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This study aimed to compare the efficacy of 2.5% sodium hypochlorite (NaOCl), 2.5% calcium hypochlorite [Ca(OCl)2], and 2% chlorhexidine (CHX) in the rapid disinfection of gutta-percha cones contaminated with Candida albicans. The minimum inhibitory and minimum fungicidal concentrations of each solution for C. albicans were determined and the ability of each solution to destroy and inhibit biofilm in culture wells was tested. In addition, ninety-eight gutta-percha cones contaminated with the fungal suspension were disinfected according to the type of solution (2.5% NaOCl, 2.5% Ca(OCl)2 or 2% CHX) in its different application methods (without agitation, ultrasonic agitation or agitation with Easy Clean), and regarding the exposure time to each irrigating solution (1 or 5 min). Next, the samples were checked for turbidity and evaluation of viable colonies. The compounds that showed the best performance in biofilm destruction were NaOCl and Ca(OCl)2 at a concentration of 2xMIC (p < 0.001). Regarding inhibited biofilm, the only compound that was effective at all MIC concentrations tested was 2.5% Ca(OCl)2 (p < 0.0001). Regarding the viable colonies, all solutions were effective concerning the control group, for all application methods, in 1 and 5 min (p < 0.05). The densitometer reading showed that CHX was the only effective solution in all application methods performed (p < 0.05). The results demonstrate that all tested solutions were effective in the rapid decontamination of cones contaminated with C. albicans.
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Compuestos de Calcio , Gutapercha , Materiales de Obturación del Conducto Radicular , Gutapercha/farmacología , Desinfección/métodos , Candida albicans , Materiales de Obturación del Conducto Radicular/farmacología , Clorhexidina/farmacología , Hipoclorito de Sodio/farmacologíaRESUMEN
Multi-walled carbon nanotubes (MWCNTs) were purified and unpurified in this study to obtain hybrid materials with improved activity. The production stage comprised a chemical purification of the produced sample. Raman spectroscopy analyzed the structural composition of purified and unpurified samples. The disc diffusion assay, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill assessment analyzed antimicrobial activity. MWCNT performed well against the tested bacteria (Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter aerogenes, Staphylococcus aureus, and Streptococcus sp. Staphylococcus epidermidis). The disc diffusion assay revealed inhibition zone differences caused by purified and unpurified MWCNTs. MIC and MBC values of purified and unpurified MWCNTs were similar. The purified and unpurified nanotubes of Staphylococcus epidermidis (ATCC 35985) exhibited inhibition zone diameters of approximately 8 mm and 9 mm, respectively. The microdilution method revealed a MIC of 1.23 mg/ml for the purified nanotube and 0.156 mg/ml for the unpurified nanotube against the same microorganism. The killing curve analysis demonstrated that unpurified carbon nanotubes were more effective against all tested microorganisms. MWCNTs represent a promising method for microbiology, but studies on the toxicity of these materials remain scarce.
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Microorganisms such as Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus are frequently isolated in samples of urinary, blood, intestinal, and respiratory infections, among others. These bacteria are also associated with microbial biofilm formation. E. coli, P. aeruginosa, and S. aureus biofilm infections are particularly hard to manage and often associated with nosocomial problems. This study investigated the influence of different culture media on E. coli, P. aeruginosa, and S. aureus biofilm formation. Bacterial performance was evaluated in brain heart infusion broth, Mueller-Hinton broth, or tryptic soy broth, with or without supplementing with different glucose levels (1-5%). The study quantified biofilm biomass and the count of viable biofilm colonies. This is the first study that compares the biofilm formation of E. coli, P. aeruginosa and S. aureus in polystyrene using different culture media and with different glucose concentrations. The most robust growth of E. coli, P. aeruginosa, and S. aureus occurred in brain heart infusion broth supplemented with 5% glucose, Mueller-Hinton broth without glucose, and tryptic soy broth with 2% glucose, respectively. Our data demonstrate that behavioral and morphological characteristics of each bacterium require a specific broth to enhance the growth of these microorganisms. These findings will contribute to future tests for therapeutic alternatives with anti-biofilm potential.
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In this study, B. cereus was detected in dialysis fluids within international parameters (ultrapure - maximum limit of 0.1 CFU/mL for heterotrophic bacteria count) by analyzing the pellet obtained through the centrifugation method. We also investigated the ability of the B. cereus isolate to form a biofilm at different temperatures, the production of virulence factors, and the susceptibility to commercial antimicrobial agents. This study demonstrated a high ability of B. cereus to persist in the hemodialysis system, which can be explained by its broad ability to produce a biofilm at 25 °C, its relevant production of virulence factors, such as ß-hemolysin, lecithinase and cereulide, and its important resistance pattern to antimicrobial drugs. In conclusion, these new findings expand the understanding that this microorganism should not be neglected and new methods for tracking it should be considered.
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Bacillus cereus , Microbiología de Alimentos , Contaminación de Alimentos , Diálisis Renal , Factores de VirulenciaRESUMEN
ABSTRACT In this study, B. cereus was detected in dialysis fluids within international parameters (ultrapure - maximum limit of 0.1 CFU/mL for heterotrophic bacteria count) by analyzing the pellet obtained through the centrifugation method. We also investigated the ability of the B. cereus isolate to form a biofilm at different temperatures, the production of virulence factors, and the susceptibility to commercial antimicrobial agents. This study demonstrated a high ability of B. cereus to persist in the hemodialysis system, which can be explained by its broad ability to produce a biofilm at 25 °C, its relevant production of virulence factors, such as β-hemolysin, lecithinase and cereulide, and its important resistance pattern to antimicrobial drugs. In conclusion, these new findings expand the understanding that this microorganism should not be neglected and new methods for tracking it should be considered.
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The irrational use of medications has increased the incidence of microbial infections, which are a major threat to public health. Moreover, conventional therapeutic strategies are starting to become ineffective to treat these infections. Hence, there is a need to develop and characterize novel antimicrobial compounds. Phytochemicals are emerging as a safe and accessible alternative to conventional therapeutics for treating infectious diseases. Curcumin is extracted from the dried rhizome of the spice turmeric (Curcuma longa (Zingiberaceae)). However, the bioavailability of curcumin is low owing to its lipophilic property and thus has a low therapeutic efficacy in the host. A previous study synthesized structural variants of curcumin, which are called monocurcuminoids (CNs). CNs are synthesized based on the chemical structure of curcumin with only one methyl bridge. The biological activities of four previously synthesized CNs (CN59, CN63, CN67, and CN77), curcumin, and turmeric powder were examined in this study. Gas chromatography-tandem mass spectrometry analysis of curcumin and turmeric powder revealed similar peaks, which indicated the presence of curcumin in turmeric powder. The antioxidant activity of the test compounds was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays. The ABTS radical scavenging activities of the test compounds were similar to those of vitamin C. The minimum inhibitory concentration (MIC) values of the test compounds against seven microbial strains were in the range of 4.06-150⯵g/mL. The MIC value was equal to minimum bactericidal concentration value for CN63 (150⯵g/mL) and CN67 (120⯵g/mL) against Staphylococcus aureus. The treatment combination of CN77 (8.75 or 4.37⯵g/mL) and turmeric powder (9.37 or 4.68⯵g/mL) exerted synergistic growth-inhibiting effects on Aeromonas hydrophila, Candida albicans, and Pseudomonas aeruginosa. Photodynamic therapy using 2X MIC of CN59 decreased the growth of Enterococcus faecalis by 4.18-fold compared to the control group and completely inhibited the growth of Escherichia coli. The results of the hemolytic assay revealed that the test compounds were not cytotoxic with half-maximal inhibitory concentration values ranging from 49.65-130.9 µM. The anticoagulant activity of most compounds was comparable to that of warfarin but higher than that of heparin. This indicated that these compounds target the intrinsic coagulation pathway. These results demonstrated that these CNs are a safe and promising alternative for curcumin.
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Antiinfecciosos/farmacología , Antioxidantes/farmacología , Bacterias/efectos de los fármacos , Bioprospección , Candida albicans/efectos de los fármacos , Diarilheptanoides/farmacología , Fotoquimioterapia , Fármacos Fotosensibilizantes/farmacología , Animales , Antiinfecciosos/síntesis química , Antiinfecciosos/toxicidad , Antioxidantes/síntesis química , Antioxidantes/toxicidad , Bacterias/crecimiento & desarrollo , Benzotiazoles/química , Compuestos de Bifenilo/química , Coagulación Sanguínea/efectos de los fármacos , Candida albicans/crecimiento & desarrollo , Diarilheptanoides/síntesis química , Diarilheptanoides/toxicidad , Farmacorresistencia Microbiana , Hemólisis/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Fármacos Fotosensibilizantes/síntesis química , Fármacos Fotosensibilizantes/toxicidad , Picratos/química , Oveja Doméstica , Ácidos Sulfónicos/químicaRESUMEN
Naringin is a flavonoid widely known for its pharmacological properties, such as: anti-inflammatory and antioxidant ones, being an ally to avoid oxidative damage. Although naringin is an active easily found in citrus fruits, it has low bioavailability, biodistribution and also undergoes biotransformation in naringenin, limiting the described effects. The use of nanocapsules as drug carriers may increase solubility, improve biodistribution, impede the biotransformation thereof, and thus could improve the performance of naringin for use in treating neurological diseases. Therefore, the objective of this work is to produce a nanocapsule containing naringin, validate an analytical method by RP-HPLC to determination of the drug in nanoparticle and evaluate the toxicity. To that end, the blank nanocapsules (NB, without the drug) or naringin-loaded nanocapsules (NN) at the concentration of 2â¯mg/mL were prepared by interfacial deposition of the preformed polymer and the quantification of naringin by HPLC. Toxicity of the formulations was evaluated in vitro in rat hippocampal slices and in vivo models with C. elegans and Danio rerio (zebrafish). The analytical parameters evaluated (linearity, limit of detection and quantification, specificity, precision, accuracy and robustness) indicated adequate method to assay of naringin in nanocapsules by HPLC. There was no indication of toxicity by the nanocapsules in the evaluated biological assays.
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Flavanonas/química , Nanocápsulas/química , Animales , Conducta Animal , Caenorhabditis elegans , Modelos Animales , Ratas , Pez CebraRESUMEN
The glycerol monolaurate (GML) is a surfactant used in the food industry and has potent antimicrobial activity against many microorganisms; however, the use of GML is not expanded due its high melting point and poor solubility in water. The aim of the study was to produce, characterize, and evaluate in vitro the cytotoxicity of GML and GML nanocapsules. The GML nanocapsules were produced and characterized by a mean diameter, zeta potential, and polydispersity index. The cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH) release, thiobarbituric acid reactive substances (TBARS), and hemolytic activity. The genotoxicity was verified by comet assay. The physicochemical parameters showed a mean diameter of 192.5 ± 2.8 nm, a polydispersity index of 0.061 ± 0.018, and a zeta potential about - 21.9 ± 1 mV. The viability test demonstrated the protector effect of GML nanocapsule compared with the GML on peripheral blood mononuclear cells (PBMC) and VERO cells (isolated from kidney epithelial cells extracted from an African green monkey). A reduction in lipid peroxidation and lactate dehydrogenase release in GML nanocapsule-exposed cells compared with GML treated cells was observed. The damage on erythrocytes was addressed in treatment with GML, while the treatment with GML nanocapsules did not cause an effect. Moreover, the comet assay showed that the GML-caused genotoxicity and GML nanocapsules do not demonstrate damage. The study showed the reduction of toxicity of GML nanocapsules by many methods used in antimicrobial therapy.
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Antiinfecciosos/toxicidad , Lauratos/toxicidad , Monoglicéridos/toxicidad , Nanocápsulas/toxicidad , Tensoactivos/toxicidad , Animales , Antiinfecciosos/química , Compuestos de Bifenilo/química , Supervivencia Celular/efectos de los fármacos , Chlorocebus aethiops , Ensayo Cometa , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Humanos , L-Lactato Deshidrogenasa/metabolismo , Lauratos/química , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Monoglicéridos/química , Nanocápsulas/química , Picratos/química , Tensoactivos/química , Células VeroRESUMEN
Background: Alphitobius diaperinus, known as the lesser mealworm, is recognized as a problem for the poultry production sector. Several chemical methods have been employed in an attempt to control it, without successful results. Thus, alternative methods should be considered as an interesting approach to control this type of infestation. A recent study showed that glycerol monolaurate (GML) possesses insecticidal effect against bees. Therefore, the aim of this study was to evaluate, for the first time, the effect of GLM against the larval and adult forms of the lesser mealworm in vitro, and to verify whether GLM treated poultry litter used as soil fertilizer exerts any negative effect on its fauna.Materials, Methods & Results: In vitro tests were performed using three concentrations of GLM: 0.2, 0.4 and 1 mg mL-1, and the number of dead larvae and adults of A. diaperinus was counted on days 0, 2, 5 and 8 post-treatment. Poultry litter was pulverized with 1 mg mL-1 of GML, maintained under controlled conditions for 20 days and revolved every two days. Two ecotoxicological tests were performed using Enchytraeus crypticus. In the first test, GML was applied directly into the soil at doses of 0.5, 1 and 2 mg kg-1 of soil, while the second test used poultry litter as soil fertilizer at concentrations of 0, 2, 4 and 8 tons per hectare. Insecticidal action of GML against larvae and adults of A. diaperinus where only the 1 mg mL-1 concentration showed positive effect. GML caused 100% mortality of larvae two days after the beginning of treatment. Similarly, GML showed high efficacy to control adult forms of A. diaperinus, causing 83 and 90% of mortality on days 5 and 8 post-treatment, respectively.[...]
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Escarabajos , Glicerol/análogos & derivados , Insecticidas/análisis , Insecticidas/toxicidad , Oligoquetos , Microbiología del SueloRESUMEN
Background: Alphitobius diaperinus, known as the lesser mealworm, is recognized as a problem for the poultry production sector. Several chemical methods have been employed in an attempt to control it, without successful results. Thus, alternative methods should be considered as an interesting approach to control this type of infestation. A recent study showed that glycerol monolaurate (GML) possesses insecticidal effect against bees. Therefore, the aim of this study was to evaluate, for the first time, the effect of GLM against the larval and adult forms of the lesser mealworm in vitro, and to verify whether GLM treated poultry litter used as soil fertilizer exerts any negative effect on its fauna.Materials, Methods & Results: In vitro tests were performed using three concentrations of GLM: 0.2, 0.4 and 1 mg mL-1, and the number of dead larvae and adults of A. diaperinus was counted on days 0, 2, 5 and 8 post-treatment. Poultry litter was pulverized with 1 mg mL-1 of GML, maintained under controlled conditions for 20 days and revolved every two days. Two ecotoxicological tests were performed using Enchytraeus crypticus. In the first test, GML was applied directly into the soil at doses of 0.5, 1 and 2 mg kg-1 of soil, while the second test used poultry litter as soil fertilizer at concentrations of 0, 2, 4 and 8 tons per hectare. Insecticidal action of GML against larvae and adults of A. diaperinus where only the 1 mg mL-1 concentration showed positive effect. GML caused 100% mortality of larvae two days after the beginning of treatment. Similarly, GML showed high efficacy to control adult forms of A. diaperinus, causing 83 and 90% of mortality on days 5 and 8 post-treatment, respectively.[...](AU)
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Glicerol/análogos & derivados , Insecticidas/análisis , Insecticidas/toxicidad , Escarabajos , Oligoquetos , Microbiología del SueloRESUMEN
Carya illinoensis is a widespread species, belonging to the Juglandaceae family, commonly known as Pecan. Popularly, the leaves have been used in the treatment of smoking as a hypoglycemic, cleansing, astringent, keratolytic, antioxidant, and antimicrobial agent. The following research aimed to identify for the first time the phytochemical compounds present in the leaves of C. illinoensis and carry out the determination of antimicrobial activity of aqueous and ethanolic extracts. The antimicrobial activity was tested against 20 microorganisms by determining the minimum inhibitory concentration (MIC). Phenolic acids (gallic acid and ellagic acid), flavonoids (rutin), and tannins (catechins and epicatechins) were identified by HPLC-DAD and may be partially responsible for the antimicrobial activity against Gram-positive, Gram-negative, and yeast. The results showed MIC values between 25 mg/mL and 0.78 mg/mL. The extracts were also able to inhibit the production of germ tubes by Candida albicans.
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Antifúngicos/análisis , Antifúngicos/farmacología , Bacterias/efectos de los fármacos , Carya/química , Fitoquímicos/análisis , Fitoquímicos/farmacología , Levaduras/efectos de los fármacos , Antifúngicos/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Flavonoides/análisis , Flavonoides/aislamiento & purificación , Flavonoides/farmacología , Hidroxibenzoatos/análisis , Hidroxibenzoatos/aislamiento & purificación , Hidroxibenzoatos/farmacología , Pruebas de Sensibilidad Microbiana , Fitoquímicos/aislamiento & purificación , Hojas de la Planta/química , Taninos/análisis , Taninos/aislamiento & purificación , Taninos/farmacologíaRESUMEN
Infections due to microbial biofilm formation on the surface of catheters and other medical devices are constantly reported as a major cause of morbidity and mortality in patients admitted to hospitals. Furthermore, sessile cells are more resistant to phagocytosis and most antimicrobial, which complicates the treatment of such infections. Researches aimed at new antimicrobial originating mainly from plants have increased in recent years and the development of new strategies for their release is critical in combating the formation of biofilms. Geranium oil (GO) has proven antimicrobial activity. Because of this, the aim of this study was to develop nanoemulsions containing this oil (NEG) and evaluate its activity after the biofilm formation of Candida albicans, Candida tropicalis, Candida glabrata, and Candida krusei in hospital medical supplies. For quantification of the biofilm, crystal violet, total protein, and ATP-bioluminescence assays were used. The results revealed that GO and NEG showed lower MIC for C. albicans and C. tropicalis. The biofilms formed by different species of Candida on the surfaces of polyethylene and polyurethane were quantified. GO and NEG significantly inhibited the formation of biofilms in all species tested on the surfaces of polyethylene. However, NEG antibiofilm has had better activity than GO for C. albicans, C. tropicalis and C. glabrata, according to the surface potential analysis by atomic force microscopy (AFM). The analysis of the biofilm formation on the polyethylene surface by ATP-bioluminescence and CFU showed similar results. In both methods the formation of biofilm in the catheter occurred in greater quantity for C. albicans and C. tropicalis. GO did not significantly inhibit the formation of biofilms only in C. krusei, although NEG significantly increased this activity GO in all species tested when compared to the control training biofilm. The following study shows that the development of NEG may become an effective alternative to reduce the adhesion of microorganisms and prevent infections resulting from the use of some hospital medical materials.
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Antifúngicos/farmacología , Biopelículas/efectos de los fármacos , Candida/efectos de los fármacos , Equipos y Suministros/microbiología , Pelargonium/química , Extractos Vegetales/farmacología , Antifúngicos/aislamiento & purificación , Candida/fisiología , Emulsiones/farmacología , Hospitales , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/aislamiento & purificaciónRESUMEN
A limpeza e desinfecção das superfícies operatórias fixas e partes expostas do equipo odontológico reduzem, significativamente, a contaminação. Este estudo teve como objetivo avaliar se há contaminação da mesa cirúrgica, ao se utilizar o TNT esterilizado nas gramaturas 20 g/m² e 40 g/m². Materiais e Métodos: O trabalho constituiu-se de 2 grupos, compostos por 30 amostras (campos cirúrgicos) para cada grupo. Após a desinfecção prévia das mesas cirúrgicas, foram colocados campos de TNT. No grupo 1, foi utilizado TNT gramatura 20, e no grupo 2, gramatura 40. A coleta das amostras dos dois grupos foi realizada logo após a colocação dos campos cirúrgicos (tempo 1) e 1 hora após (tempo 2). Resultados: Em relação à ocorrência de contaminação bacteriana, não houve diferença estatisticamente significativas entre tempo de coletas. Mesmo com os cuidados de desinfecção da mesa e paramentação adequada, esses campos não foram totalmente eficazes. Conclusão: A amostra do TNT gramatura 40, tanto no início da cirurgia quanto 1 hora após, obteve melhores resultados, comparando-se com o TNT gramatura 20 sem diferenças estatísticas... (AU)
The cleaning and disinfecting fixed operative surfaces and exposed parts of the dental unit significantly reduces contamination. This study aimed to assess whether there is contamination of the surgical table to use the TNT sterilized in the weights 20 g/m² and 40 g/m². Materials and Methods: The study consisted of two groups, composed of 30 samples (drapes) for each group. After prior disinfection of surgical tables were placed TNT fields. Group 1 was used TNT weight and 20 in group 2 weight 40. The sample collection from both groups was held soon after the placement of surgical fields (time 1) and 1 hour after (time 2). Results: Regarding the occurrence of bacterial contamination, there was no statistically significant difference between time of collection. Even with the disinfecting care of the table and adequate scrub, these fields have not been fully effective. Conclusion: Thus, the sample weight of the TNT 40, both at the beginning of surgery, as 1 hour, better results compared to the TNT weight 20 without statistical differences... (AU)
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Cirugía Bucal , Desinfección , Contaminación de Equipos , Contaminación Biológica , Mesas de Operaciones , Técnicas MicrobiológicasRESUMEN
Nanocapsule formulations containing zinc phthalocyanine (ZnPc) were investigated as drug delivery systems for use in photodynamic therapy (PDT). ZnPc loaded chitosan, PCL, and PCL coated with chitosan nanocapsules were prepared and characterized by means of their physicochemical properties, photodynamic activity, photostability and drug release profile. All formulations presented nanometric hydrodynamic radius, around 100 nm, low polydispersity index (0.08-0.24), slightly negative zeta potential for PCL nanoparticles and positive zeta potential for suspension containing chitosan. Encapsulation efficiencies were higher than 99%. The capacity of ZnPc loaded nanocapsules to produce cytotoxic singlet oxygen ((1)O2) by irradiation with red laser was monitored using 1.3-diphenylisobenzofuran as a probe. The singlet oxygen quantum yields (ΦΔ) for ZnPc loaded chitosan nanocapsules were high and similar to that of the standard (ZnPc in DMSO), displaying excellent ability to generate (1)O2. The photosensitizer loaded nanocapsules are photostable in the timescale usually utilized in PDT and only a small photobleaching event was observed when a light dose of 610J/cm(2) was applied. The in vitro drug release studies of ZnPc from all nanocapsules demonstrated a sustained release profile controlled by diffusion, without burst effect. The nature of the polymer and the core type of the nanocapsules regulated ZnPc release. Thus, the nanocapsules developed in this work are a promising strategy to be employed in PDT.
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Quitosano/química , Indoles/química , Nanocápsulas/química , Compuestos Organometálicos/química , Fármacos Fotosensibilizantes/química , Poliésteres/química , Quitosano/efectos de la radiación , Liberación de Fármacos , Estabilidad de Medicamentos , Indoles/efectos de la radiación , Isoindoles , Luz , Nanocápsulas/efectos de la radiación , Compuestos Organometálicos/efectos de la radiación , Fotoquimioterapia , Fármacos Fotosensibilizantes/efectos de la radiación , Poliésteres/efectos de la radiación , Oxígeno Singlete/química , Compuestos de ZincRESUMEN
The Gram-positive, spore-forming bacterium Paenibacillus larvae is the primary bacterial pathogen of honeybee brood and the causative agent of American foulbrood disease (AFB). One of the feasible alternative treatments being used for their control of this disease is essential oils. In this study in vitro antimicrobial activity of Andiroba and Copaíba essential oils against Paenibacillus species, including P. larvae was evaluated. Minimal inhibitory concentration (MIC) in Mueller-Hinton broth by the microdilution method was assessed. Andiroba registered MIC values of 1.56-25%, while the MICs values obtained for Copaíba oil were of 1.56-12.5%. In order to determine the time-response effect of essential oils on P. larvae, this microorganism was exposed to the oils for up to 48 h. After 24 h treatment with Andiroba oil and after 48 h treatment with Copaíba oil no viable cells of P. larvae ATCC 9545 were observed. The possible toxic effect of essential oils were assessed by the spraying application method of the same concentrations of MICs. Bee mortality was evident only in treatment with Andiroba oil and the Copaíba oil shows no toxic effects after 10 days of observation. Taking together ours results showed for the first time that these oils presented a high activity against Paenibacillus species showing that Copaíba oil may be a candidate for the treatment or prevention of AFB.