Oral mycobiome in community-dwelling elderly and its relation to oral and general health conditions.

OBJECTIVE: Oral fungal infection is generally associated with dysbiosis related to antibiotic use, immunodeficiency, or frailty. However, fungal colonization in a typical population without apparent symptoms and its associated conditions are poorly understood. In this study, oral fungal colonization in community-dwelling and independently living elderly populations was evaluated and factors affecting fungal colonization were analyzed. SUBJECTS AND METHODS: The subjects (410; 181 males and 229 females) were 75-99 years of age; those under prior antibiotic use were excluded. Fungal populations in the saliva were evaluated by PCR-based molecular techniques. Body mass index (BMI), smoking habits, and oral health conditions were examined. RESULTS: Salivary fungal amounts exceeded 104  CFU/ml in 63 (15.4%) of 410 subjects. Candida albicans was most frequently detected (98.4%), followed by Candida glabrata (54.0%), and Candida dubliniensis (38.1%) in those subjects with fungi at 104  CFU/ml or over. Fungi at 104  CFU/ml or over in the presence of C. glabrata or C. dubliniensis was significantly associated with low BMI. CONCLUSIONS: Candida albicans, C. glabrata, and C. dubliniensis dominated the oral mycobiome in Japanese community-dwelling elderly. Lower BMI might signify compromised health status and thus could result in susceptibility to specific candidiasis by C. glabrata and C. dubliniensis.

Posterior teeth occlusion and dysphagia risk in older nursing home residents: a cross-sectional observational study.

The total number of natural teeth was related to swallowing function among older adults; however, limited information is available regarding the impact of occluding pairs of teeth on swallowing function. This study aimed to examine the association between posterior teeth occlusion and dysphagia risk in older nursing home residents. This cross-sectional study included 238 residents aged ≥60 years from eight nursing homes in Aso City, Japan. Swallowing function was evaluated using the modified water swallowing test (MWST); the primary outcome was dysphagia risk (MWST score ≤3). Posterior teeth occlusion was assessed using number of functional tooth units (FTUs), determined based on number and location of the remaining natural and artificial teeth on implant-supported, fixed or removable prostheses. Univariate and multivariate logistic regression analyses were performed to examine the association between posterior teeth occlusion and dysphagia risk, adjusted for the covariates of number of natural teeth, demographic characteristics, comorbidities, physical function, body mass index and cognitive function. Of the 238 subjects, 44 (18·5%) were determined to be at risk of dysphagia based on the MWST scores. The odds ratio (OR) of dysphagia risk decreased in subjects with higher total FTUs [OR = 0·92, 95% confidence interval (CI) 0·87-0·98]. After adjusting for covariates, this association remained significant (OR = 0·90, 95% CI 0·84-0·97). Loss of posterior teeth occlusion was independently associated with dysphagia risk in older nursing home residents. Maintaining and restoring posterior teeth occlusion may be an effective measure to prevent dysphagia.

Acetaldehyde production by major oral microbes.

OBJECTIVES: To assess acetaldehyde (ACH) production by bacteria constituting the oral microbiota and the inhibitory effects of sugar alcohols on ACH production. MATERIALS AND METHODS: The predominant bacterial components of the salivary microbiota of 166 orally healthy subjects were determined by barcoded pyrosequencing analysis of the 16S rRNA gene. Bacterial ACH production from ethanol or glucose was measured using gas chromatography. In addition, inhibition by four sugars and five sugar alcohols of ACH production was assayed. RESULTS: Forty-one species from 16 genera were selected as predominant and prevalent bacteria based on the following criteria: identification in ≥95% of the subjects, ≥1% of mean relative abundance or ≥5% of maximum relative abundance. All Neisseria species tested produced conspicuous amounts of ACH from ethanol, as did Rothia mucilaginosa, Streptococcus mitis and Prevotella histicola exhibited the ability to produce ACH. In addition, xylitol and sorbitol inhibited ACH production by Neisseria mucosa by more than 90%. CONCLUSIONS: The oral microbiota of orally healthy subjects comprises considerable amounts of bacteria possessing the ability to produce ACH, an oral carcinogen. Consumption of sugar alcohols may regulate ACH production by oral microbes.

Microbial community in persistent apical periodontitis: a 16S rRNA gene clone library analysis.

AIM: To characterize the microbial composition of persistent periapical lesions of root filled teeth using a molecular genetics approach. METHODOLOGY: Apical lesion samples were collected from 12 patients (23-80 years old) who visited the Kyushu University Hospital for apicectomy with persistent periapical lesions associated with root filled teeth. DNA was directly extracted from each sample and the microbial composition was comprehensively analysed using clone library analysis of the 16S rRNA gene. Enterococcus faecalis, Candida albicans and specific fimA genotypes of Porphyromonas gingivalis were confirmed using polymerase chain reaction (PCR) analysis with specific primers. RESULTS: Bacteria were detected in all samples, and the dominant findings were P. gingivalis (19.9%), Fusobacterium nucleatum (11.2%) and Propionibacterium acnes (9%). Bacterial diversity was greater in symptomatic lesions than in asymptomatic ones. In addition, the following bacteria or bacterial combinations were characteristic to symptomatic lesions: Prevotella spp., Treponema spp., Peptostreptococcaceae sp. HOT-113, Olsenella uli, Slackia exigua, Selemonas infelix, P. gingivalis with type IV fimA, and a combination of P. gingivalis, F. nucleatum, and Peptostreptococcaceae sp. HOT-113 and predominance of Streptococcus spp. On the other hand, neither Enterococcus faecalis nor C. albicans were detected in any of the samples. CONCLUSION: Whilst a diverse bacterial species were observed in the persistent apical lesions, some characteristic patterns of bacterial community were found in the symptomatic lesions. The diverse variation of community indicates that bacterial combinations as a community may cause persistent inflammation in periapical tissues rather than specific bacterial species.

High-Resolution Detection of Translocation of Oral Bacteria to the Gut.

Ectopic enrichment of oral microbes in the gut is a notable alteration in gut microbial balance. These microbes are likely delivered from the oral cavity with saliva and food; however, evidence of oral-gut microbial transmission is insufficient and needs further investigation. In this observational study, we examined 144 pairs of saliva and stool samples collected from community-dwelling adults to verify the oral-gut microbial link and identify the relevant influencing factors on the increased abundance of oral microbes within the gut. The bacterial composition of each sample was determined using PacBio single-molecule long-read sequencing of the full-length 16S ribosomal RNA gene and amplicon sequence variant (ASV) analysis. Although the bacterial compositions of salivary and gut microbiota were distinctly different, at least 1 ASV was shared between salivary and gut microbiota in 72.9% of subjects. Shared ASVs accounted for 0.0% to 63.1% (median 0.14%) of the gut microbiota in each subject and frequently included abundant Streptococcus salivarius and Streptococcus parasanguinis. Their total relative abundance in the gut was significantly higher in older subjects or those with dental plaque accumulation. The gut microbiota with ≥5% of shared ASVs displayed a higher abundance of Streptococcus, Lactobacillus, and Klebsiella and a lower abundance of Faecalibacterium, Blautia, Megamonas, and Parabacteroides. Our study presents evidence for the translocation of oral bacteria to the gut in community-dwelling adults and suggests that aging and dental plaque accumulation contribute to an increased abundance of oral microbes in the gut, which might be relevant to the compositional shift in the gut commensals.

Molecular characterization of fungal populations on the tongue dorsum of institutionalized elderly adults.

OBJECTIVES: To characterize the global composition of oral fungal populations in frail elderly adults and to investigate the relationship with their health status. MATERIALS AND METHODS: We investigated the fungal populations on the tongue dorsum in 291 institutionalized elderly adults by molecular PCR-based techniques using internal transcribed spacer regions of nuclear ribosomal DNA. RESULTS: Quantitative PCR analysis showed that fungi were present on the tongue dorsum of 128 subjects at ≥10(4) CFU per sample, and 35 of them exceeded 10(5) CFU per sample. Length heterogeneity-PCR analysis and nucleotide sequence determinations showed that Candida albicans was most frequently detected in those subjects with fungi at ≥10(4) CFU per sample (105 subjects), followed by Candida dubliniensis (78), Malassezia restricta (57), and Candida tropicalis (45). Statistical analysis revealed that those subjects with ≥10(5) CFU of fungi other than C. albicans per sample had an increased risk of fever (≥7 febrile days per 12 months) compared with subjects with <10(5) CFU per sample, after adjustment for other fever-associated confounding factors. CONCLUSIONS: These data demonstrate that the oral cavity of the elderly is inhabited by a diverse array of fungi not limited to typical Candida species and they suggest that the diversity in distribution is associated with health status.

Periodontitis Is Associated with Chronic Obstructive Pulmonary Disease.

Although they are known to share pathophysiological processes, the relationship between periodontitis and chronic obstructive pulmonary disease (COPD) is not fully understood. The aim of the present study was to test the hypothesis that periodontitis is associated with a greater risk of development of COPD, when smoking is taken into account. The analysis in a 5-y follow-up population-based cohort study was based on 900 community-dwelling Japanese adults (age: 68.8 ± 6.3 [mean ± SD], 46.0% male) without COPD aged 60 or older with at least 1 tooth. Participants were classified into 3 categories according to baseline periodontitis severity (no/mild, moderate, and severe). COPD was spirometrically determined by a fixed ratio of <0.7 for forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and by FEV1/FVC below the lower limit of normal. Poisson regression was used to calculate the relative risk (RR) of developing COPD according to the severity of periodontitis. The population attributable fraction (PAF) was also calculated. During follow-up, 22 (2.4%) subjects developed COPD. Compared with no/mild periodontitis subjects, a significantly increased risk of COPD occurred among severe periodontitis subjects (RR = 3.55; 95% confidence interval [CI], 1.18 to 10.67), but no significant differences were observed between the no/mild and moderate categories (RR = 1.48; 95% CI, 0.56 to 3.90). After adjustment for potential confounders, including smoking intensity, the relationship between severe periodontitis and risk of COPD remained significant (RR = 3.51; 95% CI, 1.15 to 10.74). Likewise, there was a positive association of periodontitis severity with risk of COPD ( P for trend = 0.043). The PAF for COPD due to periodontitis was 22.6%. These data highlight the potential importance of periodontitis as a risk factor for COPD.

Association of ALDH(2) genotypes and alcohol consumption with periodontitis.

There is little information regarding the association between alcohol consumption and periodontitis risk. We assessed whether alcohol consumption and ALDH(2) genotypes were associated with periodontitis. Subjects' lifestyle was examined by a self-administered questionnaire, and the percentage of pocket depths > or = 3.5 mm was used as a periodontal parameter. ALDH(2) genotypes were determined with the use of a PCR/RFLP method. Multiple logistic analyses showed that alcohol consumption was significantly associated with periodontitis, and its odds ratio was 1.98. There was no significant relationship between periodontal status and ALDH(2) genotypes. However, ALDH(2)*1/*2 subjects who consumed > or = 33 g/day of alcohol had a significantly greater percentage of pocket depths > or = 3.5 mm than those whose daily consumption was lower, while there was no significant difference in periodontal status associated with alcohol consumption in ALDH(2)*1/*1 subjects. Our results suggest that alcohol consumption may be a risk indicator for periodontitis in ALDH(2)*1/*2 subjects who consume larger amounts of alcohol.

Purification and some properties of fucosyltransferase in human parotid saliva.

Fucosyltransferase was purified from human parotid saliva by affinity chromatography on GDP-hexanolamine Sepharose, followed by chromatofocusing on PBE 94 exchanger gel. The purified enzyme had the N-acetyglucosaminide alpha 1----4, the N-acetylglucosaminide alpha 1----3, and the glucoside alpha 1----3 fucosyltransferase activities. The molecular weight of the purified enzyme was estimated to be approximately 20,000. These enzyme activities showed identical pH and divalent metal ion dependencies and identical rates of inactivation upon being heated. The paper chromatographic analysis of the fucosylated products by the purified enzyme and the susceptibility of these products to linkage-specific fucosidase digestion indicated that the transferase formed the Fuc alpha 1----4GlcNAc, Fuc alpha 1----3GlcNAc, and Fuc alpha 1----3Glc linkages.

Inhibitory effects of synthetic histidine-rich peptides on haemagglutination by Bacteroides gingivalis 381.

The haemagglutinating activity of Bacteroides gingivalis 381 was significantly inhibited by the synthetic peptide, Asp-Ser-His-Ala-Lys-Arg-His-His-Gly-Tyr-Lys-Arg-Lys-Phe-His- Glu-Lys-His-His-Ser-His-Arg-Gly-Tyr. However, bradykinin potentiator C, which does not contain cationic amino acids such as L-histidine, L-arginine and L-lysine, had no inhibitory effect.

Eruptive vellus hair cyst and epidermoid cyst in a patient with pachyonychia congenita.

We report the first case of pachyonychia congenita (PC) associated with both eruptive vellus hair cyst (EVHC) and epidermoid cyst. The patient is a 12-year-old Japanese girl who presented with two natal teeth at birth. She had thickening and discoloration of the fingernails and toenails, plantar hyperkeratosis, palmar-plantar hyperhidrosis and multiple cutaneous cysts. Histologic examination revealed EVHC and epidermoid cyst.

Case report: cheilitis granulomatosa with periodontitis.

We report a case of cheilitis granulomatosa with periodontitis in a 39-year-old Japanese man. Biopsy specimens from both areas showed noncaseating epithelioid cell granuloma. Dental examination revealed that the lower left first molar had periodontitis. The lower left first molar was removed, and antibiotics and anti-inflammatory drugs were administered. After 2 months of periodontitis therapy, the lips returned to normal size without recurrence and the swelling of the buccal mucosa regressed.

Anesthetic management of a patient with Cornelia De Lange syndrome.

Cornelia de Lange syndrome presents various problems for anesthetic management, which include anatomical anomalies of face and extremities, cardiopulmonary and endocrine disorders, renal dysfunction, epileptic EEG waves, and mental retardation. The choice of anesthetic procedure must be carefully considered in view of these abnormalities. We administered halothane anesthesia to an 11-year-old child with this syndrome who needed dental treatment. Anesthesia and postoperative course were uneventful, with the exception of a transient bronchospasm-like attack during anesthesia.

Anesthetic management of a patient with Kasabach-Merritt syndrome.

Kasabach-Merritt syndrome presents various problems for anesthetic management, which include thrombocytopenia, bleeding tendency, and problems arising from the hemangioma mass itself. A 20-month-old female was scheduled for cryosurgery of a hemangioma on the face. Massive bleeding from the tumor was easily induced even by slight contact. The hematologic examination revealed a low platelet count and anemia. Anesthesia was induced carefully by applying an adult anesthetic mask to avoid the large tumor mass on the face and maintained with halothane and nitrous oxide/oxygen. Additional doses of prednisolone were administered before and during anesthesia to compensate for possible adrenal insufficiency due to steroid therapy which she had been receiving. Neither excessive bleeding nor any other particular complications occurred during anesthesia and surgery, and the postoperative course was also uneventful.

System of acute medical support to emergency during dental treatment.

The Resuscitation Committee of Hiroshima City Dental Association was established in 1983 in order to provide acute medical support in case of emergency during dental treatment at private dental clinics. This Committee is composed of representatives from the Hiroshima City Dental Association, Hiroshima University School of Dentistry, Hiroshima University School of Medicine, Hiroshima City Health Bureau, and Hiroshima City Fire and Ambulance Department. A portable ECG monitor with defibrillator and a resuscitation kit are held in readiness at the Hiroshima University Hospital. In case of emergency during dental treatment at a private dental clinic, we hurry to the clinic with the resuscitation set and give emergency treatment. We have been involved in two cases of emergency since this system started. Both of them recovered without any sequelae. Besides these activities, we give lectures annually to dentists and dental hygienists on the treatment of medical emergencies.

Association of ALDH2 genotypes with periodontitis progression.

The progression of periodontitis may be affected by ALDH2 genotypes with respect to the oxidation of acetaldehyde to acetate, which leads to the accumulation of acetaldehyde in plasma and potential toxic effects. We examined the prospective association of ALDH2 genotypes in terms of alcohol sensitivity between alcohol consumption and periodontal disease progression. In 2003, 224 of 256 (87.5%) individuals examined at baseline (1999) completed probing pocket depth measurements for the evaluation of periodontitis progression. Missing data on self-reported questionnaires and blood samples were excluded; therefore, 183 samples were analyzed. Individuals who consumed > or = 33.0 g/day of alcohol exhibited high periodontal disease progression risk (OR = 3.54). ALDH2 *1/*2 individuals who consumed > or = 33 g/day of alcohol displayed a significant odds ratio (OR = 4.28) of periodontitis progression risk, in contrast to ALDH2 *1/*1 individuals. These results suggested that alcohol consumption as well as alcohol sensitivity may be a risk factor for periodontitis progression.

Improved accuracy in terminal restriction fragment length polymorphism phylogenetic analysis using a novel internal size standard definition.

BACKGROUND: Terminal restriction fragment length polymorphism (T-RFLP) analysis is commonly used to analyze microbial communities, including oral microflora. However, accurate identification of terminal restriction fragment (T-RF) origins is prevented by unpredictable errors in sizing, thus necessitating the clone library analysis. To minimize sizing errors, we proposed optimizing the size definition of internal standards. METHODS: GeneScan-1000 ROX was regenerated as an internal standard by redefining the fragment sizes in terms of molecular weight (MW) based on their mobility relative to 6-carboxyfluorescein (FAM) -labeled restriction fragments derived from the 16S recombinant RNA gene of Porphyromonas gingivalis. Using the new size definition, the average sizing error among eight oral bacteria from six phyla was estimated and compared with that of the conventional method. Microbial communities isolated from saliva were analyzed using the new MW size definition. Bacterial species were assigned to peaks using TRFMA, a Web-based tool for T-RFLP analysis, and compared with those identified in a clone library analysis. RESULTS: Using the new size definition, the average sizing error for 40 T-RFs was drastically reduced from 2.42 to 0.62 bases, and large sizing errors (more than two bases) were eliminated. More than 90% of the total bacterial clones detected by the clone library analysis were assigned by T-RFLP. CONCLUSION: The size definition of the newly constructed internal standards reduced fragment sizing errors and allowed for accurate assignment of bacteria to peaks by the T-RFLP analysis. This provided a more effective means for studying microbial communities, including the oral microflora.

[Purification and some properties of neuraminidase from the culture medium of Bacteroides loescheii ATCC 15930].

The purpose of this study is to investigate the mechanism on enhanced hemagglutination caused by neuraminidase from Bacteroides in an aspect of zeta-potential levels on erythrocytes and inhibitors on hemagglutination activity. The neuraminidase from the culture medium of Bacteroides loescheii ATCC 15930 was purified by ultrafiltration followed by DEAE-Sephacel anion exchange chromatography, fast protein, polypeptide, polynucleotide, liquid chromatography using Mono P column and finally high performance liquid chromatography using Shim-pack Diol-300 column. The purified enzyme appeared to be homogeneous by analytical polyacrylamide gel electrophoresis. The molecular weight was measured to be approximately 87,000 and the optimal pH was at 4.8. The isoelectric point was at 5.1. The enzyme showed relatively high specificity toward the linkage of NANA alpha (2----3) oligosaccharides and glycoproteins, and less toward the linkage of NANA alpha (2----6), and/or NANA alpha (2----8) oligosaccharides. When the human erythrocytes were treated by the purified enzyme, hemagglutination activities of some strains of Bacteroides gingivalis, Bacteroides denticola and Bacteroides intermedius were enhanced. Hemagglutination inhibition experiments using B. gingivalis 381 showed that the activity of hemagglutination was strongly inhibited by the arginine-containing peptides especially salmine derived from salmon, although the activity was unaffected by the sugars, amino acids and divalent cations such as Ca2+, Mn2+ and Mg2+. The zeta-potential level on asialo-erythrocytes treated by purified enzyme was considerably decreased compared to that of sialo-erythrocytes. It seems likely that the mechanism on hemagglutination by the B. gingivalis 381 may be involved in electrochemical affinity between the erythrocytes and bacterial cells with the reduction of zeta-potential, and in arginine-containing peptides as receptors of ligand-binding on erythrocytes.

Exposure-response relationships in rhinitis and conjunctivitis caused by methyltetrahydrophthalic anhydride.

OBJECTIVE: To examine exposure-response relationships in the occurrence of symptoms of the eyes and airways in workers exposed to methyltetrahydrophthalic anhydride (MTHPA). METHODS: A population of 111 workers from 2 condenser plants (A and B) using epoxy resin with MTHPA underwent a questionnaire survey and serology investigations, and data obtained on 95 subjects in assembly and inspection lines were analyzed for this study. RESULTS: In all, 24 (65%) of 37 workers in plant A and 38 (66%) of 58 workers in plant B had positive MTHPA-specific IgE. The air levels of MTHPA detected in assembly and inspection lines were higher in plant A than in plant B (geometric mean 25.5-63.9 and 4.93-5.49 microg/m3, respectively). IgE-sensitized workers in each plant had significantly (P < 0.05) more complaints regarding the eyes and nose than did unsensitized workers, suggesting that there is an IgE-mediated mechanism in most of these symptoms. The sensitized workers in plant A had higher frequencies for symptoms of the eyes, nose, and pharynx than did those in plant B (P < 0.02). Furthermore, only 15% of persons often displayed work-related symptoms among the 20 symptomatic workers in plant B as compared with 73% of the 26 symptomatic workers in plant A (P < 0.0001). These results can be explained by the difference in the MTHPA levels measured in the lines between the two plants. In plant B the minimal level of MTHPA that was associated with work-related symptoms was 15-22 microg/m3, which was lower than the geometric mean levels detected in assembly and inspection lines in plant A. CONCLUSIONS: These results suggest that MTHPA exposure at levels above 15 microg/m3 should be avoided to prevent the development of occupational allergic diseases in most workers.