Efeito da levofloxacina na microbiota intestinal de pacientes com pneumonia adquirida na comunidade

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da microbiota associada a osteomielite crônica dos maxilares através de meio de cultura e PCR

Pós-graduação em Odontologia - FOA

Estudo das condições de saúde bucal e avaliação da microbiota periodontopatogênica de uma população indígena brasileira

Pós-graduação em Odontologia - FOA

Avaliação da microbiota bucal de pacientes com anorexia nervosa e bulimia nervosa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da microbiota bucal de mães e pares de crianças aos 6, 12, 18 e 24 meses de idade e sua relação com dieta alimentar, hábitos de higiene bucal, condição gengival, erupção dentária e prevalência de cárie dentária

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Quantitative detection of Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa in human oral epithelial cells from subjects with periodontitis and periodontal health

Epithelial cells in oral cavities can be considered reservoirs for a variety of bacterial species. A polymicrobial intracellular flora associated with periodontal disease has been demonstrated in buccal cells. Important aetiological agents of systemic and nosocomial infections have been detected in the microbiota of subgingival biofilm, especially in individuals with periodontal disease. However, non-oral pathogens internalized in oral epithelial cells and their relationship with periodontal status are poorly understood. The purpose of this study was to detect opportunistic species within buccal and gingival crevice epithelial cells collected from subjects with periodontitis or individuals with good periodontal health, and to associate their prevalence with periodontal clinical status. Quantitative detection of total bacteria and Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis in oral epithelial cells was determined by quantitative real-time PCR using universal and species-specific primer sets. Intracellular bacteria were visualized by confocal microscopy and fluorescence in situ hybridization. Overall, 33 % of cell samples from patients with periodontitis contained at least one opportunistic species, compared with 15 % of samples from healthy individuals. E. faecalis was the most prevalent species found in oral epithelial cells (detected in 20.6 % of patients with periodontitis, P = 0.03 versus healthy individuals) and was detected only in cells from patients with periodontitis. Quantitative real-time PCR showed that high levels of P. aeruginosa and S. aureus were present in both the periodontitis and healthy groups. However, the proportion of these species was significantly higher in epithelial cells of subjects with periodontitis compared with healthy individuals (P = 0.016 for P. aeruginosa and P = 0.047 for S. aureus). Although E. faecalis and P. aeruginosa were detected in 57 % and 50 % of patients, respectively, with probing depth and clinical attachment level ≥6 mm, no correlation was found with age, sex, bleeding on probing or the presence of supragingival biofilm. The prevalence of these pathogens in epithelial cells is correlated with the state of periodontal disease.

Caratterizzazione microbiologica ed epidemiologica del microbiota del cavo orale mediante metodiche colturali e molecolari

La ricerca si è focalizzata su due degli aspetti di interesse odontoiatrico più diffusi: la carie dentaria e la parodontite cronica. Il problema della carie dentaria è stato studiato in una popolazione di 39 soggetti affetti da cardiopatia congenita in cui la scarsa igiene orale è fattore di rischio per problematiche di salute generale e soprattutto per lo sviluppo di endocardite infettiva. I dati osservati e confrontati con quelli di un omogeneo gruppo di controllo dimostrano che nella dentatura decidua questi bambini hanno più denti cariati, come dimostrato dalla significativa differenza dell'indice dmft. Nella dentatura permanente non si osservano differenze tra i due gruppi. La carica microbica totale rilevata nella saliva e la presenza di Streptococcus mutans non mostrano differenze tra i due gruppi. I problemi di parodontite cronica sono stati studiati in un gruppo di 352 soggetti italiani adulti in cui si è definita la prevalenza dei 6 più importanti patogeni parodontali e la possibile correlazione con parametri clinici (pus, sanguinamento al sondaggio - BOP, profondità di sondaggio della tasca parodontale – PPD). Tra le 6 specie batteriche ricercate, quello di più frequente riscontro è stato Fusobacterium nucleatum (95%), mentre quello con carica batterica più alta è stato Tannerella forsythia. La carica batterica di Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia e Fusobacterium nucleatum ha mostrato una correlazione diretta con il BOP e la presenza di pus. Inoltre, si è riscontrato che la carica batterica di tutte le specie (tranne Aggregatibacterium actinomycetemcomitans) aumenta all'aumentare del PPD. Tra le variabili studiate, PPD rappresenta il più importante fattore di rischio per la presenza di parodontopatogeni, mentre BOP è un indicatore di rischio per la ricerca del complesso rosso.

Bacterial colonization immediately after installation on oral titanium implants

BACKGROUND: Information on bacterial colonization immediately after dental implant insertion is limited. AIMS: (1) To assess the early colonization on titanium implants immediately after placement and throughout the first 12 post-surgical weeks, (2) to compare the microbiota at interproximal subgingival implant and adjacent tooth sites. MATERIAL AND METHODS: Subgingival plaque samples from implant and neighbouring teeth were studied by checkerboard DNA-DNA hybridization before surgery, 30 min after implant placement, and 1, 2, 4, 8, and 12 weeks after surgery. RESULTS: Comparing bacterial loads at implant sites between 30 min after placement with 1-week data showed that only the levels of Veillonella parvula (P<0.05) differed with higher loads at week 1 post-surgically. Week 12 data demonstrated significantly higher bacterial loads for 15/40 species at tooth sites compared with pre-surgery (P-values varying between 0.05 and 0.01). Between the period immediately after surgery and 12 weeks at implant sites, 29/40 species was more commonly found at 12 weeks. Included among these bacteria at implant sites were Porphyromonas gingivalis (P<0.05), Tannerella forsythia, (P<0.01), and Treponema denticola (P<0.001). Immediately post-surgery 5.9% of implants, and 26.2% of teeth, and at week 12, 15% of implants, and 39.1% of teeth harbored Staphylococcus aureus. Comparing tooth and implant sites, significantly higher bacterial loads were found at tooth sites for 27/40 species after 30 min following implant placement. This difference increased to 35/40 species at 12 weeks post-surgically. CONCLUSIONS: Bacterial colonization occurred within 30 min after implant placement. Early colonization patterns differed between implant and tooth surfaces.

Human microbiota-secreted factors inhibit shiga toxin synthesis by enterohemorrhagic Escherichia coli O157:H7

Escherichia coli O157:H7 is a food-borne pathogen causing hemorrhagic colitis and hemolytic-uremic syndrome, especially in children. The main virulence factor responsible for the more serious disease is the Shiga toxin 2 (Stx2), which is released in the gut after oral ingestion of the organism. Although it is accepted that the amount of Stx2 produced by E. coli O157:H7 in the gut is critical for the development of disease, the eukaryotic or prokaryotic gut factors that modulate Stx2 synthesis are largely unknown. In this study, we examined the influence of prokaryotic molecules released by a complex human microbiota on Stx2 synthesis by E. coli O157:H7. Stx2 synthesis was assessed after growth of E. coli O157:H7 in cecal contents of gnotobiotic rats colonized with human microbiota or in conditioned medium having supported the growth of complex human microbiota. Extracellular prokaryotic molecules produced by the commensal microbiota repress stx(2) mRNA expression and Stx2 production by inhibiting the spontaneous and induced lytic cycle mediated by RecA. These molecules, with a molecular mass of below 3 kDa, are produced in part by Bacteroides thetaiotaomicron, a predominant species of the normal human intestinal microbiota. The microbiota-induced stx(2) repression is independent of the known quorum-sensing pathways described in E. coli O157:H7 involving SdiA, QseA, QseC, or autoinducer 3. Our findings demonstrate for the first time the regulatory activity of a soluble factor produced by the complex human digestive microbiota on a bacterial virulence factor in a physiologically relevant context.

Microbiota at teeth and implants in partially edentulous patients. A 10-year retrospective study.

OBJECTIVE To determine the microbiota at implants and adjacent teeth 10 years after placement of implants with a sandblasted and acid-etched surface. MATERIAL AND METHODS Plaque samples obtained from the deepest sites of 504 implants and of 493 adjacent teeth were analyzed for certain bacterial species associated with periodontitis, for staphylococci, for aerobic gram-negative rods, and for yeasts using nucleic acid-based methods. RESULTS Species known to be associated with periodontitis were detectable at 6.2-78.4% of the implants. Significantly higher counts at implants in comparison with teeth were assessed for Tannerella forsythia, Parvimonas micra, Fusobacterium nucleatum/necrophorum, and Campylobacter rectus. Higher counts of periodontopathogenic species were detectable at implants of current smokers than at those of non-smokers. In addition, those species were found in higher quantities at implants of subjects with periodontitis. The prevalence of Prevotella intermedia, Treponema denticola, C. rectus, and moreover of Staphylococcus warneri might be associated with peri-implant inflammation. Selected staphylococcal species (not Staphylococcus aureus), aerobic gram-negative rods, and yeasts were frequently detected, but with the exception of S. warneri, they did not show any association with periodontal or peri-implant diseases. CONCLUSIONS Smoking and periodontal disease are risk factors for colonization of periodontopathic bacteria at implants. Those bacterial species may play a potential role in peri-implant inflammation. The role of S. warneri needs further validation.

Effect of mode of delivery on early oral colonization and childhood dental caries: a systematic review

Background: Oral colonization starts at birth by vertical transmission. Objective: To determine whether mode of delivery influences the oral colonization of infants and contributes to the risk of childhood dental caries. Methods: A systematic review was conducted in the electronic database Web of Science for articles published from January 1995 to December 2015 by using a set of keywords. Results: From 2,644 citations identified through electronic search, ten studies met the inclusion criteria. According to the studies mode of delivery influences oral microbial density, oral microbial profile and the timing of oral colonization by cariogenic microbiota. However, there are no consistent results concerning either the prevalence of children harboring cariogenic microbiota or the prevalence of early childhood caries by mode of delivery. Conclusion: Mode of delivery influences early oral colonization. However, it seems that other determinants rather than mode of delivery could be major contributors to the development of early childhood caries. Keywords: Early childhood caries, early oral colonization, acquisition of oral microflora, mode of delivery

Cuidados de saúde oral em doentes hospitalizados

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

Growth, survival, gene expression, microbiota and tryptic activity during feeding of Scophthalmus maximus first feeding larvae with beta-glucan (MacroGard)

Reflecting the natural biology of mass spawning fish aquaculture production of fish larvae is often hampered by high and unpredictable mortality rates. The present study aimed to enhance larval performance and immunity via the oral administration of an immunomodulator, beta-glucan (MacroGard®) in turbot (Scophthalmus maximus). Rotifers (Brachionus plicatilis) were incubated with or without yeast beta-1,3/1,6-glucan in form of MacroGard® at a concentration of 0.5 g/L. Rotifers were fed to first feeding turbot larvae once a day. From day 13 dph onwards all tanks were additionally fed untreated Artemia sp. nauplii (1 nauplius ml/L). Daily mortality was monitored and larvae were sampled at 11 and 24 dph for expression of 30 genes, trypsin activity and size measurements. Along with the feeding of beta-glucan daily mortality was significantly reduced by ca. 15% and an alteration of the larval microbiota was observed. At 11 dph gene expression of trypsin and chymotrypsin was elevated in the MacroGard® fed fish, which resulted in heightened tryptic enzyme activity. No effect on genes encoding antioxidative proteins was observed, whilst the immune response was clearly modulated by beta-glucan. At 11 dph complement component c3 was elevated whilst cytokines, antimicrobial peptides, toll like receptor 3 and heat shock protein 70 were not affected. At the later time point (24 dph) an anti-inflammatory effect in form of a down-regulation of hsp 70, tnf-alpha and il-1beta was observed. We conclude that the administration of beta-glucan induced an immunomodulatory response and could be used as an effective measure to increase survival in rearing of turbot.

Pérdida de tolerancia inmune en la etiología de las úlceras aftosas recidivantes (RAU) de la mucosa oral: la ruptura de la tolerancia inmunológica causaría injuria persistente en la mucosa bucal provocando las úlceras aftosas recurrentes (2ª parte)

Se ha realizado una revisión de teorías de pérdida de tolerancia inmune publicadas tratando de encontrar aquellos conceptos modernos. Las mismas se refieren a la predisposición genética, influencia de la epigenética en la modelación de un fenotipo vulnerable, las hipótesis de higiene y de microbiota, síndrome de sensibilidad química múltiple, stress crónico, cortisol, el eje hipófisis, hipotálamo y páncreas, óxido nítrico, ataque a la membrana celular, e injuria por reperfusión. Aplicando los principios básicos de las teorías consultadas se demuestra la pérdida de homeostasis, general o parcial, que podría llegar a explicar tres características fundamentales de las úlceras recurrentes orales: dolor, vulnerabilidad y recurrencia.

Oral chondroitin sulfate and prebiotics for the treatment of canine Inflammatory Bowel Disease: a randomized, controlled clinical trial

BACKGROUND Canine inflammatory bowel disease (IBD) is a chronic enteropathy of unknown etiology, although microbiome dysbiosis, genetic susceptibility, and dietary and/or environmental factors are hypothesized to be involved in its pathogenesis. Since some of the current therapies are associated with severe side effects, novel therapeutic modalities are needed. A new oral supplement for long-term management of canine IBD containing chondroitin sulfate (CS) and prebiotics (resistant starch, β-glucans and mannaoligosaccharides) was developed to target intestinal inflammation and oxidative stress, and restore normobiosis, without exhibiting any side effects. This double-blinded, randomized, placebo-controlled trial in dogs with IBD aims to evaluate the effects of 180 days administration of this supplement together with a hydrolyzed diet on clinical signs, intestinal histology, gut microbiota, and serum biomarkers of inflammation and oxidative stress. RESULTS Twenty-seven client-owned biopsy-confirmed IBD dogs were included in the study, switched to the same hydrolyzed diet and classified into one of two groups: supplement and placebo. Initially, there were no significant differences between groups (p > 0.05) for any of the studied parameters. Final data analysis (supplement: n = 9; placebo: n = 10) showed a significant decrease in canine IBD activity index (CIBDAI) score in both groups after treatment (p < 0.001). After treatment, a significant decrease (1.53-fold; p < 0.01) in histologic score was seen only in the supplement group. When groups were compared, the supplement group showed significantly higher serum cholesterol (p < 0.05) and paraoxonase-1 (PON1) levels after 60 days of treatment (p < 0.01), and the placebo group showed significantly reduced serum total antioxidant capacity (TAC) levels after 120 days (p < 0.05). No significant differences were found between groups at any time point for CIBDAI, WSAVA histologic score and fecal microbiota evaluated by PCR-restriction fragment length polymorphism (PCR-RFLP). No side effects were reported in any group. CONCLUSIONS The combined administration of the supplement with hydrolyzed diet over 180 days was safe and induced improvements in selected serum biomarkers, possibly suggesting a reduction in disease activity. This study was likely underpowered, therefore larger studies are warranted in order to demonstrate a supplemental effect to dietary treatment of this supplement on intestinal histology and CIBDAI.