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2.
Rev. argent. microbiol ; 50(1): 70-74, mar. 2018. ilus, graf, tab
Article in English | LILACS | ID: biblio-1041801

ABSTRACT

The aim of this study was to evaluate the antifungal activity (in vitro) of thymol and carvacrol alone or in mixtures against Fusarium verticillioides and Rhizopus stolonifer, and to obtain primary growth models. Minimal inhibitory concentration (MIC) was evaluated with fungal radial growth with thymol or carvacrol concentrations (0-1600mg/l). Mixtures were evaluated using concentrations below MIC values. Radial growth curves were described by the modified Gompertz equation. MIC values of carvacrol were 200mg/l for both fungi. Meanwhile, MIC values of thymol were between 500 and 400mg/l for F verticillioides and R. stolonifer, respectively. A synergistic effect below MIC concentrations for carvacrol (100mg/l) and thymol (100-375 mg/l) was observed. Significant differences (p <0.05) between the Gompertz parameters for the antimicrobial concentrations and their tested mixtures established an inverse relationship between antimicrobial concentration and mycelial development of both fungi. Modified Gompertz parameters can be useful to determine fungistatic concentrations.


El objetivo de este trabajo fue evaluar la actividad antifúngica in vitro del timol y del carvacrol, solos o en mezclas, contra Fusarium verticillioides y Rhizopus stolonifer, y obtener modelos primarios de crecimiento. Se evaluó la concentración inhibitoria mínima (CIM) con el crecimiento radial, se ensayaron concentraciones de timol y carvacrol de 0 a 1.600 mg/l. Las mezclas se evaluaron utilizando concentraciones por debajo de los valores de CIM. Las curvas de crecimiento radial fueron descritas por la ecuación de Gompertz modificada. Se obtuvieron los siguientes valores de CIM: carvacrol, 200 mg/l para las 2 especies; timol, 500 mg/l y 400 mg/l para F. verticillioides y R. stolonifer, respectivamente. Se observó un efecto sinèrgico a concentraciones inferiores a las CIM para el carvacrol (100mg/l) y el timol (100-375 mg/l). Hubo diferencias significativas (p <0,05) entre los parámetros de crecimiento de Gompertz; se estableció que existe una relación inversa entre la concentración de los antimicrobianos y el desarrollo del micelio de ambos hongos.


Subject(s)
Rhizopus , Thymol , Monoterpenes , Fusarium , Rhizopus/growth & development , Microbial Sensitivity Tests , Fusarium/growth & development , Cymenes
3.
Braz. j. microbiol ; 49(supl.1): 185-192, 2018. tab, graf
Article in English | LILACS | ID: biblio-974316

ABSTRACT

Abstract Biosurfactants have many advantages over synthetic surfactants but have higher production costs. Identifying microorganisms with high production capacities for these molecules and optimizing their growth conditions can reduce cost. The present work aimed to isolate and identify a fungus with high biosurfactant production capacity, optimize its growth conditions in a low cost culture medium, and characterize the chemical structure of the biosurfactant molecule. The fungal strain UFSM-BAS-01 was isolated from soil contaminated with hydrocarbons and identified as Fusarium fujikuroi. To optimize biosurfactant production, a Plackett-Burman design and a central composite rotational design were used. The variables evaluated were pH, incubation period, temperature, agitation and amount of inoculum in a liquid medium containing glucose. The partial structure of the biosurfactant molecule was identified by nuclear magnetic resonance spectrometry. F. fujikuroi reduced surface tension from 72 to 20 mN m−1 under the optimized conditions of pH 5.0, 37 °C and 7 days of incubation with 190 rpm agitation. The partial identification of the structure of the biosurfactant demonstrated the presence of an α,β-trehalose. The present study is the first report of the biosynthesis of this compound by F. fujikuroi, suggesting that the biosurfactant produced belongs to the class of trehalolipids.


Subject(s)
Surface-Active Agents/metabolism , Trehalose/metabolism , Industrial Microbiology/methods , Fusarium/metabolism , Surface-Active Agents/chemistry , Temperature , Culture Media/metabolism , Fermentation , Fusarium/growth & development , Fusarium/chemistry , Hydrogen-Ion Concentration
4.
Braz. j. microbiol ; 48(4): 706-714, Oct.-Dec. 2017. tab, graf
Article in English | LILACS | ID: biblio-889164

ABSTRACT

ABSTRACT Tomato is one of the most important vegetables in the world. Decay after harvest is a major issue in the development of tomato industry. Currently, the most effective method for controlling decay after harvest is storage of tomato at low temperature combined with usage of chemical bactericide; however, long-term usage of chemical bactericide not only causes pathogen resistance but also is harmful for human health and environment. Biocontrol method for the management of disease after tomato harvest has great practical significance. In this study, antagonistic bacterium B-6-1 strain was isolated from the surface of tomato and identified as Enterobacter cowanii based on morphological characteristics and physiological and biochemical features combined with sequence analysis of 16SrDNA and ropB gene and construction of dendrogram. Effects of different concentrations of antagonistic bacterium E. cowanii suspension on antifungal activity after tomato harvest were analyzed by mycelium growth rate method. Results revealed that antifungal activity was also enhanced with increasing concentrations of antagonistic bacterium; inhibitory rates of 1 × 105 colony-forming units (cfu)/mL antagonistic bacterial solution on Fusarium verticillioides, Alternaria tenuissima, and Botrytis cinerea were 46.31%, 67.48%, and 75.67%, respectively. By using in vivo inoculation method, it was further confirmed that antagonistic bacterium could effectively inhibit the occurrence of B. cinerae after tomato harvest, biocontrol effect of 1 × 109 cfu/mL zymotic fluid reached up to 95.24%, and antagonistic bacterium E. cowanii has biocontrol potential against B. cinerea after harvest of fruits and vegetables.


Subject(s)
Plant Diseases/microbiology , Solanum lycopersicum/microbiology , Enterobacter/isolation & purification , Enterobacter/physiology , Antibiosis , Plant Diseases/prevention & control , Botrytis/growth & development , Botrytis/physiology , Enterobacter/classification , Enterobacter/genetics , Alternaria/growth & development , Alternaria/physiology , Fruit/microbiology , Fusarium/growth & development , Fusarium/physiology
5.
Braz. j. microbiol ; 47(3): 775-780, July-Sept. 2016. tab, graf
Article in English | LILACS | ID: lil-788951

ABSTRACT

ABSTRACT Lectins are non-immunogenic carbohydrate-recognizing proteins that bind to glycoproteins, glycolipids, or polysaccharides with high affinity and exhibit remarkable ability to agglutinate erythrocytes and other cells. In the present study, ten Fusarium species previously not explored for lectins were screened for the presence of lectin activity. Mycelial extracts of F. fujikuroi, F. beomiformii, F. begoniae, F. nisikadoi, F. anthophilum, F. incarnatum, and F. tabacinum manifested agglutination of rabbit erythrocytes. Neuraminidase treatment of rabbit erythrocytes increased lectin titers of F. nisikadoi and F. tabacinum extracts, whereas the protease treatment resulted in a significant decline in agglutination by most of the lectins. Results of hapten inhibition studies demonstrated unique carbohydrate specificity of Fusarium lectins toward O-acetyl sialic acids. Activity of the majority of Fusarium lectins exhibited binding affinity to D-ribose, L-fucose, D-glucose, L-arabinose, D-mannitol, D-galactosamine hydrochloride, D-galacturonic acid, N-acetyl-d-galactosamine, N-acetyl-neuraminic acid, 2-deoxy-D-ribose, fetuin, asialofetuin, and bovine submaxillary mucin. Melibiose and N-glycolyl neuraminic acid did not inhibit the activity of any of the Fusarium lectins. Mycelial extracts of F. begoniae, F. nisikadoi, F. anthophilum, and F. incarnatum interacted with most of the carbohydrates tested. F. fujikuroi and F. anthophilum extracts displayed strong interaction with starch. The expression of lectin activity as a function of culture age was investigated. Most species displayed lectin activity on the 7th day of cultivation, and it varied with progressing of culture age.


Subject(s)
Humans , Animals , Mycelium , Fusarium/metabolism , Fusarium/chemistry , Lectins/metabolism , Hemagglutination Tests , Erythrocytes/drug effects , Carbohydrate Metabolism , Fusarium/growth & development , Hemagglutination , Lectins/pharmacology
7.
Braz. j. microbiol ; 46(2): 415-424, Apr-Jun/2015. tab, graf
Article in English | LILACS | ID: lil-749732

ABSTRACT

Dyes are the most difficult constituents to remove by conventional biological wastewater treatment. Colored wastewater is mainly eliminated by physical and chemical procedures, which are very expensive and have drawbacks. Therefore, the advantage of using biological processes, such as the biotransformation of dyes, is that they may lead to complete mineralization or formation of less toxic products. To prove the possibility of using fungal processes for decolorization and other applications, the analysis of the toxicity of the processes' products is required. The decolorization of the mixture of two dyes from different classes - triphenylmethane brilliant green and azo Evans blue (GB - total concentration 0.08 g/L, proportion 1:1 w/w) - by Pleurotus ostreatus (BWPH and MB), Gloeophyllum odoratum (DCa), RWP17 (Polyporus picipes) and Fusarium oxysporum (G1) was studied. Zootoxicity (Daphnia magna) and phytotoxicity (Lemna minor) changes were estimated at the end of the experiment. The mixture of dyes was significantly removed by all the strains that were tested with 96 h of experimental time. However, differences among strains from the same species (P. ostreatus) were noted. Shaking improved the efficacy and rate of the dye removal. In static samples, the removal of the mixture reached more than 51.9% and in shaken samples, more than 79.2%. Tests using the dead biomass of the fungi only adsorbed up to 37% of the dye mixture (strain BWPH), which suggests that the process with the living biomass involves the biotransformation of the dyes. The best results were reached for the MB strain, which removed 90% of the tested mixture under shaking conditions. Regardless of the efficacy of the dye removal, toxicity decreased from class V to class III in tests with D. magna. Tests with L. minor control samples were classified as class IV, and samples with certain strains were non-toxic. The highest phytotoxicity decrease was noted in shaken samples where the elimination of dye mixture was the best.


Subject(s)
Animals , Basidiomycota/growth & development , Basidiomycota/metabolism , Evans Blue/metabolism , Fusarium/growth & development , Fusarium/metabolism , Rosaniline Dyes/metabolism , Wastewater/microbiology , Araceae/drug effects , Araceae/physiology , Biotransformation , Cell Survival/drug effects , Daphnia/drug effects , Daphnia/physiology , Evans Blue/toxicity , Rosaniline Dyes/toxicity , Water Purification/methods
8.
Braz. j. microbiol ; 46(1): 293-299, 05/2015. tab, graf
Article in English | LILACS | ID: lil-748267

ABSTRACT

The effect of fludioxonil + metalaxyl-M on the mycelial morphology, sporulation and fumonisin B1 production by Fusarium verticillioides 103 F was evaluated. Scanning electron microscopy analysis showed that the fungicide caused inhibition of hyphal growth and defects on hyphae morphology such as cell wall disruption, withered hyphae, and excessive septation. In addition, extracellular material around the hyphae was rarely observed in the presence of fludioxonil + metalaxyl-M. While promoting the reduction of mycelial growth, the fungicide increased sporulation of F. verticillioides compared to the control, and the highest production occurred on the 14th day in the treatments and on the 10th day in the control cultures. Fumonisin B1 production in the culture media containing the fungicide (treatment) was detected from the 7th day incubation, whereas in cultures without fungicide (control) it was detected on the 10th day. The highest fumonisin B1 production occurred on the 14th day, both for the control and for the treatment. Fludioxonil + metalaxyl - M can interfere in F. verticillioides mycelial morphology and sporulation and increase fumonisin B1 levels. These data indicate the importance of understanding the effects of fungicide to minimize the occurrence of toxigenic fungi and fumonisins.


Subject(s)
Fumonisins/metabolism , Fungicides, Industrial/pharmacology , Fusarium/drug effects , Fusarium/metabolism , Hyphae/drug effects , Hyphae/ultrastructure , Alanine/analogs & derivatives , Alanine/pharmacology , Dioxoles/pharmacology , Fusarium/growth & development , Fusarium/ultrastructure , Hyphae/growth & development , Microscopy, Electron, Scanning , Pyrroles/pharmacology , Spores, Fungal/growth & development
9.
Braz. j. microbiol ; 45(3): 1105-1112, July-Sept. 2014. graf, tab
Article in English | LILACS | ID: lil-727045

ABSTRACT

Studies were conducted to determine the effect of osmotic and matric stress on germination and growth of two Fusarium solani strains, the etiological agent responsible of peanut brown root rot. Both strains had similar osmotic and matric potential ranges that allowed growth, being the latter one narrower. F. solani showed the ability to grow down to -14 MPa at 25 °C in non-ionic modified osmotic medium, while under matric stress this was limited to -8.4 MPa at 25 °C. However, both strains were seen to respond differently to decreasing osmotic and matric potentials, during early stages of germination. One strain (RC 338) showed to be more sensitive to matric than osmotic (non ionic) and the other one (RC 386) showed to be more sensitive to osmotic than matric imposed water stress. After 24 h of incubation, both isolates behaved similarly. The minimum water potential for germination was -8.4 MPa on glycerol amended media and -5.6 MPa for NaCl and PEG amended media, respectively. The knowledge of the water potential range which allow mycelia growth and spore germination of F. solani provides an inside to the likely behaviour of this devastating soilborne plant pathogen in nature and has important practical implications.


Subject(s)
Fusarium/growth & development , Osmotic Pressure , Water/metabolism , Arachis/microbiology , Fusarium/drug effects , Fusarium/radiation effects , Glycerol/metabolism , Plant Diseases/microbiology , Polyethylene Glycols/metabolism , Soil Microbiology , Sodium Chloride/metabolism , Temperature
10.
Rev. argent. microbiol ; 46(1): 41-44, mar. 2014.
Article in Spanish | LILACS | ID: biblio-1009717

ABSTRACT

La fusariosis es una de las enfermedades más importantes de los cereales, Fusarium graminearum es su principal agente etiológico. Este hongo posee la capacidad de producir distintos tipos y niveles de toxinas, en especial deoxinivalenol (DON). En la campaña 2012-2013 se dieron condiciones ambientales predisponentes para el desarrollo de esta enfermedad. El objetivo de este trabajo fue evaluar la presencia del hongo y el contenido de DON en 50 muestras de trigo. Los resultados demostraron la presencia de Fusarium graminearum en el 80 % de las muestras analizadas. El 24 % de las muestras presentó valores de DON ≥ 1µg/g, el 26 % varió entre 0,5 y 0,99µg/g, mientras que el 50 % restante mostró valores inferiores a 0,5µg/g. Se observó correlación entre la presencia de Fusarium graminearum y de DON. Es necesario establecer valores límites de DON en granos de trigo destinados al consumo humano


One of the most important diseases in cereal crops is Fusarium head blight, being Fusarium graminearum the main etiological agent. This fungus has the ability to produce a wide spectrum and quantity of toxins, especially deoxynivalenol (DON). During the last crop season (2012-2013) the climatic conditions favored Fusarium colonization. The objective of this work was to determine the presence of this fungus as well as the DON content in 50 wheat grain samples. Our results showed that 80% of the samples were contaminated with Fusarium graminearum. Twenty four percent (24%) of the samples contained ≥ 1µg/g DON, 26% ranged from 0,5 and 0,99µg/g, and the remaining 50% had values lower than 0,5µg/g. Correlation was found between the presence of Fusarium graminearum and DON. It is necessary to establish DON limit values in wheat grains for human consumption


Subject(s)
Triticum/toxicity , Fusarium/pathogenicity , Fusariosis/epidemiology , Fusarium/isolation & purification , Fusarium/growth & development , Mycotoxins/analysis
11.
Braz. j. microbiol ; 44(1): 89-95, 2013. ilus, tab
Article in English | LILACS | ID: lil-676915

ABSTRACT

Ear rots caused by Fusarium spp. are among the main fungal diseases that contribute to poor quality and the contamination of maize grains with mycotoxins. This study aimed to determine the visual incidence of fungal-damaged kernels (FDKs), the incidence of two main Gibberella (a teleomorph of Fusarium) complexes (G. fujikuroi and G. zeae) associated with maize using a seed health blotter test, and the fumonisin levels, using high performance liquid chromatography, in samples of maize grains grown across 23 municipalities during the 2008/09 and 2009/10 growing seasons. Additionally, 104 strains that were representative of all of the analysed samples were identified to species using PCR assays. The mean FDK was seven per cent, and only six of the samples had levels greater than six per cent. Fusarium spp. of the G. fujikuroi complex were present in 96% of the samples, and G. zeae was present in 18% of the samples (5/27). The mean incidence of G. fujikuroi was 58%, and the incidence of G. zeae varied from 2 to 6%. FB1 was found in 58.6%, FB2 in 37.9%, and both toxins in 37.9% of the samples. The FB1 and FB2 levels were below the quantification limits for 41.3% of the samples, and the mean FB1 levels (0.66 µg/g) were higher than the mean FB2 levels (0.42 µg/g). The PCR identification separated the 104 isolates into three of the G. fujikuroi complex: F. verticillioides (76%), F. subglutinans (4%) and F. proliferatum (2%); and G. zeae (anamorph = F. graminearum) (18%). Our results confirmed the dominance of F. verticillioides, similar to other regions of Brazil, but they differed due to the relatively higher incidence of F. graminearum. Total fumonisin levels were below the maximum limit determined by current Brazilian regulations.


Subject(s)
Humans , Food Contamination , Fumonisins/analysis , Fumonisins/isolation & purification , Fusarium/growth & development , Fusarium/isolation & purification , In Vitro Techniques , Mycoses , Plant Structures , Polymerase Chain Reaction , Chromatography, High Pressure Liquid , Food Samples , Methods , Zea mays
12.
Braz. j. microbiol ; 44(2): 417-422, 2013. graf, mapas, tab
Article in English | LILACS | ID: lil-688579

ABSTRACT

Twenty six isolates of Fusarium graminearum from grains of maize hybrids harvested in ±west Argentina were grown on autoclaved rice grain to assess their ability to produce type B trichothecenes. Chemical analysis indicated that 38% of isolates were nivalenol (NIV) producers only, 31% were major NIV producers with high DON(deoxynivalenol)/NIV ratios, 8% were major DON producers with minor NIV production, and 23% were DON producers only. Isolates showed a high variability in their toxigenic potential which was not related to fungal biomass. The distribution of the different chemotypes as well as the high and the low trichothecene-producing Fusarium isolates could not be associated to a geographical origin. Our results confirmed for the first time that isolates of Fusarium graminearum from maize of northwest Argentina are able to produce DON and NIV. A substancial contamination with both NIV and DON is likely in maize from northwest Argentina. Their contents should be quantified in regional surveillances for mycotoxin contamination.


Subject(s)
Fusarium/isolation & purification , Fusarium/metabolism , Trichothecenes/metabolism , Zea mays/microbiology , Argentina , Fusarium/growth & development , Oryza/microbiology
13.
IJPR-Iranian Journal of Pharmaceutical Research. 2013; 12 (3): 289-298
in English | IMEMR | ID: emr-138285

ABSTRACT

Silver nanoparticles are increasingly used in various fields of biotechnology and applications in the medicine. Objectives of this study were optimization of production of silver nanoparticles using biotransformations by Fusarium oxysporum, and a further study on the location of nanoparticles synthesis in this microorganism. The reaction mixture contained the following ingredients [final concentrations]: AgNO[3] [1-10 mM] as the biotransformation substrate, biomass as the biocatalyst, glucose [560 mM] as the electron donor, and phosphate buffer [pH= 7, 100 mM]. The samples were taken from the reaction mixtures at different times, and the absorbance [430 nm] of the colloidal suspensions of silver nanoparticles hydrosols was read freshly [without freezing] and immediately after dilution [1:40]. SEM and TEM analyses were performed on selected samples. The presence of AgNO[3] [0.1 mM] in the culture as enzyme inducer, and glucose [560 mM] as electron donor had positive effects on nanoparticle production. In SEM micrographs, silver nanoparticles were almost spherical, single [25-50 nm] or in aggregates [100 nm], attached to the surface of biomass. The reaction mixture was successfully optimized to increase the yield of silver nanoparticles production. More details of the location of nanoparticles production by this fungus were revealed, which support the hypothesis that silver nanoparticles are synthesized intracellularly and not extracellularly


Subject(s)
Silver/chemistry , Fusarium/growth & development , Biotransformation , Culture Media
14.
Bol. micol ; 24: 51-56, dic. 2009. ilus
Article in Spanish | LILACS | ID: lil-585743

ABSTRACT

Se describe un caso de micoparasitismo biotrófico de ocurrencia natural en el suelo, entre las hifas de una cepa de Fusarium oxysporum complex y Cunninghamella sp. Las hifas de F. oxysporum se desarrollaron sobre las células vivas del hospedador, mostrando 2 tipos de efectos parasíticos: uno de enrollamiento y otro de contacto con penetración de las hifas, sin la aparente eliminación del hospedador. Esta situación poco común en la literatura, demuestra las capacidades adaptativas de esta especie al micoparasitismo en grupos filogenéticamente distantes.


This paper describes a case of mycoparasitism naturally occurring, where Fusarium oxysporum parasitizes hyphae of Cunninghamella sp, to show mycoparasitism between the two fungi. This is a case of biotrophic mycoparasitism by contact. The hyphae of F. oxysporum developed closely along the living cells of the host showing mycoparasitic effect, some for a loop, and other contact with penetration of the hyphae. This situation is rare in the literature, demonstrates the adaptive capacities of this species to mycoparasitism in phylogenetically distant groups.


Subject(s)
Cunninghamella/isolation & purification , Cunninghamella/classification , Cunninghamella/growth & development , Cunninghamella/pathogenicity , Fusarium/isolation & purification , Fusarium/classification , Fusarium/growth & development , Fusarium/pathogenicity , Fusarium/virology , Host-Parasite Interactions , Fungi , Soil
15.
Biol. Res ; 42(3): 297-304, 2009. ilus
Article in English | LILACS | ID: lil-531963

ABSTRACT

Gallic acid was artificially added to the media to grow Fusarium oxysporum f.sp.niveum to investigate its effect on the pathogenic fungus. Results indicate that gallic acid inhibited the growth of F. oxysporum f.sp.niveum. The colony diameter, the conidia germinating rate and the conidia yield were reduced by 5.7-22.9 percent percent, 35.8-55.6 percent and 38.9-62.2 percent respectively. However, the virulence factors by the fungus were stimulated. The activity of pectinase, proteinase and cellulase increased by 12.3-627.8 percent, 11.8-41.2 percent and 0.5-325.0 percent respectively, while the activity of amylase increased slightly. The results suggest that gallic acid repressed growth but facilitated the relative pathogenicity of invading pathogens.


Subject(s)
Culture Media/pharmacology , Fusarium/drug effects , Gallic Acid/pharmacology , Spores, Fungal/drug effects , Colony Count, Microbial , Culture Media/chemistry , Fusarium/growth & development , Fusarium/pathogenicity , Spores, Fungal/growth & development , Spores, Fungal/pathogenicity , Virulence Factors
16.
Arq. bras. oftalmol ; 71(6): 860-864, nov.-dez. 2008. ilus, graf, tab
Article in English | LILACS | ID: lil-503454

ABSTRACT

PURPOSE: To evaluate the efficacy of topical administration of 0.5 percent povidone-iodine in experimental Fusarium solani keratitis in rabbits. METHODS: Fungal keratitis caused by Fusarium solani was induced in the right eye of 24 New Zealand rabbits. The rabbits were randomly divided into 3 different treatment groups: Group I (povidone-iodine) - treated with topical 0.5 percent povidone-iodine; Group II (natamycin) - treated with topical 5 percent natamycin; and Group III (control) - treated with topical saline solution. In all groups the rabbits were treated for three days and then sacrificed. The corneas were excised, macerated and immersed in 10 mL BHI. Culture samples were plated daily on Sabouraud's agar for 7 days, and the number of colony-forming units (CFU) was counted. The rabbits were clinically evaluated during the treatment period. RESULTS: The povidone-iodine and natamycin groups demonstrated better efficacy than the control group based on the number of rabbits with no colonies growing. However, there were no statistically significant differences between the three groups when the number of CFU was analyzed (p>0.05). CONCLUSIONS: Our study demonstrates important methodological considerations in the use of in vivo animal models for the testing of antifungal agents. Using this sample size and methodology of counting CFU, topical 0.5 percent povidone-iodine demonstrated no benefit in the treatment of experimental Fusarium solani when compared with topical 5 percent natamycin.


OBJETIVO: Avaliar a eficácia do uso tópico de iodo-povidona 0,5 por cento em ceratite experimental por Fusarium solani em coelhos. MÉTODOS: Ceratite fúngica por Fusarium solani foi induzida no olho direito de 24 coelhos da raça New Zealand. Os coelhos foram divididos aleatoriamente em 3 diferentes grupos de tratamento: Grupo I (iodo-povidona) - tratados com iodo-povidona 0,5 por cento; Grupo II (natamicina) - tratados com natamicina 5 por cento; Grupo III (controle) - tratados com solução salina. Os coelhos dos 3 grupos foram tratados por 3 dias e sacrificados em seguida. As córneas foram removidas cirurgicamente, maceradas e incubadas em meio BHI. Semeou-se culturas em placas de ágar Sabouraud, diariamente, durante 7 dias, e contou-se o número de unidades formadoras de colônias (UFC). Os coelhos foram avaliados clinicamente durante o período de tratamento. RESULTADOS: Os grupos iodo-povidona e natamicina demonstraram melhor eficácia do que o grupo controle considerando-se o número de coelhos nos quais não houve crescimento de colônias. Entretanto, não houve diferença estatística significante entre os 3 grupos quando se analizou o número de UFC (p>0,05). CONCLUSÃO: Este estudo demonstrou considerações metodológicas importantes na utilização de modelos animais para o teste de agentes antifúngicos. Usando a metodologia de contar UFC e com este tamanho amostral, administração tópica de iodo-povidona 0,5 por cento não demonstrou benefício do tratamento de ceratite fúngica experimental causada por Fusarium solani quando comparado com a administração tópica de natamicina 5 por cento.


Subject(s)
Animals , Male , Rabbits , Antifungal Agents/administration & dosage , Fusarium , Keratitis/drug therapy , Natamycin/administration & dosage , Povidone-Iodine/administration & dosage , Colony Count, Microbial , Disease Models, Animal , Fusarium/growth & development , Keratitis/chemically induced , Keratitis/microbiology , Pilot Projects , Random Allocation
17.
Indian J Med Microbiol ; 2005 Jul; 23(3): 198-9
Article in English | IMSEAR | ID: sea-53508

ABSTRACT

An unusual manifestation of breast fusariosis was encountered in a 55-year-old female diabetic patient. Two fine needle aspirates (FNA) from the abscess were done at three days interval and they showed hyaline, septate, branched, fungal hyphae in 10% potassium hydroxide mount. Fungal infection was confirmed by demonstrating the fungal hyphae in the midst of lymphocytes, macrophages and neutrophils in Leishman stained smears. Culture of both FNAs yielded a heavy and pure growth of Fusarium solani. The patient responded to oral ketoconazole 200 mg once daily for 3 weeks. The breast fusariosis reported here is presumably the first case in India.


Subject(s)
Abscess/drug therapy , Antifungal Agents/therapeutic use , Breast Diseases/drug therapy , Female , Fusarium/growth & development , Humans , Ketoconazole/therapeutic use , Middle Aged , Mycoses/drug therapy
18.
Bol. micol ; 19: 41-47, dic. 2004. tab
Article in Spanish | LILACS | ID: lil-416851

ABSTRACT

Se estudió la micobiota alcalofílica y alcalino tolerante de suelos de intercordones del bosque nativo de Celtis tala y Scutia buxifolia en el Partido de Magdalena, provincia de Buenos Aires, Argentina. Los aislamientos de los geohongos se realizaron en agar extractos de malta en rangos de pH desde 5 hasta 11, ajustados mediante diferentes concentraciones de sales sódicas. Se aislaron e identificaron 43 taxa fúngicos. El 50 por ciento no fueron capaces de crecer a pH 10 siendo asignados a la categoría de alcalófilos. El 39 por ciento fueron alcalino-tolerantes dado que pudieron ser aislados hasta pH 10, mientras que el 11 por ciento restante creció a pH 10 pero no a pH 5-6 y fueron asignados a la categoría de alcalofílicos. Sólo Fusarium solari fue aislado con altas frecuencias en suelos de los 3 intercordones en todos lo pH probados.


Subject(s)
Fusarium/isolation & purification , Fusarium/classification , Fusarium/growth & development , Fungi/isolation & purification , Fungi/growth & development , Soil Alkalinity
19.
Indian J Exp Biol ; 2004 Jul; 42(7): 715-20
Article in English | IMSEAR | ID: sea-63139

ABSTRACT

Chitinolytic marine bacterial strains (30) were isolated from the sea dumps at Bhavnagar, India. They were screened as chitinase producers on the basis of zone of clearance on chitin agar plates incorporated with calcofluor white M2R for the better resolution. Out of these, three strains namely, Pseudomonas sp., Pantoea dispersa and Enterobacter amnigenus showed high chitinase production. They were also found to produce proteases and therefore have a good potential for use as antifungal biocontrol agents for the control of fungal plant pathogens. These strains could degrade and utilize the mycelia of Macrophomina phaseoliena (Tassi) Goidanich and Fusarium sp. In vitro, these strains could inhibit the growth of Fusarium sp. and M. phaseolina. The culture filtrate inhibiting hyphal elongation was observed microscopically.


Subject(s)
Bacteria/enzymology , Basidiomycota/growth & development , Chitin/metabolism , Chitinases/biosynthesis , Fusarium/growth & development , Hydrolysis , Marine Biology , Water Microbiology
20.
Biocell ; 27(2): 173-179, Aug. 2003.
Article in English | LILACS | ID: lil-384246

ABSTRACT

Vicilins (7S storage proteins) found in various legume seeds have been previously shown to interfere with the germination of spores or conidia of phytopathogenic fungi and inhibit yeast growth and glucose stimulated acidification of the medium by yeast cells. In the present work vicilins from cowpea (Vigna unguiculata) seeds were added to the growth medium of Saccharomyces cerevisiae cells and Fusarium oxysporum conidia. Helix pomatia lectin, wheat germ agglutinin and Ulex europaeus lectin were used to identify differences in the binding of the vicilins to the surface of cells of S. cerevisiae and F. oxysporum treated with this protein. After the growth period, the material in suspension (yeast cells) was centrifuged and the final pellet was also treated with different sugar (glucose, sucrose, glucosamine, N-acetyl-glucosamine) concentrations and 0.1 M HCl for extraction of vicilins associated to chitinous structures present in yeast cells. Our results showed that vicilin sub-units were present in the different sugar extracts of yeast cells pretreated with the vicilins and these proteins were eluted by 0.5 M solutions of sugars in the following order of efficiency of elution: N-acetyl-glucosamine, sucrose/glucose and glucosamine.


Subject(s)
Carbohydrates/pharmacology , Binding, Competitive/drug effects , Cell Membrane/drug effects , Cell Wall/drug effects , Plant Proteins/pharmacology , Acetylglucosamine/pharmacology , Fungi/drug effects , Fungi/growth & development , Fungi/ultrastructure , Fusarium/drug effects , Fusarium/growth & development , Fusarium/ultrastructure , Glucosamine/pharmacology , Glucose/pharmacology , Binding, Competitive/physiology , Microscopy, Electron , Cell Membrane/metabolism , Cell Membrane/ultrastructure , Cell Wall/metabolism , Cell Wall/ultrastructure , Sucrose/pharmacology , Saccharomyces cerevisiae/drug effects , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae/ultrastructure , Binding Sites/drug effects , Binding Sites/physiology
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