Candida species biotypes and polyclonality of potentially virulent Candida albicans isolated from oral cavity of patients with orofacial clefts.

OBJECTIVES: This study evaluated the incidence of Candida species, and the genetic diversity and virulence of C. albicans of the oral cavity from patients with cleft lip and palate (CLP). MATERIALS AND METHODS: Oral samples were investigated by microbiological and species-specific PCR methods. The genetic diversity of C. albicans was established using isoenzyme markers, Nei's statistics, and clustering analysis. Hydrolytic enzymes (SAPs and PLs) were analyzed in vitro. RESULTS: Oral colonization by Candida species was observed in 29 patients with CLP (65.9%), and C. albicans was highly prevalent. SAP and PL activities were observed in 100% and 51.9% of isolates, respectively. High genetic diversity and patterns of monoclonal and polyclonal oral colonization by C. albicans were observed among patients with CLP. Two major polymorphic taxa (A and B) and other minor polymorphic taxa (C to J) were identified. Only one of the 16 clusters (taxon A) harbored strains from patients with and without CLP, whereas other clusters harbored strains exclusively from CLP patients. CONCLUSIONS: The anatomical conditions of the oral cavity of patients with CLP contribute to the high incidence of Candida species (C. albicans, C. krusei, C. tropicalis, and/or Candida spp.). Data suggest high genetic diversity of potentially virulent C. albicans strains in the oral cavity of CLP patients. CLINICAL RELEVANCE: Microbiological niches in orofacial clefts can contribute to the emergence of a relative clinical genotypic identity of C. albicans. However, orofacial rehabilitation centers can contribute to the direct and indirect sources of transmission and propagation of Candida species.

Efficacy of true cinnamon (Cinnamomum verum) leaf essential oil as a therapeutic alternative for Candida biofilm infections.

OBJECTIVES: The essential oil (EO) extracted from Cinnamomum verum leaves has been used as an antimicrobial agent for centuries. But its antifungal and antibiofilm efficacy is still not clearly studied. The objective of this research was to evaluate the in vitro antifungal and antibiofilm efficacy of C. verum leaf EO against C. albicans, C. tropicalis, and C. dubliniensis and the toxicity of EO using an in vitro model. MATERIALS AND METHODS: The effect of EO vapor was evaluated using a microatmosphere technique. CLSI microdilution assay was employed in determining the Minimum Inhibitory (MIC) and Fungicidal Concentrations (MFC). Killing time was determined using a standard protocol. The effect of EO on established biofilms was quantified and visualized using XTT and Scanning Electron Microscopy (SEM), respectively. Post-exposure intracellular changes were visualized using Transmission Electron Microscopy (TEM). The toxicological assessment was carried out with the Human Keratinocyte cell line. The chemical composition of EO was evaluated using Gas Chromatography-Mass Spectrometry (GC-MS). RESULTS: All test strains were susceptible to cinnamon oil vapor. EO exhibited MIC value 1.0 mg/ml and MFC value 2.0 mg/ml against test strains. The killing time of cinnamon oil was 6 hr. Minimum Biofilm Inhibitory Concentration (MBIC50) for established biofilms was <0.2 mg/ml for all test strains. SEM images exhibited cell wall damages, cellular shrinkages, and decreased hyphal formation of Candida. TEM indicated intracellular vacuolation, granulation, and cell wall damages. Cinnamon leaf oil caused no inhibition of HaCaT cells at any concentration tested. Eugenol was the abundant compound in cinnamon oil. CONCLUSION: C. verum EO is a potential alternative anti-Candida agent with minimal toxicity on the human host.

Antibiofilm and Anti-Candidal Activities of the Extract of the Marine Sponge Agelas dispar.

This study aimed to determine the antifungal and antibiofilm activities of Agelas dispar on biofilm-producing Candida species. The methanolic extract of A. dispar was obtained and the fraction Ag2 showed inhibitory activity for all 13 Candida strains tested, in concentrations ranging from 2.5 to 0.15625 mg/mL. Antifungal activity of fungicidal nature was seen between 5.0 and 0.3125 mg/mL of extract against the strains. All the strains were classified as biofilm producers. The methanolic extract Ag2 was tested at concentrations of 2.5 and 1.25 mg/mL for antibiofilm activity against the biofilm formation and maturation in all the strains of the genus Candida. Treated and untreated biofilm samples were selected for visualization using scanning electron microscopy (SEM). SEM allowed the visualization of the quantitative decrease in the microbial community, alterations of structural morphology, and destruction of both the formation and maturation of biofilms, at the cellular level. The mechanism of action of this fraction is suggested to be at the plasma membrane and/or cell wall alteration level. Therefore, the use of the methanolic extract of A. dispar may be a promising antifungal and antibiofilm therapeutic strategy against different species of the genus Candida.

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.

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.

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.

Effect of Cinnamomum verum leaf essential oil on virulence factors of Candida species and determination of the in-vivo toxicity with Galleria mellonella model.

BACKGROUND: Essential oils (EO) extracted from Cinnamomum verum has been used as an antimicrobial agents for centuries. The effects of C. verum leaf oil against virulence of microorganisms is not well studied yet. OBJECTIVES: This study evaluates the effect of C. verum leaf oil against three virulence factors of Candida albicans, C. tropicalis and C. dubliniensis and its in-vivo toxicity. METHODS: Chemical composition of EO was determined using gas chromatography-mass spectrometry (GC-MS). Minimum inhibitory concentration (MIC) was determined using clinical and laboratory standards institute (CLSI) M27-A3 broth microdilution. Effect of EO on initial adhesion was quantified using XTT assay after allowing Candida cells to adhere to the polystyrene surface for 2 h. Biofilm formation of Candida in the presence of EO was quantified using XTT viability assay. Efficacy on reduction of germ tube formation was evaluated using standard protocol. Visualisation of biofilm formation and progression under the EO treatment were done using scanning electron microscope (SEM) and Time lapses microscope respectively. In-vivo toxicity of EO was determined using Galleria mellonella larvae. Chlorhexidine digluconate: positive control. RESULTS: Eugenol was the main compound of EO. MIC was 1.0 mg/mL. 50% reduction in initial adhesion was achieved by C. albicans, C. tropicalis and C. dubliniensis with 1.0, > 2.0 and 0.34 mg/mL respectively. 0.5 and 1.0 mg/mL significantly inhibit the germ tube formation. MBIC50 for forming biofilms were ≤ 0.35 mg/mL. 1.0 mg/mL prevent biofilm progression of Candida. SEM images exhibited cell wall damages, cellular shrinkages and decreased hyphal formation. No lethal effect was noted with in-vivo experiment model at any concentration tested. CONCLUSION: C. verum leaf oil acts against virulence factors of Candida and does not show any toxicity.

Antimicrobial potential, phytochemical profile, cytotoxic and genotoxic screening of Sedum praealtum A. DC. (balsam).

BACKGROUND: Sedum praealtum has been used for a long time in traditional medicine as an analgesic and anti-inflammatory agent. Its beneficial effects have been known since ancient times, when Latinos used it to treat sore and swollen eyes. This research evaluated the antimicrobial potential, the cytotoxic and genotoxic effects, and some chromatographic profiles of the hydroethanolic extract of leaves, stems and roots of S. praealtum. METHODS: The antimicrobial activities were carried out by broth microdilution and agar diffusion. In vitro cytotoxicity was evaluated by cell cultures of Aedes albopictus and the selectivity index (SI) was estimated: SI=CI50/MIC. Genotoxic and systemic toxic effects of S. praealtum leaves were analyzed by micronucleus assay in mice bone marrow. Chromatographic profiles and mass spectra were investigated by GC-MS. RESULTS: Gram-positive (B. subtilis, B. cereus, M. luteus, E. faecalis and S. aureus) and gram-negative (E. coli, E. aerogenes, S. marcescens, P. aeruginosa, P. mirabilis and S. typhimurium) bacteria exhibited MICs ranging from 12.5-50 and 0-50 mg/ml, respectively. Sedum praealtum showed no efficacy against M. tuberculosis and M. bovis. Cytotoxicity (CI50) of S. praealtum was 4.22 and 5.96 mg/ml for leaves and stems, respectively, while its roots showed no cytotoxicity. Micronucleated polychromatic erythrocytes (MNPCEs) analyzes showed no differences between treatment doses (0.5-2 g/kg) and negative control (NaCl), but the PCE/NCE ratio (polychromatic erythrocyte/normochromatic erythrocyte) showed significant differences. Phytochemical screening identified thirteen compounds in the leaves, stems and roots of S. praealtum potentially associated with their biological activities. CONCLUSIONS: This research comprises a first scientific study on genotoxicity, cytotoxicity and antimicrobial effects of S. praealtum (Balsam), and it provides an initial theoretical foundation for its comprehensive use. Results showed antibacterial action of S. praealtum against gram-positive bacteria and some gram-negative species (depending on the plant anatomical part), but ineffective antimycobacterial action. However, S. praealtum leaves and stems display potential cytotoxicity, contributing to the SI < 1 values. In addition, S. praealtum leaves exhibit no clastogenic and/or aneugenic effects, but it has systemic toxicity dose-independent.

Chemical and structural composition of black pigmented supragingival biofilm of bovines with periodontitis / Composição química e estrutural do biofilme supragengival pigmentado de bovinos com periodontite

Bovine periodontitis is a multifactorial disease primarily associated with a potentially pathogenic microbiota housed in the oral biofilm of animals. Biofilms are organized structures, in which the constituents coexist in symbiosis, already described as a predisposing factor to periodontitis in other species. The objective of the present study was to characterize the structure and chemical aspects of the bovine black pigmented supragingival biofilm using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively, and determine its relationship with bovine periodontitis. Eleven premolar teeth from different animals were evaluated; five non-pigmented samples and six samples with black pigmented biofilms were initially submitted to SEM, and three areas of these samples were selected for EDS. The structure of the pigmented biofilm was more complex and irregular because of a higher content of mineral elements. The semi-quantitative EDS data indicated an association of iron (p<0.014) and magnesium (p<0.001) with the occurrence of periodontitis, whereas carbon, phosphorus, calcium, manganese, sodium, and potassium were not associated with the disease. Carbon (p<0.039), manganese (p<0.007), and iron (p<0.015) were associated with pigmentation, whereas phosphorus, calcium, and magnesium were not associated with it. Spearman correlation test showed the relationships between calcium and phosphorus, and iron and silicon. The strong association of iron in the pigmented supragingival biofilm and with the occurrence of periodontitis suggests the presence of microorganisms that use this element in their metabolism and that are also associated with bovine periodontitis. This study suggests that the pigmented deposits in the crown of the teeth of cattle are an true biofilm with the deposition of iron, and it indicates that the presence of iron and magnesium in these formations may be involved in the metabolism of some microorganisms associated with the etiology of bovine periodontitis.(AU)

A periodontite bovina é uma infecção multifatorial associada primariamente à microbiota potencialmente patogênica presente no biofilme bucal. Biofilmes são estruturas organizadas, nas quais os constituintes convivem em simbiose, descritos em outras espécies como um fator predisponente à periodontite. O objetivo do presente estudo foi caracterizar estrutural e quimicamente o biofilme supragengival pigmentado de preto em bovinos, utilizando-se as técnicas de microscopia eletrônica de varredura (MEV) e espectroscopia de dispersão de energia (EDS), respectivamente, correlacionando os elementos identificados à ocorrência de periodontite e pigmentação. Foram avaliados 11 dentes primeiro-molares; cinco amostras sem pigmentação visível e seis amostras com biofilme pigmentado de preto, que foram submetidas inicialmente à MEV; posteriormente foram selecionadas três áreas aleatórias de cada dente para realização da EDS. A estrutura do biofilme pigmentado revelou formações irregulares e mais complexas, provavelmente devido ao maior acúmulo de elementos minerais. Os resultados semi-quantitativos da EDS apontaram associações entre a presença de ferro (p<0,014) e magnésio (p<0,001) com a ocorrência de periodontite. Carbono, fósforo, cálcio, manganês, sódio e potássio não apresentaram associação com a periodontite. Em relação à pigmentação, carbono (p<0,039), manganês (p<0,007) e ferro (p<0,015) foram os elementos estatisticamente significantes, enquanto fósforo, cálcio e magnésio não apresentaram associação com a pigmentação. O teste de correlação de Spearman demonstrou associações entre os elementos cálcio e fósforo, e ferro e silício. A forte associação do ferro presente no biofilme supragengival com a ocorrência de periodontite, sugere a presença de micro-organismos que utilizam este elemento em seu metabolismo e que possivelmente tenham envolvimento com o desenvolvimento da periodontite bovina. Os resultados inéditos do presente trabalho sugerem que os depósitos pigmentados que se formam na coroa dos dentes de bovinos são um biofilme verdadeiro com deposição de ferro, e indicam que a presença de ferro e magnésio nestas formações pode estar envolvida no metabolismo de alguns dos principais micro-organismos associados à etiologia da periodontite bovina.(AU)

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.

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.

Candida species biotypes in the oral cavity of infants and children with orofacial clefts under surgical rehabilitation.

Patients with orofacial clefts present various risk factors for oral infectious diseases, resulting from anatomical and physiological changes and those resulting from rehabilitating therapeutic interventions. The incidence of Candida species in groups of babies and children with orofacial clefts, during pre- and post-operative periods and until return to first consultation, and the profiles for antifungal sensitivity and virulence in vitro were investigated. Oral samples were collected at different times over the surgical procedures and post-surgical clinical consultation and seeded in chromogenic culture media CHROMagar Candida®. Candida biotypes were identified by accessing species-specific genomic DNA sequences by PCR techniques and electrophoretic procedures. Antifungal susceptibility testing was performed by the method of microdilution in broth using the antifungals amphotericin B (AP), nystatin (NYS) and fluconazole (FLC). SAP and PL exoenzyme activities were determined by classical microbiological methods. Some orofacial clefts occurred preferentially in male or female. Low incidence (39.1%) of oral colonization by Candida species (C. albicans, C. krusei, C. tropicalis and Candida spp.) was reported in patient admission to surgical ward, with no correlation to orofacial cleft types or surgical history. Significant reduction in frequencies of Candida and changes of species, over sampling periods, showed dynamic patterns of oral colonization: elimination, maintenance or neocolonization of the biotypes. These biotypes showed sensitivity to AP (100%), partial resistance to FLC (<10%) and variable MICs for NYS (0.125-4 µg/mL), in addition to strong exoenzyme activities, especially for SAP. Clinical and therapeutic conducts for surgical rehabilitation, anatomical and physiological characteristics of patients with orofacial clefts, and cultural behavior and regionalism of the patient population served could influence the frequencies and dynamics of oral colonization by Candida species. The data showed Candida biotypes resistant to FLC and sensitive (AP) or clinically compatible (NYS) to polyenes, especially C. albicans, in the oral cavity of patients predisposed to oral colonization and candidiases, contributing to clinical conducts in possible antifungal therapies. These biotypes were considered potentially virulent and able to partially modulate their virulence factors, especially SAP, under the conditions favored by host.

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.

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)

Genotoxicidade de Helianthus annuus Linné, 1753 (Asteraceae): novas perspectivas e tendências / Genotoxicity of Helianthus annuus Linné, 1753 (Asteraceae): new perspectives and trends

A presente revisão reúne informações acerca dos aspectos genotóxicos de Helianthus annuus Linné (girassol), até o presente momento na literatura. O girassol é uma importante fonte de óleo natural e sua ampla aplicabilidade é atribuível ao variável repertório fitoquímico. A ação preventiva da diurese, diarreia e doenças inflamatórias, além dos efeitos de alívio dos sintomas asmáticos, proteção gástrica, cicatrização, ação anti-inflamatória e antimicrobiana foram reconhecidas quanto às propriedades farmacológicas do girassol. Com um grande potencial fitoquímico, é importante também analisarmos seu potencial tóxico e genotóxico. Vários resultados inconclusivos a respeito da correlação entre a carcinogênese e o óleo de girassol foram observados na literatura. Por outro lado, um número limitado de informações sobre a mutagênese ou antimutagênese do extrato hidroalcoólico e distintas fontes do óleo de sementes de girassol, submetido ou não ao estresse térmico, foi relatado. Esta revisão apresentará os atuais trabalhos envolvendo a ação genotóxica ou anti genotóxica de H. annuus L., colaborando com a implantação de limites ao consumo, potenciais riscos à saúde ou medidas estratégicas quimiopreventivas.(AU)

The present review gathers information about the genotoxic aspects of Helianthus annuus Linné (sunflower), until the present moment in the literature. Sunflower is an important source of natural oil and its wide applicability is attributable to the variable phytochemical repertoire. The preventive action of diuresis, diarrhea and inflammatory diseases, besides the effects of relief of asthmatic symptoms, gastric protection, healing, anti-inflammatory and antimicrobial action were recognized regarding the pharmacological properties of the sunflower. With great phytochemical potential, it is also important to analyze its toxic and genotoxic potential. Several inconclusive results regarding the correlation between carcinogenesis and sunflower oil were observed in the literature. On the other hand, a limited number of information on the mutagenesis or anti-mutagenesis of the hydroalcoholic extract and different sources of sunflower seed oil, whether or not subjected to thermal stress, was reported. This review will present the current works involving the genotoxic or anti genotoxic action of H. annuus L., collaborating with the implementation of consumption limits, potential health risks or strategic chemopreventive measures.(AU)

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.

Antifungal activity of the ethanolic extracts of Punica granatum L. and evaluation of the morphological and structural modifications of its compounds upon the cells of Candida spp.

Ethanolic crude extracts prepared from the arils and seeds, pericarp, peels and from the whole fruit of Punica granatum, known as pomegranate, had their antifungal activity tested against Candida spp. The ethanolic crude extracts were analyzed by Mass Spectrometry and yielded many compounds such as punicalagin and galladydilacton. The extracts from the pericarp and peel showed activity against Candida spp., with MICs of 125 µg/mL. The effect of pericarp and peel extracts upon the morphological and structure of C. albicans and C. krusei were examined by scanning and transmission electron microscopy, with the visualization of an irregular membrane and hyphae, formation of vacuoles and thickening of the cell wall. The data obtained revealed potential antimicrobial activity against yeasts cells of the Candida genus, and the bioactive compounds could be responsible for changes in cell morphology and structure. The data obtained open new perspectives for future research in continuation to this study, where information such as determination of the site of action of the compounds could contribute to an alternative therapy against these organisms.

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.

Antifungal activity of the ethanolic extracts of Punica granatum L. and evaluation of the morphological and structural modifications of its compounds upon the cells of Candida spp.

Ethanolic crude extracts prepared from the arils and seeds, pericarp, peels and from the whole fruit of Punica granatum, known as pomegranate, had their antifungal activity tested against Candida spp. The ethanolic crude extracts were analyzed by Mass Spectrometry and yielded many compounds such as punicalagin and galladydilacton. The extracts from the pericarp and peel showed activity against Candida spp., with MICs of 125 µg/mL. The effect of pericarp and peel extracts upon the morphological and structure of C. albicans and C. krusei were examined by scanning and transmission electron microscopy, with the visualization of an irregular membrane and hyphae, formation of vacuoles and thickening of the cell wall. The data obtained revealed potential antimicrobial activity against yeasts cells of the Candida genus, and the bioactive compounds could be responsible for changes in cell morphology and structure. The data obtained open new perspectives for future research in continuation to this study, where information such as determination of the site of action of the compounds could contribute to an alternative therapy against these organisms.