Afectación intestinal por un hongo dematiáceo / Intestinal disease by a dematiaceous fungi

Resumen Introducción: Los hongos dematiáceos se caracterizan por la presencia de abundante melanina en su pared celular. Presentan una distribución mundial, siendo más comunes en climas tropicales y subtropicales. Producen infecciones cutáneas y subcutáneas, además de enfermedades alérgicas, neumonías, abscesos cerebrales o infecciones diseminadas. Caso Clínico: Presentamos el caso de un paciente con adenocarcinoma de recto intervenido quirúrgicamente con hallazgo incidental de divertículo de Meckel y en el cual en el estudio anatomopatológico reveló la presencia de un hongo dematiáceo

Introduction: Dematiaceous fungi are characterized by the presence of brown melanine or melanine like pigments in their cell wall. They are generally distributed worldwide, being more common in tropical and subtropical climates. The clinical syndromes are often cutaneous and subcutaneous infections, but can be also responsible of allergic diseases, pneumonias, cerebral abscesses or disseminated infections. Clinical Case: We present the case of a patient with a diagnosis of rectal adenocarcinoma intervening surgically and with an incidental finding of Meckel's Diverticulum. The anatomopathological study revealed the presence of a dematiaceous fungi.

Pathogenicity and transmission of fungi detected on Passiflora alata seeds / Patogenicidade e transmissão de fungos detectados em sementes de Passiflora alata

Passion fruit is usually propagated by seeds because of the ease and lower cost in seedling production. However, the seed is the most efficient agent for the spread of pathogens. The damages from seed-borne diseases occur mainly during the germination stages or at the formation of seedlings in nurseries. Considering the need for knowledge on the pathology of sweet passion fruit seeds, the objective was to evaluate the transmission and pathogenicity of the fungi Alternaria sp., Botrytis fabae, Cladosporium cladosporioides, Fusarium spp. and Lasiodiplodia theobromae, known as potentially pathogenic to this crop, and isolated from sweet passion fruit seeds. Therefore, tests on seed health, germination and seedling emergence in a sterilized commercial substrate were conducted using seeds from this species, inoculated with those fungal isolates. Leaves, stems and fruit from this plant were also inoculated with the same fungi. Alternaria sp., Fusarium spp. and L. theobromae were identified in seedlings obtained from inoculated seeds, confirming the transmission of these fungi by seeds. L. theobromae was also considered the most harmful fungus to passion fruit crop, as it causes seed rot and other disease symptoms on the leaves, stem and fruit. These findings inferred that healthy seeds of sweet passion fruit are essential for producing seedlings and to prevent the spread of the diseases caused by these fungi to exempt areas.(AU)

O maracujazeiro geralmente é propagado por meio de sementes em virtude da facilidade e do menor custo na produção de mudas. No entanto, a semente é o agente mais eficiente de disseminação de patógenos, sendo que os danos decorrentes das doenças transmitidas por elas ocorrem principalmente durante os estágios de germinação ou na formação de mudas nos viveiros. Considerando a necessidade de informações acerca da patologia de sementes de maracujá-doce nesse contexto, objetivou-se obter informações sobre a transmissão e a patogenicidade dos fungos Alternaria sp., Botrytis fabae, Cladosporium cladosporioides, Fusarium spp. e Lasiodiplodia theobromae, isolados de sementes de maracujá-doce e potencialmente patogênicos à cultura. Para tanto, testes de sanidade, germinação e emergência de plântulas em substrato comercial esterilizado foram conduzidos com sementes dessa espécie, inoculadas com esses isolados. Folhas, colo e frutos dessa planta também foram inoculados com os mesmos fungos. Alternaria sp., Fusarium spp. e L. theobromae foram identificados em plântulas obtidas de sementes inoculadas, confirmando a transmissão por sementes. L. theobromae foi considerado o mais agressivo à cultura do maracujá, por ter causado podridão nas sementes, além de maiores lesões nas folhas, no colo da planta e nos frutos. Dessa forma, infere-se que a obtenção de sementes de maracujá-doce sadias é imprescindível para a produção de mudas, evitando-se assim a disseminação desses patógenos em áreas isentas.(AU)

Seeds of weeds as an alternative host of phytopathogens / Sementes de plantas daninhas como hospedeiras alternativas de fitopatógenos

Weeds compete with agricultural crops for water, light, nutrients and space, besides having an extensive seed bank. However, another aspect to be considered relates to few studies pointing out weeds as hosts of phytopathogenic fungi. Many fungi, the main cause of diseases in plants, are known to use seeds as an efficient means of survival and dispersal. The objective of this work was to evaluate the health of weed seeds and the pathogenicity of fungi associated to plants of agricultural importance. The seeds were collected manually in Cerrado areas located in the municipality of Gurupi, Tocatins, Brazil. The blotter test method was used to evaluate seed health. The incidence of fungi was evaluated through an individual analysis of seeds using a stereoscopic and an optical microscope. The pathogenicity of fungi from weed seeds was evaluated by inoculation in plants of agronomic interest and, when pathogenic, we inoculated them in the host plant of the fungus. Weed seeds have been identified in fungi of the genus Alternaria, Aspergillus, Bipolaris, Cladosporium, Curvularia, Fusarium, Nigrospora, Papularia, Rhizopus and Pythium. The seeds of Acanthospermum australe, Bidens pilosa, Cenchrus echinatus, Digitaria horizontalis, Echinochloa crus-pavonis, Eleusine indica, Ipomoea sp., Pennisetum setosum, Sida rhombifolia, Spermacoce latifolia, Tridax procumbens and Vernonia polyanthes carry and disseminate fungi that, once inoculated, cause infection in plants of agricultural importance, such as Oryza sativa, Phaseolus vulgaris, Vigna unguiculata, Zea mays and Glycine max.(AU)

As plantas daninhas competem com culturas agrícolas por água, luz, nutrientes e espaço, além de possuírem um extenso banco de sementes. Entretanto, outra vertente a ser considerada é quanto aos poucos estudos relacionando plantas daninhas como hospedeiras de fungos fitopatogênicos. É sabido que muitos fungos, principais causadores de doenças em plantas, utilizam as sementes como meio eficiente de sobrevivência e de dispersão. Dessa forma, o trabalho objetivou avaliar a sanidade de sementes de plantas daninhas e a patogenicidade dos fungos associados às plantas de importância agrícola. As sementes foram coletadas manualmente em áreas de cerrado localizadas no município de Gurupi, Tocantins, utilizando o método blotter test para avaliação da sanidade. A incidência dos fungos foi avaliada com auxílio de microscópio estereoscópico e ótico. A patogenicidade dos fungos oriundos das sementes de plantas daninhas foi avaliada por meio da inoculação em plantas de interesse agronômico e, quando patogênico, a inoculação foi na própria planta daninha hospedeira do fungo. Foram identificados os fungos dos gêneros Alternaria, Aspergillus, Bipolaris, Cladosporium, Curvularia, Fusarium, Nigrospora, Papularia, Rhizopus e Pythium. As sementes de Acanthospermum australe, Bidens pilosa, Cenchrus echinatus, Digitaria horizontalis, Echinochloa crus-pavonis, Eleusine indica, Ipomoea sp., Pennisetum setosum, Sida rhombifolia, Spermacoce latifolia, Tridax procumbens e Vernonia polyanthes transportam e disseminam fungos que, uma vez inoculados, causam infecção em plantas de importância agrícola, como Oryza sativa, Phaseolus vulgaris, Vigna unguiculata, Zea mays e Glycine max.(AU)

Ultrastructural changes and oxidative stress markers in wild and cultivar Sesamum orientale L. following Alternaria sesami (Kawamura) Mohanty and Behera inoculation.

Alternaria sesami causes leaf spot disease in Sesamum orientale. Conidium germination, inoculation, penetration and colonization of the pathogen on the plant surfaces were studied using scanning electron microscopy. Electron microscopy analysis revealed multiple germ tubes from conidium that spread in all direction across the leaf surfaces. Penetration in the plant surface occured, directly through the epidermis or via stomata with or without the appressoria formation. Hyphal penetration continued through the substomata cavity and some of hyphal branches grew in the intercellular space of mesophyll tissue. Hyphal toxin, caused cell and cell wall damages. Changes in different biochemical parameters in the diseased sesame plants (both in wild and cultivar) were compared to control. Transmission electron microscopy showed structural changes in the chloroplast of diseased plants. Isozyme pattern and assays of different enzymes, namely catalase, acid phosphatase and peroxidase expressed varied level of activities. Meanwhile, esterase, polyphenol oxidase and superoxide dismutase in diseased plants showed remarkable levels compared to control. Due to the infection, chlorophyll content, carbohydrates and total soluble protein decreased whereas free amino acid, proline, phenols and disease-related proteins increased in the host plants. Differential SDS-PAGE band profiling of total soluble proteins were also observed in plants due to the infection.

Primer caso de queratitis fúngica en Chile debido a alternaria alternata / Fungical keratitis by alternaria alternata, first report in Chile

Un caso de queratitis fúngica debido a alternaria alternata es reportado. Este es el primer caso informado en Chile. Hifas fúngicas fueron detectadas en el raspado corneal, y cultivos fueron positivos a este hongo. El paciente fue, presumiblemente, curado después de tratamiento con Anfotericina-B e Itraconazol. Queratitis causadas por hongos filamentosos, del tipo especies de Fusarium, Aspergillus, Acremonium y Curvularia, son relativamente frecuentes, usualmente inducidos por trauma del tipo vegetales, metales y lentes de contacto. Nosotros reportamos un caso de queratitis humana debido a Alternaria alternata, posterior a traumatismo por un vegetal

Environmental effect on the reoccurrence of Alternaria alternata on Trianthema portulacastrum.

Trianthema portulacastrum is a noxious weed which spreads rapidly in the field. Pathogen Alternaria alternata was observed on this host for three years continuously i.e. 1997 to 1999. The incidence of the pathogen depended on rainfall and temperature.

Participation of the phosphoinositide metabolism in the hypersensitive response of Citrus limon against Alternaria alternata

Lemon seedlings inoculated with Alternaria alternata develop a hypersensitive response (HR) that includes the induction of Phenylalanine ammonia-lyase (PAL, E. C. 4.3.1.5) and the synthesis of scoparone. The signal transduction pathway involved in the development of this response is unknown. We used several inhibitors of the Phosphoinositide (PI) animal system to study a possible role of Inositol-1,4,5-triphosphate (IP3) in the transduction of the fungal conidia signal in Citrus limon. The HR was only partially inhibited by EGTA, suggesting that not only external but internal calcium as well are necessary for a complete development of the HR. In this plant system, Alternaria alternata induced an early accumulation of the second messenger IP3. When lemon seedlings were watered long term with LiCl, an inhibitor of the phosphoinositide cycle, the IP3 production was reduced, and the LiCl-watered plants could neither induce PAL nor synthesize scoparone in response to fungal conidia. Furthermore, neomycin, a Phospholipase C (PLC, E. C. 3.1.4.3) inhibitor, also inhibited PAL induction and scoparone synthesis in response to A. alternata. These results suggest that IP3 could be involved in the signal transduction pathway for the development of the HR of Citrus limon against A. alternata.

Los alergenos del ambiente tabacalero / Allergens of tobacco environment

Se halló 16 a 60 esporos fúngicos/litro aire y de 100 a 100.000 esporos de actinomicetos termófilos/g polvo del piso en los secaderos de tabaco. Los hongos eran Alternaria sp (21 por ciento), Aspergillus sp (15 por ciento), Asp. fumigatus (7 por ciento), Asp. glaucus (5,5 por ciento), Asp. nidulans (13,3 por ciento), Chaetomiun sp (2,3 por ciento), Chrysosporium spp (5,5 por ciento), Cladosporium sp (3,1 por ciento), Curvularia sp (0,8 por ciento), Dactylaria sp (3,1 por ciento), Nogrospora sp (5,5 por ciento), Penicillium spp (11,7 por ciento), Talaromyces sp (2,3 por ciento) y no identificado (3,9 por ciento). Los Thermoactinomyces eran Tha. thalpophilus (66,6 por ciento), Tha. sacchari (6,7 por ciento), Tha. vulgaris (6,7 por ciento) y otros Tha. spp (20 por ciento). También el humo de cigarrillos contenía esporos viables de Thermoactinomyces. El 7 ñ 3,3 por ciento de los trabajadores tenían anticuerpos anti-Tha. thalpophilus demostrados por doble inmunodifusión

Alternaria fungal keratitis successfully treated by keratoplasty

Fungal keratitis, which can be caused by various species of fungi, is a well recognized infection of the cornea and has been reported with increasing frequency due to the widespread use of corticosteroids and antibiotics. We report the case of a 55 year old Saudi male with deep stromal Alternaria keratitis, diagnosed histopathological who was treated successfully by penetrating keratoplasty in combination with antifungal therapy. To our knowledge this the first case to be reported in Saudi Arabia of fungal keratitis caused by Alternaria. Early surgical intervention appears to be a reasonable approach for the treatment of deep keratomycosis

Variación anual de la micoflora en hogares de pacientes asmáticos en la ciudad de Santa fe / Annual variation of the mycoflora in home of asthmatic patients in the Santa Fe city

Mold allergy in frequently involved in the etiopathogenesis of allergy respiratory diseases and it is important for us to determine the fungal classes that most frequently cohabit with men in our region, and under which condition of temperature and humidity they mostly develop. Mycological flora was studied bimonthly in 1989, in 8 homes from Santa Fe City, by exposing three dishes (90 mm) for 20 min. in bathrooms, kitchens and bedrooms. Afterwards, the dishes were incubated for 10 days at 28ºC. Taxonomic identification was made by microscopy of the mature sporulating colonies. Alternaria was the fungal class most frequently found (64 por ciento), followed by Cladospotium (11,4 por ciento), Aspergillus (9,2 por ciento), Curvularia (7 por ciento), Penicillium (4 por ciento), Fusarium (1,2 por ciento) and others (3,2 por ciento). Concerning the rooms, altemaria and Cladosporium were mostly found in kitchens, un like the classes Aspergillus, penicillium and Curvularia that were mostly found in bedrooms. Considering all the colonies as a whole, the totals of each room were: for kitchens 50 por ciento: for bedrooms 28,5 por ciento: and for bathrooms, 21,5 por ciento. The greatest concentration of total colonies was found to those month varied from 70 to 75 por ciento, and the average temperature was stated between 16 and 22ºC. According to the medium values for temperature and humidity in Santa Fe City, spring in the most suitable season for in home molds to develop, being the kitchen the room where a greater number of colonies was found

Causes of blackening of infected spots of tomato fruits

Fruits of tomato infected with some pathogens especially Alternaria lycopersici showed substantial increases in levels of the aromatic amino-acids alpha amino butyric acid, tryptophane, tyrosine and phenylalanine when compared with the respective amino acids in the healthy plants of the same fruits. Also, total phenolic compounds and simple phenolic fractions namely: salicylic acid, orcinol, gallic acid and syringic acid as well as indole acetic acid and indole acetonitrile were increased in the infected tissue. Blackening of the infected spots was connected with the substantial increases of these compounds, the formation and transformation of which are responsive to the invading pathogens and to resist the resulting diseases

Problemas económicos asociados con toxinas / Economical problems associated with alternaria toxins

Las especies del hongo Alternaria producen metabolitos secundarios, muchos de los cuales son tóxicos al hombre y otros mamiferos. Los metabolitos pueden ser clasificados, de una manera general, en cinco grupos estructurales: dibenzo Ó pironas, antraquinonas, ácidos tetraméricos, polipéptidos y otras toxinas. Los diferentes compuestos reportados en estos grupos fueron revisados, así como sus efectos tóxicos producidos por los compuestos más importantes (alternario, y ácido tenuazónico)