Oral microbiome sequencing revealed the enrichment of Fusobacterium sp., Porphyromonas sp., Campylobacter sp., and Neisseria sp. on the oral malignant fibroma surface of giant panda.

Introduction: Microbial community composition is closely associated with host disease onset and progression, underscoring the importance of understanding host-microbiota dynamics in various health contexts. Methods: In this study, we utilized full-length 16S rRNA gene sequencing to conduct species-level identification of the microorganisms in the oral cavity of a giant panda (Ailuropoda melanoleuca) with oral malignant fibroma. Results: We observed a significant difference between the microbial community of the tumor side and non-tumor side of the oral cavity of the giant panda, with the latter exhibiting higher microbial diversity. The tumor side was dominated by specific microorganisms, such as Fusobacterium simiae, Porphyromonas sp. feline oral taxon 110, Campylobacter sp. feline oral taxon 100, and Neisseria sp. feline oral taxon 078, that have been reported to be associated with tumorigenic processes and periodontal diseases in other organisms. According to the linear discriminant analysis effect size analysis, more than 9 distinct biomarkers were obtained between the tumor side and non-tumor side samples. Furthermore, the Kyoto Encyclopedia of Genes and Genomes analysis revealed that the oral microbiota of the giant panda was significantly associated with genetic information processing and metabolism, particularly cofactor and vitamin, amino acid, and carbohydrate metabolism. Furthermore, a significant bacterial invasion of epithelial cells was predicted in the tumor side. Discussion: This study provides crucial insights into the association between oral microbiota and oral tumors in giant pandas and offers potential biomarkers that may guide future health assessments and preventive strategies for captive and aging giant pandas.

Exploring the signature gut and oral microbiome in individuals of specific Ayurveda prakriti.

Diagnosis and treatment of various diseases in Ayurveda, the Indian system of medicine, relies on 'prakriti' phenotyping of individuals into predominantly three constitutions, kapha, pitta and vata. Recent studies propose that microbiome play an integral role in precision medicine. A study of the relationship between prakriti - the basis of personalized medicine in Ayurveda and that of gut microbiome, and possible biomarker of an individual's health, would vastly improve precision therapy. Towards this, we analyzed bacterial metagenomes from buccal (oral microbiome) and fecal (gut microbiome) samples of 272 healthy individuals of various predominant prakritis. Major bacterial genera from gut microbiome included Prevotella, Bacteroides and Dialister while oral microbiome included Streptococcus, Neisseria, Veilonella, Haemophilus, Porphyromonas and Prevotella. Though the core microbiome was shared across all individuals, we found prakriti specific signatures such as preferential presence of Paraprevotella and Christensenellaceae in vata individuals. A comparison of core gut microbiome of each prakriti with a database of 'healthy' microbes identified microbes unique to each prakriti with functional roles similar to the physiological characteristics of various prakritis as described in Ayurveda. Our findings provide evidence to Ayurvedic interventions based on prakriti phenotyping and possible microbial biomarkers that can stratify the heterogenous population and aid in precision therapy.

Porphyromonas: A neglected potential key genus in human microbiomes.

Anaerobes form a large part of microbial communities, and have begun to be specifically studied in both healthy and pathologic contexts. Porphyromonas is one of the top ten anaerobic taxa in the microbiome (anaerobiome) in healthy subjects. However, to date, most studies focused on the deleterious role of P. gingivalis, the most widely described species. Interestingly, targeted metagenomics reveals Porphyromonas other than gingivalis (POTG), highlighting other species such as P. catoniae or P. pasteri as potential biomarkers in disease progression or pathogen colonization susceptibility. From the sparse data, it appears that the Porphyromonas genus may also be a relevant target of investigation in several pulmonary diseases. Moreover, deciphering cutaneous, gastric and oral microbiomes hint that Porphyromonas may be a genus of interest in non-pulmonary diseases. This review aims to summarize the major data on POTG and to report their impact on the various human microbiomes in different clinical states.

Oral microbial profile variation during canine ligature-induced peri-implantitis development.

BACKGROUND: Dental implants have become well-established in oral rehabilitation for fully or partially edentulous patients. However, peri-implantitis often leads to the failure of dental implants. The aim of this study was to understand the core microbiome associated with peri-implantitis and evaluate potential peri-implantitis pathogens based on canine peri-implantitis model. RESULTS: In this study, three beagle dogs were used to build peri-implantitis models with ligature-induced strategy. The peri-implant sulcular fluids were collected at four different phases based on disease severity during the peri-implantitis development. Microbial compositions during peri-implantitis development were monitored and evaluated. The microbes were presented with operational taxonomic unit (OTU) classified at 97% identity of the high-throughput 16S rRNA gene fragments. Microbial diversity and richness varied during peri-implantitis. At the phylum-level, Firmicutes decreased and Bacteroides increased during peri-implantitis development. At the genus-level, Peptostreptococcus decreased and Porphyromonas increased, suggesting peri-implantitis pathogens might be assigned to these two genera. Further species-level and co-occurrence network analyses identified several potential keystone species during peri-implantitis development, and some OTUs were potential peri-implantitis pathogens. CONCLUSION: In summary, canine peri-implantitis models help to identify several potential keystone peri-implantitis associated species. The canine model can give insight into human peri-implantitis associated microbiota.

Identification and molecular characterization of Porphyromonas gulae fimA types among cat isolates.

Porphyromonas gulae, a Gram-negative black-pigmented anaerobe, is one of several major periodontal pathogens of animals. P. gulae isolates from dogs have been classified into three genotypes based on a 41-kDa filamentous appendage (FimA) on the cell surface, which is closely related to virulence in periodontal disease. However, other specific bacterial virulence factors contributing to the aggravation of periodontal disease in cats remain elusive. In the present study, we assessed FimA diversity in P. gulae isolates from cats and examined whether this diversity influenced periodontal condition. The putative amino acid sequences of FimA from 15 P. gulae isolates from 13 cats were classified into three genotypes (types A, B, and C), which showed 95-100% identity and similarity to the fimA types in dogs. The type C isolate showed greater adhesion and invasion properties in periodontal ligament fibroblasts as well as stronger inhibition of scratch closure of the cells compared with type A and B isolates. Next, a PCR-based method for identification of fimA genotype was developed and used to analyze 99 oral swab specimens from cats. High fimA type A detection rates were observed regardless of the periodontal condition, whereas types B and C were frequently detected from subjects with moderate and severe periodontitis, respectively. These results suggest that P. gulae isolates from cats can be classified into three types based on fimA genotype, which may be closely related to virulence in periodontitis.

Identification of Porphyromonas isolates from clinical origin using MALDI-TOF Mass Spectrometry.

Despite the wide implementation of MALDI-TOF MS for the rapid and reliable identification of most microorganisms, some taxonomic groups such as the Porphyromonas genus remain largely untested. In this study we evaluated the performance of MALDI-TOF MS on this genus using a collection of 39 isolates sent for routine identification to our institution over a 16-year period. All of them were identified by DNA-sequencing analysis of the 16S rRNA gene plus the hsp60 gene when the previous one did not yield species-level assignment. MALDI-TOF MS provided correct identification at least at the genus level of 21/39 isolates (53.9%). Twelve isolates were correctly identified at the species level with a score value ≥ 2.0 and 9 more with score values < 2.0 and ≥ 1.7. The species most represented in the database (P. gingivalis and P. somerae) lay within this category. However, the species poorly represented in this database (P. asaccharolytica and P. uenonis) were mostly identified with lower scores (1.35-1.67) or remained unidentified by MALDI-TOF MS. The addition of two P. asaccharolytica reference spectra to our in-house library allowed 72.9% of genus-level identifications with 17/37 isolates (45.9%) identified with score values ≥ 2.0. Our results showed a high level of correlation between MALDI-TOF MS and DNA-based identification for Porphyromonas spp. strains at the species level, even with score values < 2.0. The reliability provided by MALDI-TOF MS increased when the database was fed with spectra from the species poorly represented in the commercial database.

Western diet feeding influences gut microbiota profiles in apoE knockout mice.

BACKGROUND: Gut microbiota plays an important role in many metabolic diseases such as diabetes and atherosclerosis. Apolipoprotein E (apoE) knock-out (KO) mice are frequently used for the study of hyperlipidemia and atherosclerosis. However, it is unknown whether apoE KO mice have altered gut microbiota when challenged with a Western diet. METHODS: In the current study, we assessed the gut microbiota profiling of apoE KO mice and compared with wild-type mice fed either a normal chow or Western diet for 12 weeks using 16S pyrosequencing. RESULTS: On a western diet, the gut microbiota diversity was significantly decreased in apoE KO mice compared with wild type (WT) mice. Firmicutes and Erysipelotrichaceae were significantly increased in WT mice but Erysipelotrichaceae was unchanged in apoE KO mice on a Western diet. The weighted UniFrac principal coordinate analysis exhibited clear separation between WT and apoE KO mice on the first vector (58.6%) with significant changes of two dominant phyla (Bacteroidetes and Firmicutes) and seven dominant families (Porphyromonadaceae, Lachnospiraceae, Ruminococcaceae, Desulfovibrionaceae, Helicobacteraceae, Erysipelotrichaceae and Veillonellaceae). Lachnospiraceae was significantly enriched in apoE KO mice on a Western diet. In addition, Lachnospiraceae and Ruminococcaceae were positively correlated with relative atherosclerosis lesion size in apoE KO. CONCLUSIONS: Collectively, our study showed that there are marked changes in the gut microbiota of apoE KO mice, particularly challenged with a Western diet and these alterations may be possibly associated with atherosclerosis.

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.

Porphyromonas pogonae identification from a soft tissue infection: The first human case.

We report a first human case of Porphyromonas pogonae causing soft tissue infection in a patient with open fracture. Strong ß-hemolytic, aerotolerant, and non-pigmented gram-negative coccobacilli which matched Porphyromonas pogonae by PCR for 16S rRNA genes were identified from the pus specimen. The clinical course of the patient improved with repeated surgical drainage and tigecycline administration.

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.

[New Strains of an Aerobic Anoxygenic Phototrophic Bacterium Porphyrobacter donghaensis Isolated from a Siberian Thermal Spring and a Low-Mineralization Lake].

A strain of aerobic anoxygenic phototrophic bacteria (AAPB) isolated from the surface of a cyano- bacterial mat of an Eastern Siberian thermal spring (40 C) and designated Se 4 was identified as Porphyro- bacter donghaensis according to its 16S rRNA gene sequence. A DNA-DNA hybridization level of 95% was determined between strain Se-4 and the type strain of this species; SW-132@T. The isolate was an obligate aerobe,. forming orange round colonies on solid media, which turn red in the course of growth. The cells were motile rods capable of branching. The cells divided by uniform fission by constriction. Optimal growth was observed at pH 7.5 and NaCl concentrations from 0 to 1 g/L. The pigments present were carotenoids and bacteriochlorophyll a. Another Porphyrobacter donghaensis strain, Noj- 1, isolated from a purple mat developing on the surface of a coastal set-up in a steppe low-mineralization (1.5 g/L) soda lake Nozhii (Eastern Siberia) possessed similar characteristics. Thus, the AAPB species Porphyrobacter donghaensis was shown to-occur, apart from its known habitat, marine environments, in low-mineralization soda lakes and freshwater thermal springs. Description of the species Porphyrobacter donghaensis was amended.

Composition and Predicted Metabolic Capacity of Upper and Lower Airway Microbiota of Healthy Dogs in Relation to the Fecal Microbiota.

The upper and lower airways of healthy humans are reported to harbor stable and consistent bacterial populations, and the composition of these communities is altered in individuals affected with several respiratory diseases. Data regarding the presence of airway microbiota in other animals are scant and a better understanding of the composition and metabolic function of such bacterial populations is essential for the development of novel therapeutic and diagnostic modalities for use in both veterinary and human medicine. Based on targeted next-generation sequencing of feces and samples collected at multiple levels of the airways from 16 healthy female dogs, we demonstrate that canine airways harbor a topographically continuous microbiota with increasing relative abundance of proteobacterial species from the upper to lower airways. The lung-associated microbiota, as assessed via bronchoalveolar lavage fluid (BALF), was the most consistent between dogs and was dominated by three distinct taxa, two of which were resolved to the species level and one to the level of family. The gene content of the nasal, oropharyngeal, and lung-associated microbiota, predicted using the Phylogenetic Investigations into Communities by Reconstruction of Unobserved States (PICRUSt) software, provided information regarding the glyoxylate and citrate cycle metabolic pathways utilized by these bacterial populations to colonize such nutrient-poor, low-throughput environments. These data generated in healthy subjects provide context for future analysis of diseased canine airways. Moreover, as dogs have similar respiratory anatomy, physiology, and immune systems as humans, are exposed to many of the same environmental stimuli, and spontaneously develop similar respiratory diseases, these data support the use of dogs as a model species for prospective studies of the airway microbiota, with findings translatable to the human condition.

The use of PCR-DGGE to determine bacterial fingerprints for poultry and red meat abattoir effluent.

UNLABELLED: Strict legislation and chemical composition monitoring of effluent may be useful, but the data generated do not allow for source tracking, and enforcing legislation remains problematic in the South African setting. These difficulties emphasize the necessity for effluent source traceability. Denaturing gradient gel electrophoresis (DGGE) targeting the V3 region of the 16S rRNA gene was considered as fingerprinting technique for effluent originating from abattoirs slaughtering different animal species. The influence of treatment to remove excess fat from effluent prior to molecular analyses and different PCR approaches on the detection of bacterial diversity were considered. Use of a treatment option to remove fat and a nested PCR approach resulted in up to 51% difference in inter-sample diversity similarity. A robust approach with no pre-treatment to remove PCR inhibitors, such as fat, and direct amplification from genomic DNA yielded optimal/maximal bacterial diversity fingerprints. Repeatable fingerprints were obtained for poultry abattoir effluent over a 4-month period, but profiles for the red meat abattoir varied with maximum similarity detected only 33·2%. Genetic material from faecal indicators Aeromona spp and Clostridium spp were detected. Genera unique to each effluent were present; Anoxybacillus, Patulibacter and Oleispira in poultry abattoir effluent and Porphyromonas and Peptostreptococcus in red meat abattoir effluent. SIGNIFICANCE AND IMPACT OF THE STUDY: This study was the first to demonstrate the application of denaturing gradient gel electrophoresis (DGGE) to construct bacterial diversity fingerprints for high-throughput abattoir effluents. Proved redundancy of fat removal as PCR inhibitor and change in diversity similarity introduced by nested PCR approach. The importance of limiting excessive handling/processing which could lead to misrepresented diversity profiles was emphasized.

The Microbiome in Populations with a Low and High Prevalence of Caries.

The oral microbiota was compared between Romanian adolescents with a high prevalence of caries and no dental care and Swedish caries-active and caries-free adolescents in caries prevention programs and with a low prevalence of caries. Biofilm samples were analyzed by FLX+ pyrosequencing of the V1 to V4 hypervariable regions of the 16S rRNA gene and polymerase chain reaction (PCR)/quantitative PCR (qPCR) for Streptococcus mutans and Streptococcus sobrinus. Sequences obtained blasted to 9 phyla, 66 genera, and 401 human oral taxa (HOT) in the 16S rRNA Human Oral Microbiome Database, of which 295 were represented by ≥20 sequences. The Romanian adolescents had more sequences in Firmicutes and fewer in Actinobacteria phyla and more sequences in the genera Bacteroidetes [G-3], Porphyromonas, Abiotrophia, Filifactor, Peptostreptococcaceae [11][G-4], Pseudoramibacter, Streptococcus, and Neisseria and fewer in Actinomyces, Selenomonas, Veillonella, Campylobacter, and TM7 [G-1] than the Swedish groups. Multivariate modeling employing HOT, S. sobrinus and S. mutans (PCR/qPCR), and sugar snacks separated Romanian from Swedish adolescents. The Romanian adolescents' microbiota was characterized by a panel of streptococci, including S. mutans, S. sobrinus, and Streptococcus australis, and Alloprevotella, Leptotrichia, Neisseria, Porphyromonas, and Prevotella. The Swedish adolescents were characterized by sweet snacks, and those with caries activity were also characterized by Prevotella, Actinomyces, and Capnocytophaga species and those free of caries by Actinomyces, Prevotella, Selenomonas, Streptococcus, and Mycoplasma. Eight species including Streptococcus mitis and Streptococcus species HOT070 were prevalent in Romanian and Swedish caries-active subjects but not caries-free subjects. In conclusion, S. mutans and S. sobrinus correlated with Romanian adolescents with caries and with limited access to dental care, whereas S. mutans and S. sobrinus were detected infrequently in Swedish adolescents in dental care programs. Swedish caries-active adolescents were typically colonized by Actinomyces, Selenomonas, Prevotella, and Capnocytophaga. Hence, the role of mutans streptococci as a primary caries pathogen appears less pronounced in populations with prevention programs compared to populations lacking caries treatment and prevention strategies.

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).

Pyrosequencing Analysis of Subgingival Microbiota in Distinct Periodontal Conditions.

Subgingival microorganisms are potentially associated with periodontal diseases. However, changes in the subgingival microbiota during the progress of periodontal diseases are poorly understood. In this study, we analyzed bacterial communities in the subgingival paper point samples from 32 Korean individuals with no sign of disease, gingivitis, or periodontitis using 454 FLX Titanium pyrosequencing. A total of 256,113 reads representing 26 phyla, 433 genera, and 1,016 species were detected. Bacteroidetes, Fusobacteria, Synergistetes, and Spirochaetes were the abundant phyla in periodontitis subjects, whereas Firmicutes and Proteobacteria were identified as the dominant phyla in the gingivitis and healthy subjects, respectively. Although high levels of Porphyromonas, Fusobacterium, Fretibacterium, Rothia, Filifactor, and Treponema genera were observed in the periodontitis subjects, Streptococcus, Capnocytophaga, Leptotrichia, and Haemophilus genera were found at high frequency in the gingivitis subjects. Species including Porphyromonas gingivalis, Fusobacterium nucleatum, and Fretibacterium fastidiosum were significantly increased in periodontitis subjects. On the other hand, Streptococcus pseudopneumoniae, Haemophilus parainfluenzae, and Leptotrichia hongkongensis were preferentially observed in the gingivitis subjects. Intriguingly, the halophile Halomonas hamiltonii was revealed as a predominant species in the healthy subjects. Based on Fast UniFrac analysis, distinctive bacterial clusters were classified for the healthy, gingivitis, and periodontitis state. The current findings might be useful for understanding the pathogenesis, diagnosis, and treatment of periodontal diseases.

Molecular identification of black-pigmented bacteria from subgingival samples of cats suffering from periodontal disease.

OBJECTIVES: To characterise the black-pigmented bacterial species found in the subgingival samples of cats with periodontal disease using molecular-based microbiological techniques. METHODS: Sixty-five subgingival samples obtained from 50 cats with periodontal disease were analysed by polymerase chain reaction amplified ribosomal DNA restriction analysis and cloning and sequencing of the 16S rRNA genes. RESULTS: Among the 65 subgingival samples, eight phylogenetic profiles were obtained, of which the most prevalent species were: Porphyromonas gulae (40%), P. gingivalis/P. gulae (36 · 9%), P. gulae/Porphyromonas sp. UQD 406 (9 · 2%), Odoribacter denticanis (6 · 2%), P. gulae/Porphyromonas sp. UQD 348 (1 · 5%) and P. circumdentaria (1 · 5%). When compared with the species resulting from biochemical diagnosis, the identification of P. gulae was congruent in 70% of the cases, while colonies identified as P. intermedia-like corresponded in 80% of cases to P. gulae. CLINICAL SIGNIFICANCE: The use of molecular-based microbiological diagnostic techniques resulted in a predominance of Porphyromonas spp. in the subgingival plaque of cats suffering from periodontal disease. Further characterisation of these bacteria identified P. gulae, O. denticanis and P. circumdentaria. The more frequently detected phylogenetic profiles corresponded to P. gingivalis and P. gulae.

Mucosal microbiome in patients with recurrent aphthous stomatitis.

Recurrent aphthous stomatitis (RAS) is the most common disease affecting oral mucosae. Etiology is unknown, but several factors have been implicated, all of which influence the composition of microbiota residing on oral mucosae, which in turn modulates immunity and thereby affects disease progression. Although no individual pathogens have been conclusively shown to be causative agents of RAS, imbalanced composition of the oral microbiota may play a key role. In this study, we sought to determine composition profiles of bacterial microbiota in the oral mucosa associated with RAS. Using high-throughput 16S rRNA gene sequencing, we characterized the most abundant bacterial populations residing on healthy and ulcerated mucosae in patients with RAS (recruited using highly stringent criteria) and no associated medical conditions; we also compared these to the bacterial microbiota of healthy controls (HCs). Phylum-level diversity comparisons revealed decreased Firmicutes and increased Proteobacteria in ulcerated sites, as compared with healthy sites in RAS patients, and no differences between RAS patients with healthy sites and HCs. Genus-level analysis demonstrated higher abundance of total Bacteroidales in RAS patients with healthy sites over HCs. Porphyromonadaceae comprising species associated with periodontal disease and Veillonellaceae predominated in ulcerated sites over HCs, while no quantitative differences of these families were observed between healthy sites in RAS patients and HCs. Streptococcaceae comprising species associated with oral health predominated in HCs over ulcerated sites but not in HCs over healthy sites in RAS patients. This study demonstrates that mucosal microbiome changes in patients with idiopathic RAS--namely, increased Bacteroidales species in mucosae of RAS patients not affected by active ulceration. While these changes suggest a microbial role in initiation of RAS, this study does not provide data on causality. Within this limitation, the study contributes to the understanding of the potential role of mucosal microbiome changes in oral mucosal disease.

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 1787(T)) 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 ß-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 ± 0.62 mol%. The species name Porphyromonas pogonae sp. nov. is proposed for these isolates with the type strain of PAGU 1787(T) (=MI 10-1288(T)=JCM 19732(T)=ATCC BAA-2643(T)).