RESUMEN
The quality and safety of maize (Zea mays L.) from different grain storage units (GSUs), located in the main producing region of Rondônia State, Northern Brazil, were evaluated. Maize grains (n = 76) stored in four GSUs were collected from July to November 2014 and evaluated for grain damages, humidity, fungi and fumonisins (FBs) content. The climate conditions data were also obtained from plant growing to storage periods. Regarding the moisture content and water activity (aw), these varied from 10.0% to 16.1% and 0.5 to 0.8, respectively. As expected, fungi spores were present in 94.8% of the samples, prevailing Fusarium genera, with a fungi colony maximum of 2.2 × 104 CFU g-1. Regarding FBs, 60.5% of the samples were contaminated, below Brazilian and United States maximum limits, but 9.2% had levels higher than the European legislation.
Asunto(s)
Contaminación de Alimentos , Fumonisinas/química , Micotoxinas/química , Zea mays/química , Zea mays/microbiología , Brasil , Seguridad de Productos para el Consumidor , Almacenamiento de Alimentos , Hongos/clasificación , Hongos/aislamiento & purificación , Esporas Fúngicas/clasificación , Esporas Fúngicas/aislamiento & purificación , AguaRESUMEN
The levels of fumonisin B1 (FB1) residues in plasma, urine, feces and hair from 24 piglets fed FB1-contaminated diets containing 3.1, 6.1 or 9.0 µg FB1.g-1 for 28 days were determined using liquid chromatography coupled to mass spectrometry (LC-MS/MS). The levels of FB1 in plasma, urine, feces and pooled hair (n = 3) samples varied from 0.15 to 1.08 µg.L-1, 16.09-75.01 µg.L-1, 1.87-13.89 µg.g-1 and 2.08-8.09 ng.g-1, respectively. Significant correlations (r = 0.808-0.885; P < 0.001; N = 18) were found between FB1 intake and plasma FB1 on days 7, 14, 21 and 28. However, urinary FB1 correlated with FB1 intake only on days 7 and 14 (r = 0.561-572; P = 0.02; N = 18). A significant correlation (r = 0.509; P = 0.02; N = 24) was also found for the first time between FB1 in hair samples and FB1 intake. Plasma and urinary FB1 are good biomarkers of early exposure of pigs to low dietary FB1 levels, although plasma is recommended to assess prolonged exposure (>14 days). The possibility to evaluate hair as a biomarker of fumonisin exposure was established, although further studies are needed to provide physiologically based toxicokinetics of residual FB1 in the pig hair.
Asunto(s)
Alimentación Animal/análisis , Fumonisinas/farmacocinética , Cabello/química , Porcinos/metabolismo , Animales , Biomarcadores , Dieta/veterinaria , Heces/química , Contaminación de Alimentos , Fumonisinas/sangre , Fumonisinas/química , Fumonisinas/orina , Porcinos/sangre , Porcinos/orinaRESUMEN
Fresh and frozen pamonhas, a native Brazilian food made with sweet corn (Zea mays L.), similar to the Mexican tamal, which has been incorporated into the country's diet, were investigated for fumonisins (FBs: FB1 and FB2) contamination and product characteristics. The laboratory conditions of the applied fumonisins method with liquid chromatography and fluorescence detection were validated. Five out of the total samples showed FBs contamination above the national maximum level of 1000-1500 µg/kg. Despite this, in 59.6% (31) of the samples FB1 and in 23.1% (12) FB2 could be detected. The pamonhas characteristics did not show uniformity among the brands surveyed. The moisture content of 59.4% and water activity of 0.97 for both (fresh and frozen) samples showed to be suitable conditions for fungal growth. One sample had a quite high pH. It is essential to establish guidance criteria for pamonha production by the regulatory agencies.
Asunto(s)
Culinaria , Contaminación de Alimentos , Fumonisinas/química , Zea mays/química , Brasil , Humanos , Zea mays/microbiologíaRESUMEN
Fusarium verticillioides is a major maize pathogen and there are susceptible and resistant cultivars to this fungal infection. Recent studies suggest that its main mycotoxin fumonisin B1 (FB1) may be involved in phytopathogenicity, but the underlying mechanisms are mostly still unknown. This work was aimed at assessing whether FB1 disseminates inside the plants, as well as identifying possible correlations between the maize resistant/susceptible phenotype and the unbalances of the FB1-structurally-related sphingoid base sphinganine (Sa) and phytosphingosine (Pso) due to toxin accumulation. Resistant (RH) and susceptible hybrid (SH) maize seedlings grown from seeds inoculated with a FB1-producer F. verticillioides and from uninoculated ones irrigated with FB1 (20 ppm), were harvested at 7, 14 and 21 days after planting (dap), and the FB1, Sa and Pso levels were quantified in roots and aerial parts. The toxin was detected in roots and aerial parts for inoculated and FB1-irrigated plants of both hybrids. However, FB1 levels were overall higher in SH seedlings regardless of the treatment (infection or watering). Sa levels increased substantially in RH lines, peaking at 54-fold in infected roots at 14 dap. In contrast, the main change observed in SH seedlings was an increase of Pso in infected roots at 7 dap. Here, it was found that FB1 disseminates inside seedlings in the absence of FB1-producer fungal infections, perhaps indicating this might condition the fungus-plant interaction before the first contact. Furthermore, the results strongly suggest the existence of at least two ceramide synthase isoforms in maize with different substrate specificities, whose differential expression after FB1 exposure could be closely related to the susceptibility/resistance to F. verticillioides.
Asunto(s)
Fumonisinas/análisis , Fumonisinas/farmacología , Fusarium/química , Micotoxinas/análisis , Micotoxinas/metabolismo , Zea mays/microbiología , Fumonisinas/química , Micotoxinas/química , Enfermedades de las Plantas/microbiología , Raíces de Plantas/metabolismo , Plantones/metabolismo , Semillas/metabolismo , Esfingosina/análogos & derivados , Esfingosina/análisis , Agua/metabolismo , Zea mays/crecimiento & desarrolloRESUMEN
AIM: To evaluate the ability of probiotic Saccharomyces cerevisiae RC016 strain to reduce fumonisin B(1) (FB(1)) in vitro and to optimize the culture conditions for the growth of the yeast employing surface response methodology. METHODS AND RESULTS: Using Plackett-Burman screening designs (PBSD) and central composite designs (CCD), an optimized culture medium containing (g l(-1)) fermentable sugars provided by sugar cane molasses (CMs), yeast extract (YE) and (NH(4))(2) HPO(4) (DAP) was formulated. The S. cerevisiae RC016 strain showed the greatest binding at all assayed FB1 concentration. The CMs, YE, DAP concentrations and incubation time influenced significantly the biomass of S. cerevisiae RC016. CONCLUSION: A combination of CMs 17%; YE 4·61 g l(-1) and incubation time 60 h was optimum for maximum biomass of S. cerevisiae RC016. SIGNIFICANCE AND IMPACT OF THE STUDY: The importance of this work lies in the search for live strains with both probiotic and fumonisin B1 decontamination properties that could be sustainably produced in a medium just containing cheap carbon, nitrogen and phosphorus sources and would be included in a novel product to animal feed.
Asunto(s)
Biomasa , Fumonisinas/química , Probióticos , Saccharomyces cerevisiae/metabolismo , Alimentación Animal , Reactores Biológicos , Carbono/metabolismo , Medios de Cultivo/química , Fermentación , Microbiología Industrial , Modelos Estadísticos , Melaza , Nitrógeno/metabolismo , Saccharomyces cerevisiae/crecimiento & desarrollo , SaccharumRESUMEN
A total of 120 pelleted poultry feed samples from Entre Ríos Province, Argentina, were evaluated. The aims were to investigate (1) the presence of relevant toxigenic fungi, as well as to determine the ability to produce aflatoxins (AFs) by Aspergillus section Flavi isolated strains; and (2) the natural co-occurrence of AFs, fumonisins (FBs), gliotoxin, diacetoxyscirpenol (DAS), HT-2 and T-2 toxin by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Total fungal counts were below the established value (1 × 104 CFU g⻹). Aspergillus flavus and A. parasiticus were the only aflatoxigenic species isolated. Co-occurrence of fumonisin B1 (FB1), HT-2 and T-2 toxin was detected in 100% of the feeds, with mean levels from 4502 to 5813; 6.7 to 21.6 and 19.6 to 30.3 µg kg⻹, respectively. A large number of starter samples were co-contaminated with aflatoxin B1 (AFB1), FB1, HT-2 and T-2 toxins. Gliotoxin and DAS were not found in this survey.
Asunto(s)
Alimentación Animal/microbiología , Aspergillus/aislamiento & purificación , Contaminación de Alimentos , Micotoxinas/análisis , Aflatoxinas/análisis , Aflatoxinas/biosíntesis , Aflatoxinas/química , Alimentación Animal/análisis , Animales , Argentina , Aspergillus/crecimiento & desarrollo , Aspergillus/metabolismo , Aspergillus flavus/crecimiento & desarrollo , Aspergillus flavus/aislamiento & purificación , Aspergillus flavus/metabolismo , Cromatografía Líquida de Alta Presión , Recuento de Colonia Microbiana , Inspección de Alimentos , Fumonisinas/análisis , Fumonisinas/química , Fumonisinas/metabolismo , Isomerismo , Límite de Detección , Micotoxinas/biosíntesis , Micotoxinas/química , Aves de Corral , Análisis de Componente Principal , Reproducibilidad de los Resultados , Toxina T-2/análogos & derivados , Toxina T-2/análisis , Toxina T-2/biosíntesis , Toxina T-2/química , Espectrometría de Masas en TándemRESUMEN
The toxicity of FB1 is usually explained through the enzymatic disruption of lipidic metabolism. However, it may lie in the thermodynamics of the membrane and its cooperative phase behavior rather than in the activity of individual proteins. Here, we investigate the effects of FB1 at the molecular and mesoscopic levels in FB1-phospholipid mixed Langmuir films. Mean molecular area vs FB1 molar fractions (x(FB1)) and phase diagram analysis allowed us to define miscibility conditions and phase states at different x(FB1). Surface potential measurements, evaluated as a function of the molecular packing and x(FB1), revealed the FB1-induced change in the collective dipolar reorientation leaded to neutralization of charged films. Size, shape, and distribution of 2D-domain analysis from epifluorescence data suggested the increase in the mixing entropy and film relaxation rate. Finally, PM-IRRAS revealed the orientation of FB1 with the amine end (zwitterionic and negatively charged monolayers) or the tricarballylic acid end (positively charged monolayers) pointing to the air. The globular-extended conformational equilibrium of FB1 is dynamically defined by the membrane charge becoming a toxicity enhancing factor. The specificity of the toxin-protein interaction might also be perturbed by the FB1-induced remodeling of the membrane topography by affecting the raft-like platforms where membrane enzymes are considered to be located.
Asunto(s)
Fumonisinas/química , Fosfolípidos/química , Microscopía Fluorescente , Modelos Moleculares , Estructura Molecular , Espectrofotometría Infrarroja , Propiedades de Superficie , TermodinámicaRESUMEN
Aspergillus section Nigri populations isolated from seven growing regions from Argentina were characterized by sequencing in order to identify species responsible for production of ochratoxin A (OTA) and fumonisins (FB(s)). Sequences of genes encoding calmodulin, ß-tubulin, the second largest subunit of RNA polymerase II and translation elongation factor 1 alpha were analysed. The phylogenetic analysis showed the presence of six lineages: A. carbonarius, A. tubingensis, A. niger, A. japonicus, A. homomorphus and A. foetidus grouped in four major clusters. The molecular tools used allowed the identification for the first time of A. homomorphus from vineyards. OTA production confirmed the importance of A. carbonarius as the main ochratoxigenic species isolated and, to a variable degree, of A. niger and A. tubingensis, which were by far the most commonly occurring species on grapes in Argentina. The only strains able to produce OTA and fumonisins (B(2)-B(4)) belong to the A. niger cluster.
Asunto(s)
Aspergillus/metabolismo , Fumonisinas/metabolismo , Ocratoxinas/metabolismo , Argentina , Aspergillus/clasificación , Aspergillus/genética , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Fumonisinas/química , Ocratoxinas/química , Filogenia , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo , Vitis/microbiologíaRESUMEN
Fumonisins are mycotoxins that contaminate maize, disrupt the folate and sphingolipid metabolism, are associated with neural tube defects, and are considered by the International Agency for Research on Cancer (IARC) as possible human carcinogens. Since maize-based foods are significant components of the Mexican diet and there is a high prevalence of genetic susceptibility for folate deficiency among Mexicans, this essay presents international and national evidence of fumonisin exposure and the relevance that such exposure represents for Mexico.
Asunto(s)
Ácido Fólico/metabolismo , Contaminación de Alimentos , Fumonisinas/efectos adversos , Defectos del Tubo Neural/etiología , Adolescente , Adulto , Animales , Carcinógenos Ambientales/efectos adversos , Neoplasias del Sistema Digestivo/inducido químicamente , Neoplasias del Sistema Digestivo/epidemiología , Equidae , Femenino , Receptor 2 de Folato/antagonistas & inhibidores , Fumonisinas/química , Fumonisinas/farmacocinética , Fumonisinas/toxicidad , Homocistinuria/epidemiología , Homocistinuria/genética , Humanos , Necrosis Tubular Aguda/inducido químicamente , Leucoencefalopatías/inducido químicamente , Leucoencefalopatías/veterinaria , Masculino , Proteínas de Transporte de Membrana/metabolismo , Metilenotetrahidrofolato Reductasa (NADPH2)/deficiencia , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , México , Ratones , Espasticidad Muscular/epidemiología , Espasticidad Muscular/genética , Defectos del Tubo Neural/inducido químicamente , Defectos del Tubo Neural/epidemiología , Defectos del Tubo Neural/genética , Embarazo , Trastornos Psicóticos/epidemiología , Trastornos Psicóticos/genética , Ratas , Esfingolípidos/química , Esfingolípidos/metabolismo , Porcinos , Teratógenos/toxicidad , Adulto Joven , Zea mays/microbiologíaRESUMEN
Las fumonisinas son una familia de micotoxinas que contaminan al maíz, alteran el metabolismo de los esfingolípidos y del folato, se asocian con defectos del tubo neural y están catalogadas por la Agencia Internacional de Investigación en Cáncer (IARC por sus siglas en inglés) como posibles carcinógenos humanos. Debido a que en México los derivados de maíz constituyen una parte importante de la dieta y existe alta prevalencia de población genéticamente susceptible a la deficiencia de folato, en este ensayo se presentan las evidencias mundiales y nacionales de la exposición a fumonisinas y la relevancia que para México representa la evaluación de esta exposición.
Fumonisins are mycotoxins that contaminate maize, disrupt the folate and sphingolipid metabolism, are associated with neural tube defects, and are considered by the International Agency for Research on Cancer (IARC) as possible human carcinogens. Since maize-based foods are significant components of the Mexican diet and there is a high prevalence of genetic susceptibility for folate deficiency among Mexicans, this essay presents international and national evidence of fumonisin exposure and the relevance that such exposure represents for Mexico.
Asunto(s)
Adolescente , Adulto , Animales , Femenino , Humanos , Masculino , Ratones , Embarazo , Ratas , Adulto Joven , Ácido Fólico/metabolismo , Contaminación de Alimentos , Fumonisinas/efectos adversos , Defectos del Tubo Neural/etiología , Carcinógenos Ambientales/efectos adversos , Neoplasias del Sistema Digestivo/inducido químicamente , Neoplasias del Sistema Digestivo/epidemiología , Equidae , /antagonistas & inhibidores , Fumonisinas/química , Fumonisinas/farmacocinética , Fumonisinas/toxicidad , Homocistinuria/epidemiología , Homocistinuria/genética , Necrosis Tubular Aguda/inducido químicamente , Leucoencefalopatías/inducido químicamente , Leucoencefalopatías/veterinaria , Proteínas de Transporte de Membrana/metabolismo , /deficiencia , /genética , México , Espasticidad Muscular/epidemiología , Espasticidad Muscular/genética , Defectos del Tubo Neural/inducido químicamente , Defectos del Tubo Neural/epidemiología , Defectos del Tubo Neural/genética , Trastornos Psicóticos/epidemiología , Trastornos Psicóticos/genética , Esfingolípidos/química , Esfingolípidos/metabolismo , Porcinos , Teratógenos/toxicidad , Adulto Joven , Zea mays/microbiologíaRESUMEN
The disruption of lipidic metabolism was considered a good candidate to explain FB1 toxicity mechanism. In the present work we investigated molecular organizational changes induced by FB1-biomembrane interaction possibly involved in mycotoxic effects. FB1 was self-aggregated with a critical micellar concentration of 1.97 mM. FB1 (0-81.4 microM), decreased in a dose-dependent manner, the fluorescence anisotropy of TMA-DPH (from 0.349+/-0.003 to 0.1720+/-0.0035) in dpPC bilayers, whilst no differences were registered with DPH. At 5.6 microM in the subphase, FB1 increased the lateral surface pressure (pi) of a Langmuir film to an extent that depended on the monolayer composition (Deltapi dpPC:DOTAP 3:1>Deltapi dpPC:dpPA3:1>Deltapi dpPC), the molecular packing (Deltapi decreased linearly as a function of the initial pi) and the subphase pH (Deltapi pH 2.6>Deltapi pH 7.4 and maximal pi allowing the drug penetration pi cut-off was 34.3 and 27.7 mN/m at pH 2.63 and 7.4, respectively). FB1 increased the surface potential of dpPC and dpPC:DOTAP monolayers and decreased that of dpPC:dpPA. This suggested that FB1 acquired different orientations and/or foldings depending on the surface electrostatics and the toxin charge state. Moreover, FB1-lipid interactions were transduced into long-range effects at the mesoscopic level affecting the lipidic self-separated lateral domains shape and density.