DNA microsatellite genotyping of potentially pathogenic Candida albicans and C. dubliniensis isolated from the oral cavity and dental prostheses.

This study investigated the incidence, genetic diversity, antifungal sensitivity, and virulence of Candida albicans and C. dubliniensis isolated from subjects using dental prostheses and subjects clinically indicated for the first prosthetic rehabilitation. Subjects were divided into four groups and samples were collected twice: at first rehabilitation by removable partial (A) and total (C) dental prostheses, and replacement of the removable partial (B) and total (D) prostheses. Yeasts were genotyped using DNA microsatellite markers. Microbiological methods were used to screen for azole antifungal resistance and exoenzyme production. In the initial sampling, oral colonization by Candida was observed in 31 (53.4%) subjects in groups A (33.3%), B (68.2%), and D (65%); 20 (47.6%) subjects displayed colonization of prostheses: groups B (50%) and D (45%). The second sampling (±30 days) revealed Candida in 2 (3.4%: oral cavity) and 4 (6.9%: prosthetic) subjects from group B. C. albicans and C. dubliniensis displayed both polyclonal and monoclonal patterns of infection. Azole-resistant C. albicans and SAPs+ strains were prevalent. Related strains were found in one or several oral sites (mucosa and prosthesis), as well as intra- and inter-subject, -gender, -group, and -time of sampling. However, the patterns of clonality can be altered under dental care.

Inverted amino acids reduce the adhesion and biofilm biomass of early oral colonizers.

BACKGROUND: Early colonizers adhere to the dental surface and facilitate the initial adhesion of secondary colonizers to form oral biofilms, which may cause oral infections. OBJECTIVES: This study aimed to determine the antimicrobial, anti-adhesion and antibiofilm potency of inverted amino acids on early colonizer streptococci and their mixed species. MATERIAL AND METHODS: The following test strains were used: Streptococcus gordonii (American Type Culture Collection (ATCC) 35105); Streptococcus mitis (ATCC 49456); Streptococcus oralis (ATCC 10557); Streptococcus salivarius (ATCC 7073); and Streptococcus sanguinis (ATCC BAA-1455). The concentration-dependent antimicrobial potency of d-alanine (d-ala), d-arginine (d-arg), d-leucine (d-leu), d-methionine (d-met), and d-tryptophan (d-try) was determined using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method with AlamarBlue modification. The adhesion of primary colonizers in the presence of 25-mM d-amino acids (dAAs) was assessed using the colony forming unit (CFU) assay. The CFU assay was conducted on 24-h flow cell bacterial biofilm models after exposure to 25-mM inverted dAAs. RESULTS: No minimum inhibitory concentration (MIC) point was detected at any concentration tested. The minimum bactericidal concentration (MBC) point was not observed. The adhesion of S. mitis, S. oralis and mixed species was reduced by all tested dAAs. No adverse effects were observed on S. gordonii with any of the tested dAAs. The biofilm biomass of test strains under flow conditions was significantly reduced after a 5-min exposure to all tested dAAs at 25-mM concentration. CONCLUSIONS: D-amino acids did not inhibit bacterial growth and did not show bactericidal or bacteriostatic effects on test strains at any concentration tested (ranging from 6.25 mM to 100 mM). However, dAAs effectively inhibit the adhesion of early colonizers, thereby preventing the formation of oral biofilm.

Impact of biomineralization on resin/biomineralized dentin bond longevity in a minimally invasive approach: An "in vitro" 18-month follow-up.

OBJECTIVES: To determine the impact of treating caries-affected dentin (CAD) with: 0.2% sodium fluoride (NaF), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP/MI Paste™) or peptide P11-4 (Curodont™ Repair) on the longevity of resin/CAD interface at storage times of 24 -h, 6- and 18-month. METHODS: 255 caries-free third molars were used, and CAD was produced by a biological method. The teeth were randomly distributed into: G1- Sound dentin (SD); G2- CAD; G3- CAD + 0.2% NaF (CAD/NaF); G4- CAD + CPP-ACP (CAD/ACP); G5- CAD + Curodont™ Repair (CAD/P11-4). The Filtek Z350 composite resin block was bonded to dentin using Adper™ Single 2 (4 mm/height). Resin/dentin blocks were stored in a solution of Simulated Body Fluid at 37 °C, pressures were modified to simulate natural pulpal pressures. Specimens were investigated by microtensile bond strength (µTBS) (n = 8), Scanning Electron Microscopy (to assess the failure mode) (n = 8), nanoinfiltration (to assess the interface sealing) (n = 3), in situ zymography (to assess the gelatinolytic activity) (n = 3) and micro-computed microtomography (µ-CT) (to assess the mineralization) (n = 3). Data from µTBS, µ-CT and, nanoinfiltration and hybrid layer formation/degradation were submitted to two-way ANOVA and Tukey tests, and failure patterns and in situ zymography to Kruskal-Wallis and Dunn tests (α = 5%). RESULTS: The highest mineral density change by µ-CT, smallest silver nitrate infiltration and proteolytic activity in the adhesive layer were obtained significantly for the groups SD, CAD/ACP and CAD/P11-4, with most mixed fractures at 18-month (p < 0.001). CAD/NaF showed significantly similar values to CAD, CAD and CAD/NaF which presented a high percentage of adhesive fracture (p < 0.001) at all time periods. SIGNIFICANCE: Treating caries-affected dentin with remineralizing agents CPP-ACP and Curodont™ Repair, has the potential to be a clinically relevant treatment protocol to increase the longevity of adhesive restorations.

Antimicrobial effects of silver nanoparticles and extracts of Syzygium cumini flowers and seeds: Periodontal, cariogenic and opportunistic pathogens.

OBJECTIVE: This study aimed to analyze the antimicrobial effects of lyophilized hydroalcoholic extract (HEScSeed and HEScFlower) and silver nanoparticles (AgNPs-HEScSeed and AgNPs-HEScFlower) of S. cumini seed and flower, and to characterize some compounds of these extracts and their NPs. DESIGN: Phytochemical screening was performed by GC-MS. Nanoparticles were characterized by UV-vis spectroscopy, energy-dispersive X-ray (EDX) spectrophotometry, scanning electron microscopy (SEM) and field emission gun (FEG), dynamic light scattering (DLS) and zeta potential (ZP). Antimicrobial susceptibility tests were analyzed by broth microdilution and agar diffusion methods. RESULTS: HEScSeed and HEScFlower showed 7 and 17 phytochemical compounds, respectively. AgNPs-plant extracts were reported as stable and with variable shapes and sizes. All studied species (A. naeslundii, C. albicans, F. nucleatum, S. aureus, S. epidermidis, S. mutans, S. oralis and V. dispar) were susceptible to extracts and AgNPs-plant extracts, with varying degrees of antimicrobial activities (extract: 648.4-5,187.5 µg/mL; AgNPs-plant: 31.2-2,000 µg/mL). CONCLUSION: The extracts of S. cumini seed and flower have antimicrobial action against pathogens of medical and dental interest, whose MIC and MMC are species-dependent. The AgNPs-HEScSeed and AgNPs-HEScFlower have different shapes, sizes, organic compounds, stability and electronegativity (capping), characteristics that contribute to their bacteriostatic and fungistatic effects, but at significantly lower concentrations than plant extracts.

Conventional and alternative antifungal therapies to oral candidiasis.

Candida-associated denture stomatitis is the most common form of oral candidal infection, with Candida albicans being the principal etiological agent. Candida adheres directly or via an intermediary layer of plaque-forming bacteria to denture acrylic. Despite antifungal therapy to treat denture stomatitis, infection is reestablished soon after the treatment ceases. In addition, many predisposing factors have been identified as important in the development of oral candidiasis, including malnourishment, common endocrine disorders, such as diabetis mellitus, antibacterial drug therapy, corticosteroids, radiotherapy and other immunocompromised conditions, such as acquired immunodeficiency syndrome (AIDS). These often results in increased tolerance to the most commonly used antifungals. So this review suggests new therapies to oral candidiasis.

Isoenzymatic genotyping of Staphylococcus aureus from dairy cattle and human clinical environments reveal evolutionary divergences.

Background The genetic variability of 610 S. aureus isolates from the hands of professional dentists (A), dental clinic environment air (B), bovine milk from cows with and without mastitis (C), an insufflator for milking equipment (D) and milking environment air (E) was studied by isoenzyme genotyping and genetic and cluster analysis. Results Monoclonal and polyclonal patterns of S. aureus were detected in every bacterial population; however, isolates belonging to the same strain were not found among the populations, suggesting the genetic heterogeneity and the intrapopulation spread of strains. Genetic relationship analysis revealed the co-existence of highly related strains at low frequency among populations. Conclusion The data suggest that some strains can adapt and colonize new epidemiologically unrelated habitats. Consequently, the occurrence of an epidemiological genotypic identity can assume a dynamic character (spread to new habitats), however infrequently. A tendency of microevolutionary and genetic divergences among populations of S. aureus from human sources (AB) and bovine milk (DE), and especially the mammary quarter (C), is also suggested. This research can contribute to the knowledge on the distribution and dissemination of strains and the implementation of control measures and eradication of S. aureus in important dental clinic environments, as well as animal environments and dairy production.

Dynamics of the seasonal airborne propagation of Staphylococcus aureus in academic dental clinics.

OBJECTIVE: Staphylococcus aureus strains can be disseminated during dental treatments and occasionally lead to the contamination and infection of patients and dentists, which is an important public health problem. The dynamics of the airborne propagation and the genetic diversity of S. aureus isolated in an academic dental clinic environment were investigated using isoenzyme typing. Materials and MethodsThe isoenzymes of 44 previously reported isolates were obtained from fresh cultures and extracted using glass beads. Nine isoenzymes were investigated using multilocus enzyme electrophoresis (MLEE). The genetic diversity and relationship among the strains (electrophoretic type - ET) were determined using statistics previously described by Nei25 (1972) and the SAHN grouping method (UPGMA algorithm). RESULTS: Clonal pattern analyses indicated a high level of genetic polymorphism occurring among the 33 ETs, which were grouped into five taxa. Each taxon presented one or more clusters that were moderately related and that contained two or more identical/highly related isolates, revealing seasonal airborne propagation in these dental clinic environments. CONCLUSIONS: These data suggest the occurrence of active microevolutionary processes in S. aureus as well as the possibility of environmental propagation during a 14-month time span. Such findings are important to show that multiuser academic dental clinics can retain certain strains that are spreadable to different niches.

Identification of bacteria in endodontic infections by sequence analysis of 16S rDNA clone libraries.

A significant proportion of oral bacteria are unable to undergo cultivation by existing techniques. In this regard, the microbiota from root canals still requires complementary characterization. The present study aimed at the identification of bacteria by sequence analysis of 16S rDNA clone libraries from seven endodontically infected teeth. Samples were collected from the root canals, subjected to the PCR with universal 16S rDNA primers, cloned and partially sequenced. Clones were clustered into groups of closely related sequences (phylotypes) and identification to the species level was performed by comparative analysis with the GenBank, EMBL and DDBJ databases, according to a 98% minimum identity. All samples were positive for bacteria and the number of phylotypes detected per subject varied from two to 14. The majority of taxa (65.2%) belonged to the phylum Firmicutes of the Gram-positive bacteria, followed by Proteobacteria (10.9%), Spirochaetes (4.3%), Bacteroidetes (6.5%), Actinobacteria (2.2%) and Deferribacteres (2.2%). A total of 46 distinct taxonomic units was identified. Four clones with low similarity to sequences previously deposited in the databases were sequenced to nearly full extent and were classified taxonomically as novel representatives of the order Clostridiales, including a putative novel species of Mogibacterium. The identification of novel phylotypes associated with endodontic infections suggests that the endodontium may still harbour a relevant proportion of uncharacterized taxa.

Effect of monomer blend and chlorhexidine-adding on physical, mechanical and biological properties of experimental infiltrants.

OBJECTIVES: The aim of the study was to evaluate antimicrobial inhibition zone, degree of conversion (DC) and Knoop hardness (KH) of experimental infiltrants. Experimental low viscosity monomer blends were prepared and chlorhexidine diacetate salt (CHX) (0.1% or 0.2%) was added comprising the groups: G1) TEGDMA; G2) TEGDMA/0.1CHX; G3) TEGDMA/0.2CHX; G4) TEGDMA/UDMA; G5) TEGDMA/UDMA/0.1CHX; G6) TEGDMA/UDMA/0.2CHX; G7) TEGDMA/BISEMA; G8) TEGDMA/BISEMA/0.1CHX; G9) TEGDMA/BISEMA/0.2CHX. Icon® was used as control group. METHODS: Specimens of resin blends were made (n=9) to accomplished DC and KH. Pour plate was accomplished to evaluate antimicrobial groups' activity against Streptococcus mutans (SM) and Lactobacillus acidophilus (LA). Data obtained were submitted to two-way ANOVA and Tukey tests for blends comparisons and Dunnett's test for comparisons between experimental infiltrants and Icon® (p<0.05). RESULTS: In relation to antimicrobial effect, uncured blends showed higher antibacterial activity than cured ones for the most of blends. After polymerization, G5 showed the highest inhibition zone against SM and, G3 and G6 against LA. Concerning KH, TEGDMA/UDMA-based blends showed the highest values of KH number and it was influenced by monomeric base, regardless CHX concentration. DC was not affected by monomer blend composition, neither for CHX concentration. The antimicrobial activity was affected by monomeric base, CHX concentration and polymerization. Experimental infiltrants presented similar or higher performance than Icon® for the properties evaluated. SIGNIFICANCE: White spot lesion infiltration with low viscosity monomer blends (infiltrants) is an alternative to stop initial caries lesions progression. The incorporation of an antimicrobial agent as chlorhexidine diacetate salt in infiltrants composition could enhance the performance of these materials.

Staphylococcus aureus ampicillin-resistant from the odontological clinic environment.

The aim of this research was to evaluate the prevalence of Staphylococcus spp. and S. aureus in the odontological clinic environment (air), their production of beta-lactamase and antibacterial susceptibility to the major antibiotics utilized in medical particle. During 12 months of samples collect were isolated 9775 CFU by MSA medium suggesting a high amount of Staphylococcus spp. in the clinic environment which can appear through aerosols. A total of 3149 colonies (32.2%) were suggestive of pathogenic staphylococci. Gram coloration, catalase test, colony-mallow growing on chromogenic medium, and coagulase test confirmed the identity of 44 (0.45%) S. aureus isolates. Of these, 35 isolates (79.5%) showed production of beta-lactamase by Cefinase discs and resistance to ampicillin, erythromycin (7 isolates) and tetracycline (1 isolate) suggesting the existence of multiresistant isolates. The evaluation of the oxacillin MIC by Etest assays showed susceptibility patterns suggesting the inexistence of the mecA gene in chromosomal DNA. These results point out to the need of a larger knowledge on the contamination means and propagation of this microorganism into the odontological clinic.

Tansmission, diversity and virulence factors of Sreptococcus mutans genotypes.

Dental caries is an infectious and transmissible disease, in which many genetic, environmental and behavioral risk factors interact. The mutans streptococci (MS), mainly Streptococcus mutans and Streptococcus sobrinus are the microorganisms most strongly associated with this disease. The main virulence factors associated with MS cariogenicity include adhesion, acidogenicity and acid tolerance. These properties work together to modify the physico-chemical properties of the biofilm, resulting in ecological changes in the form of increased proportions of S. mutans and other acidogenic and aciduric species. In addition, reports of higher numbers of S. mutans genotypes with increased virulence in caries-active subjects suggest the importance of microenvironmental factors in increasing the risk of caries. This review focuses on the transmission and establishment of different genotypes of S. mutans and the role they play in the development of dental caries.

Genotypic diversity and virulence traits of Streptococcus mutans in caries-free and caries-active individuals.

The present study evaluated the relationship between clonal diversity and some virulence traits of Streptococcus mutans isolated from eight caries-free and eight caries-active subjects. A total of 155 S. mutans isolates from caries-free subjects and 144 isolates from caries-active subjects were obtained from samples of saliva, dental plaque and tongue surface and identified by PCR. The isolates were submitted to arbitrarily primed (AP)-PCR (OPA-2 and OPA-13) and multilocus enzyme electrophoresis (MLEE) to establish the genotypic diversity. Production of water-insoluble glucan (WIG) (monitored by SDS-PAGE), final pH of cultures and the ability of bacterial cells to adhere to smooth glass in the presence of sucrose were measured. High and comparable abilities of MLEE and AP-PCR were found to distinguish S. mutans genotypes, using Simpson's index of discrimination (0.971 and 0.968, respectively). The results showed a significant difference (P < 0.01) in the number of genotypes when caries-free and caries-active groups were compared by both fingerprinting methods used. Final pH (P = 0.32) and the percentage of adherence to a glass surface (P = 0.62) did not show differences between the two groups; however, the intensities of WIG bands from the caries-active group were greater than those from the caries-free group (P < 0.01). In addition, WIG was positively correlated with the ability of S. mutans to adhere to a glass surface (r = 0.34, P = 0.02) from caries-active subjects. These data showed that AP-PCR analysis and MLEE are both effective methods for assessing the genetic relatedness of S. mutans. Using these techniques, it was found that there is a larger number of genotypes of S. mutans with increased ability to synthesize WIG in caries-active individuals.

Antimicrobial activity of mouth rinses against bacteria that initially colonizes dental's surface / Atividade antimicrobiana de enxaguatórios bucais sobre bactérias que iniciam a colonização das superfícies dentais

Abstract Introduction Much advertising in mouthwash is conveyed in all media appealing to the anti-plaque effect and rendering a disservice to the community. Mouth rinses are available over-the-count and differ on their compositions and antimicrobial effectiveness. Objective In this study, we evaluated the antimicrobial activity of 35 widely available mouth rinses against bacterial species involved in initiation of dental biofilm - Streptococcus gordonii, Streptococcus mitis, Streptococcus oralis, Streptococcus salivarius, and Streptococcus sanguinis. Material and method The Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) of the evaluated mouth rinses were determined according to the Clinical & Laboratory Standards Institute protocols. Data were submitted to Kruskal-Wallis test and Mann-Whitney post hoc (α=0.05). Result About 70% of the mouth rinses achieved high antibacterial activity and 30%, a low antibacterial activity against all the species tested. The most ineffective mouth rinse showed antibacterial activity (MIC) at 1:1 dilution, while the most effective showed activity even at 1:2048 dilution, which may imply prolonged effect in the mouth. About 51% of mouth rinses showed bactericidal activity, and it was verified that cetylpyridinium chloride or chlorhexidine digluconate containing in the formulation were associated with the highest activity. Conclusion Most - but not all - mouth rinses commercially available are effective in inhibiting in vitro initial colonizers of dental surfaces.

Resumo Introdução Muita publicidade sobre enxaguatórios bucais é veiculada em todos os meios de comunicação apelando para o efeito anti-placa e prestando um desserviço à comunidade. Grande quantidade de enxaguatórios bucais está disponível no mercado e estes diferem em suas composições e eficácia antimicrobiana. Objetivo Neste estudo, avaliamos a atividade antimicrobiana de 35 enxaguatórios bucais amplamente disponíveis contra espécies bacterianas envolvidas na iniciação do biofilme dental - Streptococcus gordonii, Streptococcus mitis, Streptococcus oralis, Streptococcus salivarius e Streptococcus sanguinis. Material e método A Concentração Inibitória Mínima (CIM) e a Concentração Bactericida Mínima (CBM) dos enxaguatórios avaliados foram determinadas de acordo com os protocolos do Clinical & Laboratory Standards Institute. Os dados foram submetidos ao teste Kruskal-Wallis e Mann-Whitney post hoc (α=0,05). Resultado Aproximadamente 70% dos enxaguatórios bucais alcançaram alta atividade antibacteriana e 30%, baixa atividade antibacteriana contra todas as espécies testadas. O enxaguatório bucal mais ineficaz mostrou atividade antibacteriana (CIM) na diluição de 1:1, enquanto a mais eficaz mostrou atividade mesmo na diluição de 1:2048, o que pode implicar em efeito prolongado na boca. Cerca de 51% dos enxaguatórios bucais apresentaram atividade bactericida, e verificou-se que formulações contendo cloreto de cetilpiridíneo ou digluconato de clorexidina estavam associados à maior atividade. Conclusão A maior parte - mas não todos - dos enxaguatórios bucais comercialmente disponíveis são eficazes na inibição de colonizadores iniciais de superfícies dentárias in vitro.

Dynamics of the seasonal airborne propagation of Staphylococcus aureus in academic dental clinics

Abstract Objective Staphylococcus aureus strains can be disseminated during dental treatments and occasionally lead to the contamination and infection of patients and dentists, which is an important public health problem. The dynamics of the airborne propagation and the genetic diversity of S. aureus isolated in an academic dental clinic environment were investigated using isoenzyme typing. Material and Methods The isoenzymes of 44 previously reported isolates were obtained from fresh cultures and extracted using glass beads. Nine isoenzymes were investigated using multilocus enzyme electrophoresis (MLEE). The genetic diversity and relationship among the strains (electrophoretic type - ET) were determined using statistics previously described by Nei25 (1972) and the SAHN grouping method (UPGMA algorithm). Results Clonal pattern analyses indicated a high level of genetic polymorphism occurring among the 33 ETs, which were grouped into five taxa. Each taxon presented one or more clusters that were moderately related and that contained two or more identical/highly related isolates, revealing seasonal airborne propagation in these dental clinic environments. Conclusions These data suggest the occurrence of active microevolutionary processes in S. aureus as well as the possibility of environmental propagation during a 14-month time span. Such findings are important to show that multiuser academic dental clinics can retain certain strains that are spreadable to different niches.

Isoenzyme genotyping and phylogenetic analysis of oxacillin-resistance Staphylococcus aureus isolates

Aim: The propagation of S. aureus in hospital and dental environments is considered an important public health problem since resistant strains can cause serious infections in humans. The genetic variability of 99 oxacillin-resistant S. aureus isolates (ORSA) from the dental patients (oral cavity) and environments (air) was studied by isoenzyme genotyping. Methods: S. aureus isolates were studied using isoenzyme markers (alcohol dehydrogenase, sorbitol dehydrogenase, mannitol-1-phosphate dehydrogenase, malate dehydrogenase, glucose dehydrogenase, D-galactose dehydrogenase, glucose-6-phosphate dehydrogenase, catalase and α/ß-esterase) and genetic (Nei's statistics) and cluster analysis (UPGMA algorithm). Results: A highly frequent polyclonal pattern was observed in this population of ORSA isolates, suggesting various sources of contamination or microbial dispersion. Genetic relationship analysis showed a high degree of polymorphism between the strains, and it revealed three taxa (A, B and C) distantly genetically related (0.653≤dij≤1.432) and fifteen clusters (I to XV) moderately related (0.282≤dij<0.653). These clusters harbored two or more highly related strains (0≤dij<0.282), and the existence of microevolutionary processes in the population of ORSA. Conclusion: This research reinforces the hypothesis of the existence of several sources of contamination and/or dispersal of ORSA of clinical and epidemiologically importance, which could be associated with carriers (patients) and dental environmental (air) (AU)

Real-time polymerase chain reaction quantification of Porphyromonas gingivalis and Tannerella forsythia in primary endodontic infections.

INTRODUCTION: Porphyromonas gingivalis and Tannerella forsythia are anaerobic bacteria commonly involved in root canal infections. Although previous investigations have assessed these species by strictly qualitative approaches, accurate determination of their cell levels by a sensitive quantitative technique may contribute with additional information regarding relevance in pain of endodontic origin. METHOD: The root canal levels of P. gingivalis, T. forsythia, and total bacteria were investigated by a quantitative polymerase chain reaction (PCR) assay based on unique copy molecular markers. A total of 32 symptomatic (n = 14) and asymptomatic (n = 18) cases of endodontic infections were analyzed. Root canal samples were collected; genomic DNA was extracted and submitted to SYBR Green I real-time PCR targeting the rgpB (P. gingivalis), bspA (T. forsythia), and rpoB (total bacteria) single copy genes. RESULTS: Overall, P. gingivalis, T. forsythia, and the coexistence of both species were encountered in 28%, 66%, and 22% of the subjects, respectively. P. gingivalis and T. forsythia levels ranged from 5.65 x 10(-6) to 1.20 x 10(-2) and from 5.76 x 10(-6) to 1.35 x 10(-1). T. forsythia was highly prevalent and numerous in the study groups, whereas P. gingivalis was moderately frequent and less abundant, displaying 19-fold lower average levels than the former. CONCLUSIONS: The endodontic levels of P. gingivalis and T. forsythia, individually or in conjunction, did not display significant associations with the manifestation of pain of endodontic origin.

Avaliação in vitro da atividade de fosfolipase e proteinase de cepas de candida albicans isolada da cavidade bucal de pacientes diabéticos / In vitro evaluation of phospholipase and proteinase of candida albicans isolated from oral cavity of diabetic patients

Leveduras do gênero Candida são comuns na cavidade bucal e podem causar candidose na presença de fatores predisponentes, especialmente em paciente diabético, o qual é caracterizado por um aumento anormal da glicose no sangue. A manifestação da doença está relacionada a este conjunto de fatores locais, tais como a presença de próteses dentárias, pH salivar, fluxo salivar e tabaco. A redução da saliva é um dos principais fatores de risco para o aparecimento de infecção e o controle glicêmico inadequado causado por diabetes, em associação com todos estes fatores, pode aumentar a incidência de infecções. Os objetivos deste estudo foram: 1) isolar e identificar cepas de Candida albicans da mucosa bucal de pacientes diabéticos 2) avaliar os fatores de virulência: proteinase e fosfolipase. Amostras microbiológicas foram coletadas a partir de locais da mucosa bucal e semeadas em CHROMagar para posterior identificação de C. albicans por PCR. Foram realizados testes da atividade de proteinase e fosfolipase para todos os isolados de C. albicans. Neste estudo, 22 isolados foram identificados como C. albicans. Em relação às atividades de proteinases, todas as cepas de C. albicans foram capazes de produzir proteinase, enquanto que para fosfolipase, apenas 4,5% dos isolados não produziram esta exoenzima. Portanto, C. albicans presente na cavidade bucal de pacientes diabéticos tem potencial patogênico e pode participar de processos infecciosos e inflamatórios, causando lesões e invadindo os tecidos orais.

Candida yeasts are common in the oral cavity and can cause candidosis in the presence of predisposing factors, especially diabetes, which is characterized by an abnormal increasing in blood glucose concentration. The manifestation of the disease is related to a set of local factors such as the presence of dental prostheses, salivary pH, salivary flow and tobacco. The reduction in saliva is a major risk factor for the onset of infection and poor glycemic control caused by diabetes in association with all these factors further increases the incidence of candidosis. The objectives of this study were: 1) to isolate and identify Candida albicans strains from oral mucosa sites of diabetic patients 2) to evaluate the virulence factors: proteinase and phospholipase. Thus, microbial samples were collected from oral mucosa sites and seeded in CHROMagar for subsequent identification of C. albicans by PCR. For the phenotypic tests, all strains of C. albicans were evaluated for their proteinase and phospholipase productions. In this study, 22 isolates were identified as C. albicans. In regard to the proteinase activities, all strains of C. albicans were able to produce proteinase, while only 4.5% from those isolates were not able to produce phospholipase activity. In conclusion, C. albicans present in the oral cavity of diabetic patients is potentially pathogenic and can participate in infectious and inflammatory processes, causing injury and invading oral tissues.

Evidências científicas da colonização de Candida spp. em bolsas periodontais / Scientific evidence of Candida spp. colonization in periodontal pockets

Objetivo: o objetivo do presente trabalho é apresentar uma breve revisão de literatura a respeito da colonização de Candida spp. em bolsas periodontais, seus principais fatores de virulência e possível influência sobreas doenças periodontais. Revisão de Literatura: Apesar de a mucosa bucal ser considerada o principal reservatóriode Candida spp, este micro-organismo pode estar coagregado a bactérias do biofilme dental, sendo considerado um fator importante para o processo decolonização de bolsas periodontais. Além disso, possui vários fatores de virulência relevantes na patogênese dadoença periodontal, tais como a capacidade de aderir ao epitélio e invadir o tecido conjuntivo gengival. Também pode inibir a função de neutrófilos polimorfonucleares, bem como produzir enzimas como colagenases e proteinases, que são capazes de degradar imunoglobulinas.Considerações finais: Os fatores de virulência de Candida spp. associada à suscetibilidade do hospedeiro poderiam desempenhar um papel importante nasalterações inflamatórias associadas com as doenças periodontais destrutivas

The role of immune system in the development of periodontal disease: a brief review / O papel do sistema imune no desenvolvimento da doença periodontal: uma breve revisão

Periodontitis is a highly complex and multi-factorial disease. This review summarizes some immunological factors involved in the development and control of this oral disease, such as: the participation of inflammatory cells in local inflammation, the synthesis of chemotaxis proteins with activation of the complement system and a range of antimicrobial peptides, such as defensins, cathelicidin and saposins. The integration of pathogen-associated molecular patterns (PAMPs) from microorganisms with their surface receptors in the immune cells, induces the production of several cytokines and chemokines that presents either a pro- and/or anti-inflammatory role by stimulating the secretion of a great variety of antibody subtypes and the activation of mechanisms of controlling the disease, such as the regulatory T cells. Although several studies have tried to clarify some of the immune mechanisms involved in periodontal disease, more studies must be conducted to understand its development and progression and consequently to discover new alternatives for the prevention and treatment of this severe inflammatory disease.

A periodontite é uma doença altamente complexa e multifatorial. Esta breve revisão reúne alguns fatores imunológicos envolvidos no desenvolvimento e controle desta doença oral, tais como: a participação de células inflamatórias no local da inflamação, a síntese de proteínas quimiotáticas através da ativação do sistema complemento e a presença de alguns dos peptídeos antimicrobianos, como defensinas, catelicidinas e saposinas. A interação de padrões moleculares associados à patógenos (PAMPs) de microrganismos com seus receptores de superfície, em células imunológicas, induz a produção de várias citocinas e quimiocinas que apresentam função pró- e/ou anti-inflamatória estimulando a secreção de uma grande variedade de subtipos de anticorpos e a ativação de mecanismos de controle da doença, como as células T reguladoras. Embora vários trabalhos tentem esclarecer alguns dos mecanismos imunológicos envolvidos na doença periodontal, estudos adicionais são necessários para ampliar conhecimentos sobre o desenvolvimento, a progressão e, consequentemente, para se descobrir novas alternativas de prevenção e tratamento desta grave doença inflamatória.

Conventional and alternative antifungal therapies to oral candidiasis

Candida-associated denture stomatitis is the most common form of oral candidal infection, with Candida albicans being the principal etiological agent. Candida adheres directly or via an intermediary layer of plaque-forming bacteria to denture acrylic. Despite antifungal therapy to treat denture stomatitis, infection is reestablished soon after the treatment ceases. In addition, many predisposing factors have been identified as important in the development of oral candidiasis, including malnourishment, common endocrine disorders, such as diabetis mellitus, antibacterial drug therapy, corticosteroids, radiotherapy and other immunocompromised conditions, such as acquired immunodeficiency syndrome (AIDS). These often results in increased tolerance to the most commonly used antifungals. So this review suggests new therapies to oral candidiasis.