Effect of fungicides commonly used for Fusarium head blight management on growth and fumonisin production by Fusarium proliferatum.

Fumonisin occurrence was reported in wheat grains and F. proliferatum has been suggested to be the main contributor to its presence in wheat. Thus, a survey was performed in order to study the impact of four commercial fungicides used in Argentina for controlling Fusarium head blight disease (epoxiconazole+metconazole, tebuconazole, pyraclostrobin+epoxiconazole, and prothioconazole) on growth and fumonisin production of two F. proliferatum strains in relation to water activity (aW; 0.99, 0.97, 0.95) and temperature (15°C and 25°C). Most fungicides reduced growth rates when compared to the control (reduction increased as fungicide concentration increased), and reduced fumonisin production when they were used at high doses; however, most fungicides enhanced fumonisin production at sublethal doses, with the exception of prothioconazole. Thus, fungicides used for FHB management could enhance fumonisin production by F. proliferatum strains present in wheat grains.

Aflatoxin Decontamination in Maize Steep Liquor Obtained from Bioethanol Production Using Laccases from Species within the Basidiomycota Phylum.

Maize (Zea mays L.) is an important crop in Argentina. Aspergillus section Flavi can infect this crop at the pre-harvest stage, and the harvested grains can be contaminated with aflatoxins (AFs). During the production of bioethanol from maize, AF levels can increase up to three times in the final co-products, known as, dry and wet distiller's grain with solubles (DDGS and WDGS), intended for animal feed. Fungal enzymes like laccases can be a useful tool for reducing AF contamination in the co-products obtained from this process. The aim of the present study was to evaluate the ability of laccase enzymes included in enzymatic extracts (EE) produced by different species in the Basidiomycota phylum to reduce AF (AFB1 and AFB2) accumulation under the conditions of in vitro assays. Four laccase activities (5, 10, 15, and 20 U/mL) exerted by nine isolates were evaluated in the absence and presence of vanillic acid (VA), serving as a laccase redox mediator for the degradation of total AFs. The enzymatic stability in maize steep liquor (MSL) was confirmed after a 60 h incubation period. The most effective EE in terms of reducing AF content in the buffer was selected for an additional assay carried out under the same conditions using maize steep liquor obtained after the saccharification stage during the bioethanol production process. The highest degradation percentages were observed at 20 U/mL of laccase enzymatic activity and 1 mM of VA, corresponding to 26% for AFB1 and 26.6% for AFB2. The present study provides valuable data for the development of an efficient tool based on fungal laccases for preventing AF accumulation in the co-products of bioethanol produced from maize used for animal feed.

Influence of water activity and temperature on growth and fumonisin production by Fusarium proliferatum strains on irradiated wheat grains.

Wheat is the most important cereal consumed by the Argentine population. In previous studies performed in durum and common wheat grains in this country it has been observed fumonisin contamination as well as high incidence of Fusarium proliferatum. Fumonisins are toxic fungal metabolites, and consumption of fumonisin-contaminated maize has been epidemiologically associated with oesophageal cancer and neural tube defects in some human populations. Using irradiated wheat-grains, the effects of abiotic factors, temperature (15, 25, and 30°C) and water activity (aW; 0.995, 0.98, 0.96, 0.94, 0.92, and 0.88), on mycelial growth and fumonisin biosynthesis were compared for three F. proliferatum strains isolated from wheat grains in Argentina. Although all isolates showed similar profiles of growth, the fumonisin production profiles were slightly different. Maximum growth rates were obtained at the highest aW (0.995) and 25°C, with growth decreasing as the aW of the medium was reduced. Maximum amounts of total fumonisins (FB1, FB2 and FB3) were produced at 0.995 aW and 15°C for 2 strains, and at 25°C and 0.995 aW for the third one. Fumonisins concentrations varied considerably depending on the aW and temperature interactions assayed. Studied strains showed different fumonisin production profiles. Two-dimensional profiles of aW by temperature interactions were developed from these data to identify areas where conditions indicate a significant risk of fumonisins accumulation on wheat. As a result, temperature and aW conditions that resulted in fumonisins production are those found during wheat grain development (especially milk and dough stages) in the field. This is the first study made using irradiated wheat grains and provides useful baseline data on conditions representing a low or a high risk for fumonisins contamination of wheat grains which is of concern because this cereal is destined mainly for human consumption.

Activated carbons as potentially useful non-nutritive additives to prevent the effect of fumonisin B1 on sodium bentonite activity against chronic aflatoxicosis.

Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are mycotoxins that often co-occur in feedstuffs. The ingestion of AFB1 causes aflatoxicosis in humans and animals. Sodium bentonite (NaB), a cheap non-nutritive unselective sequestering agent incorporated in animal diets, can effectively prevent aflatoxicosis. Fumonisins are responsible for equine leukoencephalomalacia and porcine pulmonary oedema, and often have subclinical toxic effects in poultries. Fumonisin B1 and aflatoxin B1 are both strongly adsorbed in vitro on sodium bentonite. Co-adsorption studies, carried out with a weight ratio of FB1 to AFB1 that mimics the natural occurrence (200:1), showed that FB1 greatly decreases the in vitro ability of NaB to adsorb AFB1. The ability of two activated carbons to adsorb FB1 was also investigated. Both carbons showed high affinity for FB1. A complex behaviour of the FB1 adsorption isotherms with pH was observed. In vitro results suggest that under natural contamination levels of AFB1 and FB1, a mixture of activated carbon and sodium bentonite might be potentially useful for prevention of sub-acute aflatoxicosis.

Efectos fetales y posnatales del tabaquismo durante el embarazo / Fetal and postnatal effects of smoking during pregnancy

Resumen La exposición al tabaco en el útero se asocia con un menor crecimiento fetal, una disminución en el peso al nacer y un incremento significativo de nacimientos con bajo peso. Por otra parte, diversos estudios han indicado que el tabaquismo materno puede provocar sobrepeso u obesidad y un aumento rápido de peso en la infancia, lo puede aumentar el riesgo de enfermedades cardiovasculares y diabetes tipo 2 en la adultez temprana. Los niños expuestos a humo de tabaco en la vida intrauterina, tienen un sistema autónomo hiperreactivo durante las primeras semanas de vida, un crecimiento desproporcionado entre el parénquima pulmonar y las vías aéreas (crecimiento disináptico pulmonar), una disminución en la función pulmonar, un riesgo aumentado de asma, bronquitis y sibilancias en el producto. Existen asociaciones entre el tabaquismo materno y la reducción de las capacidades psicomotoras infantiles, así como los problemas de conducta incluido el trastorno por déficit de atención/hiperactividad en la niñez. Se ha observado un aumento en el riesgo de neoplasias benignas en la infancia (hemangioma y quiste tiroideo), pero no de neoplasias malignas.

Abstract Exposure to tobacco in the uterus is associated with lower fetal growth, a decrease in birth weight and a significant increase in low birth weight births. On the other hand, several studies have indicated that maternal smoking can cause overweight or obesity and a rapid increase in weight in childhood, which can increase the risk of cardiovascular disease and type 2 diabetes in early adulthood. Children exposed to tobacco smoke in intrauterine life, have a hyperreactive autonomic system during the first weeks of life, a disproportionate growth in lung parenchyma and airways (pulmonary dysynaptic growth), a reduction in lung function, an Increased risk in asthma, bronchitis and wheezing in the product. There are associations between maternal smoking and the reduction of infant psychomotor abilities, as well as behavioral problems that include children attention-deficit/hyperactivity disorder. There has been an increase in the risk of benign neoplasms in childhood (hemangioma and thyroid cyst), but not malignant neoplasms.

Intoxicación por organofosforados / Organophospate poisoning

Resumen La intoxicación por organofosforados es de gran importancia en el campo de la medicina, debido a su uso frecuente en la actividad agrícola, las intoxicaciones producidas por estos agentes pueden ser ocupacionales, accidentales, y con mayor frecuencia por ingesta voluntaria. Una de las mayores repercusiones de los organofosforados es la inhibición del acetil colinesterasa, enzima encargada de hidrolizar el acetil colina. Las manifestaciones clínicas de la intoxicación aguda se deben a la estimulación de receptores muscarínicos y nicotínicos, entre ellas broncorrea, salivación, lagrimeo, broncoespasmo, defecación, emesis, miosis, entre otros. El diagnóstico se realiza mediante la historia clínica y examen físico, de manera adicional con la detección de los niveles en sangre eritrocitaria de acetil colinesterasa o de los metabolitos de los organofosforados. El manejo incluye la descontaminación del agente, la revisión del estado respiratorio y el acceso al soporte ventilatorio, posteriormente se procede con el tratamiento farmacológico que incluye el uso de la atropina, pralidoxima y diazepam. El presente artículo constituye una revisión bibliográfica sobre la intoxicación por organofosforados, sus manifestaciones clínicas, diagnóstico y tratamiento.

Abstract Organophosphorus poisoning is of great importance in the field of medicine due to its frequent use in agriculture, the poisoning by exposure to these agents can be occupational, accidental, and frequently due to voluntary intake. Organophosphorus' intake most notable effects are produced by the inhibition of the acetyl cholinesterase, responsible for hydrolyzing acetyl choline. Clinical manifestations of acute intoxication typically include bronchorrhea, salivation, lacrimation, bronchospasm, defecation, emesis, miosis, among others and they occur due to the stimulation of muscarinic and nicotinic receptors. Diagnosis is made through the interrogation and physical examination, in addition to the detection of acetyl cholinesterase levels or the organophosphates' metabolites in blood testing. Management includes decontamination of the agent, review of respiratory status and access to ventilatory support, followed by pharmacological treatment that includes the use of atropine, pralidoxime and diazepam. The present article constitutes a bibliographic review about the organopho sphorus intoxication, its clinical manifestations, diagnosis and treatment.

Survey of Aspergillus and Fusarium species and their mycotoxins in raw materials and poultry feeds from Córdoba, Argentina.

The aims of the present work were: (1) to determine both mycobiota in raw materials and finisher poultry feed, as well as the ability to produce aflatoxin B1 by A. flavus strains, and (2) to evaluate the natural co-occurrence of aflatoxins (AFs), fumonisins (FBs), gliotoxin, diacetoxyscirpenol (DAS), HT-2 toxin, and T-2 toxin in poultry feed by LC-MS/MS. Nineteen percent of raw materials and 79% of finisher poultry feed samples exceeded the maximum allowed total fungal count (1 × 10(4) CFU g(-1)) to ensure hygienic quality. Aspergillus flavus was the only species belonging to section Flavi which was isolated while Fusarium verticilliodes was the prevalent species. Forty-seven percent of A. flavus strains were aflatoxin B1 producers and the highest frequency of aflatoxigenic strains was isolated from finisher poultry feeds. Principal component analysis showed that corn grains are closely related with total fungal and Fusarium counts. This positive relationship suggests that total fungal and Fusarium spp. counts in poultry feed might come mainly from corn grains. Regarding poultry feeds, in ground finisher type, Aspergillus spp. counts increased as water activity (aw) diminished. A positive relationship among aw, total fungal and Fusarium spp. counts was observed in both ground finisher and ground starter feed. Several mycotoxins were monitored in feeds by applying the LC MS/MS technique. One hundred percent of poultry samples were contaminated with FB1, and the highest levels were detected in pelleted finisher poultry. AFB1, gliotoxin, DAS, HT-2 toxin, and T-2 toxin were not detected in any poultry feed. The scarcity of available mycotoxicological studies from Argentinean poultry feed using a multitoxin analysis technique enhances the contribution of the findings of this report.