The cultivable human oral gluten-degrading microbiome and its potential implications in coeliac disease and gluten sensitivity.

Coeliac disease is characterized by intestinal inflammation caused by gluten, proteins which are widely contained in the Western diet. Mammalian digestive enzymes are only partly capable of cleaving gluten, and fragments remain that induce toxic responses in patients with coeliac disease. We found that the oral microbiome is a novel and rich source of gluten-degrading organisms. Here we report on the isolation and characterization of the cultivable resident oral microbes that are capable of cleaving gluten, with special emphasis on the immunogenic domains. Bacteria were obtained by a selective culturing approach and enzyme activities were characterized by: (i) hydrolysis of paranitroanilide-derivatized gliadin-derived tripeptide substrates; (ii) gliadin degradation in-gel (gliadin zymography); (iii) gliadin degradation in solution; (iv) proteolysis of the highly immunogenic α-gliadin-derived 33-mer peptide. For selected strains pH activity profiles were determined. The culturing strategy yielded 87 aerobic and 63 anaerobic strains. Species with activity in at least two of the four assays were typed as: Rothia mucilaginosa HOT-681, Rothia aeria HOT-188, Actinomyces odontolyticus HOT-701, Streptococcus mitis HOT-677, Streptococcus sp. HOT-071, Neisseria mucosa HOT-682 and Capnocytophaga sputigena HOT-775, with Rothia species being active in all four assays. Cleavage specificities and substrate preferences differed among the strains identified. The approximate molecular weights of the enzymes were ~75 kD (Rothia spp.), ~60 kD (A. odontolyticus) and ~150 kD (Streptococcus spp.). In conclusion, this study identified new gluten-degrading microorganisms in the upper gastrointestinal tract. A cocktail of the most active oral bacteria, or their isolated enzymes, may offer promising new treatment modalities for coeliac disease.

Comparison of microbial changes in early redeveloping biofilms on natural teeth and dentures.

BACKGROUND: Surfaces and fluids can affect oral bacterial colonization. The aim of this study is to compare redeveloping biofilms on natural teeth and dentures. METHODS: Supragingival plaque samples were taken from 55 dentate individuals and the denture teeth of 62 edentulous individuals before and after professional cleaning. Also, samples from seven "teeth" (samples included dentures) in randomly selected quadrants were collected after 1, 2, 4, and 7 days of no oral hygiene. Samples were analyzed using checkerboard DNA-DNA hybridization. Counts and proportions of 41 bacterial taxa were determined at each time point, and significant differences were determined using the Mann-Whitney U test. Ecological succession was determined using a modified moving window analysis. RESULTS: Mean total DNA probe counts were similar precleaning but were higher in dentate individuals at all post-cleaning visits (P <0.01). Precleaning edentate biofilms had higher counts and proportions of Streptococcus mitis, Streptococcus oralis, and Streptococcus mutans, whereas dentate individuals had higher proportions of Tannerella forsythia, Selenomonas noxia, and Neisseria mucosa. By day 2, mean counts of all taxa were higher in natural teeth, and most remained higher at day 7 (P <0.01). Succession was more rapid and complex in dentate individuals. Both groups demonstrated increased proportions of S. mitis and S. oralis by day 1. N. mucosa, Veillonella parvula, and Eikenella corrodens increased in both groups, but later in samples from edentate individuals. CONCLUSIONS: "Mature" natural and denture teeth biofilms have similar total numbers of bacteria but different species proportions. Post-cleaning biofilm redevelopment is more rapid and more complex on natural teeth than on denture teeth.

Early microbial succession in redeveloping dental biofilms in periodontal health and disease.

BACKGROUND AND OBJECTIVE: The development of dental biofilms after professional plaque removal is very rapid. However, it is not clear whether most bacterial species return at similar rates in periodontally healthy and periodontitis subjects or if there are differences in bacterial recolonization between supragingival and subgingival biofilms in periodontal health and disease. MATERIAL AND METHODS: Supragingival and subgingival plaque samples were taken separately from 28 teeth in 38 healthy and 17 periodontitis subjects immediately after professional cleaning. Samples were taken again from seven teeth in randomly selected quadrants after 1, 2, 4 and 7 d of no oral hygiene and analyzed using checkerboard DNA-DNA hybridization. The percentage of DNA probe counts were averaged within subjects at each time-point. Ecological succession was determined using a modified moving-window analysis. RESULTS: Succession in supragingival biofilms from subjects with periodontitis and from healthy individuals was similar. At 1 d, Streptococcus mitis and Neisseria mucosa showed increased proportions, followed by Capnocytophaga gingivalis, Eikenella corrodens, Veillonella parvula and Streptococcus oralis at 1-4 d. At 4-7 d, Campylobacter rectus, Campylobacter showae, Prevotella melaninogenica and Prevotella nigrescens became elevated. Subgingival plaque redevelopment was slower and very different from supragingival plaque redevelopment. Increased proportions were first observed for S. mitis, followed by V. parvula and C. gingivalis and, at 7 d, by Capnocytophaga sputigena and P. nigrescens. No significant increase in the proportions of periodontal pathogens was observed in any of the clinical groups or locations. CONCLUSION: There is a defined order in bacterial species succession in early supragingival and subgingival biofilm redevelopment after professional cleaning.

Detection of nine microorganisms from the initial carious root lesions using a TaqMan-based real-time PCR.

OBJECTIVE: The purpose of this study was to quantify nine selected cariogenic bacteria in plaque from sound root surfaces and initial carious root lesions using TaqMan PCR and to analyse a putative dependence on the kind of initial periodontal treatment. MATERIAL AND METHODS: Fifty-four subjects with generalized chronic periodontitis were randomly allocated to one of the following initial periodontal therapies: full-mouth disinfection, full-mouth scaling and root planing or scaling and root planing within 7 days. Plaque samples were taken before and after periodontal treatment and analysed by TaqMan PCR. RESULTS: The quantity of the cariogenic bacteria Actinomyces spp., Streptococcus mutans, Streptococcus sobrinus, Lactobacilllus spp., Rothia dentocariosa, Parvimonas micra, Propionibacterium acnes and Neisseria mucosa were significantly higher, while the quantity of Veillonella parvula was significantly lower on initial carious lesions than on the sound surfaces both before and after periodontal therapy. No significant differences could be found in any of the tested bacteria except P. micra on initial carious lesions and sound surfaces for both examinations between the groups. CONCLUSION: All the nine species analysed were found to be present in initial carious root lesions as well as sound root surfaces but in different quantities, independent of the different periodontal therapies.

Distribution of selected cariogenic bacteria in five different intra-oral habitats in young children.

BACKGROUND: Knowledge of the colonization patterns and composition of the oral microbiota can lead to a better understanding of disease initiation. AIM: The aim of this study was to examine the distribution of selected cariogenic bacteria in samples from five different oral habitats in young Greek children. DESIGN: Ninety-three children 3-12 years old (mean + SD 7.9 +/- 2.5) (60.2% male, 39.8% female) participated and split into three different age groups: primary (3-6 years), early mixed (6-9 years), and mixed dentition (9-12 years). Samples for bacterial enumeration were taken from saliva, supragingival and subgingival plaque, tongue dorsum, and soft tissues from each child, and were further analysed using checkerboard DNA-DNA hybridization. RESULTS: Mean counts and proportions of all the test bacteria differed significantly among sample locations. Cariogenic bacteria were present in almost all healthy children. Mean proportions of Streptococcus mutans isolated from soft tissue and Streptococcus sanguinis from soft tissue, subgingival and saliva samples increased significantly with age, whereas the opposite was seen for Lactobacillus acidophilus. CONCLUSIONS: Cariogenic bacteria were present in almost all young children. Soft tissues, saliva, and tongue were more often colonized by cariogenic streptococcal species than teeth. These surfaces may serve as reservoirs for oral pathogens, requiring attention during preventive interventions.

Does pregnancy have an impact on the subgingival microbiota?

BACKGROUND: We investigated clinical and subgingival microbiologic changes during pregnancy in 20 consecutive pregnant women > or =18 years not receiving dental care. METHODS: Bacterial samples from weeks 12, 28, and 36 of pregnancy and at 4 to 6 weeks postpartum were processed for 37 species by checkerboard DNA-DNA hybridization. Clinical periodontal data were collected at week 12 and at 4 to 6 weeks postpartum, and bleeding on probing (BOP) was recorded at sites sampled at the four time points. RESULTS: The mean BOP at week 12 and postpartum was 40.1% +/- 18.2% and 27.4% +/- 12.5%, respectively. The corresponding mean BOP at microbiologic test sites was 15% (week 12) and 21% (postpartum; not statistically significant). Total bacterial counts decreased between week 12 and postpartum (P <0.01). Increased bacterial counts over time were found for Neisseria mucosa (P <0.001). Lower counts (P <0.001) were found for Capnocytophaga ochracea, Capnocytophaga sputigena, Eubacterium saburreum, Fusobacterium nucleatum naviforme, Fusobacterium nucleatum polymorphum, Leptotrichia buccalis, Parvimonas micra (previously Peptostreptococcus micros or Micromonas micros), Prevotella intermedia, Prevotella melaninogenica, Staphylococcus aureus, Streptococcus anginosus, Streptococcus intermedius, Streptococcus mutans, Streptococcus oralis, Streptococcus sanguinis, Selenomonas noxia, and Veillonella parvula. No changes occurred between weeks 12 and 28 of pregnancy. Counts of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis, Tannerella forsythia (previously T. forsythensis), and Treponema denticola did not change. Counts of P. gingivalis and T. forsythia at week 12 were associated with gingivitis (P <0.001). CONCLUSIONS: Subgingival levels of bacteria associated with periodontitis did not change. P. gingivalis and T. forsythia counts were associated with BOP at week 12. A decrease was found in 17 of 37 species from week 12 to postpartum. Only counts of N. mucosa increased.

Microbiological findings in subjects with asymptomatic oral lichen planus: a cross-sectional comparative study.

BACKGROUND: The bacterial colonization of the oral mucosa was evaluated in patients with asymptomatic oral lichen planus (OLP) and compared to the microbiologic status in mucosally healthy subjects. METHODS: Bacteria from patients with clinically and histopathologically diagnosed OLP from the Stomatology Service, Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, were collected with a non-invasive swab system. Samples were taken from OLP lesions on the gingiva and from non-affected sites on the contralateral side of the mouth. The control population did not have OLP and was recruited from the student clinic. All samples were processed with the checkerboard DNA-DNA hybridization method using well-defined bacterial species for the analysis. RESULTS: Significantly higher bacterial counts of Bacteroides ureolyticus (P = 0.001), Dialister species (sp.) (P = 0.006), Staphylococcus haemolyticus (P = 0.007), and Streptococcus agalactiae (P = 0.006) were found in samples taken from OLP lesions compared to sites with no clinical evidence of OLP. Significantly higher bacterial counts were found for Capnocytophaga sputigena, Eikenella corrodens, Lactobacillus crispatus, Mobiluncus curtisii, Neisseria mucosa, Prevotella bivia, Prevotella intermedia, and S. agalactiae at sites with lesions in subjects with OLP compared to sites in control subjects (P <0.001). CONCLUSIONS: Microbiologic differences were found between sites with OLP and sites in subjects without a diagnosis of OLP. Specifically, higher counts of staphylococci and S. agalactiae were found in OLP lesions.

Periodontal status of patients with dentin dysplasia type I: report of three cases within a family.

BACKGROUND: Dentin dysplasia type I (DDI) is a rare hereditary disturbance of dentin formation. It is characterized by clinically normal-appearing crowns; obliteration of pulp chambers; and short, blunted and malformed roots that are commonly associated with periodontal attachment loss (PAL). In this context, we report three cases within a family with similar clinical and radiographic features of DDI but with differing microbiologic and periodontal conditions. METHODS: A 42-year-old white female and her two daughters (25 and 10 years of age) presented with a diagnosis of DDI. Probing depth (PD), clinical attachment level (CAL), visible plaque, and bleeding on probing (BOP) were recorded. Subgingival biofilm samples were randomly collected and analyzed by checkerboard DNA-DNA hybridization. RESULTS: The mother presented 34.9% of sites with PD > or =4 mm, 41.3% of sites with CAL > or =4 mm, and 57% of sites with BOP; both daughters presented no sites with PD or CAL >3 mm and <10% of sites with BOP. Microbiologic analysis detected Gemella morbillorum, Neisseria mucosa, and Staphylococcus aureus in > or =50% of the mother's samples. The daughters showed high levels (>10(4) bacterial cells) of some periodontopathic bacteria, including members of the red (Porphyromonas gingivalis) and orange (Fusobacterium periodonticum and F. nucleatum polymorphum) complexes and beneficial species of the yellow (Streptococcus gordonii) and purple (Veillonella parvula) complexes. The mother presented high mean levels only for four tested species (N. mucosa, Prevotella melaninogenica, Treponema denticola, and V. parvula). CONCLUSION: A combination of radiographs, microbiologic analysis, and preventive professional monitoring care is important to avoid PAL and to provide oral health in patients with DDI.

Septic knee arthritis after intra-articular hyaluronate injection. Two case reports.

Intraarticular sodium hyaluronate injection to treat osteoarthritis is associated with minor side effects. Infections seem uncommon. We report two cases of septic knee arthritis. One patient was an 80-year-old woman who was admitted for Staphylococcus aureus knee arthritis after several intraarticular injections of sodium hyaluronate and corticosteroids. In the other patient, a 78-year-old woman, Neisseria mucosa knee arthritis occurred after a single sodium hyaluronate injection. Faultless aseptic technique is essential when administering hyaluronate viscosupplementation. Patients should be informed of the risk of septic arthritis.

Peritonitis due to Neisseria mucosa in an adolescent receiving peritoneal dialysis.

Neisseria mucosa is part of the normal nasopharyngeal flora and rarely pathogenic in humans. Reports of serious infections associated with this pathogen are very unusual. A 17-year-old boy with end-stage renal disease due to IgA nephropathy presented with acute, spontaneous, symptomatic peritoneal dialysis-associated peritonitis without reported break in sterility or PD catheter exit site infection. beta-lactamase-negative N. mucosa was isolated from the dialysate effluent. Intraperitoneal antibiotic treatment with cephalothin/gentamicin for 5 days and subsequent ceftriaxone led to complete resolution of the infection. This case demonstrates that "non-pathogenic" Neisseria species can cause clinically severe peritonitis with high intraperitoneal neutrophil counts, elevated C-reactive protein levels in the peritoneal effluent (in the presented case, 27,600/mul and 3.6 mg/l, respectively) and impaired peritoneal membrane transport function. To our knowledge, this is the first case of N. mucosa peritonitis complicating chronic peritoneal dialysis in an adolescent patient.