Inhalation of Aspergillus fumigatus conidia can cause severe aspergillosis in immunosuppressed people. A. fumigatus produces a large number of secondary metabolites, some of which are airborne by conidia and whose toxicity to the respiratory tract has not been investigated. We found that spores of A. fumigatus contain five main compounds, tryptoquivaline F, fumiquinazoline C, questin, monomethylsulochrin and trypacidin. Fractionation of culture extracts using RP-HPLC and LC-MS showed that samples containing questin, monomethylsulochrin and trypacidin were toxic to the human A549 lung cell line. These compounds were purified and their structure verified using NMR in order to compare their toxicity against A549 cells. Trypacidin was the most toxic, decreasing cell viability and triggering cell lysis, both effects occurring at an IC50 close to 7 µM. Trypacidin toxicity was also observed in the same concentration range on human bronchial epithelial cells. In the first hour of exposure, trypacidin initiates the intracellular formation of nitric oxide (NO) and hydrogen peroxide (H2O2). This oxidative stress triggers necrotic cell death in the following 24 h. The apoptosis pathway, moreover, was not involved in the cell death process as trypacidin did not induce apoptotic bodies or a decrease in mitochondrial membrane potential. This is the first time that the toxicity of trypacidin to lung cells has been reported.

Aims:  Considering the agronomic and industrial damage that is caused by the fungus Fusarium graminearum, as well as the serious health risks it poses to humans and animals exposed to F. graminearum‐produced mycotoxin deoxynivalenol (DON), this study evaluated the ability of different lactic acid bacteria (LAB) strains to inhibit fungal development and remove DON in vitro. Methods and Results:  The antagonistic effects of strains and commercial cultures of LAB were evaluated against F. graminearum IAPAR 2218 by the agar diffusion method. Additionally, the influence of the culture media, pH and the presence of lactic and acetic acid on these effects was tested. The capacity to remove DON by viable cells and heat‐inactivated cells was analysed in liquid media and quantified by high performance liquid chromatography (HPLC). All isolated strains and commercial cultures inhibited the fungus and removed DON. The pH and culture media concentration did not influence these abilities, but heat inactivation had a strong effect on the ability of bacteria to remove mycotoxin. Conclusions:  The isolated bacteria are able to inhibit F. graminearum growth and remove DON in vitro. Significance and Impact of the Study:  This study suggests potential application of the isolated LAB strains in the inhibition of F. graminearum IAPAR 2218 and DON removal in vitro.

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The occurrence of deoxynivalenol (DON) was evaluated in 113 wheat samples from the northern and central/southwestern regions of Paraná State, Brazil during the 2008 and 2009 growing seasons, and this rate of occurrence was used to estimate the DON dietary exposure. The DON determination was carried out by an indirect competitive enzyme-linked immunosorbent assay. DON was detected in 66.4% samples at levels ranging from 206.3 to 4732.3 μg/kg (mean 1894.9 μg/kg). The estimated daily intake (EDI) of DON through bread and pasta was evaluated in the inhabitants of Londrina City in northern Paraná State, Brazil. The average intake of these inhabitants was 0.79 μg/kg body weight (b.w.) for bread and 0.35 μg/kg b.w. for pasta. The total EDI was 1.13 μg/kg, which is above the Provisional Tolerable Daily Maximum Intake (PTDMI) of 1 μg/kg b.w. To our knowledge, this is the first report on natural DON occurrence in wheat and DON dietary exposure estimation from Paraná, Brazil.

The effects of weather/season (winter and summer), milk production (high and low), and milking time (night and day) on melatonin levels were evaluated. The melatonin in the milk from 30 individual cows, the bulk tank milk (BTM) from 16 farms, and ultra-high temperature (UHT) processed milk of 12 brands over two seasons were also assessed. The melatonin average concentration was 6.98 pg/mL in the cows' milk, 4.71 pg/mL in the BTM, and 5.62 pg/mL in the UHT milk. In the night milk, the melatonin concentration averaged 14.87 pg/mL, whereas it was 6.98 pg/mL in the total daily milk. In winter, the milk melatonin concentration was, on average, 74.7% higher than in the summer (13.89 vs. 7.95 pg/mL). The night milk from the low production group in winter also had a higher concentration of melatonin (41.94 pg/mL). The variables related to illuminance, such as the time of milking and season of the year, had considerable effects on the melatonin concentration in milk. Collecting and marketing melatonin-rich milk could benefit populations and agribusiness. ARTICLE HISTORY

An indirect competitive enzyme-linked immunosorbent assay (ELISA) method using a monoclonal antibody for deoxynivalenol (DON) detection in wheat and flour was standardised and validated (detection limit = 177.1 µg kg(-1)) and its performance was compared with LC-MS, quantification limit =140 µg kg(-1)). DON recovery ranged from 88.7% to 122.6% for wheat grain and from 70.6% to 139.3% for flour. Among the 38 wheat samples evaluated, DON was detected in 29 samples (76.3%) by ic-ELISA (281.6-12 291.4 µg kg(-1)) and in 22 samples (57.9%) by LC-MS (155.3-9906.9 µg kg(-1)). The 0.93 correlation coefficient between ic-ELISA and LC-MS data in 19 positive DON wheat samples demonstrated the reliability and efficiency of ic-ELISA. Results indicated that standardised ic-ELISA was suitable for DON screening in wheat samples and the need for continuous monitoring of mycotoxin levels in foodstuffs.

Pseudomonas spp. and P. fluorescens: population in refrigerated raw milk.Ciência Rural, v.47, n.1, 2017. IntRoDuCtIonGuidelines for cooling milk in dairy farms and its transportation were established in Brazil in 2002 (BRaSIl, 2002 as a response to international regulations and market demands. Since then, changes in milk chain production profile and qualitative advances in the regulation of total bacterial (TBC) and somatic cell (SCC) counts in raw milk have occurred (BRaSIl, 2002), and the guidelines were updated in 2011 (BRaSIl, 2011