Paulo Dilkin

Toxicokinetics and toxicological effects of single oral dose of fumonisin B1 containing Fusarium verticillioides culture material in weaned piglets.

Toxicokinetics and the toxicological effects of culture material containing fumonisin B(1) (FB(1)) were studied in male weaned piglets by clinical, pathological, biochemical and sphingolipid analyses. The animals received a single oral dose of 5 mg FB(1)/kg of body weight, obtained from Fusarium verticillioides culture material. FB(1) was detected by HPLC in plasma collected at 1-h intervals up to 6h and at 12-h intervals up to 96 h. FB(1) eliminated in feces and urine was quantified over a 96-h period and in liver samples collected 96 h post-intoxication. Blood samples were obtained at the beginning and end of the experiment to determine serum enzyme activity, total bilirubin, cholesterol, sphinganine (Sa), sphingosine (So) and the Sa/So ratio. FB(1) was detected in plasma between 30 min and 36 h after administration. The highest concentration of FB(1) was observed after 2 h, with a mean concentration of 282 microg/ml. Only 0.93% of the total FB(1) was detected in urine between 75 min and 41 h after administration, the highest mean concentration (561 microg/ml) was observed during the interval after 8 at 24 h. Approximately 76.5% of FB(1) was detected in feces eliminated between 8 and 84 h after administration, with the highest levels observed between 8 and 24 h. Considering the biochemical parameters, a significant increase only occurred in cholesterol, alkaline phosphatase and aspartate aminotransferase activities. In plasma and urine, the highest Sa and Sa/So ratios were obtained at 12 and 48 h, respectively.

Equine leukoencephalomalacia associated with ingestion of corn contaminated with fumonisin B1

This article describes clinical, etiologic and pathologic diagnosis of an outbreak of equine leukoencephalomalacia. Two samples of the corn consumed by the affected horses contained fumonisin B1 at levels of 46 and 53 µg/g and Fusarium moniliforme, a good in vitro mycotoxin producer.

Production of fumonisins by strains of Fusarium moniliforme according to temperature, moisture and growth period

Producao de fumonisinas B1 (FB1) e B2 (FB2) a partir de duas cepas brasileiras (LAMIC 2999/96 e 113F) e uma cepa americana (NRRL 13616) de Fusarium moniliforme foi avaliada em culturas de laboratorio submetidas a diferentes temperaturas (20, 25 e 30oC) e a diferentes teores de umidade (25, 34 e 42%) em substrato de milho. As culturas foram realizadas em periodos de 10, 20, 30, 45 e 60 dias, totalizando135 tratamentos com duas repeticoes para cada um. As fumonisinas foram extraidas com acetonitrila/agua. A limpeza foi realizada empregando cartuchos de silica C18 encapada (C18ec) e a derivacao com o-ftalodialdeido foram realizadas por um sistema processador automatico de amostras (ASPEC), seguidas por quantificacao das toxinas por CLAE. A producao de fumonisinas variou muito, atingindo rendimentos medios de 0,25 a 5515,45 µg/g de FB1 e de 0,15 a 3032,10 µg/g de FB2. Neste trabalho, os fatores como cepa, temperatura, umidade e dias de cultura fungica foram avaliados, e todos estes influenciaram nas quantidades de fumonisinas produzidas. As mais altas producoes de FB1 foram obtidas pela cepa 113F nas seguintes condicoes: teor de umidade de 34%, 60 dias de cultura, temperatura de 25oC. A maior producao media de FB2 foi obtida pela mesma cepa com culturas durante 45 dias, a um teor de umidade de 42%, a temperatura de 25oC. A temperatura ideal para producao de fumonisinas foi calculada por meio de analise de regressao, sendo 24,5oC e 24,3oC (±2oC) para FB1 e FB2, respectivamente.

Classificação Macroscópica, identificação da microbiota fúngica e produção de aflatoxinas em híbridos de milho

To determine the resistance of five different recently harvested corn hybrids to fungal growth and aflatoxins (AFs) production the following parameters were measured: 1) Macroscopic aspect of the grain and each hybrid classified as whole, damaged by insects (DI) or damaged by fungi (DF); 2) Fungal contamination of hybrids 3) Resistance to AFs production, through the culture of Aspergillus parasiticus, NRRL 2999 strain, on each hybrid grain studied and 4) Consumption of dry matter of hybrids by the fungal culture. It was observad that 38% of all corn hybrids had macroscopic damage, being 26.7% DI and 11.3% DF. The recently harvested hybrids showed fungal contamination by Penicillium sp. (14.3%); Aspergillus sp. (23.6%) and Fusarium sp. (57.1%). The production of AFs by the different hybrids cultured for 5 and 10 days showed difference only when compared to aflatoxin G2 cultured for 5 days. The average dry matter consumption of corn hybrids was of 1.25 and 2.69%, submitted to fungal culture for 5 and 10 days respectively.

Desempenho e plumagem de frangos de corte intoxicados por aflatoxinas

This work had the goal to study the exposure effect of broiler chickens to aflatoxins during a period of 42 days related to its development in size and feathers. Two experimental groups of male chicks were treated with ad libitum food, one group without aflatoxins (control group) and other using contaminated food with 3mg/kg of aflatoxins (treated group). Birds were evaluated twice a day to observe its performance and consumption of food. The weights were measured at the end of each breeding phase (21, 35 and 42 days). At the end of the experiment animal size, weight, amount of feathers, organs and amino acids profile in blood were analyzed and compared between the two groups. The treated group showed classical signs of intoxication with aflatoxins such as less uniformity, less feed consumption and body weight gain. Also some macroscopic and microscopic organs and tissue changes were observed. Evaluation of heart and liver of the treated group showed an increase in their average relative weight. Feather mass in this group was significantly reduced (33.8%), but its amino acids concentration was not affected despite the low performance of the intoxicated animals.

Effects of fumonisin B1 on selected biological responses and performance of broiler chickens

The objective of this study was to determine the effects of three doses of fumonisin B1 (0, 100, and 200mg/kg of feed) on biological variables (relative weight of liver [RWL], total plasma protein [TPP], albumin [Alb], calcium [Ca], phosphorus [P], uric acid [UA], alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma glutamyltransferase [GGT], alkaline phosphatase [AP], total cholesterol [Chol], triglycerides [Tri], sphinganine-to-sphingosine ratio [SA:SO], and C-reactive protein [CRP]), morphological evaluation of the small intestine (villus height [VH], crypt depth [CD], and villus-to-crypt ratio [V:C]), histological evaluation, and on performance (body weight [BW], feed intake [FI], and feed conversion rate [FCR]) of broiler chickens. Significant effects of FB were observed on BW and FI (reduced), on RWL, TPP, Ca, ALT, AST, GGT, Chol, and Tri (increased) at both 14 and 28 days evaluations. In addition, significant increase was observed on FCR, Alb, P, SA:SO, and CRP and significant reduction in UA, VH, and V:C only at the 28 days evaluation. Significant histological lesions were observed on liver and kidney of FB inoculated broilers at 14 and 28 days. Those results show that FB has a significant effect on biological and histological variables and on performance of broiler chickens.

Individual and combined effects of Salmonella typhimurium lipopolysaccharide and fumonisin B1 in broiler chickens.

The aim of this research was to evaluate the individual and combined effects of Salmonella typhimurium lipopolysaccharide (sLPS) and fumonisin B(1) (FB) on performance, relative weight of liver, biological parameters, and histological evaluation of several tissues from four hundred thirty-two 1-d-old male broiler chickens divided into 9 treatments according to the dose of FB (0, 100, or 200 mg/kg, from d 1 to d 28) and sLPS (0, 250, or 500 µg/application per bird, every other day, from d 15 to 27) administered. At the end of the experiment (28 d), significant effects caused by sLPS, FB, and the interaction of sLPS × FB were observed on several parameters. Histopathological evaluations showed significant lesions in liver and kidney caused by sLPS, FB, and their association. According to these results, both sLPS and FB (isolated or in association) cause significant effects on performance and biological parameters of broilers at 28 d of age.

Prevalence and levels of deoxynivalenol and zearalenone in commercial barley and wheat grain produced in Southern Brazil: an eight-year (2008 to 2015) summary

Fusarium head blight (FHB), caused mainly by Fusarium graminearum, is one of the most important diseases of barley and wheat in Brazil. The disease causes yield losses and contaminates grain with mycotoxins produced by the fungus, mainly deoxynivalenol (DON) and zearalenone (ZEA). The objective of this study was to summarize the results of 16,487 analyses of DON and ZEA in barley and wheat commercial grain produced in Brazil from 2008 to 2015 using liquid chromatography tandem-mass spectrometry. For barley, DON and ZEA were detected in 67% and 41% of the samples, respectively, but 19% and 18% were above the maximum tolerated limits (MTL = 1250 μg/kg for DON and 100 μg/kg for ZEA). For wheat, DON and ZEA were detected in 73 and 38% with 30% and 9% of the samples above the MTL (1250 μg/kg for DON and 200 μg/kg for ZEA). The overall mean concentration of DON was 737 μg/kg in barley and 660 μg/kg in wheat. The mean yearly DON levels varied less in barley (446 μg/kg to 1114 μg/kg) compared to wheat (346 μg/kg to 1274 μg/kg). For the latter, a high peak of DON was found in 2014 when 58% of the samples were above the MTL and the toxin levels averaged 1274 μg/kg across all samples. The mean yearly concentration of ZEA was 138 and 111 μg/kg for barley and wheat, respectively, with the highest prevalence and concentration reported in 2008 and 2009, for both crops. To our knowledge, this is the most comprehensive summary of DON and ZEA contamination in barley and wheat in Brazil for almost a decade of monitoring. Continuous assessment and close inspection of highly contaminated batches are essential to ensure food safety and mitigate the risk that these mycotoxins can cause to human and animal health.

Natural occurrence of tenuazonic acid and Phoma sorghina in Brazilian sorghum grains at different maturity stages

A survey of 100 samples of sorghum grains was carried out to determine Phoma spp. and tenuazonic acid (TA) contamination using molecular tools and LC-MS/MS. Sorghum samples were obtained at the following four grain maturity stages: milk (S1), soft dough (S2), hard dough (S3), and physiological maturity (S4). The results revealed a good correlation between Phoma and TA occurrence during grain development. The samples showed Phoma contamination with frequencies ranging from 2.4% (S1) to 87.4% (S4), and the molecular identification revealed P. sorghina as the only Phoma specie isolated. Tenuazonic acid was found in sorghum grains at all maturity stages. In S2, S3 and S4, 100% of the samples showed TA contamination with levels ranging from 20 to 1234µg/kg. Low levels of TA were detected in 36% of the samples collected at S1 stage. This is the first report of tenuazonic acid in Brazilian sorghum grains.

Dois planos de amostragem para análise de fumonisinas em milho

The aim of this research was to evaluate the efficiency of two sampling plans for fumonisins (B1+B2) analysis in 11 lots of maize. For sample collection the two systems used were a manual system in whole grains, using sampling spear, and an automatic system in milled grains, using the continuous flow sampling system (CFSS). For comparison purpose, two dispersion measurements were used: variance and coefficient of variation. For each sampling plan the variance associated to the three steps of fumonisins quantification (sampling, sample preparation, and analysis), and the total coefficient of variation were determined. The correlation between the average fumonisins concentration and the variances for each phase of the detection procedure was evaluated for each sampling plan using analysis of regression. At the automatic sampling plan in milled grains for fumonisins analysis in maize both sampling variance (0.0226mg kg-1)² and total coefficient of variation (6.37%) were lower (P<0.01) than in the manual sampling plan in whole grains whit (0.0685mg kg-1)² of variance and 8.94% of coefficient of variation, showing so better efficiency for fumonisin detection on maize.