Intoxicação experimental por Brachiaria decumbens em coelhos

Brachiaria spp. are important sources of forage for ruminants in Brazil, due to the easy cultivation, good resistance to drought, good adaptation to different soils and low maintenance cost. However, the ingestion of this grass has been related to photosensitization outbreaks in cattle and sheep with significant economic losses. The hepatotoxic effects related to the ingestion of grass are the formation of crystals and foamy macrophages due to the accumulation of toxic metabolites. The use of cattle and sheep in experiments involving the plant presents several obstacles in the ethical, economic and animal management. The objective of this study was to evaluate the sensitivity of rabbits as an experimental model for B. decumbens poisoning. Two experiments were carried out. In Experiment 1 four rabbits received the fresh plant in daily doses of 10, 20, 40 and 80g/kg body weight for 120 days. In Experiment 2 three rabbits received the fresh plant in amounts of 500g daily with duration of 210 days. The animals of Experiment 1 showed no clinical signs and no macroscopic and microscopic changes characteristic of B. decumbens poisoning. In Experiment 2 the animals also showed no clinical signs or significant macroscopic alterations. Histological analysis showed isolated foamy macrophages or present in random groups of cells in the liver and mesenteric lymph nodes. Samples of liver and mesenteric lymph nodes of the rabbits of Experiment 2 were submitted to the lectin-histochemistry technique. The WGA, sWGA and RCA lectins showed reactivity in foamy macrophages in both organs. This is the first study of our knowledge that demonstrates histopathological lesions caused expetimentally by Brachiaria spp. in rabbits, demonstrating its potential as an animal model.Brachiaria ssp. são importantes fontes de forragem para ruminantes no Brasil, devido ao fácil cultivo, boa resistência a seca, boa adaptação a diferentes solos e baixo custo de manutenção. Entretanto, a ingestão desta gramínea está relacionada a surtos de fotossensibilização, em bovinos e ovinos, principalmente, ocasionando prejuízos econômicos significativos. Os efeitos hepatotóxicos relacionados à ingestão da gramínea são a formação de cristais e macrófagos espumosos causados pelo acúmulo de metabólitos tóxicos. A utilização de bovinos e ovinos em experimentos envolvendo a planta apresenta vários empecilhos, tanto no âmbito ético, econômico e no manejo dos animais. O objetivo do presente trabalho foi avaliar a sensibilidade de coelhos como modelo experimental para intoxicação por B. decumbens. No presente estudo foram realizados dois experimentos. O Experimento 1 utilizou quatro coelhos que receberam a planta fresca em doses diárias de 10, 20, 40 e 80 g/Kg de peso vivo durante 120 dias. O Experimento 2 utilizou três coelhos recebendo a planta fresca em quantidades de 500g diárias por animal com duração de 210 dias. No Experimento 1, os animais não apresentaram sinais clínicos e nem alterações macroscópicas e microscópicas características de intoxicação por B. decumbens No Experimento 2 os animais também não apresentaram sinais clínicos e alterações macroscópicas significativas. Na análise histológica observou-se presença de macrófagos espumosos isolados ou em grupos aleatórios de células no fígado e nos linfonodos mesentéricos. Amostras de fígado e linfonodos mesentéricos dos animais do Experimento 2 foram submetidos à técnica de lectino-histoquímica. As lectinas WGA, sWGA e RCA apresentaram reatividade em macrófagos espumosos nos dois órgãos. Este é o primeiro trabalho de nosso conhecimento que demonstra lesões histopatológicas por Brachiaria spp conduzido de forma experimental em coelhos, demonstrando seu potencial como modelo animal nesse campo de estudo

Diagnoses of Ovine Infection by the Serotype-4 Bluetongue Virus on Minas Gerais, Brazil

Background: Bluetongue (BT) is a viral disease transmitted by hematophagous vectors of the genus Culicoides. In Brazil, the identifcation of antibodies against the virus has been held for over thirty years, however clinicopathological diagnosis of the disease are scarce. The frst reported case occurred in the state of Paraná in 2001, confrmed by isolation and identifcation of serotype 12 of BTV. In the state of Rio Grande do Sul, in 2009, two outbreaks confrmed and was identifed the serotype 12. Serotype 4 was isolated during an outbreak in the state of Rio de Janeiro in 2013. This study describes the Diagnoses of ovine infection by the serotype-4 bluetongue virus in Minas Gerais, Brazil. Case: In a farm in the Southern region of the state of Minas Gerais, a group of 28 male sheep, was sent for necropsy at the Setor de Patologia Veterinária of Universidade Federal de Lavras (SPV-UFLA). In a flock of 80 male sheep 28 died with clinical signs of respiratory distress, whereas other showed signs of anemia and hypoproteinemia, cough, sneezing, prostration, fever, mucopurulent nasal discharge, anemia and submandibular edema. At necropsy, the main changes observed were cranioventral pulmonary consolidation, hemorrhage at the base of the pulmonary artery and ulcerating lesions in the hard palate mucosa, rumen and reticulum. The histological changes consisted of bacterial bronchopneumonia, papillary necrosis associated with bacterial structures, multifocal vasculitis in the submucosa and thrombi in blood vessels of the serosa in the rumen and reticulum, hyaline and flocculate necrosis in esophageal muscle, skeletal and cardiac muscle fbers were also observed, associated with moderate mononuclear inflammatory infltrate between fbers and around blood vessels. Discussion: The diagnosis of BT was confrmed by the identifcation of nucleic acids of the virus in blood samples and from tissues of animals from the herd by RT-PCR and by the detection of antibodies against Bluetongue virus with the agar gel immunodiffusion (AGID) test using serum samples from the remaining herd animals. Serotype 4 was identifed in three of the samples inoculated into KC cells. The hemorrhage at the base of the pulmonary artery, one characteristic fndings, was found in three of the necropsied sheep. The pulmonary lesions observed in the present study strongly suggest the occurrence of pneumonia caused by opportunistic bacteria, especially Mannheimia haemolytica, which is commonly associated with pneumonia in sheep infected with BTV. This work is the frst in the state of Minas Gerais and the fourth in Brazil to report an outbreak of the disease with clinical signs. The economic impact of bluetongue results not only from the direct losses of animals to the disease, but also to the correlation among BTV infection and other problems including pneumonia, abortion and verminoses. In a study focused on the characteristics of ovine farming in Minas Gerais, farmers from the center-southwest reported that abortion and pneumonia were among their main problems. Thus, further epidemiological studies on BTV may improve the level of identifcation of infected herds and may help promote prophylactic measures. Necropsies and histopathology exams constitute crucial tools for diagnosis, because most cases present at a sub-clinical stage or in association with other, concomitant diseases. Keywords: BTV 4, viral diseases, sheep, RT-PCR e IDG

Facing the COVID-19 pandemic with science and practice

The COVID-19 pandemic has led to a health system crisis, deaths and socioeconomic hardship. In order to minimize the consequences of the COVID-19 pandemic in the municipality of Lavras, a partnership was developed between the Lavras City Hall and the Universidade Federal de Lavras (UFLA). The present study aimed to describe the main prevention measures proposed in Lavras and to evaluate the community's perception of the management model towards COVID-19. A public online questionnaire, with 20 multiple-choice questions, about the measures to confront covid was submitted to the Google Forms platform from April 22nd to April 30th, 2020. The data regarding the strategies carried out to deal with COVID-19 was obtained from the published municipal ordinances. During the eight days that the questionnaire was applied, a total of 8,874 respondents from Lavras were obtained. Among these respondents, 31.64% (2,808) were men, 68.15% (6,047) were women, and 0.21% (19) declared "another option". When the participants were asked whether they are respecting the social distance measures, 7,452 (84.1%) of them answered "yes."Also, a total of 57.4% of the participants reported that the social distancing measures compromised their family income. However, despite the impact of this economic compromise on these families, 93.82% of the respondents believe that the measures applied are important. When analyzing the questionnaire responses, it was noticeable that despite residents suffering negative economic consequences, there was great popular approval of preventive measures, such as social distancing and the use of masks. In addition, it was possible to notice the population's trust in the measures recommended by professionals at UFLA and the city hall, highlighting the importance of establishing contact between authorities and the population during decision making

Retrospective survey of rabies in Paraíba State, Brazil, from 2004 to 2011

O objetivo desse trabalho foi realizar um estudo retrospectivo da raiva em herbívoros no estado da Paraíba, Brasil, avaliando aspectos epidemiológicos da doença no período de 2004 a 2011. Foram utilizados os registros da notificação dos casos de raiva contidos no Sistema Continental de Vigilância Epidemiológica (SIVCONT). Durante o período avaliado, foram submetidas para diagnóstico amostras de 17.454 animais de todo o Brasil, das quais 43 (0,25%) foram procedentes do estado da Paraíba, e todas elas foram positivas para raiva. A frequência de focos de raiva por município variou de 2,3% a 11,6%. A distribuição dos casos variou conforme a espécie afetada, havendo predominância nos bovinos (93%), seguidos de equinos (4,7%) e um morcego (2,3%) (p < 0,001). Foi observada predominância de casos positivos nos quais a notificação foi efetuada por proprietários (53,5%), seguido de terceiros (39,5%) e vigilância (7%) (p = 0,001). Com relação aos meses de ocorrência dos focos em todos os anos do período avaliado, as frequências variaram de 4,7% no mês de agosto a 14% no mês de abril. Houve predominância de focos no ano de 2010 (41,9%), com diferença significativa entre os anos (p < 0,001). Em conclusão, sugere-se a adoção de medidas estratégicas de controle da raiva e vigilância continua das doenças nervosas no estado da Paraíba.The aim of this work was to perform a retrospective study of rabies in herbivores in the state of Paraíba, Brazil, in order to evaluate epidemiological aspects of the disease from 2004 to 2011. Data on notification of rabies cases included in the Continental Epidemiological Surveillance System (SIVCONT) were used. During the study period samples from 17,454 animals from Brazil were sent to rabies diagnosis, from which 43 (0.25%) samples from the state of Paraiba, and all of them were positive for rabies. The frequency of rabies outbreaks by county ranged from 2.3% to 11.6%. The distribution of cases ranged according to species affected, with predominance in cattle (93%), followed by horses (4.7%) and one bat (2.3%) (p < 0.001). It was observed a predominance of positive cases when the notification was made by owners (53.5%), followed by others (39.5%) and surveillance (7%) (p = 0.001). Related to occurrence of outbreaks by month in all years of the study period, the frequencies ranged from 4.7% in August to 14% in April. It was found predominance of outbreaks in 2010 (41.9%), with significant differences among years (p < 0.001). In conclusion, it is suggested the adoption of strategic measures for the control of rabies and continuous surveillance of nervous diseases in herbivores in the state of Paraíba

Histological and immunohistochemical characterization of the inflammatory and glial cells in the central nervous system of goat fetuses and adult male goats naturally infected with Neospora caninum

Abstract\ud \ud Background\ud \ud Neospora caninum is an apicomplexan protozoan that is considered one of the main agents responsible for abortion in ruminants. The lesions found in the central nervous system (CNS) of aborted fetuses show multifocal necrosis, gliosis, and perivascular cuffs of mononuclear cells, but the inflammatory and glial cells have not been immunophenotypically characterized. The lesions in the CNS of infected adult animals have rarely been described. Therefore, in this study, we characterized the lesions, the immunophenotypes of the inflammatory and glial cells and the expression of MHC-II and PCNA in the CNS of goats infected with N. caninum. The CNS of eight aborted fetuses and six adult male goats naturally infected with N. caninum were analyzed with lectin histochemistry (RCA1) and immunohistochemistry (with anti-CD3, −CD79α, −GFAP, −MHC-II, and -PCNA antibodies). All animals were the offspring of dams naturally infected with N. caninum.\ud \ud \ud \ud Results\ud The microscopic lesions in the CNS of the aborted fetuses consisted of perivascular cuffs composed mainly of macrophages (RCA1+), rare T lymphocytes (CD3+), and rare B lymphocytes (CD79α+). Multifocal necrosis surrounded by astrocytes (GFAP+), gliosis composed predominantly of monocytic-lineage cells (macrophages and microglia, RCA1+), and the cysts of N. caninum, related (or not) to the lesions were present. Similar lesions were found in four of the six male goats, and multinucleate giant cells related to focal gliosis were also found in three adult goats. Anti-GFAP immunostaining showed astrocytes characterizing areas of glial scarring. Cysts of N. caninum were found in three adult male goats. The presence of N. caninum was evaluated with histopathology, immunohistochemistry, and PCR. Immunohistochemistry demonstrated anti-PCNA labeling of macrophages and microglia in the perivascular cuffs and the expression of MHC-II by microglia and endothelial cells in the CNS of the aborted fetuses and adult male goats.\ud \ud \ud Conclusions\ud Macrophages and microglia were the predominant inflammatory cells in the CNS of aborted fetuses and healthy adult male goats infected with N. caninum. Activated astrocytes were mainly associated with inflamed areas, suggesting that astrocytes were involved in the resolution of the lesions.FAPEMIGCAPESCNP

Leishmaniose Visceral Canina: um problema de saúde pública em expansão

As leishmanioses são doenças negligenciadas de grande importância em saúde pública. Esta doença, causada por parasitos do gênero Leishmania e transmitidos por insetos vetores pode se manifestar sob as formas visceral, cutânea e muco-cutânea. A leishmaniose visceral ganhou importante destaque na abordagem da “Saúde Única” em função da interface humana, veterinária e ambiental. Neste contexto, a detecção de novas áreas com ocorrência de casos autóctones de LV canina é o marco para iniciar a investigação, vigilância e monitoramento epidemiológico. O município de Lavras era considerado área silenciosa e não vulnerável para leishmaniose visceral canina até o ano de 2013. Diante da necessidade de confirmação da infecção canina, o objetivo do presente trabalho foi confirmar a ocorrência de casos autóctones de LV canina no município de Lavras – MG, com técnicas parasitológicas, sorológicas e moleculares. A partir da Reação em Cadeia da Polimerase em tempo real – qPCR, foi analisada a carga parasitária de amostras de baço e medula óssea de nove cães naturalmente infectados, sabidamente positivos para LVC nos testes DPP® e EIE LVC Bio-Manguinhos®. Foram observadas quatro amostras positivas para Leishmania infantum em medula óssea, e cinco amostras positivas de baço. Não houve diferença significativa para os valores de carga parasitária entre os dois tipos de tecido analisados. A confirmação da infecção por L. infantum em cães realizada neste estudo é a primeira na macrorregião de Lavras - sul do estado de Minas Gerais, e serve de alerta para implementação das ações de vigilância e controle, no sentido de evitar a dispersão da doença e a ocorrência de casos humanos

Expression of the peptide vaccine SBm7462® anti-tick Rhipicephalus microplus in transgenic plants (Arabidopsis thaliana)

A demanda por vacinas parasitárias em saúde animal é crescente. Os prejuízos causados pela infestação de carrapatos e as doenças transmitidas pelos mesmos estão na ordem de bilhões de dólares, sendo o carrapato Rhipicephalus microplus o parasito de maior impacto econômico na pecuária do Brasil e dos países com clima tropical e subtropical. Pesquisas de ponta, aplicando ferramentas de biotecnologia, são usadas em alguns ou em todos os estágios no desenvolvimento de vacinas. A produção de proteínas heterólogas é uma promissora alternativa para a fabricação de vacinas. Os vegetais representam um dos sistemas mais econômicos para a produção em larga escala de proteínas para uso industrial e farmacêutico, o que significa utilizar as plantas como biofábricas. O objetivo do presente trabalho é produzir antígenos vacinais homólogos do peptídeo sintético SBm7462® contra o carrapato R. microplus, em plantas (Arabidopsis thaliana) transformadas com gene sintético. O gene denominado seq2, que possui a seqüência da SBm7462® repetida três vezes em tandem foi inserido em vetores de doação (pDONR201) e, em seguida, em vetores de expressão binário para plantas (pk7WG2 e o pk7FWG2), utilizando-se o sistema Gateway®. Pela seleção em meio com antibiótico e reação em cadeia de polimerase (PCR), selecionaram-se as plantas transformadas positivamente, a presença do transgene nessas foi confirmado por sequenciamento genético. As plantas transgênicas com melhor desenvolvimentoapresentaram o gene seq2 integrado ao seu genoma. Para avaliar a expressão do peptídeo recombinante foram realizadas as técnicas de RT-PCR (reverse transcription-polymerase chain reaction), imunohistoquímica e análise em microscópio confocal. As proteínas recombinantes denominadas rBm7462 foram expressas no apoplasto das células epidérmicas das folhas transgênicas. As plantas com os maiores níveis de expressão foram selecionadas para, nas próximas gerações, imunizar camundongos BALB/c. Esse é o primeiro estudo da produção de subunidades vacinais em plantas transgênicas contra um ectoparasito.The demand for parasitic vaccines in animal health is growing. The damage due to infestation of ticks and diseases transmitted by them are in the billions of dollars, and the tick Rhipicephalus microplus parasite of the greater economic impact on livestock in Brazil and in countries with tropical and subtropical climates. Advanced research projects, applying tools of biotechnology are used in some or all stages in the development of vaccines. The production of heterologous proteins is a promising alternative for the manufacture of vaccines. The plants represent one of the most economical for large-scale production of proteins for industrial and pharmaceutical, which means using plants as biofactories. The objective of this work is to produce vaccine antigens homologous synthetic peptide SBm7462® against the tick R. microplus in plants (Arabidopsis thaliana) transformed with synthetic gene. The gene seq2, which has the sequence SBm7462® repeated three times in tandem was inserted into donor vector (pDONR201) and then in binary expression vectors for plants (pk7WG2 and pk7FWG2), using the Gateway® system. By selection in medium with antibiotics and polymerase chain reaction (PCR) were selected as positively transformed plants, the presence of these transgene was confirmed by genetic sequencing. Transgenic plants with improved development presented seq2 gene integrated in its genome. To evaluate the expression of the recombinant peptide were carried out RT-PCR (reverse transcription-polymerase chain reaction), immunohisto chemistry and confocal microscope analysis. The recombinant proteins were expressed rBm7462 the apoplast of epidermal cells of transgenic leaves. Plants with the highest levels of expression were selected for new generations, to immunize BALB/c. This is the first study of the production of subunit vaccine in transgenic plants against an ectoparasite.Universidade Federal de Lavra