Diversity and metabolomic characterization of Penicillium expansum isolated from apples grown in Argentina and Spain.

Apples (Malus domestica) are one of the most consumed fruits globally. It is a relevant crop in Argentina and Spain, and one of the main fruits for export and industrialization in these countries. Quality control of apples, fundamentally in the postharvest stage, is critical to prevent fungal diseases. The blue mould, caused by Penicillium expansum, is responsible for great economic losses due to the deterioration of the fruit and mycotoxin production. Many studies have characterized this pathogen; however, little is known about the differences between populations from distant geographical origins. The objective of the present study was to characterize two P. expansum populations, from Argentina and Spain, through morphological, metabolomic and molecular approaches, and to evaluate the existence of differences related to their geographical source. A total of 103 isolates, 53 from Argentina and 50 from Spain were studied. Their morphological features were consistent with the species description. The secondary metabolite profiles revealed low chemical diversity. All 103 isolates shared the production of 13 compounds, namely andrastins, aurantioclavine, chaetoglobosins, communesins, expansolides, roquefortine C and patulin. Penostatins and citrinin were produced by 102 and 101 isolates, respectively. A region of the ß-tubulin gene was selected to analyse the diversity of the P. expansum isolates. No substantial differences were observed between isolates of different geographical origins through morphology, patulin accumulation, secondary metabolite profiles and phylogenetic analysis. However, the analysis of polymorphisms revealed 29 haplotypes with a relative separation between isolates of both populations; 13 haplotypes contained Argentinean isolates, while Spanish isolates were separated into 16 haplotypes. The diversity indices of Shannon (H'=2.075; H'=2.402) and Simpson (SiD = 0.850; SiD = 0.895) for isolates from Argentina and Spain, respectively, indicated that the diversity of P. expansum is greater in Spain than in Argentina. This distribution could be explained both by the existence of haplotype exchange between both countries, with the ancestral haplotypes originating in Spain, and the subsequent adaptation to the environmental conditions or apples varieties grown in each region.

Water activity influence on the simultaneous production of DON, 3-ADON and 15-ADON by a strain of Fusarium graminearum ss of 15-ADON genotype.

The influence of aw on DON and its acetyl derivatives biosynthesis by a strain of Fusarium graminearum s.s. (ITEM 4606) which produces DON, 3-ADON and 15-ADON was evaluated. Trichothecene production was studied on agar wheat 2% at 0.95 and 0.99 aw at different temperatures (10, 15, 20, 25 and 30 °C) and incubation times (7, 14, 21 and 28 days). Statistical analysis (ANOVA) showed that aw, temperature, incubation time and their interactions were significant on the production of DON, 3-ADON and 15-ADON (p < 0.0001). The pattern of toxin production was influenced by aw, showing differences for the three toxins. The maximum accumulation of DON occurred at 30 °C at 0.99 aw (14 d) and at 25 °C at 0.95 aw (7 and 21 d). The highest concentration of 3-ADON at 0.95 aw was observed at 25 °C and 7 days, and it was significantly higher than all the other values registered. At 0.99 aw, the maximum occurred at 30 °C and 21 days, but another significantly high accumulation was observed at 28 days at the same temperature. For 15-ADON, at 0.95 aw, the highest amount of toxin was accumulated at 10 °C, both at 7 and 28 days. At 0.99 aw, a maximum was observed at 10 °C and 7 days, significantly different from the values observed at the other conditions. The toxin accumulated at a higher concentration at 0.95 aw was 15-ADON (173.2 µg/g) and at 0.99 aw, 3-ADON (370.6 µg/g). A marked influence of aw on the maximum toxin accumulation with respect to temperature and time was observed for trichothecene production. This is an important fact to consider when designing predictive models to prevent toxin contamination, both in the field and during storage, especially in intermediate drying stages.

Can discrepancies between Fusarium graminearum trichothecene genotype and chemotype be explained by the influence of temperature in the relative production of 3-ADON and 15-ADON?

Wheat is one of the most important crops in Argentina and worldwide. One of the major diseases affecting the crop is the Fusarium Head Blight (FHB). It is an endemic disease caused mainly by Fusarium graminearum, the most common agent of FHB around the world. The infection is strongly influenced by environmental parameters and occurs mostly when there are favourable conditions of moisture and temperature during wheat anthesis or flowering. This destructive disease affects wheat, barley and other small grains and has the capability of destroying crops, causing great economic losses due to reduced grain quality, and the accumulation of significant levels of mycotoxins such as trichothecenes. The aim of this study was to evaluate the influence of temperature on mycotoxin biosynthesis, on three strains of F. graminearum of 15-ADON genotype and one of 3-ADON genotype, with different capacity of synthesizing DON, 3-ADON and 15-ADON. Trichothecene production of the strains at different temperatures (5, 10, 15, 20, 25, 30 and 35 °C) was evaluated after 7, 14, 21, 28 and 35 d of incubation. The optimum temperature to produce DON and 3-ADON was between 25 and 30 °C, but the maximum production of 15-ADON occurred at a lower temperature (10 °C) for all the strains. Conversely, the minimum production of DON and 3-ADON was recorded between 5 and 10 °C and of 15-ADON between 30 and 35 °C. A possible explanation for the similar accumulation of both acetyl derivatives by strains of different chemotype and genotypes could be that the acetyl derivatives biosynthesis is regulated by temperature.

From field to process: How storage selects toxigenic Alternaria spp. causing mouldy core in Red Delicious apples.

Apple is a major crop in Argentina where 50% of the production is derived to by-products. Industries process either recently harvested apples or fruit stored for up to 9 months. This crop is susceptible to fungal diseases both external and internal, such as mouldy core (MC). The incidence of fungal pathogens changes during storage, as well as the risk associated with their presence since some contaminants belong to mycotoxigenic genera. The objective of this study was to characterize the fungal contaminants of Red Delicious apple fruit in Argentina evaluating their evolvement from field to process, with main interest on MC causal agents and mycotoxigenic species. A total of 240 apples were analysed; 140, recently harvested and intended for fresh consumption (C), and 100 stored for 9 months in a refrigerated chamber (0-3 °C) and destined to industrialization (I). The 86% of fresh consumption apples showed external fungal lesions, and only 14% were undamaged; MC incidence was 34%. High biodiversity was observed; Penicillium was the predominant genus (54%), followed by Alternaria spp. (41%). Only 3% of industrialization fruit were undamaged, 48% had external lesions and 51% MC. However, biodiversity was lower in these apples. Alternaria spp. was recovered from 60% of apples, mainly causing MC, while Penicillium spp. took second place (34%). All the Alternaria isolates belonged to Section Alternaria with A. tenuissima as the predominant species-group. Alternariol was synthesised by 75% of the isolates, while both alternariol monomethyl-ether and tenuazonic acid by 76%. From the 100 I apples, 93 were contaminated with at least one of these mycotoxins. Alternaria was the main causal agent of MC in Argentinean Red Delicious apples, and fruit affected by this disease might be incorporated into the process line, with a consequent risk of mycotoxin contamination in apple by-products.

Effects of Fusarium graminearum and Fusarium poae on disease parameters, grain quality and mycotoxin contamination in barley (part II).

BACKGROUND: Barley is one of the most sown crops in the world, with multiple uses such as human consumption, animal feed and for the malting industry. This crop is affected by different diseases, such as Fusarium Head Blight (FHB), that causes losses in yield and quality. In the last years F. graminearum and F. poae were two of the most frequently isolated species in barley grains, so the aim of this study was to evaluate the interaction between these Fusarium species and the effects on disease parameters, grain quality and mycotoxin contamination on five barley genotypes under field conditions. RESULTS: Statistical differences between Fusarium treatments for some parameters depending mainly on the year/genotype were found. The results showed that the germination process was affected by both Fusarium species. As to grain quality and the different hordein fractions, it was observed that F. graminearum affects preferentially D and C-hordeins. Different concentrations of nivalenol, deoxynivalenol and their acetylated derivatives (3-acetyl deoxynivalenol (3-ADON), 15-acetyl deoxynivalenol (15-ADON)) were detected. CONCLUSIONS: In the present work, no evidence of synergism between F. graminearum and F. poae were found regarding disease parameters and mycotoxin contamination. However, at least in the years with favorable climatic conditions to FHB development and depending on the barley genotype, a continuous monitoring is deemed necessary to prevent the negative impact on protein composition and germinative parameters © 2020 Society of Chemical Industry.

Effects of Fusarium graminearum and Fusarium poae on disease parameters, grain quality and mycotoxins contamination in bread wheat (Part I).

BACKGROUND: Wheat is the most important winter crop in the world, being affected by the presence of fungal, mainly those belonging to the Fusarium genus. Fusarium head blight (FHB) is a serious disease that causes important economic damage and quantitative/qualitative losses, with Fusarium graminearum and Fusarium poae being two of the most isolated species worldwide. The present study aimed to evaluate the interaction between F. graminearum and F. poae and the effects on disease parameters, grain quality and mycotoxin contamination on five wheat genotypes under field conditions during three growing seasons. RESULTS: Statistical differences between Fusarium treatments were found for disease parameters, grain quality and mycotoxin contamination during the 2014/2015 growing season. High values of incidence (58.00 ± 8.00%), severity (6.28 ± 1.51%) and FHB index (4.72 ± 1.35) were observed for F. graminearum + F. poae treatment. Regarding grain quality, the results showed that the degradation of different protein fractions depends on each Fusarium species: glutenins were degraded preferably by F. graminearum (-70.82%), gliadins were degraded preferably by F. poae (-29.42%), whereas both protein fractions were degraded when both Fusarium species were present (-60.91% and -16.51%, respectively). Significant differences were observed for mycotoxin contamination between genotypes, with Proteo being the most affected (DON = 12.01 ± 3.67 µg g-1 ). In addition, we report that 3-ADON predominated over 15-ADON in the three seasons evaluated. CONCLUSION: Variations in plant-pathogen interaction (Fusarium-wheat pathosystem) should be considered at least in years with favorable climatic conditions for FHB development, as a result of the potential impact of this disease on grain quality and mycotoxin contamination. © 2019 Society of Chemical Industry.

[Frequency and determinants of the delay in the diagnosis of cancer in children, in Argentina]. / Frecuencia y determinantes del retraso en el diagnóstico de cáncer infantil en Argentina.

In Argentina, mortality from childhood cancer is higher than in more developed countries, with late diagnosis being one of the possible causes. Our objective was to determine the frequency of barriers to diagnosis faced by families assisted by a Non-Governmental Organization, and some associated demographic, institutional and medical factors. A retrospective observational and quantitative analysis of the diagnosis pathway of children with cancer assisted by the N.D. Flexer Foundation, Argentina, between 1/1/2011 and 12/31/2015 was carried out. The primary outcome was the presence of barriers to diagnosis. It was considered that there was a barrier when there were consultations without diagnostic suspicion, family delay, institutional delay, self-derivation and/or more than 30 days between the onset of symptoms and diagnosis. The frequency of barriers within each category was contrasted by the y2 test. A multivariate logistic regression was used to examine its association with relevant variables. Among the 1818 families included, 63.5% faced delays/ barriers to diagnosis. Negative modulators were diagnosis at age younger than 1-year, renal tumor and first attention at a public hospital of the City of Buenos Aires or a provincial capital hospital (all p < 0.0001). Positive modulators were the diagnosis of bone tumor (p = 0.009) and first attention at a primary healthcare center (p< 0.0001) or private doctor's office (p = 0.001). The main non-biological factor associated with the possibility of facing barriers to diagnosis was the type of first contact-health institution.

En Argentina, la mortalidad por cáncer infantil es mayor que en países más desarrollados, siendo el diagnóstico tardío una de las posibles causas. Nuestro objetivo fue determinar la frecuencia de obstáculos al diagnóstico enfrentados por las familias de niños con cáncer asistidas por un Organismo No Gubernamental, y algunos factores demográficos, institucionales y médicos asociados. Se realizó un análisis retrospectivo observacional y cuantitativo del recorrido diagnóstico de los niños con cáncer asistidos por la Fundación N.D. Flexer, Argentina, entre el 1/1/2011 y el 31/12/2015. El resultado primario fue la presencia de obstáculos para acceder al diagnóstico. Se consideró que existió un obstáculo cuando tuvieron lugar consultas no orientativas, demora familiar, demora institucional, autoderivación y/o más de 30 días entre la aparición de síntomas y el diagnóstico. La frecuencia dentro de cada categoría se contrastó mediante la prueba de y2. La influencia de distintas variables se evaluó mediante una regresión logística multivariada. De 1818 familias incluidas, 63.5% enfrentaron algún tipo de obstáculos. Resultaron moduladores negativos el diagnóstico antes del año, de tumor renal y la concurrencia a un hospital público de la Ciudad de Buenos Aires o de capital provincial como centro de primer contacto (todos p < 0.0001). Resultaron moduladores positivos el diagnóstico de tumor óseo (p = 0.009) y los centros de atención primaria (p < 0.0001) y consultorios particulares (p = 0.001) como centros de primer contacto. El principal factor no biológico asociado a la frecuencia de obstáculos al diagnóstico de cáncer infantil fue el tipo de centro de primer contacto.

Frecuencia y determinantes del retraso en el diagnóstico de cáncer infantil en Argentina / Frequency and determinants of the delay in the diagnosis of cancer in children, in Argentina

En Argentina, la mortalidad por cáncer infantil es mayor que en países más desarrollados, siendo el diagnóstico tardío una de las posibles causas. Nuestro objetivo fue determinar la frecuencia de obstáculos al diagnóstico enfrentados por las familias de niños con cáncer asistidas por un Organismo No Gubernamental, y algunos factores demográficos, institucionales y médicos asociados. Se realizó un análisis retrospectivo observacional y cuantitativo del recorrido diagnóstico de los niños con cáncer asistidos por la Fundación N.D. Flexer, Argentina, entre el 1/1/2011 y el 31/12/2015. El resultado primario fue la presencia de obstáculos para acceder al diagnóstico. Se consideró que existió un obstáculo cuando tuvieron lugar consultas no orientativas, demora familiar, demora institucional, autoderivación y/o más de 30 días entre la aparición de síntomas y el diagnóstico. La frecuencia dentro de cada categoría se contrastó mediante la prueba de χ2. La influencia de distintas variables se evaluó mediante una regresión logística multivariada. De 1818 familias incluidas, 63.5% enfrentaron algún tipo de obstáculos. Resultaron moduladores negativos el diagnóstico antes del año, de tumor renal y la concurrencia a un hospital público de la Ciudad de Buenos Aires o de capital provincial como centro de primer contacto (todos p < 0.0001). Resultaron moduladores positivos el diagnóstico de tumor óseo (p = 0.009) y los centros de atención primaria (p < 0.0001) y consultorios particulares (p = 0.001) como centros de primer contacto. El principal factor no biológico asociado a la frecuencia de obstáculos al diagnóstico de cáncer infantil fue el tipo de centro de primer contacto.

In Argentina, mortality from childhood cancer is higher than in more developed countries, with late diagnosis being one of the possible causes. Our objective was to determine the frequency of barriers to diagnosis faced by families assisted by a Non-Governmental Organization, and some associated demographic, institutional and medical factors. A retrospective observational and quantitative analysis of the diagnosis pathway of children with cancer assisted by the N.D. Flexer Foundation, Argentina, between 1/1/2011 and 12/31/2015 was carried out. The primary outcome was the presence of barriers to diagnosis. It was considered that there was a barrier when there were consultations without diagnostic suspicion, family delay, institutional delay, self-derivation and/ or more than 30 days between the onset of symptoms and diagnosis. The frequency of barriers within each category was contrasted by the χ2 test. A multivariate logistic regression was used to examine its association with relevant variables. Among the 1818 families included, 63.5% faced delays/ barriers to diagnosis. Negative modulators were diagnosis at age younger than 1-year, renal tumor and first attention at a public hospital of the City of Buenos Aires or a provincial capital hospital (all p < 0.0001). Positive modulators were the diagnosis of bone tumor (p = 0.009) and first attention at a primary healthcare center (p< 0.0001) or private doctor's office (p= 0.001). The main non-biological factor associated with the possibility of facing barriers to diagnosis was the type of first contact-health institution.

Effect of moisture on wheat grains lipid patterns and infection with Fusarium graminearum.

Suitable conditions of temperature and humidity are required to maintain wheat grains quality, but during processing and storage, the grains can be exposed to adverse environmental conditions and presence of infectious fungi. Fusarium graminearum, the main causal agent of Fusarium head blight on wheat, affects crop yields and grain quality by alteration of their biochemical components and mycotoxin contamination, which reduces the possibilities of wheat end use and compromises food safety. Lipid degradation by hydrolytic, oxidative and microbial deterioration is the predominant cause of the loss of sensory acceptability, nutritional value and baking quality. The aim of this research was to determine the influence of adverse environmental conditions -as the increasing moisture - on lipid patterns of whole wheat flours contaminated with F. graminearum in relation to the infection degree. In vitro cultures of F. graminearum were carried out on wheat grains under different degrees of relative humidity (11, 50, 75 and 100%) throughout 45 days of incubation at 28 °C. The fungal biomass measured by q-PCR increased proportionally with the humidity. A decrease in the signals of saturated (palmitic and estearic) and unsaturated (oleic, linoleic and linolenic) fatty acids, analyzed as fatty acid methyl esters (FAMEs) by GC-MS, was observed in relation with the humidity and infection degree. The degradation rate of the lipids was high during the first 15 days of incubation, reaching the fatty acids content, values around 20-40% of those found in the control. From that moment on, the rate of degradation was slower or even null. It was observed that in all treatments, the linolenic acid reached the highest degradation ratio in comparison with the other fatty acids, which may be caused by the action of lipoxygenases. The lipase activity and the content of deoxynivalenol were also determinate on the flours. The lipase activity increased until day 25 of incubation reaching twice the initial value. The deoxynivalenol content also increased along incubation while fatty acids decreased. Our results demonstrated that the magnitude in the signal of fatty acids in whole wheat flours varied in relation to the degree of humidity and fungal infection of the grains from which they were obtained. Otherwise, lipids and their oxidation products are related with the pathogenesis and production of mycotoxins. These observations highlight the importance of an adequate manipulation of wheat grains on the processing chain to prevent quality changes and mycotoxins contamination.

Síndrome de Brugada por mutação no gene CACNA1C: relato de caso / Brugada Syndrome by CACNA1C mutation: case report

INTRODUÇÃO: A Síndrome de Brugada é uma cardiopatia de origem genética (autossômica dominante) que predispõe a arritmias ventriculares que podem ser fatais. É provocada geralmente por uma mutação do gene SCN5A. Tem especial prevalência em indivíduos adultos e do sexo masculino. Também ocorre com mais frequência em indivíduos de origem asiática. Pode provocar morte súbita (através de taquicardia ventricular polimórfica), principalmente em indivíduos em repouso ou durante o sono. Em raras descrições na literatura, há relatos de mutação do gene CACNA1C como causador da síndrome. DESCRIÇÃO: Indivíduo do sexo masculino, nascido em 1954, hipertenso, dislipidêmico, tabagista, histórico familiar rico em morte súbita (mãe, irmãos e tios maternos, todos durante o sono). Encaminhado ao serviço em 2009 para estratificação de risco de morte súbita. Apresentava dor torácica tipo angina. Coronariografia apenas demonstrou lesão de 20% em artéria circunflexa. Eletrocardiograma com padrão típico de Síndrome de Brugada (tipo 1). Submetido a Estudo Eletrofisiológico no mesmo ano, sendo induzida Fibrilação Ventricular com um único extraestímulo em ápice de ventrículo direito. Indicado então implante de Cardioversor Desfibrilador Implantável (CDI). Medicado para doença coronariana, manteve-se assintomático do ponto de vista cardiovascular e permanece desta forma até hoje. Em 2017 obtivemos sua análise genética, evidenciando mutação no gene CACNA1C (que é mais descrita como causadora da síndrome de QT Longo tipo 8 ou Síndrome de Timothy). Sua última avaliação ambulatorial foi em janeiro de 2019, onde se encontrava estável clinicamente, sem registros de terapias do CDI, mantendo eletrocardiograma típico de Síndrome de Brugada. CONCLUSÕES: Descrevemos um caso raro de Síndrome de Brugada causada pela mutação no gene CACNA1C. (AU)

Late ascending aortic prosthesis infection by porphyromonas pogonae: An unexpected infectious complication

Late complications in ascending aortic surgeries are uncommon and may occur by infectious processes, usually caused by gram positive bacteria. We report a case of aortic prosthesis infection by Porphyromonas pogonae, an anaerobic gram-negative coccobacillus that can grow under microaerobic conditions, three years after ascending aortic reconstruction surgery. (AU)

Tecnologias digitais de informação para a saúde: revisando os padrões de metadados com foco na interoperabilidade / Digital information technologies for health: reviewing metadata standards focusing on interoperability / Tecnologías digitales de información para la salud: una revisión de los estándares de metadatos con la atención dirigida a la interoperabilidad

Este artigo tem como objetivo apresentar o mapeamento dos padrões de metadados, bem como suas aplicações visando à interoperabilidade em sistemas de informação para a área da saúde. Trata-se de uma pesquisa exploratório-descritiva com abordagem qualitativa e levantamento bibliográfico realizado em busca de publicações atuais que abordam a temática dos padrões de interoperabilidade nacionais e internacionais no campo da saúde. Essas buscas foram pautadas nos enunciados da Portaria nº 2.073, de 31 de agosto de 2011, que regulamenta o uso de padrões de interoperabilidade para sistemas de informação em saúde no contexto brasileiro. Os resultados evidenciam que a padronização e interoperabilidade em sistemas de informação, sejam eles relativos às bibliotecas ou às organizações de saúde, são de extrema importância por possibilitar a troca e o compartilhamento de informações dentro e fora das organizações, além de tornar mais eficientes os fluxos e processos informacionais.

This article aims to present the mapping of the metadata standards as well as their applications aiming the interoperability in information systems for the health area. An exploratory-descriptive research with a qualitative approach and a literature review was carried out in search of current publications that approach the theme of national and international standards of interoperability in the field of health. These searches were based on the provisions of Portaria nº 2.073, de 31 de agosto de 2011, passed by Ministry of Health,Brazil, which regulates the use of interoperability standards for health information systems in the Brazilian context. The results show that standardization and interoperability in information systems, whether related to libraries or health organizations, are extremely important because they allow the exchange and sharing of information inside and outside organizations, as well as streamlining flows and informative processes.

Este artículo tiene como objetivo presentar el mapeo de los estándares de metadatos, así como sus aplicaciones con la atención dirigida a la interoperabilidad en sistemas de información para el área de la salud. Se trata de una investigación exploratorio-descriptiva con enfoque cualitativo y revisión literaria a través de la búsqueda de publicaciones actuales que abordan la temática de los patrones de interoperabilidad nacionales e internacionales en el campo de la salud. Essas búsquedas se basaron en los enunciados de la Portaria nº 2.073, de 31 de agosto de 2011, Resolución del Ministerio de Salud, Brasil, que regula el uso de estándares de interoperabilidad para sistemas de información en salud en el contexto brasileño. Los resultados evidencian que la estandarización e interoperabilidad en sistemas de información, sean relativas a las bibliotecas o a las organizaciones de salud, son de extrema importancia por permitir el intercambio y la compartición de informaciones dentro y fuera de las organizaciones, además de hacer más eficientes los flujos y procesos relacionados con las informaciones.

Late ascending aortic prosthesis infection by Porphyromonas pogonae: An unexpected infectious complication.

Late complications in ascending aortic surgeries are uncommon and may occur by infectious processes, usually caused by gram positive bacteria. We report a case of aortic prosthesis infection by Porphyromonas pogonae, an anaerobic gram-negative coccobacillus that can grow under microaerobic conditions, three years after ascending aortic reconstruction surgery.

Alternaria Species and Their Associated Mycotoxins.

The genus Alternaria includes more than 250 species. The traditional methods for identification of Alternaria species are based on morphological characteristics of the reproductive structures and sporulation patterns under controlled culture conditions. Cladistics analyses of "housekeeping genes" commonly used for other genera, failed to discriminate among the small-spored Alternaria species. The development of molecular methods achieving a better agreement with morphological differences is still needed. The production of secondary metabolites has also been used as a means of classification and identification. Alternaria spp. can produce a wide variety of toxic metabolites. These metabolites belong principally to three different structural groups: (1) the dibenzopyrone derivatives, alternariol (AOH), alternariol monomethyl ether (AME), and altenuene (ALT); (2) the perylene derivative altertoxins (ATX-I, ATX-II, and ATX II); and (3) the tetramic acid derivative, tenuazonic acid (TeA). TeA, AOH, AME, ALT, and ATX-I are the main. Certain species in the genus Alternaria produce host-specific toxins (HSTs) that contribute to their pathogenicity and virulence. Alternaria species are plant pathogens that cause spoilage of agricultural commodities with consequent mycotoxin accumulation and economic losses. Vegetable foods infected by Alternaria rot could introduce high amounts of these toxins to the human diet. More investigations on the toxic potential of these toxins and their hazard for human consumption are needed to make a reliable risk assessment of dietary exposure.

Natural occurrence of mycotoxins and toxigenic capacity of Alternaria strains from mouldy peppers.

Sweet pepper (Capsicum annuum) is an important crop cultivated worldwide, with Argentina being one of the major producers in South America. The fruit is susceptible to several fungal diseases, leading to severe economic losses for producers. In this study, Alternaria was found as the prevalent genus in mouldy peppers (50% fruits infected). Morphological identification revealed that all 64 Alternaria isolates belonged to small-spored species, most of them corresponding to A. tenuissima, A. arborescens and A. alternata species-groups. Their secondary metabolite profile was evaluated in vitro; alternariols were synthesized by most of the isolates (91% for alternariol and 92% for alternariol monomethyl ether). A high number of Alternaria spp. also produced tenuazonic acid (64%), altenuene (84%) and tentoxin (72%). In addition, damaged pepper fruits were analysed for the presence of tenuazonic acid and alternariols. A total 32 out of 48 spoiled pepper fruits were contaminated with at least one of these metabolites. Half of the samples were positive for tenuazonic acid (range 8-11,422µg/kg), while alternariol and its monomethyl ether were less frequently detected (21 and 29%, respectively) and at lower concentrations. This is the first report on the natural occurrence of Alternaria mycotoxins in Argentinean sweet pepper, and highlights a consumer risk when mouldy fruits are used in industrialized products because these compounds are not destroyed by conventional heat treatments.

Characterization of Alternaria strains from Argentinean blueberry, tomato, walnut and wheat.

Alternaria species have the ability to produce a variety of secondary metabolite, which plays important roles in food safety. Argentina is the second largest exporter of fresh and processed food products to Europe, however, few studies on Alternaria mycotoxins and other bioactive secondary metabolites have been carried out on Argentinean cereals, fruit and vegetables. Knowing the full chemical potential and the distribution of Alternaria spp. on crops, it is necessary to establish a toxicological risk assessment for food products for human consumption. In the present study, 87 Alternaria strains from different substrates (tomato, wheat, blueberries and walnuts) were characterized according to morphology and metabolite production. Aggressive dereplication (accurate mass, isotopic patterns and lists of all described compounds from Alternaria) was used for high-throughput evaluation of the chemical potential. Four strains belonged to the Alternaria infectoria sp.-grp., 6 to the Alternaria arborescens sp.-grp., 6 showed a sporulation pattern similar to that of "M" according to Simmons, 1 to that of Alternaria vaccinii, and the remaining 70 constituted a diverse group belonging to morphological groups "G" and "H". The cluster analysis yielded 16 almost identical dendrograms and grouped the Alternaria strains into four clusters and 11 singletons and outlier groups. The chemical analysis showed that AOH and AME were the most common metabolites produced, followed by TEN, ALXs and TeA. The A. infectoria sp.-grp. had no metabolites in common with the rest of the strains. Several secondary metabolites isolated from large-spored Alternaria species or other fungal genera were detected, such as dehydrocurvularin, pyrenochaetic acid and alternarienonic acid. The strains isolated from tomato produced lower amounts of metabolites than strains from blueberries, walnut and wheat, although individual strains from tomato produced the highest amount of some metabolites. The A. infectoria sp.-grp. was unique to cereals, whereas strains classified as belonging to the A. arborescens sp.-grp or having sporulation pattern "M" were only isolated from tomatoes. Otherwise, no clear association between substrate and identity could be found. The analyses in the study show that at least 75% of the Argentinean strains are able to produce potential mycotoxins.

Water activity and temperature effects on growth of Alternaria arborescens on tomato medium.

Alternaria arborescens is the causal agent of tomato stem canker, a disease frequently responsible of substantial economic losses. A. arborescens can produce several mycotoxins, such as alternariol, alternariol monomethyl ether and tenuazonic acid and phytotoxins such as the AAL toxins. The objective of this study was to determine the effect of water activity (aw, 0.950, 0.975, 0.995) and temperature (6, 15, 20, 25 and 30°C) on the germination and radial growth rate of A. arborescens on a synthetic tomato medium. Germination followed by growth was observed at all temperatures and aw levels analyzed. The shortest germination time (0.5 days) was observed at 0.995 aw, both at 25°C and at 30°C. The germination time increased with a reduction of aw and temperature. The highest growth rate was registered at 0.995 aw and 30°C (7.21 mm/day) while the lowest occurred at 0.950 aw and 6°C (0.52 mm/day), conditions at which the longest lag phase was observed (8 days). Growth rates increased with aw and temperature. Knowledge of the ecophysiology of the fungus in this substrate is necessary to formulate future strategies to prevent its development and evaluate the consumer health risk posed by potential exposure to the toxins.

Determinación de perfiles de producción de metabolitos secundarios característicos de especies del género Alternaria aisladas de tomate / Determination of the profiles of secondary metabolites characteristic of Alternaria strains isolated from tomato

Antecedentes. Muchas especies de Alternaria han sido estudiadas por su capacidad de producir metabolitos secundarios bioactivos como la tentoxina (TEN), algunos de los cuales tienen propiedades tóxicas. Las principales toxinas de Alternaria contaminantes de alimentos son el ácido tenuazónico, el alternariol (AOH), el alternariol monometil éter (AME), el altenueno y las altertoxinas i , ii y iii . Objetivos. Determinar los perfiles de metabolitos secundarios característicos de cepas de Alternaria aisladas de tomate para su clasificación quimiotaxonómica. Métodos. Los perfiles de metabolitos secundarios se determinaron por HPLC-MS. Resultados. Los aislamientos de Alternaria obtenidos a partir de tomates con «enmohecimiento negro» pertenecen, según sus características morfológicas, a los grupos especie Alternaria alternata, Alternaria tenuissima y Alternaria arborescens, siendo A. tenuissima el más frecuentemente aislado. Se determinaron los perfiles más característicos de metabolitos secundarios de los grupos especie A. alternata (AOH, AME, TEN), A. tenuissima (AOH, AME, TEN, ácido tenuazónico) y A. arborescens (AOH, AME, TEN, ácido tenuazónico), siendo algunas cepas de este último grupo especie capaces de sintetizar toxinas AAL. Conclusiones. Los perfiles de producción de metabolitos secundarios son una herramienta útil para la diferenciación de aislamientos de Alternaria pertenecientes a grupos especie de esporas pequeñas difícilmente identificables por sus características morfológicas (AU)

Background. Many Alternaria species have been studied for their ability to produce bioactive secondary metabolites, such as tentoxin (TEN), some of which have toxic properties. The main food contaminant toxins are tenuazonic acid, alternariol (AOH), alternariol monomethyl ether (AME), altenuene, and altertoxins i, ii and iii. Aims. To determine the profiles of secondary metabolites characteristic of Alternaria strains isolated from tomato for their chemotaxonomic classification. Methods. The profiles of secondary metabolites were determined by HPLC MS. Results. The Alternaria isolates obtained from spoiled tomatoes belong, according to their morphological characteristics, to the species groups Alternaria alternata, Alternaria tenuissima and Alternaria arborescens, with A. tenuissima being the most frequent. The most frequent profiles of secondary metabolites belonging to the species groups A. alternata (AOH, AME, TEN), A. tenuissima (AOH, AME, TEN, tenuazonic acid) and A. arborescens (AOH, AME, TEN, tenuazonic acid) were determined, with some isolates of the latter being able to synthesize AAL toxins. Conclusions. Secondary metabolite profiles are a useful tool for the differentiation of small spored Alternaria isolates not easily identifiable by their morphological characteristics (AU)