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AIMS: Alternaria alternata is a major contaminant of wine grapes, meaning a health risk for wine consumers due to the accumulation of toxic metabolites. To develop a successful biofungicide, the effectiveness of epiphytic wine grape yeasts against A. alternata growth and toxin production was assessed in vitro under temperature and aW conditions that simulate those present in the field. METHODS AND RESULTS: The effect of 14 antagonistic yeasts was evaluated on growth and alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) production by three A. alternata strains in a synthetic medium with composition similar to grape (SN) at three temperatures (15, 25 and 30°C). All Metschnikowia sp. yeast strains evaluated completely prevented A. alternata growth and mycotoxin production at all temperatures in SN medium. Meanwhile, the growth inhibition exerted by Starmerella bacillaris yeast strains was higher at 30°C, followed by 25 and 15°C, being able to show a stimulating or inhibiting effect. Hanseniaspora uvarum yeast strains showed a growth promoting activity higher at 15°C, followed by 25 and 30°C. Even at conditions where A. alternata growth was stimulated by the S. bacillaris and H. uvarum yeasts, high inhibitions of mycotoxin production (AOH, AME and TA) were observed, indicating a complex interaction between growth and mycotoxin production. CONCLUSION: There is a significant influence of temperature on the effectiveness of biocontrol against A. alternata growth and mycotoxin production. Metschnikowia sp. strains are good candidates to compose a biofungicide against A. alternata. SIGNIFICANCE AND IMPACT OF THE STUDY: Among the different antagonistic yeasts evaluated, only Metschnikowia sp. strains were equally effective reducing A. alternata growth and mycotoxin at different temperatures underlining the importance of considering environmental factors in the selection of the antagonists.

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Abstract Mycotoxins are secondary metabolites produced by fungal species that mainly belong to Aspergillus, Fusarium, Penicillium and Alternaria, which can grow in a variety of crops including cereals, oilseeds and fruits. Consequently, their prevalence in foods and by-products not only affects human and animal health but also causes important losses in both domestic and international markets. This review provides data about toxigenic fungal species and mycotoxin occurrence in different crops commonly grown in Argentina. This information will be relevant to establish adequate management strategies to reduce the impact of mycotoxins on human food and animal feed chains and to implement future legislation on the maximum permitted levels of these fungal metabolites.

Resumen Las micotoxinas son metabolitos secundarios producidos por diferentes especies fúngicas pertenecientes, principalmente, a los géneros Aspergillus, Fusarium, Penicillium y Alternaria. Dichos microorganismos pueden crecer en una gran variedad de cultivos, entre los que se incluyen cereales, oleaginosas y frutas. La presencia de micotoxinas en alimentos y subproductos no sólo afecta la salud humana y animal, sino que también causa pérdidas importantes en los mercados nacionales e internacionales. Esta revisión proporciona datos sobre la prevalencia de especies fúngicas toxigénicas y de micotoxinas en diferentes cultivos y productos cosechados en Argentina. Dicha información será relevante para establecer estrategias de manejo adecuadas para reducir la entrada de las micotoxinas en las cadenas alimentarias del hombre y de los animales, así como para establecer futuras legislaciones sobre los niveles máximos permitidos de dichos metabolitos.

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We studied the epidemiologic triad-related factors influencing human papilloma virus (HPV) persistence in Mexican women with systemic lupus erythematosus (SLE). Patients aged ≥18 years with SLE (American College of Rheumatology criteria), with and without HPV persistence, were selected. Groups were analyzed by (1) host: clinical disease characteristics; (2) agent: (I) infectious (prevalence, incidence, HPV genotype and co-infections (≥2 HPV genotypes or mycoplasmas)), (II) chemical (contraceptives and immunosuppressive drugs) and (III) physical (vitamin D deficiency) and (3) environment. A total of 121 SLE patients were selected over a two-year period. (1) Host: mean age 45.8 years and disease duration 12.7 years. (2) Agent: (I) infectious. HPV infection prevalence in the second sample was 26.4%, high-risk HPV genotypes 21.5% and co-infections 7.4%. HPV infection incidence was 13.2%, persistence 13.2% and clearance 15.7%. (II) Chemical: use of oral hormonal contraceptives 5% and immunosuppressive treatment 97.5%. (III) Physical: Vitamin D levels were similar in both groups. (3) Environment: (I) natural. A total of 60.6% of patients were residents of Puebla City. (II) Social: The mean education level was 10.9. Poverty levels were: III degree 52.4%, IV degree 28% and II degree 17%. (III) Cultural behavioral: Onset of sexual life was 20.5 years, 10% had ≥3 sexual partners and 51.2% were postmenopausal. In conclusion, no factor of the epidemiologic triad was associated with HPV infection prevalence.

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AIMS: To study the effects of water activity (aW ; 0·99, 0·98, 0·97, 0·96 and 0·95), temperature (15, 25 and 30°C), incubation time (7-28 days), and their interactions on mycelial growth and alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) mycotoxin production on a synthetic nutrient (SN) media similar to grape composition by three strains of Alternaria alternata isolated from wine grapes from Argentina. METHODS AND RESULTS: Interacting conditions of aW , temperature and time of incubation were used to examine growth and mycotoxin production. All strains were able to grow at 0·95 aW , but maximum growth rates were obtained at 0·99 aW and 25°C. Maximum levels of AOH, AME and TA were obtained at 0·99 aW and 25°C, but high amounts of TA were also obtained at 0·96 aW and 15 or 30°C. Production of AOH and AME was favoured over TA at 25°C. TA levels were more sustained than AOH and AME. CONCLUSION: The optimum and marginal conditions for growth and mycotoxin production by A. alternata on a SN media similar to grape composition were in agreement, but certain stressful conditions for growth evaluated also promote mycotoxin production. SIGNIFICANCE AND IMPACT OF THE STUDY: Temperature and aW conditions that allows growth and mycotoxin production are those normally found during wine grape ripeness in the field. Therefore, efforts should be made to prevent Alternaria presence and mycotoxin production in wine grapes.

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Dekkera/Brettanomyces bruxellensis is considered a major cause of wine spoilage, and 4-ethylphenol and 4-ethylguaiacol are the most abundant off-aromas produced by this species. They are produced by decarboxylation of the corresponding hydroxycinnamic acids (HCAs), followed by a reduction of the intermediate 4-vinylphenols. The aim of the present study was to examine coumarate decarboxylase (CD) and vinylphenol reductase (VR) enzyme activities in 5 native D. bruxellensis strains and determine their relation with the production of ethylphenols under 'wine-like' conditions. In addition, biomass, cell culturability, carbon source utilization and organic acids were monitored during 60 days. All strains assayed turned out to have both enzyme activities. No significant differences were found in CD activity, whilst VR activity was variable among the strains. Growth of D. bruxellensis under 'wine-like' conditions showed two growth phases. Sugars were completely consumed during the first growth phase. Transformation of HCAs into ethylphenols also occurred during active growth of the yeast. No statistical differences were observed in volatile phenol levels produced by the strains growing under 'wine-like' conditions, independently of the enzyme activity previously recorded. Furthermore, our results demonstrate a relationship between the physiological state of D. bruxellensis and its ability to produce ethylphenols. Inhibition of growth of D. bruxellensis in wine seems to be the most efficient way to avoid ethylphenol production and the consequent loss of wine quality.

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Fusarium proliferatum is a member of the Fusarium fujikuroi species complex (FFSC) involved in the maize ear rot together with Fusarium verticillioides, which is a very closely related species. Recently, different studies have detected natural fumonisin contamination in wheat kernels and most of them have shown that the main species isolated was F. proliferatum. Fusarium strains obtained from freshly harvested durum wheat samples (2008 to 2011 harvest seasons) from Argentina were characterized through a phylogenetic analysis based on translation elongation factor-1 alpha (EF-1α) and calmodulin (CaM) genes, determination of mating type alleles, and evaluation of fumonisin production capability. The strains were identified as F. proliferatum (72%), F. verticillioides (24%) and other Fusarium species. The ratio of mating type alleles (MAT-1 and MAT-2) obtained for both main populations suggests possible occurrence of sexual reproduction in the wheat fields, although this seems more frequent in F. proliferatum. Phylogenetic analysis revealed greater nucleotide variability in F. proliferatum strains than in F. verticillioides, however this was not related to origin, host or harvest year. The fumonisin-producing ability was detected in 92% of the strains isolated from durum wheat grains. These results indicate that F. proliferatum and F. verticillioides, among the fumonisin producing species, frequently contaminate durum wheat grains in Argentina, presenting a high risk for human and animal health.

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The present study uses a probabilistic model to determine the growth/no growth interfaces of the spoilage wine yeast Dekkera bruxellensis CH29 as a function of ethanol (10-15%, v/v), pH (3.4-4.0) and free SO2 (0-50 mg/l) using time (7, 14, 21 and 30 days) as a dummy variable. The model, built with a total of 756 growth/no growth data obtained in a simile wine medium, could have application in the winery industry to determine the wine conditions needed to inhibit the growth of this species. Thereby, at 12.5% of ethanol and pH 3.7 for a growth probability of 0.01, it is necessary to add 30 mg/l of free SO2 to inhibit yeast growth for 7 days. However, the concentration of free SO2 should be raised to 48 mg/l to achieve a probability of no growth of 0.99 for 30 days under the same wine conditions. Other combinations of environmental variables can also be determined using the mathematical model depending on the needs of the industry.

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Knowledge and lessons from past accidental exposures in radiotherapy are very helpful in finding safety provisions to prevent recurrence. Disseminating lessons is necessary but not sufficient. There may be additional latent risks for other accidental exposures, which have not been reported or have not occurred, but are possible and may occur in the future if not identified, analyzed, and prevented by safety provisions. Proactive methods are available for anticipating and quantifying risk from potential event sequences. In this work, proactive methods, successfully used in industry, have been adapted and used in radiotherapy. Risk matrix is a tool that can be used in individual hospitals to classify event sequences in levels of risk. As with any anticipative method, the risk matrix involves a systematic search for potential risks; that is, any situation that can cause an accidental exposure. The method contributes new insights: The application of the risk matrix approach has identified that another group of less catastrophic but still severe single-patient events may have a higher probability, resulting in higher risk. The use of the risk matrix approach for safety assessment in individual hospitals would provide an opportunity for self-evaluation and managing the safety measures that are most suitable to the hospital's own conditions.

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The natural occurrence of alternariol (AOH) and alternariol monomethyl ether (AME) in soya beans harvested in Argentina was evaluated. Both toxins were simultaneously detected by using HPLC analysis coupled with a solid phase extraction column clean-up. Characteristics of this in-house method such as accuracy, precision and detection and quantification limits were defined by means of recovery test with spiked soya bean samples. Out of 50 soya bean samples, 60% showed contamination with the mycotoxins analyzed; among them, 16% were only contaminated with AOH and 14% just with AME. Fifteen of the positive samples showed co-occurrence of both mycotoxins analyzed. AOH was detected in concentrations ranging from 25 to 211 ng/g, whereas AME was found in concentrations ranging from 62 to 1,153 ng/g. Although a limited number of samples were evaluated, this is the first report on the natural occurrence of Alternaria toxins in soya beans and is relevant from the point of view of animal public health.

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Soybean (Glycine max L.), the main source of protein throughout the world, is used both as a food and a feedstuff. Currently, limited information about the occurrence of Fusarium species and mycotoxins in soybean grain and by-products is available. The aims of the present study were: (1) to identify toxigenic Fusarium species associated with soybean during crop reproductive stages; (2) to determine the occurrence of deoxynivalenol (DON) and nivalenol (NIV) in soybean seeds; (3) to determine the genotype and chemotype of selected Fg complex strains using molecular and chemical analysis, respectively; and (4) to characterize the strains using AFLP(s) markers. One soybean field located at Córdoba Province, Argentina, was monitored and samples of soybean tissue were harvested at three reproductive stages: flowering (R2), full seed (R6) and full maturity (R8). A total of 389 Fusarium strains F. equiseti (40%) was the most frequently species recovered followed by F. semitectum (27%) and F. graminearum (Fg) (11%). From the 40 soybean samples analysed, only two presented detectable DON levels. Based on DON occurrence on soybean seeds at ripening stages, the toxigenic ability of Fg complex strains isolated from soybean seeds, pods and flowers were analysed. The trichothecene genotype was determined by a multiplex PCR using primers based on Tri3, Tri5 and Tri7 toxin genes and then the chemotype was verified by chemical analysis. Most Fg complex strains showed 15-ADON genotype and five strains presented a DON/NIV; these also produced both toxins under in vitro culture. Neither the NIV nor the 3-ADON genotypes were detected among the members of the population evaluated. All the 15-ADON genotype strains were characterized as F. graminearum sensu stricto (lineage 7), while the strains presented a DON/NIV genotype were characterized as F. meridionale (lineage 2). The present study contributes new information on the occurrence of Fusarium species and trichothecenes toxins on soybean at the pre-harvest stages. Also, this is the first report on the chemotype, genotype and lineages among Fg complex isolated from soybean.

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