Cholinesterase Activities and Oxidative Stress in Cattle Experimentally Exposed to Nitrate/Nitrite in Cultivated Pasture with Different Fertilization Schemes

Background: Nitrate and nitrite poisoning is associated with pasture intake that has high nitrate levels and leads to acute methemoglobinemia. Pasture may accumulate nitrate under certain conditions, such as excessively fertilized soil or environmental conditions that enhance the N absorption (rain preceded by a period of drought). After ingestion of plants, this substrate reaches the rumen and, in physiological conditions, is reduced to nitrite and afterward to ammonia. The aim of this study was to evaluate changes in cholinesterase activities and oxidative stress caused by subclinical poisoning for nitrate and nitrite in cattle fed with Pennisetum glaucum in three different fertilization schemes.Materials, Methods & Results: In order to perform the experimental poisoning, the pasture was cultivated in three different paddocks: with nitrogen topdressing (urea; group 1), organic fertilizer (group 2) or without fertilizer (group 3; control). Nitrate accumulation in forage was evaluated by the diphenylamine test. After food fasting of 12 h, nine bovine were randomly allocated to one of the experimental groups and fed with fresh forage (ad libitum) from respective paddock. In different time points from beginning of pasture intake (0, 2, 4, 6 and 9 h) heart rate and respiratory frequency were assessed, as well as mucous membrane color and behavioral changes. Blood samples from jugular vein into vials with and without anticoagulant were collected. From blood samples, serum nitrite levels, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzyme activity were evaluated, as well as oxidative stress through the following parameters: levels of nitrate/nitrite (NOx ), thiobarbituric acid reactive substances (TBARS) and reactive oxygen species (ROS), beyond the antioxidant system by enzyme activity measurement of catalase (CAT) and superoxide dismutase (SOD). The diphenylamine test was positive to group 1 and 2, so that the pasture presented 3.16 mg/kg, 2.98 mg/kg and 1.67 mg/kg of nitrate for group 1, 2 and 3, respectively. In addition, cows from group 1 demonstrated increased (P < 0.05) nitrite levels in serum, compared to other groups, and greater heart rate after 9 h (P < 0.05). The AChE and BChE activity in group 1 showed significant increase (P < 0.05) at 4 and 6 h (AChE), and 4 and 9 h (BChE) compared to group 3. Also, NOx levels were lower at 6 and 9 h (P < 0.05) and at 9 h (P < 0.05) for animals of group 1 and 2, respectively, when compared to group 3. Furthermore, in the group 1 levels of ROS and TBARS were significantly higher (P < 0.05) after 2 and 4 h, and 6 and 9 h compared to other groups, respectively. The CAT activity increased significantly (P < 0.05) with 2 and 4 h of the experiment, but on the other hand, decreased at 6 and 9 h in group 1. Nevertheless, the animals from group 2 presented only a significant reduction in this enzyme activity at 9 h. Furthermore, SOD activity was reduced in animals of groups 1 (P < 0.05) at 4, 6 and 9 h, compared to other groups.Discussion: It was concluded that the nitrate and nitrite poisoning by pasture intake cultivated and fertilized with urea leads to increased levels of serum nitrite, as well as the cholinesterase activity and causes oxidative stress in cattle. It is conjectured that the cholinesterase activity and oxidative stress may assist in understanding the pathophysiology of changes caused by poisoning

Diagnóstico de maedi-visna em ovinos no estado de Santa Catarina

Maedi-visna is a progressive and multisystemic disease that affects sheep, resulting in significant economic losses due to animal mortality and possible trade barriers. This work aimed to describe the occurrence of the lentivirus that causes maedi-visna in sheep through the conventional PCR technique in biological samples. To our knowledge, the disease has never been diagnosed in the state of Santa Catarina, south of Brazil. Five adult Texel sheep, from two properties in the city of Concórdia (SC), presented clinical signs of dyspnea and/or ataxia, progressive weight loss, followed by death; were sent to the Veterinary Pathology Laboratory (LPV) for diagnosis. The animals were submitted to necropsy, fragments of several organs, including lung and brain, were collected in 10% formalin for histopathological analysis, and frozen for PCR. In one of the properties, whole blood of 11 sheep was collected to detect the circulation of the virus in the herd. Tissue and blood samples were subjected to different DNA extraction techniques and tested by conventional PCR specific for the maedi-visna virus. At necropsy, the main lesions observed in sheep were: non-collapsed lungs, with elastic and hypocrepting consistency (4/5); and brain with diffuse hyperemia and a focal area of ​​malacia in the white matter (1/5). On histopathology, lymphocytic interstitial pneumonia with lymphoid peribronchial nodular proliferation was described in four animals, and non-suppurative encephalitis with malacia and Gitter cells in one animal. The anatomopathological lesions were compatible with maedi-visna disease, and the diagnosis was confirmed by PCR in the lung. Of the 11 live animals evaluated, five samples of leukocyte porridge were positive by PCR, confirming the circulation of the virus in the herd. The probable causes of these cases in Santa Catarina state are the acquisition of animals from regions where the disease already occurs, as well as the possibility of transmission through semen or infected embryos. The recommended prevention and control measures aim to restrict the horizontal transmission of the virus between animals, avoiding the contact of healthy with infected animals, especially the contact of infected sheep with their lambs. Performing sensitive diagnostic tests such as PCR at regular intervals is also recommended. Maedi-visna is a disease that lacks a vaccine and treatment, and therefore effective control and prevention measures are necessary to prevent its spread in the state.Maedi-visna es una enfermedad progresiva y multisistémica que afecta a los ovinos, y que provoca importantes pérdidas económicas debido a la mortalidad de los animal y posibles barreras comerciales. Este trabajo tuvo como objetivo describir la ocurrencia del lentivirus que causa maedi-visna en ovinos mediante la técnica de PCR convencional en muestras biológicas. Hasta donde sabemos, la enfermedad nunca ha sido diagnosticada en el estado de Santa Catarina, sur de Brasil. Cinco ovejas Texel adultas, de dos propiedades en la ciudad de Concórdia (SC), presentaron signos clínicos de disnea y/o ataxia, pérdida de peso progresiva, seguida de muerte; fueron enviados al Laboratorio de Patología Veterinaria (LPV) para diagnóstico. Los animales fueron sometidos a necropsia, fragmentos de varios órganos, incluyendo pulmón y cerebro, fueron recolectados en formalina al 10% para análisis histopatológico, y congelados para PCR. En una de las propiedades se recolectó sangre entera de 11 ovejas para detectar la circulación del virus en el rebaño. Las muestras de tejido y sangre se sometieron a diferentes técnicas de extracción de ADN y se analizaron mediante PCR convencional específica para el virus maedi-visna. En la necropsia, las principales lesiones observadas fueron: pulmones no colapsados, con consistencia elástica e hipocreptante (4/5); y cerebro con hiperemia difusa y un área focal de malacia en la sustancia blanca (1/5). En la histopatología se observó neumonía intersticial linfocítica con proliferación nodular peribronquial linfoide en cuatro animales y encefalitis no supurativa con malacia y células Gitter en un animal. Las lesiones anatomopatológicas eran compatibles con enfermedad de maedi-visna y el diagnóstico se confirmó mediante PCR en pulmón. De los 11 animales vivos evaluados, cinco muestras de papa de leucocitos resultaron positivas por PCR, lo que confirmó la circulación del virus en el rebaño. Las causas probables de estos casos en el estado de Santa Catarina son la adquisición de animales de regiones donde ocurre la enfermedad, así como la posibilidad de transmisión a través de semen o embriones infectados. Las medidas de prevención y control recomendadas tienen como objetivo restringir la transmisión horizontal del virus entre animales, evitando el contacto de animales sanos con infectados, especialmente el contacto de ovejas infectadas con sus corderos. También se recomienda realizar pruebas de diagnóstico sensibles como PCR a intervalos regulares. Maedi-visna es una enfermedad que carece de vacuna y tratamiento, por lo que son necesarias medidas eficaces de control y prevención para evitar su propagación en la región.Maedi-visna é uma doença progressiva e multissistêmica que acomete ovinos, resultando em prejuízos socioeconômicos significativos, devido à mortalidade de animais e à possíveis barreiras comerciais. Esse trabalho teve por objetivo descrever a ocorrência do lentivírus que causa a maedi-visna em ovinos através da técnica de PCR convencional em amostras biológicas. Ao nosso conhecimento, a enfermidade nunca foi diagnosticada no estado de Santa Catarina. Cinco ovinos adultos da raça Texel, oriundos de duas propriedades do município de Concórdia (SC), apresentaram quadro clínico de dispneia e/ou ataxia, emagrecimento progressivo, seguido de morte e foram enviados ao Laboratório de Patologia Veterinária (LPV) para diagnóstico. Os animais foram submetidos à necropsia, sendo fragmentos de vários órgãos, incluindo pulmão e encéfalo, colhidos em formol 10% para análise histopatológica, e congelados para PCR. Em uma das propriedades, o sangue total de 11 ovinos foi colhido para detectar a circulação do vírus no rebanho. As amostras de tecido e sangue foram submetidas a técnicas distintas de extração de DNA e testadas por PCR convencional específica para o vírus de maedi-visna. Na necropsia, as principais lesões observadas nos ovinos foram: pulmões não colabados, de consistência elástica e hipocreptante (4/5); e encéfalo com hiperemia difusa e área focal de malácia na substância branca (1/5). Na histopatologia, foram descritos pneumonia intersticial linfocítica com proliferação nodular peribronquiolar de tecido linfóide em quatro animais, e encefalite não supurativa com malácia e células Gitter em um animal. As lesões anatomopatológicas foram compatíveis com a doença maedi-visna, e o diagnóstico confirmado por PCR de pulmão.&nbsp; Dos 11 animais vivos avaliados, cinco amostras de papa de leucócitos tiveram resultado positivo através da PCR, confirmando a circulação do vírus no rebanho. As prováveis causas de introdução da doença no estado são pela aquisição de animais de regiões onde a doença já ocorre, assim como a possibilidade de transmissão através de sêmen ou embriões infectados. As medidas de prevenção e controle preconizadas tem o intuito de restringir a transmissão horizontal do vírus entre os animais, evitando o contato de animais sadios com animais infectados, principalmente o contato de ovelhas infectadas com seus borregos. A realização de testes de diagnóstico sensível como a PCR, em intervalos regulares, também é recomendada. Maedi-visna é uma enfermidade que carece de vacina e tratamento e, portanto, medidas eficazes de controle e prevenção são necessárias para evitar a disseminação no estado

Doenças diagnosticadas pelo Laboratório de Patologia Veterinária em 2018

This work presents the case series of diagnoses in farm animals in the year 2018 of the Laboratory of Veterinary Pathology at IFC Campus Concórdia. There were 185 diagnoses in cattle, 18 in sheep and 40 in pigs, totaling 243. Of these, 191 (81.9%) were through necropsies and 44 (18.1%) through biopsies samples sent by veterinarians. In cattle, the most frequent diseases were clostridial myositis with 9 cases (5.0%); poisoning by Prunus (sphaerocarpa) myrtifolia with 9 cases (5.0%); nitrate/nitrite poisoning with 7 cases (3.9%); and squamous cell carcinoma with 7 cases (3.9%). In sheep, it was haemonchosis with 7 cases (38.9%) and in swine, circovirus with 6 cases (15.0%).Este artículo describe la serie de casos de diagnósticos en animales de granja del año 2018 del Laboratorio de Patología Veterinaria del IFC Campus Concórdia. Hubo 185 diagnósticos en bovinos, 18 en ovinos y 40 en porcinos, totalizando 243. De estos, 191 (81,9%) fueron por necropsias y 44 (18,1%) por muestras de biopsias enviadas por veterinarios. En bovinos, las enfermedades más frecuentes fueron la miositis por clostridios con 9 casos (5,0%); intoxicación por Prunus (sphaerocarpa) myrtifolia con 9 casos (5,0%); intoxicación por nitratos/nitritos con 7 casos (3,9%); y carcinoma de células escamosas con 7 casos (3,9%). En ovinos fue la hemoncosis con 7 casos (38,9%) y en porcinos el circovirus con 6 casos (15,0%).              Este trabalho apresenta a casuística de diagnósticos no ano de 2018 do Laboratório de Patologia Veterinária do IFC Campus Concórdia. Foram 185 diagnósticos em bovinos, 18 em ovinos e 40 em suínos, totalizando 243. Destes, 191 (81,9%) foram através de necropsias e 44 (18,1%) através de amostras formolizadas enviadas por veterinários. Em bovinos as doenças mais incidentes foram miosite clostridial com 9 casos (5,0%); intoxicação por Prunus (sphaerocarpa) myrtifolia com 9 casos (5,0%); intoxicação por nitrato/nitrito com 7 casos (3,9%); e carcinoma de células escamosas com 7 casos (3,9%). Já em ovinos, foi hemoncose com 7 casos (38,9%) e, em suínos, a circovirose com 6 casos (15,0%)

12,500+ and counting: biodiversity of the Brazilian Pampa

Knowledge on biodiversity is fundamental for conservation strategies. The Brazilian Pampa region, located in subtropical southern Brazil, is neglected in terms of conservation, and knowledge of its biodiversity is fragmented. We aim to answer the question: how many, and which, species occur in the Brazilian Pampa? In a collaborative effort, we built species lists for plants, animals, bacteria, and fungi that occur in the Brazilian Pampa. We included information on distribution patterns, main habitat types, and conservation status. Our study resulted in referenced lists totaling 12,503 species (12,854 taxa, when considering infraspecific taxonomic categories [or units]). Vascular plants amount to 3,642 species (including 165 Pteridophytes), while algae have 2,046 species (2,378 taxa) and bryophytes 316 species (318 taxa). Fungi (incl. lichenized fungi) contains 1,141 species (1,144 taxa). Animals total 5,358 species (5,372 taxa). Among the latter, vertebrates comprise 1,136 species, while invertebrates are represented by 4,222 species. Our data indicate that, according to current knowledge, the Pampa holds approximately 9% of the Brazilian biodiversity in an area of little more than 2% of Brazil’s total land. The proportion of species restricted to the Brazilian Pampa is low (with few groups as exceptions), as it is part of a larger grassland ecoregion and in a transitional climatic setting. Our study yielded considerably higher species numbers than previously known for many species groups; for some, it provides the first published compilation. Further efforts are needed to increase knowledge in the Pampa and other regions of Brazil. Considering the strategic importance of biodiversity and its conservation, appropriate government policies are needed to fund studies on biodiversity, create accessible and constantly updated biodiversity databases, and consider biodiversity in school curricula and other outreach activities