RESUMO

Background: Poisoning of animals due to toxic plants is found in Brazil and other countries. One of the known toxic plantsin Brazil, with the active ingredient sodium fluoroacetate (SF), is Palicourea marcgravii. Dehalogenases that inactivatethe fluor-carbon bonds are enzymes found in microorganisms and may prevent intoxication. This study evaluated the occurrence of rumen microorganisms naturally resistant to SF.Materials, Methods & Results: Two samples of rumen fluid of cattle from the Experimental Farm of Federal University ofMato Grosso fed with Brachiaria sp. were obtained via fistula in flasks. An aliquot of 2 mL was placed in a microtube andcentrifuged at 9000 g for 1 min. Then, the sample was inoculated into 2 tubes, one containing 100 µL of clarified rumenfluid in 2 mL of modified liquid culture medium (0.1% ammonium sulfate, 0.1% potassium phosphate monobasic, 0.05%sodium phosphate dibasic, 0.01% magnesium sulfate, 0.01% yeast extract, pH 7.0) and 0.4% of SF and the other samplecontaining 2 mL of liquid culture medium and 100 µL of clarified rumen fluid. The 2 samples were incubated at 40°C for24 h. Dilutions were performed under the same conditions every 24 h until the attainment of microorganisms resistant toSF, and the finaldilution containing 50 µL of each sample was plated in the middle containing SF (0.4%) and incubated at40°C for 24 h for the isolation of bacteria. The bacterial colonies resistant to SF were identified by morphological methods, stained, and subjected to DNA extraction sequencing using the universal primers 27f and 1492r (16S rDNA) for theidentification of the bacterial genus using Blast DNA identity analysis. These bacteria were cultured with and without SF(0.4%), and the presence of fluoride ions was detected by an ion-selective electrode (fluoride) during incubation for 0, 30,60, 90, and 120 min. Two resistant microorganisms were isolated, one was a Gram-positive coccus and the other was aGram-positive rod...(AU)

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RESUMO

Background: Poisoning of animals due to toxic plants is found in Brazil and other countries. One of the known toxic plantsin Brazil, with the active ingredient sodium fluoroacetate (SF), is Palicourea marcgravii. Dehalogenases that inactivatethe fluor-carbon bonds are enzymes found in microorganisms and may prevent intoxication. This study evaluated the occurrence of rumen microorganisms naturally resistant to SF.Materials, Methods & Results: Two samples of rumen fluid of cattle from the Experimental Farm of Federal University ofMato Grosso fed with Brachiaria sp. were obtained via fistula in flasks. An aliquot of 2 mL was placed in a microtube andcentrifuged at 9000 g for 1 min. Then, the sample was inoculated into 2 tubes, one containing 100 µL of clarified rumenfluid in 2 mL of modified liquid culture medium (0.1% ammonium sulfate, 0.1% potassium phosphate monobasic, 0.05%sodium phosphate dibasic, 0.01% magnesium sulfate, 0.01% yeast extract, pH 7.0) and 0.4% of SF and the other samplecontaining 2 mL of liquid culture medium and 100 µL of clarified rumen fluid. The 2 samples were incubated at 40°C for24 h. Dilutions were performed under the same conditions every 24 h until the attainment of microorganisms resistant toSF, and the finaldilution containing 50 µL of each sample was plated in the middle containing SF (0.4%) and incubated at40°C for 24 h for the isolation of bacteria. The bacterial colonies resistant to SF were identified by morphological methods, stained, and subjected to DNA extraction sequencing using the universal primers 27f and 1492r (16S rDNA) for theidentification of the bacterial genus using Blast DNA identity analysis. These bacteria were cultured with and without SF(0.4%), and the presence of fluoride ions was detected by an ion-selective electrode (fluoride) during incubation for 0, 30,60, 90, and 120 min. Two resistant microorganisms were isolated, one was a Gram-positive coccus and the other was aGram-positive rod...

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RESUMO

This study was designed to assess the influence of genetic resistance against brachiaria poisoning in sheep. Two groups of sheep, one identified as susceptible (formed by two ewes and one ram) and the other as resistant against brachiaria poisoning (formed by three ewes and one ram) were selected. Sheep considered susceptible were those that presented clinical signs of brachiaria poisoning at any time of their life; resistant sheep were those that even raised on Brachiaria spp. pastures, did not developed any sign of the poisoning during their life. The offspring of the two flocks (15 lambs from the sensitive flock and 9 lambs from the resistant flock) were placed into brachiaria pasture (initially Brachiaria decumbens and B. brizantha,and only B. decumbens after weaning) and followed up during two years (2013-2014). The determination of protodioscin levels in B. decumbens pasture was performed only in 2014 and revealed significant amounts of the toxic principle. Eleven lambs of the susceptible group were affected to some degree of brachiaria poisoning and six died; no lamb of the resistant group was affected. Clinical signs consisted of varying degrees of subcutaneous edema of the face and, erythema and loss of hair of the ears, crusts on the skin of ears, around the eyes and on planum nasale, scar deformation of the ears, and bilateral ocular discharge; affected lambs also sought for shadowy shelters and they were poor doers. Several sheep recovered from the condition and then relapsed. Necropsy findings in six lambs included pale mucous membranes, emaciation, dermatitis, scar deformation of the ears, large yellow livers with marked lobular pattern, and moderate infestation by Haemonchus contortus...

Este estudo avaliou a resistência genética na ocorrência de intoxicação por braquiária em ovinos. Foram selecionados dois grupos de ovinos, um identificado como suscetível (formado por duas ovelhas e um carneiro) e o outro como resistente (formado por três ovelhas e um carneiro). Foram considerados suscetíveis ovinos que apresentaram sinais de intoxicação por Brachiaria spp. em algum ponto de suas vidas e resistentes aqueles ovinos que, mesmo criados em pastagem de braquiária, nunca desenvolveram qualquer sinal da intoxicação. A progênie desses dois grupos (15 cordeiros do grupo suscetível e 9 no grupo resistente) foi colocada numa pastagem de braquiária (inicialmente Brachiaria decumbens e B. brizantha e, após o desmame, apenas B. decumbens) e acompanhada durante dois anos (2013-2014). A determinação dos níveis de protodioscina em B. decumbens foi realizada apenas em 2014 e foram encontradas quantidades significativas do princípio tóxico. Onze cordeiros do grupo suscetível foram afetados por algum grau de intoxicação por braquiária; nenhum cordeiro do grupo resistente foi afetado. Os sinais clínicos consistiam de graus variáveis de edema subcutâneo da face e eritema e alopecia da pele das orelhas, crostas na pele das orelhas e ao redor dos olhos e no plano nasal, retração cicatricial das orelhas, fotofobia e corrimento ocular bilateral. Três cordeiros apresentaram desenvolvimento retardado. Vários cordeiros se recuperaram da condição, mas posteriormente quando foram colocados na pastagem apresentaram recidivas. Achados de necropsia em seis cordeiros incluíam mucosas pálidas, pobre condição corporal, dermatite, deformação cicatricial das orelhas, fígado aumentado de volume, amarelo e com padrão lobular evidenciado e graus moderados de infestação por Haemonchus contortus...

Assuntos

RESUMO

This study was designed to assess the influence of genetic resistance against brachiaria poisoning in sheep. Two groups of sheep, one identified as susceptible (formed by two ewes and one ram) and the other as resistant against brachiaria poisoning (formed by three ewes and one ram) were selected. Sheep considered susceptible were those that presented clinical signs of brachiaria poisoning at any time of their life; resistant sheep were those that even raised on Brachiaria spp. pastures, did not developed any sign of the poisoning during their life. The offspring of the two flocks (15 lambs from the sensitive flock and 9 lambs from the resistant flock) were placed into brachiaria pasture (initially Brachiaria decumbens and B. brizantha,and only B. decumbens after weaning) and followed up during two years (2013-2014). The determination of protodioscin levels in B. decumbens pasture was performed only in 2014 and revealed significant amounts of the toxic principle. Eleven lambs of the susceptible group were affected to some degree of brachiaria poisoning and six died; no lamb of the resistant group was affected. Clinical signs consisted of varying degrees of subcutaneous edema of the face and, erythema and loss of hair of the ears, crusts on the skin of ears, around the eyes and on planum nasale, scar deformation of the ears, and bilateral ocular discharge; affected lambs also sought for shadowy shelters and they were poor doers. Several sheep recovered from the condition and then relapsed. Necropsy findings in six lambs included pale mucous membranes, emaciation, dermatitis, scar deformation of the ears, large yellow livers with marked lobular pattern, and moderate infestation by Haemonchus contortus. Histologically the liver lesions were similar in all necropsied lambs but with varying degrees of severity; they were consistent with brachiaria poisoning and included architectural disruption of hepatocellular trabecula, clusters of foamy macrophages [...](AU)

Este estudo avaliou a resistência genética na ocorrência de intoxicação por braquiária em ovinos. Foram selecionados dois grupos de ovinos, um identificado como suscetível (formado por duas ovelhas e um carneiro) e o outro como resistente (formado por três ovelhas e um carneiro). Foram considerados suscetíveis ovinos que apresentaram sinais de intoxicação por Brachiaria spp. em algum ponto de suas vidas e resistentes aqueles ovinos que, mesmo criados em pastagem de braquiária, nunca desenvolveram qualquer sinal da intoxicação. A progênie desses dois grupos (15 cordeiros do grupo suscetível e 9 no grupo resistente) foi colocada numa pastagem de braquiária (inicialmente Brachiaria decumbens e B. brizantha e, após o desmame, apenas B. decumbens) e acompanhada durante dois anos (2013-2014). A determinação dos níveis de protodioscina em B. decumbens foi realizada apenas em 2014 e foram encontradas quantidades significativas do princípio tóxico. Onze cordeiros do grupo suscetível foram afetados por algum grau de intoxicação por braquiária; nenhum cordeiro do grupo resistente foi afetado. Os sinais clínicos consistiam de graus variáveis de edema subcutâneo da face e eritema e alopecia da pele das orelhas, crostas na pele das orelhas e ao redor dos olhos e no plano nasal, retração cicatricial das orelhas, fotofobia e corrimento ocular bilateral. Três cordeiros apresentaram desenvolvimento retardado. Vários cordeiros se recuperaram da condição, mas posteriormente quando foram colocados na pastagem apresentaram recidivas. Achados de necropsia em seis cordeiros incluíam mucosas pálidas, pobre condição corporal, dermatite, deformação cicatricial das orelhas, fígado aumentado de volume, amarelo e com padrão lobular evidenciado e graus moderados de infestação por Haemonchus contortus. Histologicamente, as lesões hepáticas eram semelhantes em todos os cordeiros necropsiados, mas apresentavam vários [...](AU)

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This study investigated possible immunotoxic effects of Senna occidentalis (So) seeds incorporated in broiler chicken rations at different concentrations (0.0%, 0.25%, 0.50% and 0.75%), for 28 or 42 days. We evaluated innate immune function (macrophage activities of spreading, phagocytosis, peroxide and nitric oxide production) and acquired immune function (humoral and cellular immune responses), as well as lymphoid organ weights and pathology. There was enhanced macrophage activity, as hydrogen peroxide production increased (P < 0.05) in cells of birds given 0.75%So, but there were no other pro-inflammatory effects. Birds receiving 0.75% of So in ration for 42 days gained less weight (P < 0.01), and showed a decrease in relative weight of the bursa of Fabricius (P < 0.05) and spleen (P < 0.01). In addition, morphological changes were also noted in these lymphoid organs, with depletion of lymphoid cells on the spleen and bursa of Fabricius, resulting in lower relative weight of both lymphoid organs. No impairment of humoral immune response against Newcastle disease and in cellular immune response after a phytohaemagglutinin challenge was found. It is probable that mitochondrial damage and related apoptosis may be responsible for the enhanced peroxide production and the reduced relative weight of the bursa of Fabricius and spleen.

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Brachiaria decumbens and B. brizantha (signal grass), which occupy millions of acres in Brazil, are an important source of fodder for ruminants. Sporadic outbreaks of photosensitization in ruminants grazing on signal grass have been reported. Intoxicated animals showed the presence of foamy cells in the liver, spleen, intestinal submucosa and lymph nodes. These foamy cells are macrophages. They are very difficult to distinguish with haematoxylin and eosin stain, especially in the case of isolated cells. The purpose of the present study was to detect specific carbohydrate residues of storage material in the foamy cells in tissues of cattle exposed to Brachiaria spp. The characterization of glycoconjugates provides clues to the pathogenesis of these cells. Besides, the lectin peanut agglutinin was found to be an excellent marker to differentiate and quantify the foam cells, and could be used as a specific marker.

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Cinco bovinos imunizados contra a ação tóxica das sementes de Abrus precatorius L. ("tento", "jiquiriti") não adoeceram ou somente levemente pela administração das sementes de Ricinus communis L. ("mamona"), em doses que em bovinos que antes nunca ingeriram sementes de A. precatorius ou R. communis, causaram intoxicação de intensidade de grau moderado a acentuado ou até a morte. Um sexto bovino, que não ficou bem imunizado contra a ação tóxica das sementes de A. precatorius, adoeceu em grau acentuado pela administração de dose elevada das sementes de R. communis. Já dos cinco bovinos imunizados contra a ação tóxica das sementes de R. communis quatro adoeceram em grau acentuado, oquinto em grau moderado, pela administração das sementes de A. precatorias em doses que em bovinos que antes nunca ingeriram sementes de R. communis ou A. precatorius causaram intoxicação de intensidade leve a acentuada. Estes resultados permitem concluir que bovinos imunizados contra a ação tóxica das sementes de A. precatorius são resistentes à ação tóxica das sementes de R. communis, mas que o contrário não ocorre, isto é, bovinos imunizados contra a ação tóxica das sementes de R. communis, não se mostraram protegidos contra a intoxicação por A. precatorius. Estudos anteriores por outros autores mostraram que as toxalbuminas de A. precatorius e R. communis, respectivamente abrina e ricina, são diferentes do ponto de vista antigênico. Uma explicação para a divergência desses resultados com os nossos poderia estar no fato de que no presente estudo foram usados poligástricos que receberam as sementes por via oral, enquanto que nos estudos anteriores foram usados monogástricos em que as sementes ou as toxinas foram aplicadas por via parenteral. A administração de folhas frescas ou do pericarpo do fruto de R. communis a bovinos imunizados contra a ação das sementes desta planta tiveram o mesmo efeito tóxico que em animais não imunizados, demonstrando que a imunidade conferida pela ricina não inibe a ação da ricinina, o principio tóxico das folhas e do pericarpo

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