Human milk xanthine oxidase and neonatal salivary nucleotide precursors generate hydrogen peroxide; a novel pathway with potential role in regulating oral microflora

Background: Xanthine oxidase (XO) is a complex molybdeno-flavoprotein occurring with high activity in the milk fat globule membrane (MFGM) in all mammalian milk and is involved in the final stage of degradation of purine nucleotides. It catalyzes the sequential oxidation of hypoxanthine to xanthine and uric acid, accompanied by production of hydrogen peroxide and superoxide anion. Human saliva has been extensively described for its composition of proteins, electrolytes, cortisol, melatonin and some metabolites such as amino acids, but little is known about nucleotide metabolites. Method: Saliva was collected with swabs from babies; at full-term 1-4 days, 6-weeks, 6-months and 12-months. Unstimulated fasting (morning) saliva samples were collected directly from 77 adults. Breast milk was collected from 24 new mothers. Saliva was extracted from swabs and ultra-filtered. Nucleotide metabolites were analyzed by RP-HPLC with UV-photodiode array and ESI-MS/MS. XO activity was measured as peroxide production from hypoxanthine. Bacterial inhibition over time was assessed using CFU/mL or OD. Results: Median concentrations (μmol/L) of salivary nucleobases and nucleosides for neonates/6-weeks/6-months/12-months/adult respectively were: uracil 5.3/0.8/1.4/0.7/0.8, hypoxanthine 27/7.0/1.1/0.8/2.0, xanthine 19/7.0/2.0/2.0/2.0, adenosine 12/7.0/0.9/0.8/0.1, inosine 11/5.0/0.3/0.4/0.2, guanosine 7.0/6.0/0.5/0.4/0.1, uridine 12/0.8/0.3/0.9/0.4. Deoxynucleosides and dihydropyrimidines concentrations were essentially negligible. XO activity (Vmax:mean ± SD) in breast milk was 8.9 ± 6.2 μmol/min/L and endogenous peroxide was 27 ± 12 μmol/L; mixing breast milk with neonate saliva generated ~40 μmol/L peroxide,which inhibited Staphylococcus aureus. Conclusions: Salivary metabolites, particularly xanthine/hypoxanthine, are high in neonates, transitioning to low adult levels between 6-weeks to 6-months (p < 0.001). Peroxide occurs in breast milk and is boosted during suckling as an antibacterial system.

Changes in oral microflora in prosthetic patients on hygiene protocol

Poster presented at the 1st International Congress of CiiEM - From Basic Sciences to Clinical Research, 27-28 November 2015, Egas Moniz, Caparica, Portugal.

Efeito da penicilina G a cada três semanas sobre o surgimento de Streptococcus viridans resistentes à penicilina na microflora oral

FUNDAMENTO: Penicilina G benzatina a cada 3 semanas é o protocolo padrão para a profilaxia secundária para febre reumática recorrente. OBJETIVO: Avaliar o efeito da penicilina G benzatina em Streptococcus sanguinis e Streptococcus oralis em pacientes com doença valvular cardíaca, devido à febre reumática com recebimento de profilaxia secundária. MÉTODOS: Estreptococos orais foram avaliados antes (momento basal) e após 7 dias (7º dia) iniciando-se com penicilina G benzatina em 100 pacientes que receberam profilaxia secundária da febre reumática. Amostras de saliva foram avaliadas para verificar a contagem de colônias e presença de S. sanguinis e S. oralis. Amostras de saliva estimulada pela mastigação foram serialmente diluídas e semeadas em placas sobre agar-sangue de ovelhas seletivo e não seletivo a 5% contendo penicilina G. A identificação da espécie foi realizada com testes bioquímicos convencionais. Concentrações inibitórias mínimas foram determinadas com o Etest. RESULTADOS: Não foram encontradas diferenças estatísticas da presença de S. sanguinis comparando-se o momento basal e o 7º dia (p = 0,62). No entanto, o número existente de culturas positivas de S. oralis no 7º dia após a Penicilina G benzatina apresentou um aumento significativo em relação ao valor basal (p = 0,04). Não houve diferença estatística existente entre o momento basal e o 7º dia sobre o número de S. sanguinis ou S. oralis UFC/mL e concentrações inibitórias medianas. CONCLUSÃO: O presente estudo mostrou que a Penicilina G benzatina a cada 3 semanas não alterou a colonização por S. sanguinis, mas aumentou a colonização de S. oralis no 7º dia de administração. Portanto, a susceptibilidade do Streptococcus sanguinis e Streptococcus oralis à penicilina G não foi modificada durante a rotina de profilaxia secundária da febre reumática utilizando a penicilina G.

Effects of eating disorders on oral fungal diversity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Frequency of Candida spp. in the Oral Cavity of Brazilian HIV-Positive Patients and Correlation with CD4 Cell Counts and Viral Load

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Oral microbial colonization in children with sickle cell anaemia under long-term prophylaxis with penicillin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento da microbiota oral de bebês: análise longitudinal por pirosequenciamento da microbiota de bebês e suas mães dentro de um Programa de Saúde Bucal para Primeira Infância

Pós-graduação em Biopatologia Bucal - ICT

Effects of eating disorders on oral fungal diversity

Background. The eating disorders anorexia and bulimia nervosa can cause several systemic and oral alterations related to poor nutrition and induced vomiting; however, the oral microflora of these patients is poorly studied. Objective. The aim of this study was to evaluate fungal microflora in the oral cavity of these patients by culture-dependent and culture-independent methods. Study Design. Oral rinse samples were cultured to assess the prevalence of Candida species, and the isolates were identified by API system. Microorganism counts were compared by the Mann-Whitney test (5%). Ribotyping, a type of molecular analysis, was performed by sequencing the D1/D2 regions of 28S rRNA. Results. Our results demonstrated that the eating disorder group showed higher oral Candida spp. prevalence with culture-dependent methods and higher species diversity with culture-independent methods. Conclusions. Eating disorders can lead to an increased oral Candida carriage. Culture-independent identification found greater fungal diversity than culture-dependent methods. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;113:512-517)

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

Evaluation of dental pulp repair using low level laser therapy (688 nm and 785 nm) morphologic study in capuchin monkeys

The aim of this study was to evaluate the hypothesis that low-level laser therapy (LLLT) 688 nm and 785 nm accelerate dentin barrier formation and repair process after traumatic pulp exposure. The sample consisted of 45 premolars of capuchin monkeys (Cebus apella) with pulp exposure Class V cavities. All premolars were treated with calcium hydroxide (Ca(OH)(2)), divided in groups of 15 teeth each, and analyzed on 7(th), 25(th), and 60(th) day. Group GI - only Ca(OH)(2), GIF- laser 688 nm, and GIII - laser 785 nm. Laser beam was used in single and punctual dose with the parameters: continuous, 688 nm and 785 nm wavelength, tip`s area of 0.00785 cm(2), power 50 mW, application time 20 s, dose 255 J/cm(2), energy 2 J. Teeth were capped with Ca(OH)(2), Ca(OH)(2) cement and restored with amalgam. All groups presented pulp repair. On 25(th) day the thickness of the formed dentin barrier was different between the groups GI and GII (p < 0.05) and between groups GI and GIII (p < 0.01). On 60(th) day there was difference between GI and GIII (p < 0.01). It may be concluded that, LLLT 688 nm and 785 nm accelerated dentin barrier formation and consequently pulp repair process, with best results using infrared laser 785 nm. (c) 2009 by Astro Ltd. Published exclusively by WLLEY-VCH Verlag GmbH & Co. KGaA

Ozone therapy in medicine and dentistry

Aim: The purpose of this review is to present the potential for the incorporation of ozone therapy into the practice of dentistry. Background: Ozone gas has a high oxidation potential and is 1.5 times greater than chloride when used as an antimicrobial agent against bacteria, viruses, fungi, and protozoa. It also has the capacity to stimulate blood circulation and the immune response. Such features justify the current interest in its application in medicine and dentistry and have been indicated for the treatment of 260 different pathologies. It can be used for the treatment of alveolitis as a replacement for antibiotic therapy, as a mouthwash for reducing the oral microflora, as well as the adherence of microorganisms to tooth surfaces. Ozone has been shown to stimulate remineralization of recent caries-affected teeth after a period of about six to eight weeks. Conclusion: The future of ozone therapy must focus on the establishment of safe and well-defined parameters in accordance with randomized, controlled trials to determine the precise indications and guidelines in order to treat various medical and dental pathologies. Scientific support, as suggested by demonstrated studies, for ozone therapy presents a potential for an atraumatic, biologically-based treatment for conditions encountered in dental practice.

Presença de Candida, staphylococcus, enterobacteriaceae e pseudomonadaceae na cavidade bucal de pacientes HIV positivos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise do perfil de susceptibilidade antimicrobiana de microrganismos isolados de processos infecciosos bucais

Pós-graduação em Odontologia - FOA

Ocorrência de microrganismos periodontopatogênicos e viruses herpéticos na cavidade bucal de pacientes portadores de Síndrome de Down

Pós-graduação em Ciência Odontólogica - FOA

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)