Colonización micorrízica y diversidad de hongos micorrízicos de algunas especies de orquídeas epifitas tropicales en el Sureste de Chiapas, México

El status de la colonización micorrízica, los factores que la influyen y la diversidad fúngica asociada, fue investigada en orquídeas de hábitos epifitos que crecen en las ramitas de los cafetales y en árboles remanentes de la selva tropical del Sureste de México. El 97% de los individuos presentaron algún grado de colonización micorrízica. La intensidad de colonización estuvo inversamente relacionada con el diámetro de la raíz. Orquídeas de raíces delgadas estuvieron intensamente colonizadas, alcanzando en algunos casos hasta 98%. Así también, existió una relación positiva entre la edad de las raíces y su intensidad de colonización. Las raíces más viejas concentraron la mayor colonización. En términos generales, las células recién colonizadas se ubicaron en las áreas cercanas al ápice de las raíces, mientras que pelotones altamente digestados se concentraron de la parte media a la base de la raíz. Orquídeas que crecían sobre las ramitas del café presentaron una intensa colonización activa, representado por la presencia de pelotones con hifas intactas, durante la época de secas. En contraste, orquídeas que crecían en árboles de fuste grueso localizadas en zonas de menor precipitación, solo presentaron células con pelotones altamente digestados. En cuanto a la diversidad fúngica asociada, se obtuvieron aislados de pelotón y de tejido cortical. Siete morfotipos (MT) del género forma-Rhizoctonia fueron reconocidos. Un MT coincidió con las características morfotaxonómicas de Ceratorhiza y cuatro más con Epulorhiza. Más de un MT fue aislado de una misma planta. MT-1 y MT-7 fueron aislados de la misma raíz joven de Epidendrum stamfordianum. MT-7 es un aislado característico de Epulorhiza. Un mismo morfotipo de hongo, afín a Epulorhiza, fue aislado de pelotón en dos especies de orquídeas colectadas en el mismo árbol. De acuerdo al alto grado de colonización micorrízica observada en las especies de orquídeas que crecen sobre las ramitas del café, este hábitat constituye un refugio para los simbiontes fúngicos de orquídeas epifitas tropicales en el Sureste de México___________The status of mycorrhizal colonization, the factors influencing it and the associated fungal diversity was investigated in orchids of epiphytic habits growing in the branches of coffee plantations and in remnant trees of the tropical forest of Southeastern Mexico. Some degree of mycorrhizal colonization was observed in 97% of the individuals. The intensity of colonization was inversely related to the root diameter. Orchids of thin roots were intensely colonized, some them reaching up to 98%. Similarly a positive relationship was observed between the rot age and their colonization. The older roots had higher colonization. In general the recently colonized cells were located near to the root apices, while the highly digested pelotons were concentrated from the middle part to the root base. Orchids growing on the coffee branches showed an intense active colonization represented by the presence of pelotons with intact hyphae during the dry period. On the contrary, the orchids growing on the trees having thick trunk located in lower precipitation zones only showed cells with highly digested pelotons. As far as associated fungal diversity is concerned, isolates of pelotons and cortical tissues were obtained. Seven morphotypes (MT) of genus forma-Rhizoctonia were recognized. One MT coincided with morphotaxonomic characteristics of Ceratorhiza and four of them more with Epulorhiza. More than one MT was isolates from the same plant. MT-1 and MT-7 were isolated from the same young root of Epidendrum stamfordianum.MT-7 is a characteristic isolate of Epulorhiza. A same fungal morphotype similar to Epulorhiza was isolated from pelotons in two orchid species collected from the same tree. Keeping in view the high extent of mycorrhizal colonization observed in orchid species growing on coffee branches, their habitat constitutes a refuge for the fungal symbionts of tropical epiphytic orchids of Southeast Mexico.Tesis ( Maestría en Ciencias, especialista en Edafología).-Colegio de Postgraduados, 2007.CONACY

cDf International Congress : proceedings : actes, actas : actes, Barcelona Jun. 2013

El Congrés Internacional coupDefouet Barcelona 2013 ha estat una iniciativa de l'Art Nouveau European Route – Ruta Europea del Modernisme, organitzada per l'Institut del Paisatge Urbà de l'Ajuntament de Barcelona i el grup de recerca GRACMON de la Universitat de BarcelonaCoordinació: Lluís Bosch, Mireia Freixa.[eng] In 2013 the magazine coupDefouet reached its first decade of existence. As a way of celebrating this, the Art Nouveau European Route – the association of cities and other local institutions for the promotion and diffusion of Art Nouveau heritage that created the magazine – organised a magnificent international congress as a framework for scientific exchange and raising public awareness. The first coupDefouet International Congress on Art Nouveau was held in Barcelona, the city from which coupDefouet is published and one of the undisputable world capitals of Art Nouveau. This volume of the Singularitats series comprises the proceedings of that event.[cat] L’any 2013 va fer deu anys de l’aparició de coupDefouet, la revista de la Ruta Europea del Modernisme, una associació de municipis i altres entitats locals per a la promoció i la difusió del patrimoni modernista o Art Nouveau. Per commemorar-ho, s’organitzà un congrés internacional amb l’objectiu de contribuir al coneixement científic i la difusió d’aquest moviment artístic. El primer Congrés Internacional coupDefouet se celebrà a Barcelona, la ciutat en què s’edita coupDefouet i una de les capitals indiscutibles de l’Art Nouveau. En aquest volum de Singularitats s’apleguen les actes d’aquell esdeveniment

Candida bloodstream infections in intensive care units: analysis of the extended prevalence of infection in intensive care unit study

Item does not contain fulltextOBJECTIVES: To provide a global, up-to-date picture of the prevalence, treatment, and outcomes of Candida bloodstream infections in intensive care unit patients and compare Candida with bacterial bloodstream infection. DESIGN: A retrospective analysis of the Extended Prevalence of Infection in the ICU Study (EPIC II). Demographic, physiological, infection-related and therapeutic data were collected. Patients were grouped as having Candida, Gram-positive, Gram-negative, and combined Candida/bacterial bloodstream infection. Outcome data were assessed at intensive care unit and hospital discharge. SETTING: EPIC II included 1265 intensive care units in 76 countries. PATIENTS: Patients in participating intensive care units on study day. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: Of the 14,414 patients in EPIC II, 99 patients had Candida bloodstream infections for a prevalence of 6.9 per 1000 patients. Sixty-one patients had candidemia alone and 38 patients had combined bloodstream infections. Candida albicans (n = 70) was the predominant species. Primary therapy included monotherapy with fluconazole (n = 39), caspofungin (n = 16), and a polyene-based product (n = 12). Combination therapy was infrequently used (n = 10). Compared with patients with Gram-positive (n = 420) and Gram-negative (n = 264) bloodstream infections, patients with candidemia were more likely to have solid tumors (p < .05) and appeared to have been in an intensive care unit longer (14 days [range, 5-25 days], 8 days [range, 3-20 days], and 10 days [range, 2-23 days], respectively), but this difference was not statistically significant. Severity of illness and organ dysfunction scores were similar between groups. Patients with Candida bloodstream infections, compared with patients with Gram-positive and Gram-negative bloodstream infections, had the greatest crude intensive care unit mortality rates (42.6%, 25.3%, and 29.1%, respectively) and longer intensive care unit lengths of stay (median [interquartile range]) (33 days [18-44], 20 days [9-43], and 21 days [8-46], respectively); however, these differences were not statistically significant. CONCLUSION: Candidemia remains a significant problem in intensive care units patients. In the EPIC II population, Candida albicans was the most common organism and fluconazole remained the predominant antifungal agent used. Candida bloodstream infections are associated with high intensive care unit and hospital mortality rates and resource use