Influence of Surface Treatment on the Physical Properties and Biofilm Formation of Zirconia- Reinforced Lithium Silicate Ceramics: In Vitro Trial.

PURPOSE: To evaluate the performance of fully crystallized zirconia-reinforced lithium silicate (Celtra Duo, ZLS-CD), partially crystallized zirconia-reinforced lithium silicate (Vita Suprinity, ZLS-VS), and partially sintered lithium disilicate-based (IPS e.max CAD, LD) glass-ceramics submitted to polishing, glazing, or no surface treatment after aging. MATERIAL AND METHODS: Samples of each glass-ceramic material were subjected to polishing with rubber cups (POL), glazing (GL), or no treatment (control: unpolished) and afterward aged with 18,000 thermal cycles (5.C to 55.C). The average roughness, 2D and 3D morphology, contact angle, multispecies biofilm formation (Streptococcus mutans and Candida albicans), and mechanical strength were evaluated with atomic force microscopy (AFM, n = 5), sessile-drop goniometry (n = 5), spectrophotometry (n = 5), and the flexural strength test (n = 10), respectively. Data were analyzed using two-way ANOVA and Tukey test (α = 5%). RESULTS: POL produced lower surface roughness than GL, and ZLS-CD presented higher roughness than LD (P < .05). Surfaces without polishing displayed higher roughness than the POL group (P < .001), greater contact angle (P < .001), and significant morphologic changes, regardless of the glass-ceramic material. Irrespective of the treatment, the contact angle was higher in the ZLS-CD group, and regardless of the material, there was higher biofilm formation and lower flexural strength of the unpolished compared to the POL or GL ceramics. CONCLUSIONS: POL promoted lower roughness and minor morphologic surface alterations, but biofilm formation and flexural strength were similar to the GL group. In general, ZLS-CD and ZLS-VS showed more similar behavior than LD, which makes ZLS glass-ceramic a good option for indirect restorations.

Biosynthesis of silver nanoparticles from Syzygium cumini leaves and their potential effects on odontogenic pathogens and biofilms.

This study analyzed the antimicrobial and antibiofilm action and cytotoxicity of extract (HEScL) and silver nanoparticles (AgNPs-HEScL) from Syzygium cumini leaves. GC-MS, UV-Vis, EDX, FEG/SEM, DLS and zeta potential assays were used to characterize the extract or nanoparticles. Antimicrobial, antibiofilm and cytotoxicity analyses were carried out by in vitro methods: agar diffusion, microdilution and normal oral keratinocytes spontaneously immortalized (NOK-SI) cell culture. MICs of planktonic cells ranged from 31.2-250 (AgNPs-HEScL) to 1,296.8-10,375 µg/ml (HEScL) for Actinomyces naeslundii, Fusobacterium nucleatum, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Streptococcus oralis, Veillonella dispar, and Candida albicans. AgNPs-HEScL showed antibiofilm effects (125-8,000 µg/ml) toward Candida albicans, Streptococcus mutans and Streptococcus oralis, and Staphylococcus aureus and Staphylococcus epidermidis. The NOK-SI exhibited no cytotoxicity when treated with 32.8 and 680.3 µg/ml of AgNPs-HEScL and HEScL, respectively, for 5 min. The data suggest potential antimicrobial and antibiofilm action of HEScL, and more specifically, AgNPs-HEScL, involving pathogens of medical and dental interest (dose-, time- and species-dependent). The cytotoxicity of HEScL and AgNPs-HEScL detected in NOK-SI was dose- and time-dependent. This study presents toxicological information about the lyophilized ethanolic extract of S. cumini leaves, including their metallic nanoparticles, and adds scientific values to incipient studies found in the literature.

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.

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.

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.

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)

Genotypic diversity and phenotypic traits of Streptococcus mutans isolates and their relation to severity of early childhood caries.

BACKGROUND: Early childhood caries (ECC) is an aggressive condition that can affect teeth of young children. This study aimed to evaluate genotypic diversity and phenotypic traits of S. mutans isolated from dental biofilms of children with different caries status in comparison with caries free (CF) children. METHODS: Streptococcus mutans strains were isolated from supragingival biofilm samples of CF, ECC and severe-ECC (S-ECC) children and genotyped by arbitrary-primer polymerase chain reaction - AP-PCR. S. mutans genotypes were tested for their ability to reduce the suspension pH through glycolysis, to tolerate extreme acid challenge and by their ability to form biofilm. Response variables were analyzed by ANOVA/Tukey or Kruskal-Wallis/Mann-Whitney tests at a 5% of significance. RESULTS: There was an increase in the prevalence of Streptococcus mutans in biofilms with the severity of dental caries. No differences in genotypic diversity and in acidogenicity of genotypes were found among CF, ECC and S-ECC children. S mutans strains with genotypes more characteristic for ECC and S-ECC children formed more biofilms than those identified in CF children. The strains isolated from S-ECC children were highly acid tolerant. CONCLUSION: Although S. mutans genotypic diversity was similar among the groups of children, phenotypic traits of S. mutans, especially the acid tolerance response, could explain the severity of early childhood caries.

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)

In vitro mutagenicity assay (Ames test) and phytochemical characterization of seeds oil of Helianthus annuus Linné (sunflower).

The objective of this research was to investigate the genotoxic potential of the oil of H. annuus L. (sunflower) seeds via the Ames test as well as its oxidative properties and lipid composition. The pre-incubation method, system metabolic activation (S9 fraction) and five S. typhimurium strains (TA97, TA98, TA100, TA1535 and TA102) were employed for the Ames test. The oxidative stability and fatty acid composition were analyzed by standard methods and gas chromatography. A revertant analysis showed no significant differences between the treatment doses (10-200 µl/plate) and the negative controls, regardless of S9+ and S9-, and included all of the S. typhimurium strains. Chromatographic analysis showed high levels of polyunsaturated fatty acids, followed by monounsaturated, saturated and total trans-isomers. Among the polyunsaturated, monounsaturated and saturated fatty acids, linoleic, oleic and palmitic acids predominated. The results suggest that the sunflower oil is not genotoxic as indicated by frameshift mutations and base pair substitutions regardless of the treatment dose, but shows dose-dependent toxicity. The oxidative properties of the sunflower oil were consistent with the requirements of national and international standards. However, its composition could also indicate phytotherapeutic properties.

In vitro screening antibacterial activity of Bidens pilosa Linné and Annona crassiflora Mart. against oxacillin resistant Staphylococcus aureus (ORSA) from the aerial environment at the dental clinic.

Currently multiresistant Staphylococcus aureus is one common cause of infections with high rates of morbidity and mortality worldwide, which directs scientific endeavors in search for novel antimicrobials. In this study, nine extracts from Bidens pilosa (root, stem, flower and leaves) and Annona crassiflora (rind fruit, stem, leaves, seed and pulp) were obtained with ethanol: water (7:3, v/v) and their in vitro antibacterial activity evaluated through both the agar diffusion and broth microdilution methods against 60 Oxacillin Resistant S. aureus (ORSA) strains and against S. aureus ATCC6538. The extracts from B. pilosa and A. crassiflora inhibited the growth of the ORSA isolates in both methods. Leaves of B. pilosa presented mean of the inhibition zone diameters significantly higher than chlorexidine 0.12% against ORSA, and the extracts were more active against S. aureus ATCC (p < 0.05). Parallel, toxicity testing by using MTT method and phytochemical screening were assessed, and three extracts (B. pilosa, root and leaf, and A. crassiflora, seed) did not evidence toxicity. On the other hand, the cytotoxic concentrations (CC50 and CC90) for other extracts ranged from 2.06 to 10.77 mg/mL. The presence of variable alkaloids, flavonoids, tannins and saponins was observed, even though there was a total absence of anthraquinones. Thus, the extracts from the leaves of B. pilosa revealed good anti-ORSA activity and did not exhibit toxicity.

Evaluation of the mutagenicity and antimutagenicity of Ziziphus joazeiro Mart. bark in the micronucleus assay.

The aim of this study was to evaluate the mutagenicity (clastogenicity/aneugenicity) of a glycolic extract of Ziziphus joazeiro bark (GEZJ) by the micronucleus assay in mice bone marrow. Antimutagenic activity was also assessed using treatments associated with GEZJ and doxorubicin (DXR). Mice were evaluated 24-48 h after exposure to positive (N-nitroso-N-ethylurea, NEU - 50 mg.kg(-1) and DXR - 5 mg.kg(-1)) and negative (150 mM NaCl) controls, as well as treatment with GEZJ (0.5-2 g.kg(-1)), GEZJ (2 g.kg(-1)) + NEU and GEZJ (2 g.kg(-1)) + DXR. There were no significant differences in the frequencies of micronucleated polychromatic erythrocytes in mice treated with GEJZ and GEJZ + DXR compared to the negative controls, indicating that GEZJ was not mutagenic. Analysis of the polychromatic:normochromatic erythrocyte ratio revealed significant differences in the responses to doses of 0.5 g.kg(-1) and 1-2 g.kg(-1) and the positive control (NEU). These results indicated no systemic toxicity and moderate toxicity at lower and higher doses of GEZJ. The lack of mutagenicity and systemic toxicity in the antimutagenic assays, especially for treatment with GEZJ + DXR, suggested that phytochemical compounds in Z. joazeiro bark attenuated DXR-induced mutagenicity and the moderate systemic toxicity of a high dose of Z. joazeiro bark (2 g.kg(-1)). Further studies on the genotoxicity of Z. joazeiro extracts are necessary to establish the possible health risk in humans and to determine the potential as a chemopreventive agent for therapeutic use.

In vitro SCREENING ANTIBACTERIAL ACTIVITY OF Bidens pilosa LINNÉ AND Annona crassiflora MART. AGAINST OXACILLIN RESISTANT Staphylococcus aureus (ORSA) FROM THE AERIAL ENVIRONMENT AT THE DENTAL CLINIC / Triagem in vitro da atividade antibacteriana de Bidens pilosa Linné e Annona crassiflora Mart. contra Staphylococcus aureus resistente à oxacilina (ORSA) provenientes do ambiente aéreo na clínica odontológica

Currently multiresistant Staphylococcus aureus is one common cause of infections with high rates of morbidity and mortality worldwide, which directs scientific endeavors in search for novel antimicrobials. In this study, nine extracts from Bidens pilosa (root, stem, flower and leaves) and Annona crassiflora (rind fruit, stem, leaves, seed and pulp) were obtained with ethanol: water (7:3, v/v) and their in vitro antibacterial activity evaluated through both the agar diffusion and broth microdilution methods against 60 Oxacillin Resistant S. aureus (ORSA) strains and against S. aureus ATCC6538. The extracts from B. pilosa and A. crassiflora inhibited the growth of the ORSA isolates in both methods. Leaves of B. pilosa presented mean of the inhibition zone diameters significantly higher than chlorexidine 0.12% against ORSA, and the extracts were more active against S. aureus ATCC (p < 0.05). Parallel, toxicity testing by using MTT method and phytochemical screening were assessed, and three extracts (B. pilosa, root and leaf, and A. crassiflora, seed) did not evidence toxicity. On the other hand, the cytotoxic concentrations (CC50 and CC90) for other extracts ranged from 2.06 to 10.77 mg/mL. The presence of variable alkaloids, flavonoids, tannins and saponins was observed, even though there was a total absence of anthraquinones. Thus, the extracts from the leaves of B. pilosa revealed good anti-ORSA activity and did not exhibit toxicity.

Atualmente Staphylococcus aureus multirresistente é causa comum de infecções com altas taxas de morbidade e mortalidade mundialmente, o que direciona esforços científicos na busca de novos antimicrobianos. Neste estudo, nove extratos de Bidens pilosa (raiz, caule, flor e folhas) e de Annona crassiflora (casca do fruto, caule, folha, semente e polpa) foram obtidos com etanol:água (7:3, v/v) e suas atividades antibacteriana in vitro avaliadas através de difusão em agar e microdiluição em caldo contra 60 cepas de Oxacillin Resistant S. aureus (ORSA) e contra S. aureus ATCC 6538. Os extratos de B. pilosa e A. crassiflora inibiram o crescimento dos isolados ORSA em ambos os métodos. O extrato da folha de B. pilosa apresentou média dos diâmetros dos halos de inibição significativamente maior que a clorexidina 0,12%, contra os isolados ORSA, e os extratos foram mais ativos contra S. aureus ATCC (p < 0,05). Paralelamente, teste de toxicidade pelo método MTT e triagem fitoquímica foram avaliadas, e três extratos (raiz e folha de B. pilosa e semente de A. crassiflora) não apresentaram toxicidade. Por outro lado, as concentrações citotóxicas (CC50 e CC90) para os outros extratos variaram de 2,06 a 10,77 mg/mL. Observou-se variável presença de alcalóides, flavonóides, taninos e saponinas, apesar de total ausência de antraquinonas. Portanto, os extratos das folhas de B. pilosa revelaram boa atividade anti-ORSA e não exibiram toxicidade.

Nongenotoxic effects and a reduction of the DXR-induced genotoxic effects of Helianthus annuus Linné (sunflower) seeds revealed by micronucleus assays in mouse bone marrow.

BACKGROUND: This research evaluated the genotoxicity of oil and tincture of H. annuus L. seeds using the micronucleus assay in bone marrow of mice. The interaction between these preparations and the genotoxic effects of doxorubicin (DXR) was also analysed (antigenotoxicity test). METHODS: Experimental groups were evaluated at 24-48 h post treatment with N-Nitroso-N-ethylurea (positive control - NEU), DXR (chemotherapeutic), NaCl (negative control), a sunflower tincture (THALS) and two sources of sunflower oils (POHALS and FOHALS). Antigenotoxic assays were carried out using the sunflower tincture and oils separately and in combination with NUE or DXR. RESULTS: For THALS, analysis of the MNPCEs showed no significant differences between treatment doses (250-2,000 mg.Kg-1) and NaCl. A significant reduction in MNPCE was observed when THALS (2,000 mg.Kg-1) was administered in combination with DXR (5 mg.Kg-1). For POHALS or FOHALS, analysis of the MNPCEs also showed no significant differences between treatment doses (250-2,000 mg.Kg-1) and NaCl. However, the combination DXR + POHALS (2,000 mg.Kg-1) or DXR + FOHALS (2,000 mg.Kg-1) not contributed to the MNPCEs reduction. CONCLUSIONS: This research suggests absence of genotoxicity of THALS, dose-, time- and sex-independent, and its combination with DXR can reduce the genotoxic effects of DXR. POHALS and FOHALS also showed absence of genotoxicity, but their association with DXR showed no antigenotoxic effects.

Caries experience in a sample of adolescents and young adults with cleft lip and palate in Brazil.

Objective : To compare the caries experience of adolescents and young adults with cleft lip and/or palate (CL/P) with a noncleft control group. Design : Thirty CL/P subjects and 30 controls were clinically examined to obtain the decayed, missing and filled teeth (DMFT) and the decayed, missing and filled surfaces (DMFS) indices, gingival bleeding index, plaque index, and active caries lesions. Data concerning oral hygiene, access to fluoridated water, mother's education level, and family income were also collected. Setting : Pro-Smile Center, a reference center for the treatment of facial deformities, Alfenas, Minas Gerais, Brazil. Subjects : Subjects aged 12 to 21 years with CL/P and without associated syndromes were matched to noncleft controls by sex, age, living habits, and use of orthodontic devices. Null Hypothesis Formulated Prior to Data Collection : Caries experience in CL/P adolescents and young adults is similar to that observed in noncleft controls. Statistical Analysis : Data were analyzed using SPSS 17.0 software for Windows Data Editor. The CL/P and control groups were compared using the McNemar test, paired t test and Wilcoxon test. A significance level of 5% was adopted for all tests. Results : There were no significant differences between the groups for oral hygiene and contact with fluoride. Significant differences were found in per capita income, presence of active caries, decayed surfaces, plaque index, and gingival bleeding. Conclusions : The caries experience of CL/P subjects was higher than that of the noncleft individuals.

Typing Candida albicans oral isolates from healthy Brazilian schoolchildren using multilocus enzyme electrophoresis reveals two highly polymorphic taxa

The genetic diversity of C. albicans oral isolates from 75 healthy schoolchildren from eight schools located in different geographic areas of Piracicaba city, São Paulo state, Brazil, was established using isoenzymes marker (Multilocus Enzyme Electrophoresis - MLEE) and cluster analysis. Patterns of monoclonal and polyclonal oral colonization by C. albicans within and between groups of schoolchildren were identified. However, significant divergence between the observed and the expected genotypic frequencies (Hardy-Weinberg equilibrium test) was not detected in the geographically adjacent groups, suggesting the hypothesis that populations of healthy schoolchildren do not correspond to the selection factor (differential survival) of strains. Two highly polymorphic and distantly genetically related taxa (A and B) were identified within the total population of yeasts, each contained subgroups (A1, A2, A3, A4, B1 and B2) and clusters of moderately related strains (from I to X), suggesting the existence of strains restricted or not to certain groups of geographically limited, healthy students. However, the coexistence of identical strains in healthy schoolchildren from the same school (geographically related) reinforces the hypothesis of oral transmission, where the sources of propagation could be explored. Furthermore, this could also be used in current and retrospective analyses of C. albicans isolated from immunocompetent and immunocompromised people, in order to detect commensal or potentially pathogenic yeast groups, predominantly in candidiasis, and in the development of strategies to prevent transmission or human propagation.

Efeito do extrato hidroalcoólico de Pyrostegia venusta na mutagênese "in vivo", e avaliação antimicrobiana, e interferência no crescimento e diferenciação celular "in vitro" / Effect of the hydroalcoholic extract of Pyrostegia venusta on "in vivo" mutagenesis and antimicrobial evaluation and interference on the "in vitro" cellular growth and differentiation

Analisa-se a atividade antibacteriana e antifúngica, o crescimento, a diferenciação celular e a ação mutagênica do extrato hidroalcoólico de Pyrostegia venusta (cipó- de-são-joão) em Herpetomonas samuelpessoai. As atividades antimicrobianas foram analisadas por intermédio de métodos de difusão em ágar e macrodiluição. O crescimento e a diferenciação celular de H. samuelpessoai foram realizados em meio quimicamente definido a 28ºC/48 h e analisados quantitativa (câmara de Neubauer) e qualitativamente (formas pró/para/opistomastigota) após coração panótica. A avaliação mutagênica foi realizada pelo teste do micronúcleo em eritroblastos de camundongos Swiss albinus após tratamentos via gavagem (1.000-2.000mg/kg) e decorridos os tempos de 24-48 h. Os resultados mostraram: a) ausência de atividade antimicrobiana para todas as cepas testadas, isto é, B. cereus, B. stearothermophilus, B. subtilis, E. aerogenes, E. coli, K. pneumoniae, M. luteus, P. mirabilis, P. aeruginosa, S. typhimurium, S. aureus, S. epidermidis, S. pyogenes, S. salivarius, C. albicans, C. neoformans e S. cerevisiae, independentemente das concentrações (72,6-145,2 mg/mL); b) ausência de efeitos sobre o crescimento e a diferenciação celular de H. samuelpessoai; c) ausência de efeitos potencialmente clastogênico e/ou aneugênico, independentemente de sexo, tempo e dosagem. Esses dados sugerem que o extrato de Pyrostegia venusta é seguro, podendo ser administrado por via tópica e oral, uma vez que não apresenta potencial carcinogênico/mutagênico. Pelas condições propostas o mesmo não deve ser usado como antimicrobiano.

This study aimed at analyzing the antibacterial and antifungic activity, the cell growth and differentiation in Herpetomonas samuelpessoai and the mutagenic action of the hydroalcoholic extract of Pyrostegia venusta (flame vine; ?cipó-de-são-joão? in Brazil). Antimicrobial activities were determined by agar diffusion and macrodilution techniques. Cellular growth and differentiation of H. samuelpessoai were assessed in a chemically defined medium at 28ºC/48 hours and quantitatively (Neubauer chamber) and qualitatively (pro-/para-/opistomatigote forms) analyzed after panoptic staining. Mutagenesis was evaluated by the micronucleus test in erythroblasts of Swiss albinus mice after treatment by gavage (1000-2000mg/kg) and 24-48 hours. The results showed (i) absence of antimicrobial activity for all the strains tested: B. cereus, B. stearothermophilus, B. subtilis, E. aerogenes, E. coli, K. pneumoniae, M. luteus, P. mirabilis, P. aeruginosa, S. typhimurium S. aureus, S. epidermidis, S. pyogenes, S. salivarius, C. albicans, C. neoformans and S. cerevisiae, independently of the concentrations (72.6-145.2mg/mL; (ii) absence of effects on the cellular growth and differentiation in H. samuelpessoai; and (iii) absence of potentially clastogenic and/or aneugenic effects, independently of sex, time and dose. These data suggest that the Pyrostegia venusta extract can safely be used topically and orally, once they do not exhibit carcinogenic/mutagenic effects, but under the conditions of this experiment it should not be used as antimicrobial agent.