Evaluación antifúngica del ozono contra Candida albicans: estudio in vitro / Antifungal evaluation of ozone against Candida albicans: in vitro study

Introducción: la Candida albicans (C. albicans) es un patógeno fúngico que puede causar infecciones superficiales o potencialmente mortales. Los biofilms de C. albicans muestran rasgos fenotípicos únicos, el más destacado es su notable resistencia a una amplia variedad de agentes antimicóticos. Una de las alternativas para inhibir el crecimiento de este microorganismo es el ozono debido a sus propiedades bactericidas, fungicidas y virucidas; sin embargo, escasa información ha sido reportada en C. albicans. Objetivo: el objetivo de este estudio fue evaluar el efecto fungicida del ozono en C. albicans. Material y métodos: la metodología consistió en agregar ozono a tubos de ensayo con medios de caldo nutritivo en diversas concentraciones y tiempos de ozonización. El efecto fungicida fue determinado con la determinación del número de colonias de C. albicans en agar nutritivo a través de procedimiento microbiológicos estandarizados por triplicado. Resultados: todas las muestras con ozono mostraron adecuados niveles de inhibición de crecimiento del microorganismo. Además, el efecto fungicida del ozono se encontró para ser significativamente dependiente del tiempo de ozonización y de la concentración. Conclusión: el uso de terapia con ozono podría tener potencial en el control de infecciones micóticas causadas por la presencia de C. albicans (AU)

Introduction: Candida albicans (C. albicans) is a fungal pathogen that can cause superficial or life-threatening infections. Biofilms of C. albicans display unique phenotypic traits, the most prominent being their remarkable resistance to a wide variety of antifungal agents. One of the alternatives to inhibit the growth of this microorganism is ozone due to its bactericidal, fungicidal and virucidal properties; however, little information has been reported on C. albicans. Objective: the objective of this study was to evaluate the fungicidal effect of ozone on C. albicans. Material and methods: the methodology consisted in adding ozone to test tubes with nutrient broth media in various concentrations and ozonation times. The fungicidal effect was determined by determining the number of colonies of C. albicans in nutrient agar through standardized microbiological procedures in triplicate. Results: all the ozone samples showed adequate levels of growth inhibition of the microorganism. Furthermore, the fungicidal effect of ozone was found to be significantly dependent on ozonation time and concentration. Conclusion: the use of ozone therapy could have potential in the control of fungal infections caused by the presence of C. albicans (AU)

Propyl (E)-3-(furan-2-yl) Acrylate: a synthetic antifungal potential with a regulatory effect on the biosynthesis of ergosterol in Candida Albicans

Abstract The genus Candida represents the main cause of infections of fungal origin. Some species stand out as disease promoters in humans, such as C. albicans, C. glabrata, C. parapsilosis, and C. tropicalis. This study evaluated the antifungal effects of propyl (E)-3-(furan-2-yl) acrylate. The minimum inhibitory concentration of the synthetic compound, amphotericin B and fluconazole alone against four species of Candida ranged from 64 to 512 µg/mL, 1 to 2 µg/mL, and 32 to 256 µg/mL, respectively. The synergistic effect of the test substance was observed when associated with fluconazole against C. glabrata, there was no antagonism between the substances against any of the tested strains. The potential drug promoted morphological changes in C. albicans, decreasing the amount of resistance, virulence, and reproduction structures, such as the formation of pseudohyphae, blastoconidia, and chlamydospores, ensuring the antifungal potential of this substance. It was also possible to identify the fungicidal profile of the test substance through the study of the growth kinetics of C. albicans. Finally, it was observed that the test compound inhibited the ergosterol biosynthesis by yeast

Estudio comparativo de la actividad anti-fúngica de extractos secuenciales de Fuchsia lycioides contra Candida sp / comparative study of the antifungal activity of sequencial extracts of Fuchsia lycioides against Candida sp

The genus Fuchsia is generally used in herbal preparations to treat conditions caused by microorganisms. Based on the popular use of this type of plants, the objective of this study was to obtain sequential extracts of increasing polarity from the branches of Fuchsia lycioides by maceration at room temperature and by the Soxhlet method at 60ºC, to later evaluate the antifungal capacity of the extracts against different clinical isolates of the Candida genus. The ethyl acetate extract exhibited strong anti-fungal activity, selectively inhibiting C. albicans strains with MIC and CMF values of 10 and 15 µg/mL, respectively; comparable with the drug itraconazole®. The analysis of the extract by GC-MS showed a high concentration of terpenoids (mainly phytol) and phenylpropanoids (mainly cinnamic acid), possibly responsible for the antifungal activity of the ethyl acetate extract of F. lycioides.

El género Fuchsia se usa generalmente en preparaciones de hierbas para tratar afecciones provocadas por microorganismos. En base al uso popular de este tipo de plantas, el objetivo de este estudio fue obtener los extractos secuenciales de polaridad creciente de las ramas de Fuchsia lycioides por maceración a temperatura ambiente y por el método Soxhlet a 60ºC, para luego evaluar la capacidad antifúngica de los extractos frente a diferentes aislados clínicos del genero Candida. El extracto de acetato de etilo exhibió una fuerte actividad antifúngica inhibiendo en forma selectiva las cepas de C. albicans con valores de CMI y de CMF de 10 y 15 µg/mL, respectivamente; comparables con el fármaco itraconazol®. El análisis del extracto por CG-EM mostró una alta concentración de terpenoides (principalmente fitol) y fenilpropanoides (principalmente ácido cinámico), posibles responsables de la actividad antifúngica del extracto de acetato de etilo de F. lycioides.

Efecto antimicrobiano in vitro de extractos de Caesalpinia Spinosa (algarrobo) sobre patógenos orales / In vitro antimicrobial effect of Caesalpinia Spinosa (carob tree) extracts on oral pathogens

La resistencia antimicrobiana es un problema de sa-lud pública mundial. Las infecciones por microorga-nismos resistentes pueden ser altamente transmisi-bles e incluso causar la muerte. Este hecho genera grandes costos para los pacientes y para los servi-cios de salud. El objetivo del presente trabajo fue de-terminar el efecto antimicrobiano in vitro de extractos etanólicos de Caesalpinia spinosa sobre el crecimien-to de Enterococcus faecalis, Staphylococcus aureus y Candida albicans. Se recolectaron y certificaron muestras de C. spinosa. Se obtuvieron extractos de hojas, vainas y semillas en concentraciones de 100%, 75%, 50% y 25%. Mediante Kirby - Bauer, se cargaron los discos con los extractos y se depositaron en el medio inoculado con cepas de E. faecalis, S. aureus y C. albicans; junto a un CP (antimicrobiano), y un CN (etanol). Las placas se incubaron a 370°C durante 24 horas, y posteriormente se midieron los halos de inhi-bición con un vernier digital. Destaca el valor del halo de extracto de vainas; superó al de Ampicilina 10mg, sobre el E. faecalis. El extracto de vainas presentó ma-yor diámetro de inhibición (19mm), el de semillas pre-sentó el más bajo (1mm). ANOVA arrojó diferencia es-tadísticamente significativa entre los datos obtenidos para todos los extractos. En conclusión, los extractos etanólicos de Caesalpinia spinosa tienen efecto anti-microbiano in vitro sobre Enterococcus faecalis, Sta-phylococcus aureus y Candida albicans. La actividad antimicrobiana del extracto es directamente propor-cional a su concentración. Los extractos de C. spinosa podrían ser utilizados como coadyuvantes en el trata-miento contra Enterococcus faecalis, Staphylococcus aureus, Candida albicans, que están relacionados con patologías orales (AU)

Antimicrobial resistance is a global public health problem. Infections with resistant microorganisms can be highly transmissible and even cause death. This fact generates great costs for patients and for health services. The objective of this work was to determine the in vitro antimicrobial effect of ethanolic extracts of Caesalpinia spinosa on the growth of Enterococcus faecalis, Staphylococcus aureus and Candida albicans. Samples of C. spinosa were collected and certified. Leaf, pod and seed extracts were obtained at concentrations of 100%, 75%, 50% and 25%. Using Kirby-Bauer, the disks were loaded with the extracts and deposited in the medium inoculated with strains of E. faecalis, S. aureus and C. albicans; together with a CP (antimicrobial), and a CN (ethanol). The plates were incubated at 370°C for 24 hours, then the inhibition halos were measured with a digital vernier. The value of the pod extract halo stands out, surpassing that of Ampicillin 10mg, over E. faecalis. The pod extract presented the greatest diameter of inhibition (19mm), the seed extract presented the lowest (1mm). ANOVA showed a statistically significant difference between the data obtained for all the extracts. In conclusion, the ethanolic extracts of Caesalpinia spinosa have an in vitro antimicrobial effect on Enterococcus faecalis, Staphylococcus aureus and Candida albicans. The antimicrobial activity of the extract is directly proportional to its concentration. C. spinosa extracts could be used as adjuvants in the treatment against Enterococcus faecalis, Staphylococcus aureus, Candida albicans, which are related to oral pathologies (AU)

Antimicrobial activity of the essential oils from the leaves and stems of Amomum rubidum Lamxay & N. S. Lý / Actividad antimicrobiana de los aceites esenciales de las hojas y tallos de Amomum rubidum Lamxay & N. S. Lý

This paper described the chemical compositions and antimicrobial activity of the essential oils from the leaves and stem of Amomum rubidumLamxay & N. S. Lý, collected from Bidoup Nui Ba National Park, Lam Dong, Vietnam. The essential oils were obtained by hydrodisitllation method while antimicrobial activity was evaluetd by microdilution broth susceptibility assay. The main constituents of the leaf essential oil were identified as 1,8-cineole (37.7%), δ-3-carene (19.5%) and limonene (16.3%) while δ-3-carene (21.9%), limonene (17.8%) and ß-phellandrene (14.6%) dominated in the stem essentialoil. The leaf and stem essential oils displayed stronger inhibition of Pseudomonas aeruginosa with MIC of 25 µg/mLand 50 µg/mL respectively. The stem essential oil was active against Candida albicans (MIC, 50 µg/mL) while both essential oils inhibited the growth of Fusarium oxysporum (MIC 50 µg/mL). This is the first report on chemical constituents and antimicrobial activity of the essential oils of A. rubidum.

Este artículo describe la composición química y la actividad antimicrobiana de aceites esenciales de las hojas y el tallo de Amomum rubidum Lamxay & N. S. Lý recolectados del Parque Nacional Bidoup Nui Ba, Lam Dong, Vietnam. Los aceites esenciales se obtuvieron mediante el método de hidrodisitilación, mientras que la actividad antimicrobiana se evaluó mediante un ensayo de susceptibilidad de caldo de microdilución. Los principales componentes del aceite esencial de la hoja se identificaron como 1,8-cineol (37,7%), δ-3-careno (19,5%) y limoneno (16,3%), mientras que δ-3-careno (21,9%), limoneno (17,8 %) y ß-felandreno (14,6%) dominaron en el aceite esencial del tallo. Los aceites esenciales de hoja y tallo mostraron una inhibición más fuerte de Pseudomonas aeruginosa con un MIC de 25 µg/mL y 50 µg/mL, respectivamente. El aceite esencial del tallo fue activo contra Candida albicans (MIC, 50 µg/mL) mientras que ambos aceites esenciales inhibieron el crecimiento de Fusarium oxysporum (MIC 50 µg/mL). Este es el primer informe sobre los componentes químicos y la actividad antimicrobiana de los aceites esenciales de A. rubidum.

Nanopartículas de prata em bases de próteses de PMMA para controle de atividade microbiana / Silver nanoparticles in PMMA prosthesis bases to control microbial activity

Objetivo:Avaliar in vitro a atividade de Staphylococcus aureus e Candida albicans em bases de próteses convencionais à base de polimetilmetacrilato de metila com nanopartículas de prata incorporadas a sua composição. Métodos: Foi realizado um estudo experimental laboratorial com resinas acrílicas autopolimerizáveis comercialmente disponíveis, Vipi Flash/VIPI e JET/Clássico. Foram confeccionados 80 corpos de prova, divididos em 16 grupos (n = 5), referentes ao tipo de resina, tratamento (incorporação e imersão na solução de nanopartículas de prata) e microrganismo inoculado. As nanopartículas foram sintetizadas com ácido polimetacrílico, nitrato de prata e irradiadas com luz ultravioleta de baixa potência (~8W) por 6 horas, e as suas concentrações idealizadas pelo método de microdiluição em placas para determinação da concentração mínima inibitória frente aos microrganismos selecionados. Verificou-se ação bactericida e fungicida com concentração inicial de 25% e após fator de diluição 12,5%. Resultados: Houve dificuldade de incorporação das nanopartículas na resina acrílica, que pode decorrer da alteração da proporção 3:1 recomendada pelo fabricante ou pela redução ou inativação da ação da nanopartícula de prata pela interação com o polimetilmetacrilato. VIPI com inclusão de nanopartícula obteve menor aderência de biofilme de Candida albicans. Conclusão:A nanopartícula de prata mostrou-se eficaz na sua ação de controle de Candida albicans e Staphylococcus aureus no método de imersão, entretanto, a sua ação antimicrobiana foi comprometida após inclusão nas resinas acrílicas.

Aim:To perform an in vitro evaluation of the activity of Staphylococcus aureus and Candida albicansin conventional prosthesis bases, based on methyl polymethylmethacrylate with silver nanoparticles incorporated into the composition. Methods: An experimental laboratory study was carried out using commercially available self-curing acrylic resins, Vipi Flash/VIPI and JET/Clássico. Eighty specimens were manufactured and divided into 16 groups (n = 5), referent to the resin brand, treatment (incorporation and immersion in the silver nanoparticle solution), and inoculated microorganism. The nanoparticles were synthesized with polymethacrylic acid and silver nitrate, and were irradiated with a low power (~ 8W) ultraviolet light for 6 hours. Their concentrations were idealized by the method of microplate dilution to determine the minimum inhibitory concentration when compared to the selected microorganisms. Bactericidal and fungicidal activities were identified with an initial concentration of 25% and a subsequent dilution factor of 12.5%. Results:It was difficult to incorporate the AgNPs into the acrylic resin, which may well have resulted from the change from the 3:1 proportion recommended by the manufacturer or by reducing or inactivating the action of the silver nanoparticle by interaction with polymethylmethacrylate. VIPI with the inclusion of nanoparticles obtained a lesser Candida albicans biofilm adherence. Conclusion: Silver nanoparticles were effective in controlling Candida albicans and Staphylococcus aureus in the immersion method; however, the antimicrobial activity was compromised after inclusion in acrylic resins.

Ação inibitória de dentifrícios sobre Streptococcus mutans e Candida albicans: estudo in vitro / Inhibitory effect of dentifrices on Streptococcus mutans and Candida albicans: in vitro study

Introdução: este estudo avaliou a ação antimicrobiana de sete dentifrícios nacionais com ação antiplaca ou antimicrobiana, conforme os fabricantes, sobre os patógenos orais Streptococcus mutans e Candida albicans. Métodos: a avaliação dos dentifrícios foi realizada pelo teste de difusão em ágar. Placas de Petri com meios de cultura ágar cérebro coração e ágar Sabourad foram semeadas com suspensão microbiana padronizada de S. mutans e C. albicans. Poços foram confeccionados no ágar semeado e preenchidos com as soluções dos dentifrícios diluídas em 1:1, 1:2, 1:4 e 1:8, além dos controles positivo (solução de clorexidina 2%) e negativo (dentifrício sem princípios ativos). Após incubação por 48h/37°C, os halos de inibição do crescimento microbiano foram medidos com paquímetro e régua milimetrada, e os resultados finais dos halos obtidos em milímetros. Resultados e conclusão: verificou-se que todos os dentifrícios, na diluição de 1:1, foram efetivos sobre C. albicans e S. mutans, exceto o composto de bicarbonato de sódio e extratos vegetais, o qual não inibiu S. mutans. Na diluição de 1:2, somente o dentifrício contendo triclosan inibiu C. albicans, enquanto todos mostraram algum potencial de inibição ao S. mutans. Nas demais diluições, não foram observados halos de inibição de ambos os microrganismos. A C. albicans demonstrou ser mais resistente à ação inibitória dos antimicrobianos dos dentifrícios testados neste estudo. S. mutans demonstrou ser mais sensível à ação dos dentifrícios, no entanto, a diluição durante a escovação dentária reduz a ação inibitória esperada, indicando a importância da remoção mecânica do biofilme.(AU)

Introduction: this study analyzed the antimicrobial activity in seven national dentifrices with antiplaque or antimicrobial substances in their composition, according the manufacturer, on the oral pathogens Streptococcus mutans and Candida albicans. Methods: the dentifrices antimicrobial effect evaluation was carried out by agar diffusion test. S. mutans and C. albicans. Padronized microbial suspension was cultured on Petri dishes containing Brain Hearth Agar and Sabourad Agar, respectively. Wells were prepared in the cultured agar and filled with 1:1, 1:2, 1:4 and 1:8 dilutions of dentifrice solutions, and besides positive (2% chlorhexidine solutions) and negative controls (dentifrices without active ingredients). After 48h/37°C incubation, the microbial growing inhibition zones were measured with a paquimeter and a millimeter rule, being the final zone results obtained in millimeters. Results and conclusion: on 1:1 dilution, all dentifrices were effective on C. albicans and S. mutans, except one with vegetal extract and sodium bicarbonate composition, which did not inhibit S. mutans. In 1:2 dilution, only tricolsan-containing dentifrice inhibited C. albicans, while all dentifrices presented some inhibition potential on S. mutans. There were no inhibition zones for both microorganims in other dilutions. We concluded that C. albicans showed to be more resistant to antimicrobial agents tested in the dentifrices, in this study. S. mutans showed to be more sensitive to tested dentifrices, however, the product dilution during toothbrushing reduces the expected inhibitory action, strengthening the importance of the mechanical removal of dental biofilm.(AU)

Efeito do extrato da própolis e do digluconato de clorexidina sobre a formação de biofilme por Candida albicans em resina acrílica / Effect of propolis extract and chlorhexidine digluconate on the biofilm formation by Candida albicans in acrylic resin

Objetivo: avaliar in vitro a ação antimicrobiana do extrato da própolis (EP) e do digluconato de clorexidina (DCHX) na formação de biofilme por Candida albicans em resina acrílica termopolimerizada. Métodos: o efeito do EP e DCHX em biofilmes de C. albicans foi avaliado pela quantificação de Unidades Formadoras de Colônias (UFCs), pela quantificação da biomassa por cristal violeta e de polissacarídeos por safranina. Para tanto, C. albicans foram pré-aderidas em corpos de prova e somente em microplacas de poliestireno, posteriormente foi realizado o tratamento com diferentes concentrações de EP (221 µg/mL e 443 µg/mL) e DCHX (0,25% e 0,5%). Resultados: foi demonstrada uma redução significativa na formação de biofilme por C. albicans com ambas as substâncias testadas e em todas as concentrações. Conclusão: de acordo com os resultados, observou-se que ambos os tratamentos foram eficazes na redução do biofilme e que o EP, por ser um produto natural, de baixo custo e sem afeitos colaterais, representa uma alternativa inovadora para o tratamento da candidose oral em usuários de próteses removíveis.(AU)

Objective: to evaluate in vitro the antimicrobial action of propolis extract (EP) and chlorhexidine digluconate (DCHX) in the biofilm formation by Candida albicans in thermopolymerized acrylic resin. Methods: the effect of EP and DCHX on C. albicans biofilms were evaluated through the quantification of Colony Forming Units (CFU's), the quantification of biomass by violet crystal and polysaccharides by safranin. For this purpose, C. albicans were pre-adhered to specimens and only on polystyrene microplates and subsequently the treatment was performed with different concentrations of EP (221 µg/mL and 443 µg/mL) and DCHX (0.25% and 0,5%). Results: a significant reduction in the biofilm formation by C. albicans was demonstrated, with both substances tested and in all concentrations. Conclusion: according to the results, it was observed that both treatments were effective in reducing biofilm and EP, being a natural product, low cost and without side effects, represents an innovative alternative for the treatment of oral candidiasis in users removable dentures.(AU)

Efficacy of copper sulphate on candida albicans on heat-polymerized acrylic resin / Eficacia del sulfato de cobre sobre candida albicans en resinas acrílicas de termocurado

The ageing of population is increasing, and a great percentage of these patients wear removable prostheses, and can suffer denture stomatitis, a condition that has been associated with candidiasis. Aims: To evaluate in vitro the effectiveness of Copper Sulfate against Candida albicans in samples of heat-polymerized acrylic resin, compared to nystatin, sodium hypochlorite and chlorhexidine. Materials and Methods: Initially, the minimum inhibitory concentration (MIC) of copper sulfate for Candida albicans was determined by microdilution. Then, 54 resin samples were divided into 6 treatment groups corresponding to Nystatin 100.000 UI, Sodium Hypochlorite 0.5%, chlorhexidine 0.12%, Copper Sulfate 4.7µg/ml, Copper Sulfate 9.4µg/ml and physiological saline solution, in which samples were submerged for 6 hours. Resin samples were then washed and cultured on solid media at 37°C for 72 hours. The number of colony-forming units was determined using a Quebec colony counter. The statistical analysis was performed using the Kruskal-Wallis test and the Mann-Whitney U test. Results: Copper sulfate at a concentration of 9.4µg/ml presented a similar effectiveness as the other control products regarding the reduction in the number of colonies of Candida albicans post-treatment. Conclusion: The effectiveness of copper sulfate against Candida albicans on acrylic resin was similar to that of nystatin, sodium hypochlorite and chlorhexidine.

En las últimas décadas se ha observado un aumento de la población de adultos mayores, de los cuales un gran porcentaje es portador de prótesis removible, y dos tercios pueden sufrir estomatitis subprotésica, enfermedad que es asociada a infecciones como candidiasis. Objetivo: Evaluar la efectividad antimicótica in vitro del sulfato de cobre en placas de resinas acrílicas de termocurado inoculadas con Candida albicans, frente a Nistatina, Hipoclorito de Sodio y Clorhexidina. Material y Métodos: Inicialmente, y mediante microdilución del sulfato de cobre, se determinó la concentración mínima inhibitoria (CMI) para Candida albicans. En la fase experimental, 54 muestras de resina se dividieron en 6 grupos correspondientes a Nistatina 100.000 UI, Hipoclorito 0.5%, Clorhexidina 0.12%, Sulfato de Cu 4.7µg/ml, Sufato de Cu 9.4 µg/ml y suero fisiológico. Las muestras fueron sumergidas en estos agentes por 6 horas, para posteriormente ser lavadas y cultivada en medios solidos a 37°C por 72 horas. Luego se realizó el conteo de unidades formadoras de colonias mediante contador tipo Quebec. El análisis estadístico se realizó mediante la prueba de Kruskal-Wallis y la prueba U de Mann-Whitney. Resultado: El sulfato de cobre a una concentración de 9.4µg/ ml presentó una efectividad similar a los otros productos, en la reducción de colonias de Candida albicans. Conclusión: La efectividad del sulfato de cobre contra Candida albicans fue semejante a la de Nistatina, Hipoclorito y Clorhexidina.

Relationship between antifungal susceptibility profile and virulence factors in Candida albicans isolated from nail specimens

Abstract INTRODUCTION: The aim of this study was to evaluate some virulence factors in Candida albicans isolates from patients with onychomycosis and determine the correlation between these factors and the antifungal resistance profile. METHODS: Seventy species of C. albicans were confirmed using polymerase chain reaction amplification of the HWP1 gene. According to the Clinical & Laboratory Standards Institute guidelines, the susceptibility profile of four antifungal agents was investigated, and the production of aspartyl protease, phospholipase, haemolysin, and biofilm was determined. The correlation between these profiles was also investigated. RESULTS: The isolates indicated different levels of resistance and production of virulence factors. Significant correlations were observed between the minimum inhibitory concentration (MIC) of fluconazole/itraconazole and biofilm production, between phospholipase production and fluconazole/itraconazole MIC, and between fluconazole MIC and hemolytic activity in C. albicans isolates. The results also showed significant correlations between phospholipase activity and biofilm production. CONCLUSIONS: Our findings will contribute to a better understanding of the pathogenesis of C. albicans and characterize the relationship between virulence factors and antifungal resistance, which may suggest new therapeutic strategies considering the possible involvement of the virulence mechanism in the effectiveness of treatment.

Antibiofilm efficacy of tea tree oil and of its main component terpinen-4-ol against Candida albicans

Abstract Candida infection is an important cause of morbidity and mortality in immunocompromised patients. The increase in its incidence has been associated with resistance to antimicrobial therapy and biofilm formation. The aim of this study was to evaluate the efficacy of tea tree oil (TTO) and its main component - terpinen-4-ol - against resistant Candida albicans strains (genotypes A and B) identified by molecular typing and against C. albicans ATCC 90028 and SC 5314 reference strains in planktonic and biofilm cultures. The minimum inhibitory concentration, minimum fungicidal concentration, and rate of biofilm development were used to evaluate antifungal activity. Results were obtained from analysis of the biofilm using the cell proliferation assay 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) and confocal laser scanning microscopy (CLSM). Terpinen-4-ol and TTO inhibited C. albicans growth. CLSM confirmed that 17.92 mg/mL of TTO and 8.86 mg/mL of terpinen-4-ol applied for 60 s (rinse simulation) interfered with biofilm formation. Hence, this in vitro study revealed that natural substances such as TTO and terpinen-4-ol present promising results for the treatment of oral candidiasis.

Hydroalcoholic Extract of Eugenia uniflora as Denture Disinfectant: Antimicrobial Activity and Effect on the Physical Properties of Polymethylmethacrylate

Abstract To the moment, there is no ideal substance for home-based denture disinfection. This study assessed in vitro the antimicrobial effect of the hydroalcoholic extract of Eugenia uniflora and the effect on the physical properties of denture polymethylmethacrylate (PMMA). Candida albicans, Staphylococcus aureus, and Klebsiella oxytoca were isolated from samples of saliva collected from denture wearers. The extracts were produced in three concentrations, according to the Brazilian Pharmacopeia. One hundred eighty-eight disc-shaped specimens of thermopolymerizable PMMA were prepared and randomly allocated to five treatment groups: sterile saline solution (0.85%; control); chlorhexidine digluconate (0.2%); and hydroalcoholic extract of E. uniflora (0.2%, 0.8%, and 1.16%). The specimens were disinfected for 8 hours/day for 30 days. Adherence of microorganisms to the surface, PMMA surface roughness, and color stability were assessed. Inferential statistics were performed with one- and two-way ANOVA/Tukey test, and Kruskal Wallis, Mann-Whitney U, and paired t-tests, at α=0.05. The extract of E. uniflora at 0.2% and 1.16% reduced the microbial load of K. oxytoca, while chlorhexidine digluconate significantly reduced microbial load of all microrganisms. Microbial adherence at day 10 was reduced by all experimental substances (p<0.001). Surface roughness was not affected by the disinfecting substances (p>0.05). Nevertheless, all experimental groups produced unacceptable color change at the end of the disinfection protocol (p<0.001). The non-adherent potential against microorganisms isolated from the oral cavity confirm the potential of use of the hydroalcoholic extract of E. uniflora as a denture disinfectant. Yet, unacceptable color changes may occur, regardless of extract concentration.

Evaluation of the physical and antifungal effects of chlorhexidine diacetate incorporated into polymethyl methacrylate

Abstract This study aimed to evaluate the physical properties and antifungal activities of polymethyl methacrylate (PMMA) acrylic resins after the incorporation of chlorhexidine diacetate salt (CDA). Methodology: First, acrylic resin specimens were fabricated with Vipi Cor® and DuraLay® resins with and without the incorporation of 0.5%, 1.0% or 2.0% CDA. The residual monomer and CDA release were measured at intervals ranging from 2 hours to 28 days using ultraviolet spectrometry combined with high-performance liquid chromatography. The antifungal activity against C. albicans was evaluated with the agar diffusion method. Fourier transform infrared spectroscopy was used to analyze the degree of resin conversion. Finally, the water sorption values of the resins were also measured. Results: The incorporated CDA concentration significantly changed the rate of CDA release (p<0.0001); however, the brand of the material appeared to have no significant influence on drug release. Subsequently, the inhibition zones were compared between the tested groups and within the same brand, and only the comparisons between the CDA 2% and CDA 1% groups and between the CDA 1% and CDA 0.5% groups failed to yield significant differences. Regarding the degrees of conversion, the differences were not significant and were lower only in the CDA 2% groups. Water sorption was significantly increased at the 1.0% and 2.0% concentrations. Conclusions: We concluded that the incorporation of CDA into PMMA-based resins enabled the inhibition of C. albicans growth rate, did not alter the degrees of conversion of the tested resins and did not change the release of residual monomers.

Antibacterial and Antifungal Activities of Compounds Isolated from Gymnosporia Royleana (Celastraceae) / Actividades antibacterianas y antifúngicas de compuestos aislados de Gymnosporia Royleana (Celastraceae)

ABSTRACT Objective: In the present study, five new source compounds isolated from aerial parts of Gymnosporia royleana (G royleana) were screened for antibacterial and antifungal activities. Methods: Extraction from plant material was carried out using cold maceration technique. Isolation of pure compounds was accomplished through repeated column chromatography of different fractions obtained from crude extract and using silica gel as stationary phase. Their structures were established via advanced spectroscopic techniques along with the spectral data previously reported for these compounds. Dilution method was used for the evaluation of antimicrobial potential of the compounds against various microbial strains. Results: Among the tested compounds, Gymnosporin B displayed moderate antimicrobial activity against Escherichia Coli (E coli), Staphylococcus aureus (S aureus), Candida albicans (C albicans) and Aspergillus flavus (A flavus) [minimum inhibitory concentration (MIC) range; 32-64 μg/mL]. Similarly, Gymnosporin C also showed moderate activity against E coli and S aureus (MIC; 32 μg/mL each) as well as weak activity against C albicans and A flavus (MIC; 64 μg/mL each). However, Royaflavone showed moderate antibacterial activity against S aureus only (MIC; 32 μg/mL). Antimicrobial activity of the rest of the compounds was weak and negligible. Conclusion: The present study has provided fascinating results of antimicrobial activities of the isolated compounds. However, the broad antimicrobial spectrum of Gymnosporin B and Gymnosporin C demands for further exploration of these triterpenes, both on the basis of mechanism and quantitative structure-activity relationship.

RESUMEN Objetivo: En el presente estudio, cinco nuevos compuestos de origen aislados de partes aéreas de Gymnosporia royleana (G royleana) fueron tamizados en sus actividades antibacterianas y antifúngicas. Métodos: La extracción de material vegetal se realizó mediante la técnica de maceración en frío. El aislamiento de compuestos puros se logró a través de la cromatografía en columna repetida de diversas fracciones obtenidas del extracto crudo y usando gel de silicona como fase estacionaria. Sus estructuras fueron establecidas mediante técnicas espectroscópicas avanzadas junto con los datos espectrales previamente reportados para estos compuestos. El método de dilución fue usado para evaluar el potencial antimicrobiano de los compuestos contra diversas cepas microbianas. Resultados: Entre los compuestos sometidos a prueba, Gymnosporina B mostró una actividad antimicrobiana moderada contra Escherichia Coli (E coli), Staphylococcus aureus (S aureus), Candida Albicans (C albicans) y Aspergillus flavus (A flavus) [rango de concentración inhibitoria mínima (CIM); 32 - 64 μg/mL]. De manera similar, Gymnosporina C también mostró actividad moderada contra E coli y S aureus (CIM; 32 μg/mL cada uno) así como débil actividad frente a C albicans y A flavus (CIM; 64 μg/mL cada uno). Sin embargo, Royaflavone mostró actividad antibacteriana moderada sólo frente a S aureus (CIM; 32 μg/mL). La actividad antimicrobiana del resto de los compuestos fue débil e insignificante. Conclusión: El presente estudio ha proporcionado resultados interesantes acerca de las actividades antimicrobianas de los compuestos aislados. Sin embargo, el amplio espectro antimicrobiano de la Gymnosporina B y la Gymnosporina C exige una mayor exploración de estos triterpenos, tanto sobre la base del mecanismo como a partir de la relación cuantitativa estructura-actividad.

The effect of nanodiamonds on candida albicans adhesion and surface characteristics of PMMA denture base material - an in vitro study

Abstract Candida albicans is the main causative pathogen of denture stomatitis, which affects many complete denture patients. Objective: To evaluate the effect of different concentrations of nanodiamonds (NDs) added to polymethyl methacrylate (PMMA) denture base material on Candida albicans adhesion as well as on surface roughness and contact angle. Methodology: Acrylic resin specimens sized 10×10×3 mm3 were prepared and divided into four groups (n=30) according to ND concentration (0%, 0.5%, 1%, 1.5% by wt). Surface roughness was measured with a profilometer, and the contact angle with a goniometer. The effect of NDs on Candida albicans adhesion was evaluated using two methods: 1) slide count and 2) direct culture test. Analysis of variance (ANOVA) and Tukey's post hoc test were used in the statistical analyses. Results: Addition of NDs decreased the Candida albicans count significantly more than in the control group (p<0.05), with a lowest of 1% NDs. Addition of NDs also significantly decreased the surface roughness (p<0.05), but the contact angle remained the same. Incorporation of NDs into the PMMA denture base material effectively reduced Candida albicans adhesion and decreased surface roughness. Conclusion: PMMA/NDs composites could be valuable in the prevention of denture stomatitis, which is considered one of the most common clinical problems among removable denture wearers.

Antifungal efficiency of chemically and thermally-activated acrylic resins after surface treatment using poly (diallyldimethylammonium chloride)

Abstract INTRODUCTION: Acrylic resins are used in the preparation of facial prostheses and may be colonized by fungi. Here, we verified the antifungal efficacy of this material after surface treatment using poly (diallyldimethylammonium chloride). METHODS: Acrylic resin specimens with and without surface treatment were subjected to tests for fungistatic and fungicidal activities. Standard strains of Candida albicans and Aspergillus niger were used. RESULTS: After surface treatment, the fungistatic and fungicidal efficacies of the resins against C. albicans and fungistatic action against A. niger were verified. CONCLUSIONS: The surface treatment was a determinant of the antifungal activity of the material.

Nanopartículas de prata biossintetizadas por mikania glomerata sprengel inibem o crescimento de candida albicans e staphylococcus aureus / Biosynthesized silver nanoparticles by mikania glomerata sprengel inhibit the growth of candida albicans and staphylococcus aureus

Introdução: Nos últimos anos ocorreu o aumento de casos relacionados com a infecção por Candida spp. e Staphylococcus spp., bem como o aparecimento de cepas resistentes a antibióticos convencionais. A biossíntese de nanopartículas consiste na redução de um íon metálico por compostos de origem natural como metabólitos secundários de plantas e organismos, sendo a forma mais indicada por apresentar menor toxicidade quando comparada à síntese química. Desta forma, a síntese biológica constitui uma alternativa para a obtenção de novos agentes ativos para o tratamento de infecções microbianas. Objetivos: Sintetizar nanopartículas de prata a partir do extrato aquoso de Mikania glomerata Sprengel e avaliar possível atividade microbicida e citotóxica. Material e Métodos: Para a síntese das nanopartículas de prata (AgNPs) foi utilizado um extrato aquoso das folhas de M. glomerata e uma solução de nitrato de prata. As AgNPs sintetizadas foram avaliadas por espectrofotômetro UV-vis e espectrometria de absorção atômica com chama. Além disso, a atividade antimicrobiana foi avaliada contra cepas de Candida albicans e Staphylococcus aureus e atividade citotóxica contra linhagens celulares HeLa e Vero. Resultados: As AgNPs são mais eficientes no combate à linhagem de Candida albicans e Staphylococcus aureus quando comparadas ao extrato puro administrado. Até a concentração de 100 mg/mL do extrato puro não foi observado efeito inibitório em ambos os micro-organismos. Entretanto quando em contato com as AgNPs, a concentração inibitória foi de 0,006 mg/mL e 0,1 mg/mL para S. aureus e C. albicans, respectivamente. O efeito citotóxico nas células se comportou de maneira dose-dependente, apresentando maior potencial citotóxico contra a linhagem celular cancerosa HeLa. Conclusão: As AgNPs sintetizadas apresentaram potencial antimicrobiano contra C. albicans e S. aureus, além de baixa atividade contra células normais, indicando sua confiabilidade para aplicação das AgNPs como forma alternativa de tratamento. Estes resultados são promissores e contribuem para pesquisa relacionada à produção de medicamentos utilizando extrato de plantas e metais.

Introduction: In recent years there has been an increase in cases related to infection by Candidaspp. and Staphylococcus spp., as well as the appearance of strains resistant to conventional antibiotics. Nanoparticle biosynthesis consists of the reduction of a metal ion by compounds of natural origin as secondary metabolites of plants and organisms, being the most indicated form because it presents less toxicity when compared to the chemical synthesis. In this way, the biological synthesis is an alternative to obtain new active agents for the treatment of microbial infections. Objective: Synthesize silver nanoparticles from the aqueous extract of Mikania glomerata Sprengel and evaluate possible microbicidal and cytotoxic activity. Material and Methods: For the synthesis of the silver nanoparticles (AgNPs) an aqueous extract of the leaves of Mikania glomerata plus a solution of silver nitrate was used. AgNPs synthesized was evaluated by UV-vis spectrophotometer and FAAS. Furthermore, antimicrobial activity was evaluated against strains of Candida albicans and Staphylococcus aureus and cytotoxicity activity against HeLa and Vero cell lines. Results: AgNPs are shown to be more efficient in combating Candida albicans and Staphylococcus aureusstrains when compared to the pure administered extract. Up to the concentration of 100 mg/mL of the pure aqueous extract no inhibitory effect was observed on both microorganisms. However when the strains were in contact with AgNPs, the inhibitory concentration was 0.006 mg/mL and 0.1 mg/mL for S. aureus and C. albicans, respectively. The cytotoxic effect on the cells behaves in a dose-dependent manner, presenting greater cytotoxic potential against the HeLa cancer cell line. Conclusion: Thus, these results are promising and contribute to research related to the production of drugs using plant extract and metals. The AgNPs synthesized presented the antimicrobial potential against C. albicans and S. aureus, in addition to low activity against normal cells, indicating their reliability for application of AgNPs as an alternative form of treatment.

Evaluación in vitro de la actividad antimicrobiana de un propóleo chileno sobre muestras clínicas de exudados bucofaríngeos y cepas ATCC / In vitro evaluation of the antimicrobial activity of a Chilean propolis on clinical samples of oropharyngeal exudates

Propolis is a substance manufactured by Apis mellifera and has been widely used in folk medicine due to its high concentration of bioactive compounds. The purpose of the following study was to characterize and evaluate in vitro the antimicrobial properties of propolis on clinical samples and ATCC strains. The chemical characterization of propolis presents a concentration of total polyphenols of 247 ± 9 mg EAG g-1 MS, flavones and flavonols 75± 4 mg EQ g-1 MS, flavanonones and flavanonols 118 ± 11 EP g-1 MS. HPLC-DAD identified apigenin, galangin, phenethyl ester of caffeic acid and pinocembrin, in addition to 16 compounds by HPLC MS/MS. Chilean propolis is a natural antimicrobial, showing effectiveness in strains ATCC Staphylococcus aureus, Candida albicans, Trichophyton rubrum and clinical samples of Staphylococcus aureus unlike Escherichia coli. These results demonstrate the antimicrobial effectiveness of the synergy of compounds present in propolis against different human pathogens.

El propóleos es una substancia fabricada por Apis mellifera y ha sido utilizado ampliamente en la medicina popular debido a su alta concentración de compuestos bioactivos. El propósito del siguiente estudio fue caracterizar y evaluar in vitro las propiedades antimicrobianas del propóleos sobre muestras clínicas y cepas ATCC. La caracterización química de propóleos presenta una concentración de polifenoles totales de 247 ± 9 mg EAG g-1 de MS, flavonas y flavonoles 75 ± 4 mg EQ g-1 de MS, flavanononas y flavanonoles 118 ± 11 EP g-1 de MS. Mediante HPLC-DAD se identificó apigenina, galangina, fenetil éster del ácido cafeico y pinocembrina, además de 16 compuestos mediante HPLC MS/MS. El propóleos chileno es un antimicrobiano natural, observándose efectividad en cepas ATCC Staphylococcus aureus, Candida albicans, Trichophyton rubrum y muestras clínicas de Staphylococcus aureus a diferencia de Escherichia coli. Estos resultados demuestran la efectividad antimicrobiana de la sinergia de compuestos presentes en el propóleos ante diferentes patógenos humanos.

Interactions between Terpinen-4-ol and Nystatin on biofilm of Candida albicans and Candida tropicalis

Abstract The aim of this study was to evaluate the antifungal activity of Terpinen-4-ol associated with nystatin, on single and mixed species biofilms formed by Candida albicans and Candida tropicalis, as well as the effect of terpinen-4-ol on adhesion in oral cells and the enzymatic activity. The minimum inhibitory concentrations and minimum fungicide concentrations of terpinen-4-ol and nystatin on Candida albicans and Candida tropicalis were determined using the microdilution broth method, along with their synergistic activity ("checkerboard" method). Single and mixed species biofilms were prepared using the static microtiter plate model and quantified by colony forming units (CFU/mL). The effect of Terpinen-4-ol in adhesion of Candida albicans and Candida tropicalis in coculture with oral keratinocytes (NOK Si) was evaluated, as well as the enzymatic activity by measuring the size of the precipitation zone, after the growth agar to phospholipase, protease and hemolysin. Terpinen-4-ol (4.53 mg mL-1) and nystatin (0.008 mg mL-1) were able to inhibit biofilms growth, and a synergistic antifungal effect was showed with the drug association, reducing the inhibitory concentration of nystatin up to 8 times in single biofilm of Candida albicans, and 2 times in mixed species biofilm. A small decrease in the adhesion of Candida tropicalis in NOK Si cells was showed after treatment with terpinen-4-ol, and nystatin had a greater effect for both species. For enzymatic activity, the drugs showed no action. The effect potentiated by the combination of terpinen-4-ol and nystatin and the reduction of adhesion provide evidence of its potential as an anti-fungal agent.

Resumo O objetivo desse estudo foi avaliar a atividade antifúngica do Terpinen4-ol associado à nistatina em biofilmes simples e misto, formados por Candida albicans e Candida tropicalis, bem como o efeito do terpinen-4-ol na adesão em células orais e atividade enzimática. As concentrações inibitórias mínimas e as concentrações fungicidas mínimas do terpinen-4-ol e da nistatina em Candida albicans e Candida tropicalis foram determinadas pelo método de microdiluição em caldo, juntamente com a atividade sinérgica (método do tabuleiro de "xadrez"). Biofilmes simples e misto foram preparados usando o modelo de placa de microtitulação estática e quantificados por unidades formadoras de colônias (CFU/mL). O efeito do Terpinen-4-ol na adesão de Candida albicans e Candida tropicalis em co-cultura com queratinócitos orais (NOK Si) foi avaliado, bem como a atividade enzimática, medindo o tamanho da zona de precipitação, após o crescimento em ágar fosfolipase, protease e hemolisina. O terpinen-4-ol (4.53 mg mL-1) e a nistatina (0,008 mg mL-1) conseguiram inibir o crescimento de biofilmes e um efeito antifúngico sinérgico foi demonstrado com a associação de fármaco, reduzindo a concentração inibidora de nistatina até 8 vezes em biofilme simpes de Candida albicans e 2 vezes em biofilme misto. Uma pequena diminuição na adesão de Candida tropicalis em células NOK Si foi mostrada após o tratamento com terpinen-4-ol e a nistatina teve um efeito maior para ambas as espécies. Para a atividade enzimática, as drogas não apresentaram ação. O efeito potencializado pela combinação de terpinen-4-ol e nistatina e a redução de adesão evidenciam seu potencial como agente anti-fúngico.