206 research outputs found

    Diversity and antibiotic resistance of aeromonas spp. in drinking and waste water treatment plants

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    The taxonomic diversity and antibiotic resistance phenotypes of aeromonads were examined in samples from drinking and waste water treatment plants (surface, ground and disinfected water in a drinking water treatment plant, and raw and treated waste water) and tap water. Bacteria identification and intra-species variation were determined based on the analysis of the 16S rRNA, gyrB and cpn60 gene sequences. Resistance phenotypes were determined using the disc diffusion method. Aeromonas veronii prevailed in raw surface water, Aeromonas hydrophyla in ozonated water, and Aeromonas media and Aeromonas puntacta in waste water. No aeromonads were detected in ground water, after the chlorination tank or in tap water. Resistance to ceftazidime or meropenem was detected in isolates from the drinking water treatment plant and waste water isolates were intrinsically resistant to nalidixic acid. Most of the times, quinolone resistance was associated with the gyrA mutation in serine 83. The gene qnrS, but not the genes qnrA, B, C, D or qepA, was detected in both surface and waste water isolates. The gene aac(6’)-ib-cr was detected in different waste water strains isolated in the presence of ciprofloxacin. Both quinolone resistance genes were detected only in the species A. media. This is the first study tracking antimicrobial resistance in aeromonads in drinking, tap and waste water and the importance of these bacteria as vectors of resistance in aquatic environments is discussed.info:eu-repo/semantics/acceptedVersio

    Endocrine disrupting chemicals removal in an aerobic granular sludge reactor treating simulated saline wastewater

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    The occurrence of Endocrine disrupting chemicals (EDCs) in the environment is a topic of concern. It is commonly accepted that the major source of EDCs to the environment is wastewater treatment plants effluents. Salinity is an additional common stress factor in wastewater treatment. Aerobic granular sludge (AGS) has a number of properties that make it more attractive than conventional biological systems for treatment of wastewater containing EDCs. In the present study, an AGS sequencing batch reactor adapted to salinity was operated for 140 days for treating synthetic saline wastewater containing 17β–estradiol (E2), 17α–ethinylestradiol (EE2) and bisphenol-A (BPA). E2 was removed by biodegradation. EE2 adsorption/desorption to the aerobic granules was observed. The increasing of BPA removal efficiency after bioaugmentation with a degrading bacterial strain shows that biodegradation was the removal mechanism. COD removal was not significantly affected by EDCs shock loads. Activity of ammonia oxidizing bacteria and nitrite oxidizing bacteria did not seem to be inhibited by the presence of EDCs. The activity of phosphate accumulating organisms was affected.info:eu-repo/semantics/publishedVersio

    Rhodococcus sp. ED55: a bacterial strain with ability to degrade endocrine disrupting chemicals and potential for bioaugmentation

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    The occurrence of Endocrine disrupting chemicals (EDCs) in the environment is a topic of concern. It is commonly accepted that the major source of EDCs to the environment is wastewater treatment plants (WWTPs’) effluents, due to the inefficiency of WWTPs to remove this kind of pollutants. A bacterial strain – Rhodococcus sp. ED55 was isolated from the sediments of a discharge point of a WWTP in Coloane, Macau, for its ability to degrade EDCs. The bacterium was able to biodegrade 17β–estradiol (E2), 17α–ethinylestradiol (EE2), bisphenol-A (BPA) and bisphenol-S (BPS) at different extents. Strain ED55 was able to completely degrade the supplied amount of E2 in few hours, both in synthetic medium and in real wastewater from a municipal WWTP (Parada, Maia – Portugal). Estrone (E1), 4OH-E1 and 4OH-E2 were identified as intermediate degradation metabolites and the metabolic pathway is under elucidation. Bioaugmentation with Rhodococcus sp. ED 55 significantly improved the natural attenuation of the compound in municipal wastewater in batch assays. The acute test with luminescent marine bacterium Vibrio fischeri revealed elimination of the toxicity of the treated effluent and the standardized yeast estrogenic (S-YES) assay with the recombinant strain of Saccharomyces cerevisiae revealed decrease of estrogenic activity of samples. Rhodococcus sp. ED55 was applied in a strategy of an AGS sequencing batch reactor adapted to salinity, which was operated for treating a synthetic saline wastewater containing E2, EE2 and BPA. E2 was no longer detected in the bulk liquid after 10 min of aerobic reaction throughout reactor operation, suggesting that this compound was quickly removed by biodegradation. EE2 adsorption/desorption to the aerobic granules was observed. Removal of BPA significantly increased after bioaugmentation with Rhodococcus sp. ED55, showing that biodegradation was the governing removal mechanism. COD removal was not significantly affected by EDCs shock loads. Rhodococcus sp. ED55 can potentially be applied in bioaugmentation strategies for ameliorating treatment of wastewater contaminated with EDCs.info:eu-repo/semantics/publishedVersio

    Inhibition of Fas expression by RNAi modulates 5-fluorouracil-induced apoptosis in HCT116 cells expressing wild-type p53

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    AbstractDrug resistance to 5-fluorouracil (5-FU) is still a major limitation to its clinical use. In addition, the clinical value of p53 as a predictive marker for 5-FU-based chemotherapy remains a matter of debate. Here, we used HCT116 human colorectal cancer cells expressing wild-type p53 and investigated whether inhibition of Fas expression by interference RNA modulates 5-FU-induced apoptosis. Cells were treated with 5-FU (1, 4 or 8 μM) for 8–48 h. Cell viability was evaluated by trypan blue dye exclusion. Apoptosis was assessed by changes in nuclear morphology and caspase activity. The interference RNA technology was used to silence Fas expression. Caspase activation, p53, Fas, cytochrome c, and Bcl-2 family protein expression was evaluated by immunoblotting. 5-FU was cytotoxic in HCT116 cells (p<0.001). Nuclear fragmentation and caspase-3, -8 and -9 activities were also markedly increased in HCT116 cells after 5-FU (p<0.001). In addition, wild-type p53 and Fas expression were 25- and 4-fold increased (p<0.05). Notably, when interference RNA was used to inhibit Fas, 5-FU-mediated nuclear fragmentation and caspase activity were markedly reduced in HCT116 cells. Finally, western blot analysis of mitochondrial extracts from HCT116 cells exposed to 5-FU showed a 6-fold increase in Bax, together with a 3-fold decrease in cytochrome c (p<0.001). In conclusion, 5-FU exerts its cytotoxic effects, in part, through a p53/Fas-dependent apoptotic pathway that involves Bax translocation and mitochondrial permeabilization

    Proteome of the phytopathogen Xanthomonas citri subsp. citri: a global expression profile

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    <p>Abstract</p> <p>Background</p> <p>Citrus canker is a disease caused by <it>Xantomonas citri </it>subsp.<it>citri (Xac)</it>, and has emerged as one of the major threats to the worldwide citrus crop because it affects all commercial citrus varieties, decreases the production and quality of the fruits and can spread rapidly in citrus growing areas. In this work, the first proteome of <it>Xac </it>was analyzed using two methodologies, two-dimensional liquid chromatography (2D LC) and tandem mass spectrometry (MS/MS).</p> <p>Results</p> <p>In order to gain insight into the metabolism of <it>Xac</it>, cells were grown on two different media (<b>NB </b>- Nutrient Broth and <b>TSE </b>- Tryptone Sucrose broth enriched with glutamic acid), and proteins were proteolyzed with trypsin and examined by 2D LC-MS/MS. Approximately 39% of all predicted proteins by annotation of <it>Xac </it>were identified with their component peptides unambiguously assigned to tandem mass spectra. The proteins, about 1,100, were distributed in all annotated functional categories.</p> <p>Conclusions</p> <p>This is the first proteomic reference map for the most aggressive strain of <it>Xanthomonas </it>pathogen of all orange varieties. The compilation of metabolic pathways involved with bacterial growth showed that <it>Xac </it>expresses a complete central and intermediary metabolism, replication, transcription and translation machineries and regulation factors, distinct membrane transporters (ABC, MFS and pumps) and receptors (MCP, TonB dependent and metabolites acquisition), two-component systems (sensor and regulatory components) and response regulators. These data corroborate the growth curve <it>in vitro </it>and are the first reports indicating that many of these genome annotated genes are translated into operative in <it>Xac</it>. This proteomic analysis also provided information regarding the influence of culture medium on growth and protein expression of <it>Xac</it>.</p

    INFLUÊNCIA DA UNIFORMIDADE DA PARTÍCULA DE MILHO SOBRE O DESEMPENHO ZOOTÉCNICO E DIGESTIBILIDADE DE NUTRIENTES DA DIETA DE FRANGOS DE CORTE

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    A crescente demanda por proteína animal impulsiona o setor avícola a otimizar a produção com vistas à nutrição, um dos fatores mais importantes nesta indústria, seja pelo custo ou pela resposta animal frente à qualidade da ração. Deste modo, objetivou-se avaliar a influência do diâmetro geométrico médio (DGM) da partícula do milho e a forma física da ração (farelada e peletizada) sobre o desempenho zootécnico e digestibilidade dos nutrientes da ração em frangos de corte. Foram utilizados 3.600 frangos machos ROSS 91, avaliados entre 14 a 39 dias de idade, alojados em 72 boxes com 50 animais cada e 9 repetições por tratamento na granja da Seara Alimentos em Timbé do Sul. O estudo foi aprovado pelo Comitê de Ética no Uso de Animais do Instituto Federal Catarinense – Campus Araquari sob o protocolo nº 218/2018. O delineamento foi inteiramente casualizado em arranjo fatorial 2 X 4, sendo duas formas físicas da ração, farelada e peletizada, e quatro intervalos de DGMs (DGM1: 0,819-0,824; DGM2: 1,022-1,084; DGM3: 1,154-1,248; DGM4: 1,250-1,312) em mm. O DGM do milho foi obtido por moagem, peneiramento específico e cálculo Granucalc® para compor a ração. Foi realizada a pesagem individual dos frangos com 14, 21, 30 e 39 dias de idade e da ração consumida em balança digital para determinar ganho de peso (GP), consumo de ração (CR) e conversão alimentar (CA). Foi determinada a digestibilidade ileal dos nutrientes de 144 aves aos 34 dias de idade, por meio de coleta da digesta ileal (5 cm anteriores a junção ileocecal, extensão de 30 cm do intestino). As coletas foram avaliadas para proteína bruta, extrato etéreo, energia bruta, matéria orgânica e cinza insolúvel em ácido no Laboratório de Nutrição Animal da Universidade da Federal do Paraná. Todos os dados foram submetidos ao teste de Shapiro Wilk, sendo o ganho de peso, conversão alimentar e consumo de ração submetidos à análise de variância e o teste de Tukey. As aves alimentadas com raçãopeletizada apresentaram melhor GP (2,37±0,005 Kg) comparada a ração farelada (2,31±0,005 Kg) (P&lt;0,05), além disso a dieta peletizada proporcionou melhor Índice de Conversão Alimentar (1,593) quando comparada a ração farelada (1,614) (P&lt;0,001). Foram observados melhores resultados para GP em dietas com DGM2, DGM3 e DGM4 (P&lt;0,001), independente da forma física da ração. Porém na fase de 30 a 39 dias de idade, o GP das aves que consumiram ração farelada (935,25g) foi maior comparado a ração peletizada (914g), da mesma forma que para o CR. Para a CA os melhores resultados foram encontrados para os DGM2, DGM3 e DGM4 em todo período do experimento (P&lt;0,05). Não foi observado diferença na digestibilidade dos nutrientes da dieta para granulometria e a forma física da ração (P&gt;0,05). Conclui-se que aves alimentadas com dietas peletizadas obtiveram melhor desempenho zootécnico, e com ranulometria do milho a partir do DGM2 (1,022-1,084 mm), apresentaram melhor GP e CA, independente da forma física da ração. Não houve influência dos tratamentos sobre a digestibilidade dos nutrientes da dieta de frangos de corte

    Role of nutrients on lipid peroxidation and antioxidant defense system

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    Espécies reativas de oxigênio são formadas durante o metabolismo aeróbico e podem danificar lipídios, proteínas, carboidratos e o DNA. Essas reações, potencialmente deletérias, são controladas por um sistema de antioxidantes enzimáticos e não enzimáticos, que eliminam os próoxidantes e “varrem” os radicais livres. Esta revisão mostra o papel de alguns nutrientes na peroxidação lipídica e no sistema de defesa antioxidante. Enfatizam-se os mecanismos que levam ao dano oxidativo e sua proteção, assim como as implicações na saúde humana.Reactive oxygen species are generated in aerobic metabolism and can damage lipids, proteins, carbohydrates and DNA. These potentially deleterious reactions are controlled by a system of enzymatic and non-enzymatic antioxidants which eliminates prooxidants and scavenge free radicals. This revision focuses the role of particular nutrients in lipid peroxidation and antioxidant defense system. Emphasis was placed on mechanisms for damage and protection, as well implications in human healthy issues

    Dinâmicas socioecológicas no semiárido baiano a partir do acesso a água : O caso da família Farias

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    A dinâmica socioecológica dos camponeses do semiárido brasileiro vem mudando há algumas décadas em decorrência do acesso a programas e políticas públicas para a convivência com o semiárido. Este trabalho apresenta o resultado da avaliação socioecológica em um agroecossistema no semiárido baiano após o acesso a tecnologias de captação e armazenamento de água da chuva, visando contribuir com a discussão sobre a sustentabilidade de agroecossistemas no semiárido brasileiro. Para construção desses dados foram utilizadas as metodologias e ferramentas de um Diagnóstico Rural Participativo. As tecnologias de captação e armazenamento de água da chuva possibilitaram mudanças significativas na vida dessas famílias, permitindo o acesso além da água para consumo humano e ampliando esse acesso para a água de produção, permitindo o cultivo de espécies e a criação de animais que garantem a manutenção da família no tempo e no espaço.The socioecological dynamics of the Brazilian semi-arid farmers has changed a few decades as a result of access to programs and policies for coexistence with the semiarid region. This paper presents the results of socio-ecological evaluation in a semi-arid agroecosystem in Bahia after access to rainwater capture and storage technologies, to contribute to the discussion about the sustainability of agro-ecosystems in the Brazilian semiarid region. Construction of such data the methodologies and tools of a Participatory Rural Appraisal. The capture and rainwater storage technologies enabled significant changes in the lives of these families, allowing access in addition to drinking water and expanding such access for the production of water, allowing the cultivation of species and breeding that guarantee family maintenance in time and space.Eje A6: Desarrollo Rural, Movimientos Sociales, Estado y AgroecologíaFacultad de Ciencias Agrarias y Forestale
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