14 research outputs found
Aplicación de biología molecular en veterinaria: Pcr como método de diagnóstico para investigar presencia de Escherichia Coli productora de Verotoxina (Vtec) en caninos de zonas rurales y periurbanas. Su implicancia en salud pública
El síndrome urémico hemolítico (SUH) se caracteriza por anemia hemolítica microangiopática, plaquetopenia y daño renal. Constituye la primera causa de insuficiencia renal aguda en la edad pediátrica y la segunda de insuficiencia renal crónica. Escherichia coli productor de verotoxina es el primer agente etiológico de SUH. Los objetivos del presente trabajo son determinar si los perros pueden constituir un riesgo para la salud pública como portadores de VTEC y poner a punto la técnica de la reacción en cadena de la polimerasa (PCR). Hasta la fecha se han tomado 26 muestras de zonas peri urbanas y de caninos de la Sociedad Mendocina Protectora de Animales (SMPA). Las muestras fueron obtenidas mediante hisopado rectal de caninos y fueron sembradas en el medio de cultivo selectivo Agar Mac Conkey Sorbitol y Agar Levine e incubadas 24 horas a 37°C
Impactos ambientais da piscicultura de tanque escavado no reservatório Itaparica, semiárido Pernambucano / Environmental impacts of excavated tank pisciculture in the Itaparica reservoir, Pernambuco’s semiarid
A piscicultura possui importância econômica e social, mas é capaz de provocar impactos ambientais. Com objetivo de avaliar os impactos do efluente de piscicultura de tanque escavado no reservatório Itaparica foram realizadas análises físico-químicas e ecotoxicológicas, utilizando Daphnia similis, em cultivos de alevinos, no efluente de cultivos de juvenis antes e após tratamento e no reservatório Itaparica, rio São Francisco. Além de ensaios ecotoxicológicos com 17 ?-metiltestosterona, que causou toxicidade para D. similis, e com oxitetraciclina. O fósforo total no reservatório foi o único parâmetro acima do limite indicado pela legislação. Os resultados mostraram potencial de reuso do efluente, como estratégia para gestão sustentável da atividade e dos recursos hídricos. É evidente a necessidade de controle dos fármacos e monitoramento dos efluentes, para garantir a qualidade da água para os usos múltiplos, e mais importante, segurança hídrica no abastecimento humano
Phytoplankton evolution during the creation of a biofloc system for shrimp culture
[EN] Microalgae play a key role in the dynamics of biofloc technology aquaculture systems. Some phytoplankton groups, such as diatoms, are desired for their high nutritional value and contribution to water quality. Other groups, such as cyanobacteria, are undesired because of their low nutritional value and capacity of producing toxins. So, monitoring the phytoplankton community structure and succession is key for managing biofloc systems. However, research on phytoplankton in these systems is scarce and mostly done by microscopy. The primary objective of this research was to estimate phytoplankton community structure in shrimp biofloc system water samples, using high-performance liquid chromatography methods and CHEMTAX software. The major groups present in our system were diatoms, euglenophytes, cyanobacteria and chlorophytes, while dinoflagellates were only remarkable at the initial period. We observed a clear dominance of diatoms all along the 5 months that comprised a complete biofloc system culture. The characteristic succession of autotrophic processes by heterotrophs of the biofloc systems, was observed by the reduction of net primary production. Light intensity played a key role in determining the phytoplankton composition and abundance. Algal pigment analyses using high-performance liquid chromatography and subsequent CHEMTAX analysis in water samples was useful for estimating the phytoplankton community structure in the biofloc systems. However, we found some limitations when the biofloc system was in heterotrophic mode. Under these conditions, some dinoflagellates and cyanobacteria behaved as heterotrophs and lost or decreased their biomarkers pigments. So, further research is needed to increase knowledge on the accuracy of high-performance liquid chromatography /CHEMTAX under these conditions.Financial support for this research was provided by Conselleria d’Educació, Investigació, Cultura i Esport of the Generalitat Valenciana, through the program VALi+D, fle number ACIF/2014/244. We would like to express our deepest thanks to Professor Luis Henrique da Silva Poersch of FURG (Universidade Federal do Rio Grande) and Ivan Vidal (Langostinos el Real) for his support. Finally, the authors wish to thank Le Gouessant and Michaël Metz for providing the commercial feed.Llario-Sempere, F.; Rodilla, M.; Escrivá-Perales, J.; Falco, S.; Sebastiá-Frasquet, M. (2018). Phytoplankton evolution during the creation of a biofloc system for shrimp culture. 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Tuneable surface modification of PLGA nanoparticles carrying new antitubercular drug candidate
Plankton and water quality variability in an estuary before and after the shrimp farming effluents: possible impacts and regeneration
Análise da presença do fitoplâncton em bacia integrante do Projeto de Integração do Rio São Francisco, região semiárida, Nordeste brasileiro
Structure and dynamics of the phytoplankton community within a maturation pond in a semiarid region
Abstract In northeastern Brazil, stabilization ponds are very suitable for wastewater treatment because of the relative great land availability and environmental conditions (e.g., high temperature) favorable for microorganism optimal development. However, blooms of potentially toxic cyanobacteria may affect the use of these treatment ponds due to resulting effluent poor quality. The objective of this study was to evaluate the dynamics of phytoplankton communities and the occurrence of cyanobacteria in a maturation pond located immediately after a series of two ponds. Temperature, dissolved oxygen, pH, BOD, N, and P were measured during a period of four months when samples were collected from the surface and the bottom of 7 sampling points distributed inside the pond. The phytoplankton of collected samples was also identified and classified using a conventional optical microscopy. Analysis of variance and Tukey test were used to evaluate the results. The three phytoplankton divisions found (Cyanophyta, Chlorophyta, and Euglenophyta) did not change considerably through surface and bottom. However, they changed greatly over the sampled months; great dominance of Cyanophyta was found at April and October, while Chlorophyta dominated the lagoon in September. Low superficial organic loads (between 78 and 109 kg BOD.ha–1.d–1) and N:P ≤ 10 were the determinant factors that favored the predominance of Cyanophyta. The presence of two potentially toxic species of Cyanophyta, Oscillatoria sp. and Microcystis aeruginosa, indicates that caution is required when considering the final destination of treated effluent and suggests a need to assess the risks and benefits associated with the use of the treatment technology