+C content was 43.0±0.62mol%. The species name Porphyromonas pogonae sp. nov. is proposed for these isolates with the type strain of PAGU 1787T (=MI 10-1288T=JCM 19732T=ATCC BAA-2643T).

A large genomic island allows Neisseria meningitidis to utilize propionic acid, with implications for colonization of the human nasopharynx.

Neisseria meningitidis is an important human pathogen that is capable of killing within hours of infection. Its normal habitat is the nasopharynx of adult humans. Here we identify a genomic island (the prp gene cluster) in N. meningitidis that enables this species to utilize propionic acid as a supplementary carbon source during growth, particularly under nutrient poor growth conditions. The prp gene cluster encodes enzymes for a methylcitrate cycle. Novel aspects of the methylcitrate cycle in N. meningitidis include a propionate kinase which was purified and characterized, and a putative propionate transporter. This genomic island is absent from the close relative of N. meningitidis, the commensal Neisseria lactamica, which chiefly colonizes infants not adults. We reason that the possession of the prp genes provides a metabolic advantage to N. meningitidis in the adult oral cavity, which is rich in propionic acid-generating bacteria. Data from classical microbiological and sequence-based microbiome studies provide several lines of supporting evidence that N. meningitidis colonization is correlated with propionic acid generating bacteria, with a strong correlation between prp-containing Neisseria and propionic acid generating bacteria from the genus Porphyromonas, and that this may explain adolescent/adult colonization by N. meningitidis.

Identification of key markers of normal and pathogenic microbiota determining health of periodontium by NGS-sequencing 16S-rDNA libraries of periodontal swabs

By using NGS-sequencing libraries of DNA from periodontal swabs with primers specific to V6 region of 16S rDNA prevalence of bacterial genera and species in periodontal microbiota of patients with aggressive periodontitis and healthy donors was analyzed. Six genera of putative periodontal protectors and eight periodontal pathogens were identified with respect to aggressive (but not chronic) periodontitis. Statistically relevant over-colonization by general Porphyromonas, Treponema, Synergistes, Tannerella, Filifactor, Ruminococcus, Parvimonas and Mycoplasma was found to be associated with the condition. From these, only three genera Porphyromonas, Treponema and Tannerella are traditionally considered as periodontal pathogens. Statistically confidential over-colonization by genus Veillonella was found in healthy patients. This genus should be considered as a relevant marker of a healthy periodontium. Genera Streptococcus, Bergeyella, Granulicatella, Kingella and Corynebacterium may be considered as putative periodontal protectors. Comparison of data of NGS-sequencing and real-time PCR demonstrated a good agreement if different PCR efficiency using independent primer pairs is taken into account.

Bacterial Community Shift in Treated Periodontitis Patients Revealed by Ion Torrent 16S rRNA Gene Amplicon Sequencing

Periodontitis, one of the most common diseases in the world, is caused by a mixture of pathogenic bacteria and inflammatory host responses and often treated by antimicrobials as an adjunct to scaling and root planing (SRP). Our study aims to elucidate explorative and descriptive temporal shifts in bacterial communities between patients treated by SRP alone versus SRP plus antibiotics. This is the first metagenomic study using an Ion Torrent Personal Genome Machine (PGM). Eight subgingival plaque samples from four patients with chronic periodontitis, taken before and two months after intervention were analyzed. Amplicons from the V6 hypervariable region of the 16S rRNA gene were generated and sequenced each on a 314 chip. Sequencing reads were clustered into operational taxonomic units (OTUs, 3% distance), described by community metrics, and taxonomically classified. Reads ranging from 599,933 to 650,416 per sample were clustered into 1,648 to 2,659 non-singleton OTUs, respectively. Increased diversity (Shannon and Simpson) in all samples after therapy was observed regardless of the treatment type whereas richness (ACE) showed no correlation. Taxonomic analysis revealed different microbial shifts between both therapy approaches at all taxonomic levels. Most remarkably, the genera Porphyromonas, Tannerella, Treponema, and Filifactor all harboring periodontal pathogenic species were removed almost only in the group treated with SPR and antibiotics. For the species T. forsythia and P. gingivalis results were corroborated by real-time PCR analysis. In the future, hypothesis free metagenomic analysis could be the key in understanding polymicrobial diseases and be used for therapy monitoring. Therefore, as read length continues to increase and cost to decrease, rapid benchtop sequencers like the PGM might finally be used in routine diagnostic.

Predominant bacterial species in subgingival plaque in dogs

The dog has been used extensively for experimental and microbiological studies on periodontitis and peri-implantitis without detailed knowledge about the predominant flora of the subgingival plaque. This study was designed to evaluate the predominant cultivable bacterial species in dogs and compare them phenotypically and genotypically with corresponding human species. Four subgingival samples were taken from two upper premolars in each of six Labrador retrievers. The samples from each dog were processed for anaerobic culture. From the samples of each dog, the five or six predominating bacteria based on colony morphology were selected and pure cultured. Each of the strains was characterized by Gram stain, anaerobic/aerobic growth and API-ZYM test. Eighteen strains showing clear-cut phenotypic differences were further classified based on DNA sequencing technology. Cross-reactions of DNA probes from human and dog strains were also tested against a panel of both human and dog bacterial species. Thirty-one strains in the dogs were isolated and characterized. They represented 21 different species, of which six belonged to the genus Porphyromonas. No species was found consistently in the predominant flora of all six dogs. Porphyromonas crevioricanis and Fusobacterium canifelinum were the two most prevalent species in predominant flora in dogs. DNA probes from human and dog species cross-reacted to some extent with related strains from humans and dogs; however, distinct exceptions were found. The predominant cultural subgingival flora in dogs shows great similarities with the subgingival bacteria from humans at the genus level, but distinct differences at the species level; however, a genetic relatedness could be disclosed for most strains investigated.

Asp- and Glu-specific Novel Dipeptidyl Peptidase 11 of Porphyromonas gingivalis Ensures Utilization of Proteinaceous Energy Sources

Porphyromonas gingivalis and Porphyromonas endodontalis, asaccharolytic black-pigmented anaerobes, are predominant pathogens of human chronic and periapical periodontitis, respectively. They incorporate di- and tripeptides from the environment as carbon and energy sources. In the present study we cloned a novel dipeptidyl peptidase (DPP) gene of P. endodontalis ATCC 35406, designated as DPP11. The DPP11 gene encoded 717 amino acids with a molecular mass of 81,090 Da and was present as a 75-kDa form with an N terminus of Asp(22). A homology search revealed the presence of a P. gingivalis orthologue, PGN0607, that has been categorized as an isoform of authentic DPP7. P. gingivalis DPP11 was exclusively cell-associated as a truncated 60-kDa form, and the gene ablation retarded cell growth. DPP11 specifically removed dipeptides from oligopeptides with the penultimate N-terminal Asp and Glu and has a P2-position preference to hydrophobic residues. Optimum pH was 7.0, and the k(cat)/K(m) value was higher for Asp than Glu. Those activities were lost by substitution of Ser(652) in P. endodontalis and Ser(655) in P. gingivalis DPP11 to Ala, and they were consistently decreased with increasing NaCl concentration. Arg(670) is a unique amino acid completely conserved in all DPP11 members distributed in the genera Porphyromonas, Bacteroides, and Parabacteroides, whereas this residue is converted to Gly in all authentic DPP7 members. Substitution analysis suggested that Arg(670) interacts with an acidic residue of the substrate. Considered to preferentially utilize acidic amino acids, DPP11 ensures efficient degradation of oligopeptide substrates in these Gram-negative anaerobic rods.