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The Latin America region has a considerable extent of varied climate conditions: from tropical, subtropical, and warm temperate to temperate. Among the surface territory, different agricultural products are produced, making them an important food source for human consumption. Fungal species commonly colonize those important agricultural products and often contaminate them with mycotoxins that have a major impact on health, welfare, and productivity. Nowadays, special attention is paid to modified mycotoxins, which are those that cannot be detected by conventional analytical methods. However, little data about their natural occurrence in food and feed is available, especially in Latin American countries, where, among all the countries in this region, only a few of them are working on this subject. Thus, the present review summarizes the published information available in order to determine the possible human exposure risk to these toxins.
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Contaminação de Alimentos , Micotoxinas , América Latina , Micotoxinas/análise , Humanos , Contaminação de Alimentos/análise , Fungos/isolamento & purificação , Microbiologia de AlimentosRESUMO
Fusarium cerealis is a causal agent of Fusarium Head Blight in wheat, and it produces both deoxynivalenol (DON) and nivalenol (NIV). Nevertheless, the effect of environmental factors on the growth and mycotoxin production of this species has not been studied so far. The objective of this study was to investigate the impact of environmental factors on the growth and mycotoxin production of F. cerealis strains. All strains were able to grow in a wide range of water activity (aW) and temperatures, but their mycotoxin production was influenced by strain and environmental factors. NIV was produced at high aW and temperatures, while optimal conditions for DON production were observed at low aW. Interestingly, some strains were able to simultaneously produce both toxins, which could pose a more significant risk for grain contamination.
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Chickpea is susceptible to fungal infection and mycotoxin contamination. Argentina exports most of its chickpea production; thus, its quality is of concern. The Alternaria fungal genus was found to be prevalent in chickpea samples from Argentina. The species within this genus are able to produce mycotoxins, such as alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TA). In this context, we evaluated the effect of water activity (0.99, 0.98, 0.96, 0.95, 0.94, 0.92, and 0.90 aW), temperature (4, 15, 25, and 30 °C), incubation time (7, 14, 21, and 28 days), and their interactions on mycelial growth and AOH, AME, and TA production on chickpea-based medium by two A. alternata strains and one A. arborescens strain isolated from chickpea in Argentina. Maximum growth rates were obtained at the highest aW (0.99) and 25 °C, with growth decreasing as the aW of the medium and the temperature were reduced. A. arborescens grew significantly faster than A. alternata. Mycotoxin production was affected by both variables (aW and temperature), and the pattern obtained was dependent on the strains/species evaluated. In general, both A. alternata strains produced maximum amounts of AOH and AME at 30 °C and 0.99-0.98 aW, while for TA production, both strains behaved completely differently (maximum levels at 25 °C and 0.96 aW for one strain and 30 °C and 0.98 aW for the other). A. arborescens produced maximum amounts of the three toxins at 25 °C and 0.98 aW. Temperature and aW conditions for mycotoxin production were slightly narrower than those for growth. Temperature and aW conditions assayed are those found during chickpea grain development in the field, and also could be present during storage. This study provides useful data on the conditions representing a risk for contamination of chickpea by Alternaria toxins.
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INTRODUCTION: Owing to its ability to reduce the toxicity of environmental pollutants that are risk factors for diabetes and obesity, the use of probiotic bacteria might aid the treatment of these diseases. OBJECTIVE: To determine the effects of chronic exposure to low-dose malathion on weight and glucose levels in mice, as well as to evaluate the protective role of a probiotic supplement. METHODS: Weight and serum glucose levels of four groups of mice (control, malathion-exposed [10 ppm], probiotics and malathion + probiotics) were determined every 10 days for 180 days. RESULTS: Malathion administration induced an increase in weight and glucose levels in the malathion group mice in comparison with the other groups. CONCLUSIONS: Consumption of food contaminated with malathion residues increases glucose levels and favors weight gain, while consumption of probiotics reduces the effects generated by residues in food.
INTRODUCCIÓN: Debido a su capacidad para reducir la toxicidad de contaminantes ambientales que constituyen factores de riesgo de diabetes y obesidad, el uso de bacterias probióticas podría ayudar al tratamiento de esas enfermedades. OBJETIVO: Determinar los efectos de la exposición crónica a malatión a dosis bajas sobre el peso y los niveles de glucosa de ratones, así como evaluar el papel protector de un suplemento probiótico. MÉTODOS: Cada 10 días se determinó el peso y la glucosa sérica de cuatro grupos de ratones (de control, expuestos a malatión (10 ppm), probióticos y malatión + probióticos) durante 180 días. RESULTADOS: La administración de malatión provocó un incremento del peso y los niveles de glucosa en los ratones del grupo con malatión comparados con los demás grupos. CONCLUSIONES: El consumo de alimentos contaminados con residuos de malatión aumenta los niveles de glucosa y favorece el incremento del peso; el consumo de probióticos disminuye los efectos generados por los residuos en los alimentos.
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Malation , Probióticos , Camundongos , Animais , Malation/toxicidade , Aumento de Peso , Obesidade/prevenção & controle , Probióticos/uso terapêutico , GlucoseRESUMO
Resumen Introducción: Debido a su capacidad para reducir la toxicidad de contaminantes ambientales que constituyen factores de riesgo de diabetes y obesidad, el uso de bacterias probióticas podría ayudar al tratamiento de esas enfermedades. Objetivo: Determinar los efectos de la exposición crónica a malatión a dosis bajas sobre el peso y los niveles de glucosa de ratones, así como evaluar el papel protector de un suplemento probiótico. Métodos: Cada 10 días se determinó el peso y la glucosa sérica de cuatro grupos de ratones (de control, expuestos a malatión (10 ppm), probióticos y malatión + probióticos) durante 180 días. Resultados: La administración de malatión provocó un incremento del peso y los niveles de glucosa en los ratones del grupo con malatión comparados con los demás grupos. Conclusiones: El consumo de alimentos contaminados con residuos de malatión aumenta los niveles de glucosa y favorece el incremento del peso; el consumo de probióticos disminuye los efectos generados por los residuos en los alimentos.
Abstract Introduction: Owing to its ability to reduce the toxicity of environmental pollutants that are risk factors for diabetes and obesity, the use of probiotic bacteria might aid the treatment of these diseases. Objective: To determine the effects of chronic exposure to low-dose malathion on weight and glucose levels in mice, as well as to evaluate the protective role of a probiotic supplement. Methods: Weight and serum glucose levels of four groups of mice (control, malathion-exposed [10 ppm], probiotics and malathion + probiotics) were determined every 10 days for 180 days. Results: Malathion administration induced an increase in weight and glucose levels in the malathion group mice in comparison with the other groups. Conclusions: Consumption of food contaminated with malathion residues increases glucose levels and favors weight gain, while consumption of probiotics reduces the effects generated by residues in food.
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In enteropathogenic Escherichia coli (EPEC), the production of flagella and the type III secretion system (T3SS) is activated in the presence of host cultured epithelial cells. The goal of this study was to investigate the relationship between expression of flagella and the T3SS. Mutants deficient in assembling T3SS basal and translocon components (ΔespA, ΔespB, ΔespD, ΔescC, ΔescN, and ΔescV), and in secreting effector molecules (ΔsepD and ΔsepL) were tested for flagella production under several growth conditions. The ΔespA mutant did not produce flagella in any condition tested, although fliC was transcribed. The remaining mutants produced different levels of flagella upon growth in LB or in the presence of cells but were significantly diminished in flagella production after growth in Dulbecco's minimal essential medium. We also investigated the role of virulence and global regulator genes in expression of flagella. The ΔqseB and ΔqseC mutants produced abundant flagella only when growing in LB and in the presence of HeLa cells, indicating that QseB and QseC act as negative regulators of fliC transcription. The ΔgrlR, ΔperA, Δler, Δhns, and Δfis mutants produced low levels of flagella, suggesting these regulators are activators of fliC expression. These data suggest that the presence of an intact T3SS is required for assembly of flagella highlighting the existence in EPEC of a cross-talk between these two virulence-associated T3SSs.
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Escherichia coli Enteropatogênica , Proteínas de Escherichia coli , Humanos , Escherichia coli Enteropatogênica/genética , Escherichia coli Enteropatogênica/metabolismo , Sistemas de Secreção Tipo III/genética , Sistemas de Secreção Tipo III/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Células HeLa , Regulação Bacteriana da Expressão Gênica , Flagelos/genética , Flagelos/metabolismoRESUMO
The flagella of enteropathogenic Escherichia coli (EPEC) O127:H6 E2348/69 mediate adherence to host proteins and epithelial cells. What environmental and nutritional signals trigger or down-regulate flagella expression in EPEC are largely unknown. In this study, we analyzed the influence of pH, oxygen tension, cationic and anionic salts (including bile salt), carbon and nitrogen sources, and catecholamines on the expression of the flagellin gene (fliC) of E2348/69. We found that sodium bicarbonate, which has been shown to induce the expression of type III secretion effectors, down-regulated flagella expression, explaining why E2348/69 shows reduced motility and flagellation when growing in Dulbecco's Minimal Essential Medium (DMEM). Further, growth under a 5% carbon dioxide atmosphere, in DMEM adjusted to pH 8.2, in M9 minimal medium supplemented with 80 mM glucose or sucrose, and in DMEM containing 150 mM sodium chloride, 0.1% sodium deoxycholate, or 30 µM epinephrine significantly enhanced fliC transcription to different levels in comparison to growth in DMEM alone. When EPEC was grown in the presence of HeLa cells or in supernatants of cultured HeLa cells, high levels (4-fold increase) of fliC transcription were detected in comparison to growth in DMEM alone. Our data suggest that nutritional and host signals that EPEC may encounter in the intestinal niche activate fliC expression in order to favor motility and host colonization.
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The Chaco wetland is among the most biologically diverse regions in Argentina. In collections of fungi from asymptomatic native grasses (Poaceae) from the wetlands, we identified isolates of Fusarium that were morphologically similar to F. armeniacum, but distinct from it by their production of abundant microconidia. All the isolates had identical, or nearly identical, partial sequences of TEF1 and RPB2. But they were distinct from reference sequences from F. armeniacum and Fusarium species closely related to it. Phylogenetic analysis of 34 full-length housekeeping gene sequences retrieved from whole genome sequences of three Chaco wetland isolates, 29 genes resolved the isolates as an exclusive clade within the F. sambucinum species complex. Based on results of the morphological and phylogenetic analysis, we concluded that the Chaco wetland isolates are a distinct and novel species, herein described as Fusarium chaquense, sp. nov., which is closely related to F. armeniacum. F. chaquense in culture can produce the trichothecenes T-2 and HT-2 toxin, neosolaniol, diacetoxyscirpenol, and monoacetoxyscirpenol, as well as beauvericin and the pigment aurofusarin. Genome sequence analysis also revealed the presence of three previously described loci required for trichothecene biosynthesis. This research represents the first study of Fusarium in a natural ecosystem in Argentina.
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Fusarium , Tricotecenos , Argentina , Ecossistema , Filogenia , Poaceae , Áreas AlagadasRESUMO
Fusarium chaquense, a recently formally described novel species, has been identified as an T-2 toxin (T-2), HT-2 toxin (HT-2) and other toxins producer in natural grasses (Poaceae) from Argentina. The major objective of this study was to describe the effect of water activity (aW, 0.995, 0.98, 0.95, 0.93 and 0.91), temperature (15, 25 and 30 °C) and incubation time (5, 15 and 25 days) on growth and to evaluate the production of T-2, HT-2 toxins and beauvericin (BEA) by two F. chaquense strains in a grass-based media. The results showed a wide range of conditions for F. chaquense growth and mycotoxin production. Both strains had a maximum growth rate at the highest aW (0.995) and 25 °C. Regarding mycotoxin production, more T-2 than the other analysed mycotoxins were produced by the two strains. T-2 production was favoured at 0.995 aW and 30 °C, while HT-2 production at 0.98-0.95 aW and 15 °C. The maximum levels of BEA were produced at 0.995 aW and 25-30 °C. Two-dimensional profiles of aW by temperature interactions were obtained from these data in order to identify areas where conditions indicate a significant risk of mycotoxins accumulation on grass. For its versatility on growth and mycotoxin production in a wide range of aW and temperatures, F. chaquense would have an adaptive advantage over other Fusarium species, and this would explain its high frequency of isolation in natural grasses grown up in the Chaco wetlands.
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Fusarium/fisiologia , Tricotecenos do Tipo A/metabolismo , Proliferação de Células , Regulação Fúngica da Expressão Gênica , Micotoxinas/metabolismo , Poaceae/química , TemperaturaRESUMO
BACKGROUND: Human brucellosis is a global health problem. Mexico is one of the main countries affected; timely diagnosis and serological tests are the basis for detection. AIM: To know the frequency of confirmed cases of brucellosis in different of Family Medicine Units of the Mexican Social Security Institute in the state of Puebla, Mexico. METHODS: Cross-sectional study in patients of both genders, adults and pediatrics, with clinical manifestations suggestive of brucellosis; serological tests were performed for the confirmatory diagnosis. RESULTS: Out of a total of 77 patients, 39 (50.6%) were positive, 21 (27.3%) cases coming out of infection, 9 (11.7%) were negative and 8 (10.4%) were defined with immunological memory; of positive cases, 32 (82.1%) were found in the adult group and 30 (76.9%) were female. CONCLUSION: Around half of samples were confirmed as brucellosis, the clinical manifestations of the patients studied were non-specific, which highlights the importance of laboratory diagnosis.
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Brucella , Brucelose , Adulto , Brucelose/diagnóstico , Brucelose/epidemiologia , Criança , Estudos Transversais , Feminino , Humanos , Masculino , México/epidemiologia , Testes SorológicosRESUMO
INTRODUCCIÓN: La brucelosis humana es un problema zoo-sanitario global. México es uno de los principales países que se ven afectados, el diagnóstico oportuno y las pruebas serológicas confirmatorias son la base para la detección. OBJETIVO: Conocer la frecuencia de casos confirmados de brucelosis en diferentes Unidades de Medicina Familiar del Instituto Mexicano del Seguro Social en el estado de Puebla, México. PACIENTES Y MÉTODOS: Estudio transversal en pacientes de ambos sexos, adultos y pediátricos, con manifestaciones clínicas sugestivas de brucelosis; se realizaron pruebas serológicas para el diagnóstico confirmatorio. RESULTADOS: De un total de 77 pacientes, se obtuvieron 39 (50,6%) casos positivos, 21 (27,3%) casos saliendo de la infección, 9 (11,7%) negativos y 8 (10,4%) con memoria inmunológica; de los casos positivos, 32 (82,1%) eran adultos y 30 (76,9%) fueron del género femenino. CONCLUSIÓN: Del total de muestras, la mitad tuvo diagnóstico de brucelosis, las manifestaciones clínicas de los pacientes estudiados fueron inespecíficas, lo cual resalta la importancia del diagnóstico de laboratorio.
BACKGROUND: Human brucellosis is a global health problem. Mexico is one of the main countries affected; timely diagnosis and serological tests are the basis for detection. AIM: To know the frequency of confirmed cases of brucellosis in different of Family Medicine Units of the Mexican Social Security Institute in the state of Puebla, Mexico. METHODS: Cross-sectional study in patients of both genders, adults and pediatrics, with clinical manifestations suggestive of brucellosis; serological tests were performed for the confirmatory diagnosis. RESULTS: Out of a total of 77 patients, 39 (50.6%) were positive, 21 (27.3%) cases coming out of infection, 9 (11.7%) were negative and 8 (10.4%) were defined with immunological memory; of positive cases, 32 (82.1%) were found in the adult group and 30 (76.9%) were female. CONCLUSION: Around half of samples were confirmed as brucellosis, the clinical manifestations of the patients studied were non-specific, which highlights the importance of laboratory diagnosis.
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Humanos , Masculino , Feminino , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Adulto Jovem , Brucella , Brucelose/diagnóstico , Brucelose/epidemiologia , Testes Sorológicos , Estudos Transversais , México/epidemiologiaRESUMO
We are reporting for the first time the synthesis and application of an innovative nanometric system for the controlled topic release of melatonin in the retina. The ethylcellulose nanocapsules were characterized by diverse physicochemical techniques (scanning electron microscopy, zeta potential, hydrodynamic diameters) and an in vitro release study was done. A complete ex vivo and in vivo trans-corneal permeation and an irritation study were carried out with the new formulations in albino rabbits, to which a retinal degenerative model was induced. The results obtained demonstrate that the in vitro release of melatonin (1 mg/mL and 2 mg/mL) transported by nanocapsules is slower when compared to a solution of melatonin. Greater penetration of melatonin through the cornea was demonstrated by ex vivo and in vivo tests. This can be attributable to an enhanced neuroprotective effect of melatonin on retinal ganglion cells when it is included in ethylcellulose nanocapsules compared to a solution of melatonin. These outstanding findings add promising new perspectives to current knowledge about administrations using nano-technological tools in the treatment of neurodegenerative diseases at the ocular level.
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Celulose/análogos & derivados , Melatonina/administração & dosagem , Degeneração Retiniana/tratamento farmacológico , Células Ganglionares da Retina/patologia , Animais , Antioxidantes/administração & dosagem , Celulose/farmacologia , Modelos Animais de Doenças , Composição de Medicamentos , Microscopia Eletrônica de Varredura , Nanopartículas/ultraestrutura , Coelhos , Degeneração Retiniana/diagnóstico , Células Ganglionares da Retina/efeitos dos fármacosRESUMO
The growing interest in the chemistry of unsaturated ring-fused 1,3-heterocycles, in this particular case 1,3-oxazines, arise in part from their versatile pharmacological applications. In the present article, the evaluation of the in vitro and ex vivo antioxidant activity of two cyclohexene-fused oxazines is discussed. The in vitro antioxidant activity was evaluated by trapping the ABTS and hydroxyl radicals as well as the inhibition of the enzyme acetyl-cholinesterase and hemolysis of erythrocytes by 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH). The results suggest that both unsaturated 1,3-oxazines are auspicious sources of biologically active compounds with good antioxidant properties. In addition, a comprehensive analysis of the interaction between these heterocycles with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals, as well as the measurements of redox potential, provided evidence for a mechanism of antioxidant activity that takes place through electron transfer (ET) processes.
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Pioglitazone (PGZ) is a peroxisome proliferator-activated receptor agonist. Its role in the inflammatory response modulation paves the way for additional therapeutic applications. The purpose of this study was to develop a pioglitazone nanoemulsion (PGZ-NE) in order to investigate its anti-inflammatory efficacy on the skin. To that end, an NE vehicle developed for skin delivery was optimized and characterized. The resulting PGZ-NE showed good anti-inflammatory efficacy by decreasing the expression of inflammatory cytokines IL-6, IL-1ß and TNF-α. The properties of the developed nanocarrier allowed achievement of a high permeation flux of PGZ through the skin as well as a high retained amount in the skin, likely due to the depot effect of ingredients, which assured a prolonged local action, with good skin tolerability among participating individuals. Consequently, these results suggest that PGZ-NE may be used as an alternative treatment for inflammatory skin diseases such as rosacea, atopic dermatitis or psoriasis.
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Emulsões/química , Inflamação/tratamento farmacológico , Nanopartículas/química , Pioglitazona/uso terapêutico , Dermatopatias/tratamento farmacológico , Adulto , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Citocinas/metabolismo , Liberação Controlada de Fármacos , Feminino , Humanos , Inflamação/patologia , Camundongos Endogâmicos BALB C , Nanopartículas/ultraestrutura , Permeabilidade , Pioglitazona/efeitos adversos , Pioglitazona/farmacologia , Reologia , Pele/efeitos dos fármacos , Pele/patologia , Dermatopatias/patologia , ViscosidadeRESUMO
The objectives of the present study were to determine the combined effects of chitosan and water activity (aW) on growth and mycotoxin production in situ on the two most important Fusarium species (F. proliferatum and F. verticillioides) present on maize, and on F. graminearum, the main pathogen causing Fusarium head blight on wheat. Results showed that low-molecular-weight chitosan with more than 70% deacetylation at the lowest dose used (0.5 mg/g) was able to reduce deoxynivalenol (DON) and fumonisin (FBs) production on irradiated maize and wheat grains. Growth rates of F. graminearum also decreased at the lowest chitosan dose used (0.5 mg/g), while F. verticillioides and F. proliferatum growth rates were reduced at 0.98 aW at the highest chitosan dose used (2 mg/g). Since mycotoxins are unavoidable contaminants in food and feed chains, their presence needs to be reduced in order to minimize their effects on human and animal health and to diminish the annual market loss through rejected maize and wheat; in this scenario, pre- and post-harvest use of chitosan could be an important alternative.
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In Argentina, wheat is the most consumed cereal by the human population. Since fumonisins occurence in wheat grains and wheat-based products have been reported worldwide, a survey was conducted in order to determine fumonisin contamination in 91 wheat-based products (white wheat flour samples, wheat flour used at bakery products and whole-wheat flour samples) collected from different retail stores of Rio Cuarto city in Argentina using HPLC-MS/MS. Sixty-seven samples (74%) showed contamination by fumonisins. From these samples, 16 showed fumonisin levels between LOD and LOQ (between 0.01 to 0.05 ng/g), while fumonisins (FB1 + FB2) in quantifiable samples ranged from 0.05 ng/g to 18.9 ng/g. Although FB1 was more prevalent, FB2 was foun3d in higher levels than FB1. Overall, fumonisin prevalence was high, but concentrations were far below EU or USA limits set for maize and maize-based products.
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Contaminação de Alimentos/análise , Fumonisinas/análise , Triticum/química , Argentina , Carcinógenos , Cromatografia Líquida de Alta Pressão/métodos , Farinha/análise , Humanos , Limite de Detecção , Espectrometria de Massas em Tandem/métodosRESUMO
A survey was carried out to determine natural occurrence of tenuazonic acid (TA) in healthy and rotten wine grapes samples from different varieties (n = 37) collected during 2016 vintage in the region of DOC San Rafael (Argentina). In addition, inoculation experiments with three Alternaria alternata strains in wine grapes were done to elucidate TA production and its major influencing factors. The 16.2% (6/37) of total wine grape samples showed TA contamination with 4% (1/25) of incidence in healthy samples (77 µg·kg-1) and 42% (5/12) in rotten samples (10-778 µg·kg-1). Malbec, Cabernet Sauvignon, and Syrah varieties showed TA contamination, whereas Bonarda, Ancelota, Torrontés, Semillón, and Chenin did not. During inoculation experiments in wine grapes, two of three strains were able to produce TA among the evaluated conditions and the highest TA production was observed at 15°C and 25°C after 24 days of incubation. Nutritional composition of grapes results appropriate for A. alternata infection and TA production and, together with the adequate field conditions, favors TA natural occurrence in wine grapes.
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Epiphytic isolates with yeast characteristics from grapes of the Malbec cultivar were obtained in order to find antagonists against Alternaria alternata. From a total of 111 isolates, 82% corresponded to the yeast-like organism Aureobasidium pullulans and the rest to the non-Saccharomyces yeasts Hanseniaspora uvarum (6.3%), Metschnikowia pulcherrima or spp. (5.4%), Cryptoccocus laurentti II (2.7%), Starmerella bacilaris or Candida zemplinina (2.7%) and Rhodotorula spp. (0.9%). The 22.4% (15 out of 67) of epiphytic yeasts and yeast-like organisms evaluated were able to reduce A. alternata infection from 0.0 to 4.4% when applied 2h previous to pathogen inoculation on wounds of grape berries. From these selected strains, 14 out of 15 strains completely prevented A. alternata infection (0.0%), which implies potential for field application. All Metschnikowia (pulcherrima or spp.), S. bacillaris and almost all H. uvarum evaluated strains showed antagonist capability against A. alternata. Meanwhile, none of the lesser nutritional requirement strains belonging to A. pullulans, Cr. laurenti II and Rhodotorula spp. did. All the yeasts with capacity to prevent A. alternata infection also reduced tenuazonic acid (TA) production by 81.2 to 99.8%, finding TA levels similar to negative controls. Therefore, the epiphytic yeasts selected are promising as biological control agents against Alternaria infection and toxin production in grapes for winemaking.
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Alternaria/fisiologia , Agentes de Controle Biológico , Microbiologia de Alimentos , Vitis/microbiologia , Leveduras/metabolismo , Argentina , Frutas/microbiologia , Ácido Tenuazônico/biossíntese , Leveduras/isolamento & purificaçãoRESUMO
Fusarium proliferatum produces fumonisins B not only on maize but also on diverse crops including wheat. Using a wheat-based medium, the effects of abiotic factors, temperature and water activity (aW), on growth, fumonisin biosynthesis, and expression of FUM genes were compared for three F. proliferatum strains isolated from durum wheat in Argentina. Although all isolates showed similar profiles of growth, the fumonisin production profiles were slightly different. Regarding FUM gene transcriptional control, both FUM8 and FUM19 expression showed similar behavior in all tested conditions. For both genes, expression at 25°C correlated with fumonisin production, regardless of the aw conditions. However, at 15°C, these two genes were as highly expressed as at 25°C although the amounts of toxin were very weak, suggesting that the kinetics of fumonisin production was slowed at 15°C. This study provides useful baseline data on conditions representing a low or a high risk for contamination of wheat kernels with fumonisins.
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Fumonisinas/metabolismo , Fusarium/crescimento & desenvolvimento , Fusarium/metabolismo , Regulação Fúngica da Expressão Gênica/genética , Estresse Fisiológico/fisiologia , Triticum/microbiologia , Argentina , Fusarium/genética , Fusarium/isolamento & purificação , Expressão Gênica/genética , Temperatura , Triticum/metabolismo , Água/metabolismoRESUMO
OBJECTIVE: To assess the prevalence of genital Mycoplasma spp. among women with systemic lupus erythematosus (SLE) and to identify factors associated with such infection. METHODS: A cross-sectional study was conducted among patients with SLE and healthy women who attended a hospital in Puebla, Mexico, between July 29, 2014, and January 4, 2015. All participants were aged 18 years or older and sexually active. A structured interview assessed sociodemographic, obstetric, gynecologic, and clinical characteristics. Disease activity was evaluated using the Mexican SLE Disease Activity Index. Polymerase chain reaction was used to detect the presence of Mycoplasma spp. in genital samples. RESULTS: Ureaplasma urealyticum was the only genital mycoplasma detected; it was present in 32 (24.6%) of 130 patients with SLE and 12 (12.8%) of 94 healthy women. Patients with SLE had increased odds of infection (odds ratio 2.120, 95% confidence interval 1.046-4.296). Among patients with SLE, multiparity was more common in those with U. urealyticum infection (P=0.043). CONCLUSION: One-quarter of women with SLE had genital infection with U. urealyticum. An association was found between infection and multiparity among women with SLE.