Bovine abortion due to Bacillus cereus in Midwest Brazil / Aborto bovino por Bacillus cereus no Centro-Oeste do Brasil

Bacillus cereus is a Gram-positive bacterium commonly reported in soils and plants that occupy various ecological habitats, and the main source of contamination for cattle is silage. This report described a case of fetal loss associated with B. cereus infection in a cow. An 8-month-old, Nelore female bovine fetus from a beef farm was submitted for necropsy. A gross examination revealed fibrinous pleuropneumonia and fibrin exudation on the liver surface. The morphological diagnosis was restricted to the lungs and liver. In the lungs there was fibrinosuppurative pleuropneumonia associated with numerous aggregates of rod-shaped bacteria. In the liver there was moderate focally extensive fibrinous peri hepatitis.The lungs, liver, thoracic, and abomasal fluid cultures yielded pure cultures of B. cereus, indicating that these bacteria should be recognized as a cause of bovine abortion in fetuses that macroscopically present fibrin in the abdominal and thoracic cavity.

Bacillus cereus é uma bactéria Gram-positiva, comumente encontrada em solos e plantas que ocupam diversos habitats ecológicos sendo a silagem a principal fonte de contaminação para bovinos. Este relato descreve um caso de perda fetal associada à infecção por B. cereus em uma vaca. Um feto bovino fêmea da raça Nelore, de oito meses de idade, procedente de uma fazenda de corte, foi submetido à necropsia. Ao exame macroscópico observou-se pleuropneumonia fibrinosa e exsudação de fibrina na superfície do fígado. Histologicamente, as lesões estavam restritas aos pulmões e fígado. Nos pulmões havia pleuropneumonia fibrinosupurativa associado a numerosos agregados de bactérias em forma de bastonete. No fígado haviaperi hepatitefibrinosa focalmente extensa moderada. As culturas de pulmão, fígado, líquido torácico e abomasal produziram cultura pura de B. cereus indicando que esta bactéria deve ser reconhecida como causa de aborto bovino em fetos que apresentem macroscopicamente fibrina nas cavidades abdominal e torácica.

Descriptive cross-sectional study on major bovine diseases and associated risk factors in north-eastern Ecuadorian Amazon / Estudo transversal descritivo sobre as principais doenças bovinas e fatores de risco associados no nordeste da Amazônia equatoriana

Cattle raising is a crucial element of production systems in the tropics and subtropics. However, in recent years, global public health security has been threatened by disease emergence. In Orellana Province, livestock is the most important activity to generate economic income. Nevertheless, there is no available data about Animal Health status. With this objective, a study was performed to describe the major Bovine diseases recorded between 2011 to 2019, and the main Risk factors associated. Data on main Bovine diseases were retrieved from the World Animal Health Information System database. Whereas Bovine population data used to calculate the prevalence rates and confidence intervals were obtained from Ecuador's Ministry of Agriculture. By contrast, the Risk factors identified with an epidemiological questionnaire were applied to 300 livestock farmers. As a result, from 2011 to 2019 in Orellana has been confirmed: 90 cases of Infectious Bovine Rhinotracheitis (31.58%), Bovine Rabies by hematophagous bats (Desmodus rotundus), 83 cases (29.12%), Bovine viral diarrhea with 43 cases (15.10%), Brucellosis by Brucella abortus 35 cases, which was (12.28%), and 34 cases related to Enzootic bovine leukosis (11.92%). Overall, the prevalence rates ranged from (0.24 to 15.37%). In addition, farm size, presence of forest, herd, and paddock sizes, cutting frequency of forages, and other animal species were involved as Risk factors (OR = 3.15 to 11.75; 95% CI, 0.01 to 0.69). In conclusion, there are animal diseases with reproductive and neurologic symptomology and high-Risk factors implicated in the transmission. Consequently, space-temporal and seroprevalence epidemiological studies should be performed in Orellana.

A criação de gado é um elemento crucial dos sistemas de produção nos trópicos e subtrópicos. No entanto, nos últimos anos, a segurança da saúde pública global tem sido ameaçada pelo surgimento de doenças. Na província de Orellana, a pecuária é a atividade mais importante para gerar renda econômica. Contudo, não há dados disponíveis sobre o estado de saúde animal. Com este objetivo, foi realizado um estudo para descrever as principais doenças dos bovinos registradas entre 2011 e 2019, além dos principais fatores de risco associados. Os dados sobre as principais doenças bovinas foram recuperados do banco de dados do World Animal Health Information System. Os dados da população bovina usados para calcular as taxas de prevalência e os intervalos de confiança foram obtidos do Ministério da Agricultura do Equador. Por outro lado, os fatores de risco identificados com um questionário epidemiológico foram aplicados a 300 criadores de gado. Como resultado, de 2011 a 2019 em Orellana foram confirmados: 90 casos (31,58%) de rinotraqueíte infecciosa bovina, 83 casos (29,12%) de raiva bovina por morcegos hematófagos (Desmodus rotundus), 43 casos (15,10%) de diarreia viral bovina, 35 casos (12,28%) de brucelose por Brucella abortus e 34 casos relacionados à leucose enzoótica bovina (11,92%). No geral, as taxas de prevalência variaram de 0,24 a 15,37%. Além disso, tamanho da fazenda, presença de floresta, tamanho do rebanho e dos piquetes, frequência de corte de forragens e outras espécies animais estiveram envolvidos como fatores de risco (OR = 3,15-11,75; IC 95% 0,01-0,69). Em conclusão, existem doenças animais com sintomatologia reprodutiva e neurológica e fatores de alto risco implicados na transmissão. Portanto, estudos epidemiológicos espaço-temporais e de soroprevalência devem ser realizados em Orellana.

Aborto em bovinos e bubalinos: causas específicas e inespecíficas / Abortion in cattle and buffaloes: specific and non-specific causes

O aborto é caracterizado como a expulsão do feto sem viabilidade para fora do ambiente uterino da progenitora durante o período que vai do 42° dia a o 260° dia. São descritos diversos fatores infecciosos e não infecciosos como etiologia para o aborto. Dentre os infecciosos, destacam-se as infecções por bactérias, vírus, protozoários e fungos. Enquanto as causas não infecciosas englobam falhas de manejo nutricional, intoxicações e medicamentos que ocasionalmente podem levar à morte fetal. Essa mortalidade fetal é causa importante de perdas reprodutivas na cadeia produtiva de animais domésticos, especialmente bovinos e bubalinos. Ambas as espécies participam da produtividade econômica no Brasil e compartilham de diversas doenças que são causas de aborto. Nesse contexto, o objetivo desta revisão foi reunir e discorrer sobre as principais informações concernentes às possíveis etiologias do aborto, sejam elas de origem infecciosa ou não infecciosas nas espécies bovinas e bubalinas no Brasil.

Abortion is characterized as the expulsion of the non-viable fetus outside the mother's uterine environment during the period between the 42nd day to the 260th day. Several infectious and non-infectious factors are described as etiology for miscarriage. Among the infectious, infections by bacteria, viruses, protozoa, and fungi stand out, while non-infectious causes include failures in nutritional management, poisoning, and medications that occasionally can lead to fetal death. This fetal mortality is an important cause of reproductive losses in the production chain of domestic animals, especially cattle and buffaloes. Both species participate in economic productivity in Brazil and share several diseases that are causes of abortion. In this context, this review aimed to gather and discuss the main information concerning the possible etiologies of abortion, whether of infectious or non-infectious origin in bovine and buffalo species in Brazil.

Natural association between bovine leukemia virus and reproductive infectious diseases

Background: Enzootic bovine leukosis (EBL) is a widespread infectious disease caused by the bovine leukemia virus (BLV), which results in immune system dysfunction. The resulting immunosuppression may lead to an increased prevalence of other diseases. Dairy cows infected have altered immune function associated with decreased milk production and shortened lifespan and decreased immune response to immunization. BLV infection, however, is often asymptomatic, so any connection between subclinical infection and common reproductive diseases remains unknown. This study aimed to describe the relationship between naturally occurring subclinical BLV and infectious reproductive diseases seroconversion in the field. Materials, Methods & Results: The diseases investigated included Bovine viral diarrhoea (BVD), Bovine alfaherpesvirus 1 (BoHV-1), Bovine gammaherpesvirus 4 (BoHV-4), Chlamydiosis, Leptospirosis, Brucellosis and Neosporosis in dairy cattle. Six hundred fifty-five sera samples from the northern and south-central regions of Uruguay, from asymptomatic female Holstein and Holstein crosses without a history of vaccination against reproductive diseases were processed using reference diagnostic methods (Seronautalization, ELISA, MAT, Rose Bengal Plate test). The seroprevalence of BLV was 20.0%. Seroprevalence of reproductive diseases BVD, BoHV-1 and BoHV-4 were 99.3%, 41.2% and 27.3% of the populations, respectively, and the total seroprevalence of Leptospirosis, bovine Neospora caninum and Chlamydiosis were 19.8%, 29.8% and 33.0% respectively. The results revealed positive associations between naturally contracted BLV and the presence of antibodies against BoHV-1 (P = 0.002), as well as between naturally contracted BLV and presence of antibodies against Leptospira spp. (P = 0.028). Discussion: BLV infection can impact innate and adaptive immune system cells and alter the proper functioning of uninfected cells. BLV infection may also induce changes in the complex balance of cytokine expression, cell proliferation, and programmed cell death in T- and B-lymphocytes, which is critical for immune competence and effective response to infectious challenges. The progression of BLV infection has a substantial effect on host defense mechanisms. Indeed, lowmagnitude serologic responses to a commercial foot-and-mouth disease vaccine and a J5 Escherichia coli vaccine have been observed. These results are supported by recent trial studies showing a reduced immune response to vaccination against BoHV-1 and Leptospira spp. in asymptomatic animals infected with BLV. These are 2 of the most prevalent infectious reproductive diseases in cattle worldwide, and our results provide evidence that a link between BLV and susceptibility to these diseases may exist. Although there is evidence of the co-occurrence of these diseases, it remains unknown whether there is a direct or indirect effect of BLV on infertility, embryonic loss, or abortion. Another possibility is that natural infection with these reproductive pathogens (BoHV-1, Leptospira, or others) promotes BLV expression, negatively affecting the farms where these pathogens are endemic. Considering the high seroprevalence of BLV in dairy herds in North and South America where the infection is endemic, it was explored BLV's role as an immunosuppressant by quantifying its co-occurrence with diseases that affect reproductive performance in breeding herds. Future work should clarify the role of BLV and the co-occurring pathogens in causing infertility or abortions.

Spatial distribution and evaluation of risk factors for bovine neosporosis in Rondônia, Brazil / Distribuição espacial e avaliação dos fatores de risco para neosporose bovina em Rondônia, Brasil

Neospora caninum is an important worldwide parasite responsible for causing abortion in animals. Due to limited information on the occurrence of infection by this parasite in the state of Rondônia, Brazil, this study aimed to determine the seroprevalence and identify the risk factors associated with the infection in slaughtered cattle, from 19 municipalities distributed in seven microregions of the state. A total of 494 samples were obtained and subjected to anti-N. caninum antibodies, using the Indirect Immunofluorescence Reaction technique. Antibodies were detected in 5.06% (25/494) of the samples, in 30.30% (10/33) of farms, in nine municipalities located in four microregions of Rondônia. Of all the animals analyzed, 4.81% of the females (20/416) and 6.41% of the males (05/78) were seropositive for the parasite, with "abortion in the last 12 months" being considered an important risk factor for the occurrence of infection (OR = 9.54; p = 0.01). The present study points out the prevalence of anti-N. caninum antibodies in 5.06% of slaughtered animals and abortion as the main risk factor associated with infection by N. caninum, thus contributing to the elucidation of the epidemiology of this protozoan in Rondônia, Brazil.

Neospora caninum é um importante parasito, responsável por causar aborto em animais e distribuído mundialmente. Devido às informações limitadas sobre a ocorrência da infecção por esse parasito no estado de Rondônia, Brasil, este estudo teve como objetivo determinar a soroprevalência e identificar os fatores de risco associados à infecção em bovinos abatidos, oriundos de 19 municípios, distribuídos em sete microrregiões do estado. Um total de 494 amostras foi obtido e submetido à pesquisa de anticorpos anti-N. caninum, por meio da técnica de reação de imunofluorescência indireta. Os anticorpos foram detectados em 5,06% (25/494) das amostras, em 30,30% (10/33) das propriedades rurais, de nove municípios, localizados em quatro microrregiões de Rondônia. De todos os animais analisados, 4,81% das fêmeas (20/416) e 6,41% dos machos (05/78) foram soropositivos para o parasito, sendo o "aborto nos últimos 12 meses" considerado um importante fator de risco para a ocorrência da infecção (OR = 9,54; P = 0,01). O presente estudo aponta a prevalência de anticorpos anti-N. caninum em 5,06% dos animais abatidos e o aborto como o principal fator de risco associado à infecção por N. caninum, contribuindo assim para a elucidação da epidemiologia desse protozoário em Rondônia, Brasil.

Seroprevalence and risk factors associated with leukosis in cattle from Villlavicencio, Colombia / Soroprevalência e fatores de risco associados à leucose em bovinos de Villlavicencio, Colômbia

Bovine leukosis is caused by an oncogenic virus of the genus Deltaretrovirus, causing losses associated with decreased production indicators and restrictions on exports of cattle and cattle products. The disease has a prolonged incubation period of between 1-5 years and the antibodies can be detected 2-3 weeks post infection. The disease can present asymptomatically, and develop persistent lymphocytosis or lymphosarcoma. The objective of this study was to estimate the prevalence and risk factors associated with bovine leukosis in Villavicencio, Colombia. Blood samples were taken from 636 animals, and obtained randomly from 24 herds. The samples were analysed using a Competition ELISA kit for the detection of anti-gp51 antibodies. Information on possible risk factors was collected, then OR and X2 were calculated, and statistically significant with p < 0.05 variables were included in a linear regression multivariate analysis. The general seroprevalence was 24.6% and the herd seroprevalence was 83.3%. The seroprevalence was 21.3% in males and 25.0% in females. The risk factors identified were abortion, non-bearing cows, artificial insemination, and use of common needles, Creole breed and participation in cattle exhibitions. The study confirmed the presence of bovine leukosis associated with reproductive and management factors.(AU)

A leucose bovina é causada por um vírus oncogênico do gênero Deltaretrovirus, causando prejuízos associados à queda dos indicadores produtivos e restrições à exportação de bovinos e derivados.Adoença tem um período de incubação prolongado entre 1 e 5 anos e os anticorpos podem ser detectados 2 a 3 semanas após a infecção. A doença pode se apresentar de forma assintomática, e evoluir para linfocitose persistente ou linfossarcoma. O objetivo do estudo foi estimar a prevalência e os fatores de risco associados à leucose bovina em Villavicencio, Colômbia. Amostras de sangue foram coletadas de 636 animais, obtidos aleatoriamente de 24 rebanhos.As amostras foram analisadas com o kit Competition ELISA para detecção de anticorpos anti-gp51. Foram coletadas informações sobre possíveis fatores de risco, se realizo um analise univariado entre as variáveis e a presença da seropositividad a leukosis bovina mediante o cálculo do OR e X2, as variáveis estatisticamente significativas com p<0,05 foram incluídas em uma análise multivariada de regressão linear. A soroprevalência geral foi de 24,6% e a soroprevalência do rebanho foi de 83,3%.Asoroprevalência foi de 21,3% em machos e 25,0% em fêmeas. Os fatores de risco identificados foram: aborto, vacas não reprodutivas, inseminação artificial e uso de agulha comum, raça crioula e exposições de gado. O estudo confirmou a presença de leucose bovina associada a fatores reprodutivos e de manejo.(AU)

Leptospirosis in dairy cattle from southern Brazil - risk factors

Background: Cattle are susceptible to chronic leptospirosis infection, that results in reduced milk production and reproductive disorders such as abortions, stillbirths, fetal malformation, and mummified fetuses, causing significant economic losses.Commercially available vaccines against leptospirosis offer limited protection to cattle because they contain only the mostprevalent serovars worldwide, even though they are not prevalent in the specific region. This study aimed to evaluate theprevalence of specific antibodies against Leptospira serogroups, reproductive disorders and the risk factors in dairy herdsfrom different mesoregions of Rio Grande do Sul State, Southern Brazil.Materials, Methods & Results: An epidemiological survey was conducted, and serum samples from the bovine population representative of three mesoregions (MR1, MR2, and MR3) were studied; the samples were collected and tested forleptospirosis using the microscopic agglutination test (MAT) for 12 serogroups checking for the presence of agglutination.A total of 442 blood samples were collected from dairy cattle from November to December 2019 (MR1, 187; MR2, 88;and MR3, 167), including cows vaccinated with different commercial vaccines during the three months before sample collection (n = 295) and non-vaccinated against leptospirosis (n = 147). At the time of collection, an interview was conductedwith the owners with questions about the health of the animals, management, habitat, feeding and reproduction. Chi-squaretests univariate analysis with the SPSS® version 20.0 were performed to estimate the association of serogroup Djasimanseroreactivity with the occurrence of reproductive problems and related risk factors. The mean prevalence of antibodiesagainst leptospires was 78.7% (MR1, 74.9 %; MR2, 84.1 %; and MR3, 80.2 %). Serogroup prevalence was different in...

Neospora caninum in aborted bovine fetuses in Trakya Region, Turkey - histopathological, immunohistochemical and molecular detection

Background: Being the major cause of bovine abortion in the world, Neosporosis is considered to be a very important protozoal infection in dairy cattle. Vertical transplacental transmission is the major route of the infection causing either abortion or birth of calves with persistent infection. As the seropositivity in individual cows and in fetal serology only indicate exposure to the protozoa, the diagnosis of the infection has to be based on histopathology of aborted fetuses. Additional techniques such as immunohistochemistry (IHC) and PCR are required for the detection of the etiological agent. The purpose of the current study was to diagnose Neospora caninum infection in aborted bovine fetuses in Trakya Region of Turkey. For this purpose, serological, histopathological, IHC, and PCR methods were used. Materials, Methods & Results: The blood samples and the fetuses of 55 aborted dairy cattle from various farms located in 3 provinces of Trakya, Turkey constituted the material of the present study. The sera obtained from the blood samples were tested using a Neospora caninum Antibody Test Kit cELISA and anti-N. caninum antibodies were detected in the sera of the dams of the 8 aborted fetuses (8/55; 14.54%). Following the necropsy, samples from the brain, heart, liver, lung, kidney, spleen, and placenta of 55 fetuses were routinely processed for histopathological examination and evaluated under a light microscope. Nonsuppurative encephalitis (15/55; 27.27%), necrosis (5/55; 9%) and gliosis (1/55; 1.8%) in the brain, mild to severe nonsuppurative myocarditis and epicarditis (14/55; 25.45%), and portal to mid-zonal nonsuppurative hepatitis (13/55; 23.63%) were the relevant findings. PCR analysis was performed on fresh frozen fetal tissues. Nested PCR detected N. caninum DNA in the brain, heart, liver, lung, and kidney tissues of 6 fetuses (6/55; 10.9%). IHC was performed on the brain, heart, and liver tissues of all the fetuses using avidin-biotin-complex peroxidase method. Immunoreactivity was observed in the brain of 1 fetus (1/55; 1.8%). Discussion: In the present study, histopathological, immunohistochemical and PCR analyses were performed to detect N. caninum in 55 spontenously aborted bovine fetuses in Trakya Region, Turkey. Histopathologic hallmark of the study was nonsuppurative inflammation found mostly in the brain, heart and liver followed by kidneys and lungs. No protozoa was observed in the microscopic examination supporting the fact that definitive diagnosis of N. caninum infection requires ancillary techniques such as IHC and PCR. Nested PCR detected N. caninum DNA in the tissues of 6 fetuses (6/55; 10.9%). Brain was the most reliable organ for detection by PCR (6/6; 100%), compatible with the previous reports. IHC diagnosis revealed only 1.8% positivity in the present study which was remarkably lower than found in the previous studies. Even though histopathology in conjunction with IHC are accepted as the "gold standard" methods to detect N. caninum infection in aborted bovine fetuses, there are studies claiming that IHC is relatively insensitive in the diagnosis of neosporosis as parasite numbers can be low and thus, false negative results can be obtained. Other factors affecting the sensitivity of the technique are thoroughly discussed by many authors. Supportively, the findings of the current study showed that using both IHC and PCR as complementary techniques, increases the success of detection of N. caninum as recommended in previous studies. In conclusion, the present study demonstrated the first molecular diagnosis of Neospora caninum infection in bovine aborted fetuses in Trakya Region of Turkey which has a critical geographical location bordering Europe.

Prevalence and risk factors associated with anti-Leptospira spp agglutinins in cattle from dairy farmers in Ji-Paraná, RO, Brazil / Prevalência e fatores associados ao risco da presença de aglutininas anti-Leptospira spp em bovinos de agricultores familiares da bacia leiteira do município de Ji-Paraná - RO, Brasil

Leptospirosis affects several animal species, including man. This study aimed to evaluate the prevalence of Leptospira spp. and to identify factors associated with the risk of Leptospira spp. in dairy cattle in the municipality of Ji-Paraná, RO, Brazil, sampled by rural sector, from September 2012 to November 2013. Blood samples from 627 dairy cows were randomly collected from 63 farms belonging to six rural sectors. Leptospirosis was diagnosed by the microscopic serum agglutination technique. Of the 627 animals tested, 255 had anti-Leptospira antibodies (40.48%, 95% CI: 36.64-44.31) and 57 of the 63 studied dairy farms (90.5%, 95% CI: 83.23-97.72) had at least one reactive animal. The results indicate that serovar Hardjo had the highest (12.38%. 95% CI: 10.03-15.18) followed by serovars Shermani, Wolffi, Hebdomadis and Canicola occurrence in dairy cows. Additionally, infection was also associated with abortion occurrences in cows of 36 farms (57.14%) and the presence of dogs roaming free with access to pasture, water and cattle in 47 farms (74.60%). Therefore, free-roaming animals are considered a predisposing factor, highlighting the need for adopting prophylactic measures while raising the awareness from rural producers about the importance and the economic losses that leptospirosis may cause.

A leptospirose acomete diversas espécies animais, inclusive o homem. Este estudo teve como objetivo avaliar a prevalência de anticorpos contra Leptospira spp., bem como identificar fatores associados ao risco da infecção por Leptospira spp. em bovinos de leite do município de Ji-Paraná - RO, amostrados por setor rural, de setembro de 2012 a novembro de 2013. Amostras de sangue foram coletadas sistematicamente de 627 fêmeas leiteiras, oriundas de 63 propriedades pertencentes a seis setores rurais. O diagnóstico da leptospirose foi realizado por meio da soroaglutinação microscópica. Constatou-se que 255 animais possuíam anticorpos anti-Leptospira (40,48%, IC95%: 36,64-44,31). Das 63 propriedades estudadas, 57 (90,5%, IC95%: 83,23-97,72) apresentavam pelo menos um animal reagente. Observou-se maior ocorrência do sorovar Hardjo nas fêmeas bovinas (12,38%, IC95%: 10,03-15,18), seguido dos sorovares Shermani, Wolffi, Hebdomadis e Canicola. Observaram-se, como fatores associados à infecção por sorovar, a ocorrência de aborto em fêmeas de 36 propriedades estudadas (57,14%), bem como a existência de cães criados livres em 47 propriedades (74,60%) e com acesso ao pasto, à água e aos bovinos, o que reforça a necessidade de adoção de medidas profiláticas e a conscientização dos produtores rurais sobre a importância e os prejuízos que podem ser causados pela leptospirose.

In vitro toxicity of Niedenzuella (Tetrapterys) multiglandulosa on bovine embryos / Toxicidade in vitro da Niedenzuella (Tetrapterys) multiglandulosa em embriões bovinos

Niedenzuella (Tetrapterys) multiglandulosa, a vine plant found in Brazil, has been correlated to outbreaks of poisoning in cattle and buffaloes, generating economic losses related to the death due to heart failure, miscarriage, abortion, stillbirth, and neonatal mortality. The aim of this study was to examine the embryotoxic potential of the aqueous plant extract on in vitro bovine embryos. In vitro study was performed in five replicates of bovine embryo culture assigned in two groups: control, in vitro embryo culture medium without the aqueous plant extract; treated group, with addition of 2.7mg/mL of aqueous plant extract (10%) to the embryo culture on the sixth day of culture. Cleavage rate was evaluated at day 2 of the cell culture. Viability, hatchability and underdevelopment of blastocysts on the seventh, eighth, and ninth days (D7, D8, and D9, respectively) of culture were assessed under stereoscopic microscope. On day 7, blastocysts were submitted to TUNEL assay to determine apoptotic index. In vitro exposure of bovine embryos to of N. multiglandulosa resulted in reduced embryo development and survival, evaluated by dark cytoplasm indicating poor morphology and poor quality with marked reduction of hatchability. We observed a significant reduction of blastocyst production/number of cleaved embryos (60.6% vs 41.5%); reduction of blastocysts production/total number of matured bovine oocytes (35.1% vs 21.3%); and embryonic hatching rates (38.0% vs 10.0%). However, no effects were observed on the apoptotic rate. In conclusion, aqueous extract of N. multiglandulosa leaves reduces bovine embryo viability in vitro, suggesting possible detrimental effects on embryo development.(AU)

Niedenzuella (Tetrapterys) multiglandulosa, uma videira encontrada no Brasil, tem sido correlacionada a surtos de intoxicações em bovinos e búfalos, gerando perdas econômicas relacionadas à morte por insuficiência cardíaca, aborto, natimorto e mortalidade neonatal. O objetivo deste estudo foi examinar o potencial embriotóxico do extrato vegetal aquoso em embriões bovinos in vitro. O estudo in vitro foi realizado em cinco repetições de cultura de embriões bovinos distribuídos em dois grupos: controle, meio de cultura de embriões in vitro sem o extrato aquoso da planta; grupo tratado, com adição de 2,7mg / mL de extrato vegetal aquoso (10%) à cultura do embrião no sexto dia de cultivo. A taxa de clivagem foi avaliada no dia 2 da cultura de células. Viabilidade, eclodibilidade e subdesenvolvimento de blastocistos no sétimo, oitavo e nono dia (D7, D8 e D9, respectivamente) de cultura foram avaliados em microscópio estereoscópico. No dia 7, os blastocistos foram submetidos ao ensaio TUNEL para determinar o índice apoptótico. Observamos redução significativa da produção de blastocisto / número de embriões clivados (60,6% vs 41,5%); redução da produção de blastocistos / número total de oócitos bovinos maturados (35,1% vs 21,3%); e taxas de eclosão embrionária (38,0% vs 10,0%). No entanto, nenhum efeito foi observado na taxa de apoptose. Em conclusão, o extrato aquoso das folhas de N. multiglandulosa reduz a viabilidade do embrião bovino in vitro, sugerindo possíveis efeitos prejudiciais no desenvolvimento embrionário.(AU)

Inquérito sorológico de brucelose em machos e fêmeas bovinas em fazendas do Estado de Mato Grosso do Sul / Serological survey of brucellosis in males and females of cattle in the State of Mato Grosso do Sul

Objetivou-se avaliar a ocorrência de animais soro reagentes à brucelose bovina em fazendas localizadas no Estado de Mato Grosso do Sul, por meio de exame sorológico utilizando o Antígeno Acidificado Tamponado (AAT) e discutir as possíveis diferenças entre as soroprevalências de fêmeas e machos. Foram avaliados, a partir do teste de triagem com Antígeno Acidificado Tamponado (AAT), 724 bovinos da raça Nelore, sendo 274 machos e 450 fêmeas, provenientes de oito propriedades com histórico de problemas reprodutivos. O teste foi procedido conforme o protocolo determinado pelo Ministério da Agricultura, Pecuária e Abastecimento (MAPA). Os resultados demonstraram baixa soroprevalência da doença nos bovinos testados, sendo detectada prevalência para a doença de 1,10% nos machos e 2,88% nas fêmeas.Quando se considera o touro isoladamente nos rebanhos, pode-se perceber que a fertilidade é muito mais importante nos machos do que nas fêmeas individualmente, uma vez que os touros podem se acasalar com um número muito maior de fêmeas, seja na monta natural ou na inseminação artificial, demonstrando a importância do inquérito epidemiológico na população geral, principalmente nos machos. A maior frequência da doença foi encontrada nas fêmeas podendo estar relacionada à infecção por Brucella spp. no ambiente decorrente de parto ou aborto tornando as fêmeas transmissoras permanentes da doença.

The objective of this study was to evaluate the occurrence of seroreactive animals to bovine brucellosis in farms located in the State of Mato Grosso do Sul, by means of a serological examination using the Acidified Buffered Antigen (AAT) and to discuss the possible differences between the seroprevalence of females and males. A total of 724 Nellore cattle, 274 males and 450 females, from eight farms with a history of reproductive problems, were evaluated using the screening test with Acidified Buffered Antigen (AAT). The test was carried out according to the protocol determined by the Ministry of Agriculture, Livestock and Food Supply (MAPA).The results showed a low seroprevalence of the disease in the tested cattle, with a prevalence of 1.10% in males and 2.88% in females.When considered the bull alone in herds, it can be shown that fertility is much more important in males than in females individually, since bulls can mate with a much larger number of females, either in natural mating or in artificial insemination, demonstrating the importance of epidemiological survey in the general population, especially in males. The highest frequency of the disease was found in females and may be related to infection by Brucella spp. in the environment from childbirth or abortion making females permanent transmitters of the disease.

Campylobacter fetus in abomasal fluid from spontaneously aborted bovine and ovine fetuses

Pregnancy losses are a major concern in livestock industry due to their economic impact on producers. Campylobacter fetus subspecies fetus (Cff) and C. fetus subspecies venerealis (Cfv) are directly related to reproductive failures in ruminants. Cff colonizes the gastrointestinal tract of a wide range of hosts leading to abortion, while Cfv is restricted to genital tract being generally associated to infertility in bovine. Considering the great economic losses related to campylobacteriosis in cattle and ovine herds, this study aims to investigate the occurrence of C. fetus, considering Cff and Cfv subspecies, in bovine and ovine spontaneously aborted fetuses in state of Rio Grande do Sul, Brazil. In this study, samples of abomasal fluid collected from 30 spontaneously aborted bovine (n = 18) and ovine (n = 12) fetuses were investigated for the detection of Campylobacter fetus throughout conventional PCR. Positive fetuses for C. fetus presence were further analyzed by molecular assays for Cff and Cfv detection, in order to determine subspecies identification. When available, samples of the main organs of the thoracic and abdominal cavities, as well as the brain, skeletal muscle, eyelid, skin, and placenta were collected for further histopathological analyses and bacterial culture, aiming to assess the presence of infection lesions and pathogens in those sites, respectively. Additionally, RT-qPCR assays were also performed for the detection of ruminant pestivirus, in order to detect bovine viral diarrhea cases. Throughout the present methodology, C. fetus was detected in the abomasal fluid samples of 2 bovine fetuses, being both identified as Cfv subspecies by PCR. Histopathological analyses demonstrated that macroscopic and microscopic changes found in the Cfv-positive animals were not either specific or directly related to Campylobacter infections. Moreover, no significant bacterial growth was observed in microbiological culture from the collected tissues, and both fetuses were negative for ruminant pestivirus. Differently, there was no detection of C. fetus in any of the analyzed ovine fetuses. Considering that abortion diagnosis rates reported in cattle and sheep industry are highly variable among the published studies, and that abortion diagnoses are commonly inconclusive due to difficulties in sampling methodology and inadequate identification of the pathogen involved, it is important to investigate the etiological causes of abortion the herds for better understanding the causes of pregnancy issues and monitoring their occurrence. In addition, the absence of pathognomonic lesions in the tissues investigated in the histopathological analyses observed in this study strongly suggests that well-known etiological agents commonly associated to abortion, such as Leptospira spp., Toxoplasma spp., Chlamydia spp. and Neospora caninum, are unlikely to be the cause of infection of the analyzed fetuses. Taking this into account, the presence of C. fetus in the abomasal fluid samples from two bovine fetuses demonstrated in the present study suggests the possible association of Cfv not only with infertility, but also with cases of bovine abortion, highlighting the importance of investigating unusual causal agents of abortions in sheep and cattle. Overall, an adequate diagnosis is essential for establishing better prevention strategies to avoid the circulation of abortion-related infectious agents in the herds.(AU)

Economic impacts of Bovine alphaherpesvirus 1 infection in Brazil: Meta-analysis based on epidemiological indicators / Impactos econômicos da infecção por Bovine alphaherpesvirus 1 no Brasil: Metanálise a partir de indicadores epidemiológicos

This study aimed to conduct a systematic review to estimate the economic impact of Bovine alphaherpesvirus 1 (BoAHV1) infection in Brazil using epidemiological indicators through a meta-analysis. Specific descriptors were used to retrieve studies from the Scopus, PubMed, Biblioteca Digital Brasileira de Teses e Dissertações, and Catálogo de Teses e Dissertações da Capes databases, selecting those that met the inclusion criteria established between the years 2000 and 2020. The selected studies were subjected to descriptive statistical analysis using prevalence data as the primary outcome with a 95% confidence interval (CI) with a meta-analysis of random effects and measures of heterogeneity, significance, magnitude of the effect, and measurement of publication bias. Abortion costs and estimates were calculated based on the prevalence of BoAHV1 infection in Brazil and the characteristics of the agent as viral subtypes that cause abortion, period of occurrence, average pregnancy rate, and morbidity applied to susceptible animals and animal replacement values. The results were obtained from 49 studies included for meta-analysis where a prevalence of BoAHV1 infection of 54.12% (95% CI: 49.07% - 59.26%) in the bovine population and 88.53% (95% CI: 82.97%­92.43%) was present. From the structured formula, it is estimated that 258,779 bovine abortions occur, which causes a total loss, based only on the occurrence of abortion, of US $ 48,402,244.00 to the country. It is noteworthy that because of the losses caused, strict control and eradication measures need to be implemented based on the elaboration of normative instruction that includes health education measures, vaccination, tests for traffic, and animal trade so that BoAHV1 infections do not continue to negatively impact national producers economically, productively, and socially.(AU)

Objetivou-se com o presente estudo realizar uma revisão sistemática para estimar os impactos econômicos da infecção por Alfaherpesvirus Bovino 1 no Brasil a partir dos indicadores epidemiológicos por meio de uma metanálise. Foram usados descritores específicos para a recuperação de estudos a partir das bases Scopus, Pubmed, Biblioteca Digital Brasileira de Teses e Dissertações e do Catálogo de Teses e Dissertações da Capes, selecionando-se aqueles que se enquadraram nos critérios de inclusão estabelecidos entre os anos 2000 e 2020. Os estudos selecionados foram submetidos à análise estatística descritiva utilizando-se os dados de prevalência como desfecho primário com intervalo de confiança de 95%, sendo realizado metanálise de efeito randômico e avaliadas as medidas de heterogeneidade, significância, magnitude do efeito e aferição do viés de publicação. Os custos e estimativas de aborto foram calculados com base na prevalência encontrada para BoAHV1 no Brasil e as características do agente como subtipos virais que provocam o aborto, período de ocorrência, taxa média de prenhez e morbidade aplicados aos animais suscetíveis e aos valores de reposição animal. Os resultados foram obtidos a partir de 49 estudos incluídos para metanálise, onde se verificou uma prevalência de BoAHV1 de 54,12% (IC95%: 49,07% ­ 59,26%) na população bovina e 88,53% (IC95%: 82,97% ­ 92,43%) para os rebanhos. A partir da fórmula estruturada, se estima que ocorram 258.779 abortos bovinos, que totalizam um prejuízo, apenas baseado na ocorrência do aborto, de US$ 48.402.244,00 ao país. Destaca-se que em virtude dos prejuízos ocasionados, medidas de controle e erradicação mais rigorosas precisam ser implementadas a partir da elaboração de uma instrução normativa que contemple medidas de educação sanitária, vacinação, realização de exames para o trânsito e comércio de animais para que as infecções pelo BoAHV1 não continuem a impactar negativamente os produtores nacionais de forma econômica, produtiva e socialmente.(AU)

Cloning and expression of Neospora caninum rhoptry 2 and its potential as an immunobiological for neosporosis control

ABSTRACT: The protozoan Neospora caninum is known worldwide as one of the main causes of abortion in cattle. During infection, rhoptry proteins present in the apical complex of the parasite play important roles in adhesion and parasitophorous vacuole formation. The use of N. caninum ROP2 in experimental vaccines has shown promising protective results. In our study we performed cloning and expression in Escherichia coli of an antigenic portion of N. caninum ROP2. The recombinant protein (rROP2) was obtained in insoluble form, and the purified protein showed a size of approximately 18kDa. Even being a small truncate NcROP2 region, it was possible to conserve the antigenic epitopes which were recognized by bovine serum naturally infected with N. caninum. Vaccination with rROP2 on aluminum hydroxide adjuvant induced high levels of rROP2-specific IgG antibodies capable of recognizing native protein in tachyzoite lysates. In conclusion, our approaches were effective in obtaining the rROP2 protein, which induced specific mouse immune response and was also recognized by sera from N. caninum naturally infected cattle. These results suggest that it is a promising antigen for the development of neosporosis subunit vaccines as well as a suitable antigen for use in immunodiagnosis.

RESUMO: O protozoário Neospora caninum é conhecido mundialmente como uma das principais causas de aborto em bovinos. Durante a infecção, as proteínas rhoptry presentes no complexo apical do parasita desempenham papel importante na adesão e formação de vacúolos parasitóforos. O uso de ROP2 de N. caninum em vacinas experimentais tem mostrado resultados de proteção promissores. Em nosso estudo, realizamos a clonagem e expressão em Escherichia coli de uma porção antigênica de N. caninum ROP2. A proteína recombinante (rROP2) foi obtida na forma insolúvel, e a proteína purificada apresentou tamanho aproximado de 18kDa. Mesmo sendo uma pequena região truncada de NcROP2, foi possível conservar os epítopos antigênicos que foram reconhecidos pelo soro de bovinos naturalmente infectados com N. caninum. A vacinação com rROP2 adsorvida no adjuvante de hidróxido de alumínio induziu altos níveis de anticorpos IgG anti-rROP2, capazes de reconhecer a proteína nativa em lisados de taquizoítos. Em conclusão, nossas abordagens foram eficazes na obtenção da proteína rROP2, que induziu resposta imune específica em camundongos e também foi reconhecida por soros de bovinos naturalmente infectados com N. caninum. Estes resultados sugerem que rROP2 é um antígeno promissor para o desenvolvimento de vacinas de subunidades de neosporose, bem como um antígeno adequado para uso em imunodiagnóstico.

Inquérito sorológico de brucelose em machos e fêmeas bovinas em fazendas do Estado de Mato Grosso do Sul / Serological survey of brucellosis in males and females of cattle in the State of Mato Grosso do Sul

Objetivou-se avaliar a ocorrência de animais soro reagentes à brucelose bovina em fazendas localizadas no Estado de Mato Grosso do Sul, por meio de exame sorológico utilizando o Antígeno Acidificado Tamponado (AAT) e discutir as possíveis diferenças entre as soroprevalências de fêmeas e machos. Foram avaliados, a partir do teste de triagem com Antígeno Acidificado Tamponado (AAT), 724 bovinos da raça Nelore, sendo 274 machos e 450 fêmeas, provenientes de oito propriedades com histórico de problemas reprodutivos. O teste foi procedido conforme o protocolo determinado pelo Ministério da Agricultura, Pecuária e Abastecimento (MAPA). Os resultados demonstraram baixa soroprevalência da doença nos bovinos testados, sendo detectada prevalência para a doença de 1,10% nos machos e 2,88% nas fêmeas.Quando se considera o touro isoladamente nos rebanhos, pode-se perceber que a fertilidade é muito mais importante nos machos do que nas fêmeas individualmente, uma vez que os touros podem se acasalar com um número muito maior de fêmeas, seja na monta natural ou na inseminação artificial, demonstrando a importância do inquérito epidemiológico na população geral, principalmente nos machos. A maior frequência da doença foi encontrada nas fêmeas podendo estar relacionada à infecção por Brucella spp. no ambiente decorrente de parto ou aborto tornando as fêmeas transmissoras permanentes da doença.(AU)

The objective of this study was to evaluate the occurrence of seroreactive animals to bovine brucellosis in farms located in the State of Mato Grosso do Sul, by means of a serological examination using the Acidified Buffered Antigen (AAT) and to discuss the possible differences between the seroprevalence of females and males. A total of 724 Nellore cattle, 274 males and 450 females, from eight farms with a history of reproductive problems, were evaluated using the screening test with Acidified Buffered Antigen (AAT). The test was carried out according to the protocol determined by the Ministry of Agriculture, Livestock and Food Supply (MAPA).The results showed a low seroprevalence of the disease in the tested cattle, with a prevalence of 1.10% in males and 2.88% in females.When considered the bull alone in herds, it can be shown that fertility is much more important in males than in females individually, since bulls can mate with a much larger number of females, either in natural mating or in artificial insemination, demonstrating the importance of epidemiological survey in the general population, especially in males. The highest frequency of the disease was found in females and may be related to infection by Brucella spp. in the environment from childbirth or abortion making females permanent transmitters of the disease.(AU)

Inquérito sorológico de brucelose em machos e fêmeas bovinas em fazendas do Estado de Mato Grosso do Sul / Serological survey of brucellosis in males and females of cattle in the State of Mato Grosso do Sul

Objetivou-se avaliar a ocorrência de animais soro reagentes à brucelose bovina em fazendas localizadas no Estado de Mato Grosso do Sul, por meio de exame sorológico utilizando o Antígeno Acidificado Tamponado (AAT) e discutir as possíveis diferenças entre as soroprevalências de fêmeas e machos. Foram avaliados, a partir do teste de triagem com Antígeno Acidificado Tamponado (AAT), 724 bovinos da raça Nelore, sendo 274 machos e 450 fêmeas, provenientes de oito propriedades com histórico de problemas reprodutivos. O teste foi procedido conforme o protocolo determinado pelo Ministério da Agricultura, Pecuária e Abastecimento (MAPA). Os resultados demonstraram baixa soroprevalência da doença nos bovinos testados, sendo detectada prevalência para a doença de 1,10% nos machos e 2,88% nas fêmeas.Quando se considera o touro isoladamente nos rebanhos, pode-se perceber que a fertilidade é muito mais importante nos machos do que nas fêmeas individualmente, uma vez que os touros podem se acasalar com um número muito maior de fêmeas, seja na monta natural ou na inseminação artificial, demonstrando a importância do inquérito epidemiológico na população geral, principalmente nos machos. A maior frequência da doença foi encontrada nas fêmeas podendo estar relacionada à infecção por Brucella spp. no ambiente decorrente de parto ou aborto tornando as fêmeas transmissoras permanentes da doença.

The objective of this study was to evaluate the occurrence of seroreactive animals to bovine brucellosis in farms located in the State of Mato Grosso do Sul, by means of a serological examination using the Acidified Buffered Antigen (AAT) and to discuss the possible differences between the seroprevalence of females and males. A total of 724 Nellore cattle, 274 males and 450 females, from eight farms with a history of reproductive problems, were evaluated using the screening test with Acidified Buffered Antigen (AAT). The test was carried out according to the protocol determined by the Ministry of Agriculture, Livestock and Food Supply (MAPA).The results showed a low seroprevalence of the disease in the tested cattle, with a prevalence of 1.10% in males and 2.88% in females.When considered the bull alone in herds, it can be shown that fertility is much more important in males than in females individually, since bulls can mate with a much larger number of females, either in natural mating or in artificial insemination, demonstrating the importance of epidemiological survey in the general population, especially in males. The highest frequency of the disease was found in females and may be related to infection by Brucella spp. in the environment from childbirth or abortion making females permanent transmitters of the disease.

Abortamento por Neospora caninum em bovinos de leite no sul de Santa Catarina, Brasil / Abortion due to Neospora caninum in dairy cattle in Southern Santa Catarina state, Brazil

Background: Neosporosis is a cosmopolitan disease known as the main infectious cause of abortion in cattle, reported in several states in Brazil. The transplacental transmission in cattle is responsible for perpetuating the disease in the herd. In the state of Santa Catarina, previous studies on this protozoan in cattle are mostly serological surveys. To increase information about this reproductive disorder, this work describes the diagnosis of abortions due to Neospora caninum in dairy cattle from state of Santa Catarina and the follow-up for 4 years in a farm affected by neosporosis. Cases: From 2015 to 2019, necropsy was performed on 10 aborted bovine fetuses, between fifth and eighth month of pregnancy, with 1 fetus aborted in 2015, 3 in 2016, 2 in 2017 and, 4 in 2019, all originating from the same dairy property in the southern region of state of Santa Catarina. No macroscopic lesions were found. Histopathology revealed mild to moderate multifocal mononuclear necrotizing encephalitis in 5 fetuses, and multifocal mild mononuclear myositis and myocarditis in 4 and 3 fetuses, respectively. Polymerase Chain Reaction (PCR) using primers based on the Nc-5 gene was positive for N. caninum in five fetuses. Three visits were performed in the farm for epidemiological evaluation and blood samples collection for IgG antibodies anti-N. caninum (IFAT). The total herd was 170 Jersey, Holstein and crossbred cattle, raised in a semi-confined system with mechanical milking system. Since 2014, there has been a significant increase in abortions cases, approximately 20 cows had abortions; in the year 2015, approximately 10; in 2016, less than 5; in 2017, 4 cows aborted; in 2018, 11 abortions and, in 2019, there were 4 abortions. An increase in the rate of return to estrus was also reported, and both primiparous and multiparous cows had reproductive disorders. Abortions were recorded throughout the year and occurred predominantly between the fourth and sixth month of pregnancy. In 2016, an Indirect Immunofluorescence Reaction (IFAT) was performed on sera from 26 cows (13 with a history of reproductive disorders and another 13 without disorders). Of these, 50.0% (13/26) were seropositive, with titers ranging from 100 to 1600 (cutoff ≥100). The Enzyme Immunoassay (ELISA) of the entire herd was carried out in 2017, with 26.54% (43/162) of seropositivity, 8.02% (13/162) suspect, and 30.4% (17/56) had reproductive disorders. It was observed that only animals born on the property were used for replacement, there was less possibility of direct contact between dogs on the property with milking facilities, placental and fetal remains, properly disposing of these, incinerating or burying. Thirty animals were discarded from the property, 25 of which had reproductive disorders. All young female daughters of seropositive cows remained on the property for replacement. During the evaluation period, all dogs were eliminated. Discussion: In this study, the diagnosis of neosporosis was made through epidemiology, histopathological lesions characterized by mononuclear encephalitis, myocarditis and myositis, and detection of the agent by PCR, associated with serological techniques. The lesions observed are indicative of N. caninum infection and are compatible with lesions observed in other studies. Serological screening is important to complement the diagnosis of abortion by N. caninum and to help control the agent in herds. From this report it is concluded that N. caninum is an important agent of reproductive disorders in cattle in the southern region of Santa Catarina, the different serological analyzes showed a good screening index for the inclusion of control strategies. In addition, the monitoring of reproductive rates of affected properties becomes necessary over the years, allowing better observation of control strategies.

Cloning and expression of Neospora caninum rhoptry 2 and its potential as an immunobiological for neosporosis control / Clonagem e expressão de rhoptry 2 Neospora caninum e seu potencial como um imunobiológico para o controle de neosporose

The protozoan Neospora caninum is known worldwide as one of the main causes of abortion in cattle. During infection, rhoptry proteins present in the apical complex of the parasite play important roles in adhesion and parasitophorous vacuole formation. The use of N. caninum ROP2 in experimental vaccines has shown promising protective results. In our study we performed cloning and expression in Escherichia coli of an antigenic portion of N. caninum ROP2. The recombinant protein (rROP2) was obtained in insoluble form, and the purified protein showed a size of approximately 18kDa. Even being a small truncate NcROP2 region, it was possible to conserve the antigenic epitopes which were recognized by bovine serum naturally infected with N. caninum. Vaccination with rROP2 on aluminum hydroxide adjuvant induced high levels of rROP2-specific IgG antibodies capable of recognizing native protein in tachyzoite lysates. In conclusion, our approaches were effective in obtaining the rROP2 protein, which induced specific mouse immune response and was also recognized by sera from N. caninum naturally infected cattle. These results suggest that it is a promising antigen for the development of neosporosis subunit vaccines as well as a suitable antigen for use in immunodiagnosis.(AU)

O protozoário Neospora caninum é conhecido mundialmente como uma das principais causas de aborto em bovinos. Durante a infecção, as proteínas rhoptry presentes no complexo apical do parasita desempenham papel importante na adesão e formação de vacúolos parasitóforos. O uso de ROP2 de N. caninum em vacinas experimentais tem mostrado resultados de proteção promissores. Em nosso estudo, realizamos a clonagem e expressão em Escherichia coli de uma porção antigênica de N. caninum ROP2. A proteína recombinante (rROP2) foi obtida na forma insolúvel, e a proteína purificada apresentou tamanho aproximado de 18kDa. Mesmo sendo uma pequena região truncada de NcROP2, foi possível conservar os epítopos antigênicos que foram reconhecidos pelo soro de bovinos naturalmente infectados com N. caninum. A vacinação com rROP2 adsorvida no adjuvante de hidróxido de alumínio induziu altos níveis de anticorpos IgG anti-rROP2, capazes de reconhecer a proteína nativa em lisados de taquizoítos. Em conclusão, nossas abordagens foram eficazes na obtenção da proteína rROP2, que induziu resposta imune específica em camundongos e também foi reconhecida por soros de bovinos naturalmente infectados com N. caninum. Estes resultados sugerem que rROP2 é um antígeno promissor para o desenvolvimento de vacinas de subunidades de neosporose, bem como um antígeno adequado para uso em imunodiagnóstico.(AU)

Cloning and expression of Neospora caninum rhoptry 2 and its potential as an immunobiological for neosporosis control / Clonagem e expressão de rhoptry 2 Neospora caninum e seu potencial como um imunobiológico para o controle de neosporose

The protozoan Neospora caninum is known worldwide as one of the main causes of abortion in cattle. During infection, rhoptry proteins present in the apical complex of the parasite play important roles in adhesion and parasitophorous vacuole formation. The use of N. caninum ROP2 in experimental vaccines has shown promising protective results. In our study we performed cloning and expression in Escherichia coli of an antigenic portion of N. caninum ROP2. The recombinant protein (rROP2) was obtained in insoluble form, and the purified protein showed a size of approximately 18kDa. Even being a small truncate NcROP2 region, it was possible to conserve the antigenic epitopes which were recognized by bovine serum naturally infected with N. caninum. Vaccination with rROP2 on aluminum hydroxide adjuvant induced high levels of rROP2-specific IgG antibodies capable of recognizing native protein in tachyzoite lysates. In conclusion, our approaches were effective in obtaining the rROP2 protein, which induced specific mouse immune response and was also recognized by sera from N. caninum naturally infected cattle. These results suggest that it is a promising antigen for the development of neosporosis subunit vaccines as well as a suitable antigen for use in immunodiagnosis.(AU)

O protozoário Neospora caninum é conhecido mundialmente como uma das principais causas de aborto em bovinos. Durante a infecção, as proteínas rhoptry presentes no complexo apical do parasita desempenham papel importante na adesão e formação de vacúolos parasitóforos. O uso de ROP2 de N. caninum em vacinas experimentais tem mostrado resultados de proteção promissores. Em nosso estudo, realizamos a clonagem e expressão em Escherichia coli de uma porção antigênica de N. caninum ROP2. A proteína recombinante (rROP2) foi obtida na forma insolúvel, e a proteína purificada apresentou tamanho aproximado de 18kDa. Mesmo sendo uma pequena região truncada de NcROP2, foi possível conservar os epítopos antigênicos que foram reconhecidos pelo soro de bovinos naturalmente infectados com N. caninum. A vacinação com rROP2 adsorvida no adjuvante de hidróxido de alumínio induziu altos níveis de anticorpos IgG anti-rROP2, capazes de reconhecer a proteína nativa em lisados de taquizoítos. Em conclusão, nossas abordagens foram eficazes na obtenção da proteína rROP2, que induziu resposta imune específica em camundongos e também foi reconhecida por soros de bovinos naturalmente infectados com N. caninum. Estes resultados sugerem que rROP2 é um antígeno promissor para o desenvolvimento de vacinas de subunidades de neosporose, bem como um antígeno adequado para uso em imunodiagnóstico.(AU)

Effect of vaccination on the apparent prevalence of bovine brucellosis in the state of Tocantins, Brazil / Efeito da vacinação na prevalência aparente da brucelose bovina no estado de Tocantins, Brasil

A cross-sectional study on the epidemiological situation of bovine brucellosis was carried out in the state of Tocantins to evaluate the effectiveness of its vaccination program. The state was divided into five regions, and a predetermined number of farms was randomly selected in each one. Females aged 24 months or older were randomly selected in each farm and diagnosed with brucellosis by serial serology (AAT and 2-ME). A total of 6,846 animals from 756 farms were examined. The prevalence of seropositive herds in the state was 6.42% [CI95%: 4.76-8.62], and the prevalence of seropositive animals was 2.21% [CI95%: 1.05-4.01]. The prevalence of seropositive herds was homogeneously distributed among regions. The 2002/2003 study estimated the prevalence of seropositive herds in the state to be 21.22% [CI95%: 19.33-23.11]. In conclusion, the vaccination program implemented in Tocantins, reaching vaccination coverage above 70% as of 2010, significantly reduced the prevalence of seropositive herds. Thus, continuing the vaccination program in the state is recommended, preferably increasing the quality of the processes involved, from commercialization to inoculation in animals, since immunization remains the most effective means to reduce the prevalence of brucellosis. In addition, animal replacement remains a major risk factor for bovine brucellosis in Tocantins since 20022003; therefore, the state must implement a strong health education program explaining to farmers the importance of testing animals for brucellosis before introducing them into their herds.(AU)

Foi realizado um estudo seccional sobre a situação epidemiológica da brucelose bovina no estado de Tocantins com o objetivo de avaliar a eficácia do programa de vacinação implementado. O estado foi dividido em cinco regiões e em cada uma delas foi aleatoriamente amostrado um número pré-estabelecido de propriedades. Dentro de cada propriedade, fêmeas com idade igual ou superior a 24 meses foram aleatoriamente selecionadas e submetidas à sorologia em série para o diagnóstico da brucelose (AAT e 2-Mercaptoetanol). Ao todo foram examinados 6.846 animais oriundos de 756 propriedades. A prevalência aparente de focos no estado foi de 6,42% [IC95%: 4,76-8,62] e a de animais 2,21% [IC95%: 1,05-4,01]. A prevalência aparente de focos apresentou-se homogeneamente distribuída entre as cinco regiões. Como o estudo realizado em 2002/2003 estimou a prevalência aparente de focos no estado em 21,22% [IC95%: 19,33-23,11], conclui-se que o programa de vacinação implementado pelo Tocantins, atingindo coberturas vacinais acima de 70% a partir de 2010, reduziu a prevalência de maneira importante. Assim, recomendase que o estado continue seu programa de vacinação, dando grande ênfase para a qualidade dos procedimentos, desde a comercialização do insumo até a inoculação nos animais, pois a imunização ainda é a maneira mais racional de se reduzir a prevalência da brucelose bovina no seu território. Adicionalmente, o estado deve implementar uma forte ação de educação sanitária para que os produtores passem a testar os animais para brucelose antes de introduzi-los nos seus rebanhos, pois verificou-se que a reposição de animais permanece associada à condição de foco da brucelose bovina desde 2002/2003.(AU)