Histopathological, immunohistochemical, and molecular study of BHV-5 infection in the central nervous system of experimentally infected calves

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Histophilus somni-induced thrombotic meningoencephalitis in cattle from northern Paraná, Brazil

Thrombotic meningoencephalitis (TME) is a fatal neurological disease of cattle, predominantly from North America, that is caused by Histophilus somniwith sporadic descriptions from other countries. This manuscript describes the occurrence of spontaneous TME in cattle from northern Paraná, Brazil. Most cattle had acute neurological manifestations characteristic of brain dysfunction. Hematological and cerebrospinal fluid analyses were not suggestive of bacterial infections of the brain. Histopathology revealed meningoencephalitis with vasculitis and thrombosis of small vessels that contained discrete neutrophilic and/or lymphocytic infiltrates admixed with fibrin at the brainstem, cerebral cortex, and trigeminal nerve ganglion of all animals. All tissues from the central nervous system used during this study were previously characterized as negative for rabies virus by the direct immunofluorescence assay. PCR and RT-PCR assays investigated the participation of infectious agents associated with bovine neurological disease by targeting specific genes of H. somni, Listeria monocytogenes, bovine herpesvirus -1 and -5, bovine viral diarrhea virus, and ovine herpesvirus-2. PCR and subsequent sequencing resulted in partial fragments of the 16S rRNA gene of H. somni from brain sections of all animals with histopathological diagnosis of TME; all other PCR/RT-PCR assays were negative. These findings confirmed the participation of H. somni in the neuropathological disease observed in these animals, extend the geographical distribution of this disease, and support previous findings of H. somni from Brazil.

Surto de polioencefalomalacia por ingestão excessiva de enxofre na dieta em bezerros no Rio Grande do Sul

Neste trabalho descreve-se surto de polioencefalomalacia em bovinos decorrente da ingestão de dieta com excessiva concentração de enxofre em uma propriedade no Rio Grande do Sul. O lote era composto por 30 bezerros, mantidos em um piquete com azevém (Lolium multiflorum) e suplementados com ração e sal mineral. Seis bezerros morreram e dois deles foram necropsiados; amostras de tecido hepático para dosagem de chumbo e fragmentos do sistema nervoso central para histopatológico foram colhidos. Um dos bezerros foi examinado antes da morte e sinais neurológicos encefálicos foram constatados. Foi estabelecido o teor de enxofre nos componentes da dieta e água, a produção de sulfeto de hidrogênio ruminal em cinco bovinos do mesmo lote e realizada PCR de um bloco de parafina para detecção de DNA do herpevirus bovino tipo 5. O consumo total de enxofre foi de 0,38% da matéria seca fornecida aos animais e as dosagens de sulfeto de hidrogênio ruminal em animais do mesmo lote variaram de 1.000 a 2.500ppm. Os achados histopatológicos indicaram necrose laminar do córtex cerebral. Não foi detectado chumbo na amostra de tecido hepático e não foi identificado DNA do herpesvirus bovino tipo 5 no encéfalo. O quadro clínico de síndrome cerebrocortical associado aos elevados valores do sulfeto de hidrogênio ruminal, alta ingestão de enxofre na dieta e os achados histopatológicos permitem estabelecer o excesso de enxofre como causador da polioencefalomalacia.

Uso de la inmunohistoquímica como herramienta epidemiológica para el diagnóstico de rabia bovina a partir de casos no conclusivos

Objective. Identify the rabies virus in cases of nervous disease archived in the laboratory with diagnosis of nonspecific encephalitis. Materials and methods. Twelve samples of bovine brain suspected of rabies, were processed by indirect immunoperoxidase technique using polyclonal antibodies against the viral agent. Results. Was demonstrated the presence of viral antigens in three cases in the form of small aggregates in the cytoplasm of neurons, with a pattern of round or oval and a variable number of viral inclusion bodies. We discussed the importance of the results in Colombia, the usefulness of the technique in the difficult conditions for sending samples to the laboratory, plus the possible relationship of the negative cases with bovine herpesvirus 5. Conclusions. The use of immunohistochemical technique to demonstrate rabies virus antigens in formalin fixed bovines tissues can help in the construction of an epidemiological map of rabies disease in Colombia and may reduce the high under-diagnosis of diseases of the nervous system of cattle, reported in some regions.

Enfermidades do sistema nervoso de bovinos de corte das regiões centro-oeste e sudeste do Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Distribuição genômica e antigênica do BHV5 em encéfalos bovinos com meningoencefalite não supurativa: casos clínicos

Pós-graduação em Ciência Animal - FMVA

A simple way to decompress the left ventricle during venoarterial bypass

OBJECTIVE: The aim of this investigation was to improve the hemodynamics during venoarterial bypass by remote decompression of the left ventricle (LV). METHODS: Venoarterial bypass was established in 5 bovine experiments (69+/-10 kg) by the transjugular insertion of a self-expanding cannula (smartcanula) with return through a carotid artery. Cardiogenic shock was simulated with ventricular fibrillation induced by an external stimulator. Left ventricular decompression was achieved by switching to transfemoral drainage of the pulmonary artery (PA) with a long self-expanding cannula. RESULTS: Initial pump flow was 4.7+/-0.9 l/min and the aortic pressure accounted for 75+/-21 mmHg. After induction of ventricular fibrillation, the pump flow dropped after 11+/-8 min to 2.5+/-0.1 l/min. Transfemoral decompression increased the pump flow to 5.6+/-0.7 l/min, while the RV pressure decreased from 27+/-9 to 3+/-5 mmHg, the PA pressure decreased from 29+/-7 to 5+/-4 mmHg, the LV pressure decreased from 29+/-6 to 7+/-2 mmHg, and the aortic pressure increased from 31+/-3 to 47+/-11 mmHg. CONCLUSIONS: Remote drainage of the pulmonary artery during venoarterial bypass allows for effective decompression of the left ventricle and provides superior hemodynamics.

Inhibition of glutathione efflux in the perfused rat liver and isolated hepatocytes by organic anions and bilirubin. Kinetics, sidedness, and molecular forms.

Using isolated, in situ, single-pass perfused rat livers, incubations of freshly isolated hepatocytes, and sinusoidal membrane-enriched vesicles, we and others have shown the saturability of transport (efflux) of hepatic glutathione (GSH). These observations have implicated a carrier mechanism. Our present studies were designed to provide further evidence in support of a carrier mechanism for hepatic GSH efflux by demonstrating competition by liver-specific ligands which are taken up by hepatocytes. Perfusing livers with different substances, we found that: (a) sulfobromophthalein-GSH (BSP-GSH) had a dose-dependent and fully reversible inhibitory effect on GSH efflux, while GSH alone did not have any effect; (b) taurocholate had no inhibitory effect; (c) all of the organic anions studied, i.e., BSP, rose bengal, indocyanine green, and unconjugated bilirubin (UCB), manifested potent, dose-dependent inhibitory effects, with absence of toxic effects and complete reversibility of inhibition in the case of UCB. The inhibitory effects of UCB could be overcome partially by raising (CoCl2-induced) hepatic GSH concentration. Because of the physiological importance of UCB, we conducted a detailed study of its inhibitory kinetics in the isolated hepatocyte model in the range of circulating concentrations of UCB. Studies with Cl- -free media, to inhibit the uptake of UCB by hepatocytes, showed that the inhibition of GSH efflux by UCB is apparently from inside the cell. This point was confirmed by showing that the inhibition is overcome only when bilirubin-loaded cells are cleared of bilirubin (incubation with 5% bovine serum albumin). Using Gunn rat hepatocytes and purified bilirubin mono- and diglucuronides, we found that both UCB and glucuronide forms of bilirubin inhibit GSH efflux in a dose-dependent manner. We conclude that the organic anions, although taken up by a mechanism independent of GSH, may competitively inhibit the carrier for GSH efflux from inside the hepatocyte.

Herpesviruses including novel gammaherpesviruses are widespread among phocid seal species in Canada.

Little is known about herpesviruses in Canadian pinnipeds. We measured prevalence of antibodies to herpesviruses in the sera from Canadian phocid seals by an indirect enzyme-linked immunosorbent assay. Wild harbor seals (Phoca vitulina) and captive harbor seals were positive for antibodies to Phocid herpesvirus 1 (PhoHV-1) at prevalences of 91% and 100%, respectively. Sera from wild hooded seals (Cystophora cristata), harp seals (Pagophilus groenlandica), and grey seals (Halichoerus grypus) were positive for antibodies to PhoHV-1 antigenically related herpesvirus antigens at 73%, 79%, and 96%, respectively. We isolated new herpesviruses in cell culture from two hunter-harvested ringed seals (Pusa hispida) in poor body condition from Ulukhaktok, Northwest Territories, Canada; one lethargic hooded seal from the St. Lawrence Estuary, Québec, Canada; and one captive, asymptomatic harp seal from the Magdalen Islands, Québec. Partial sequencing of the herpesvirus DNA polymerase gene revealed that all four virus isolates were closely related to PhoHV-2, a member of the Gammaherpesvirinae subfamily, with nucleotide similarity ranging between 92.8% and 95.3%. The new seal herpesviruses were genetically related to other known pinniped herpesviruses, such as PhoHV-1, Otariid herpesvirus 3, Hawaiian monk (Monachus schauinslandi) seal herpesvirus, and Phocid herpesvirus 5 with 47–48%, 55%, 77%, and 70–77% nucleotide similarities, respectively. The harp seal herpesvirus and both ringed seal herpesviruses were almost identical to each other, whereas the hooded seal herpesvirus was genetically different from the three others (92.8% nucleotide similarity), indicating detection of at least two novel seal herpesviruses. These findings are the first isolation, partial genome sequencing, and identification of seal gammaherpesviruses in three species of Canadian phocid seals; two species of which were suspected of exposure to one or more antigenically related herpesviruses based on serologic analyses.

Rastreabilidade da farinha de carne e ossos bovinos em ovos de poedeiras comerciais pela técnica dos isótopos estáveis do carbono e nitrogênio

Objetivou-se com este estudo rastrear a inclusão de farinha de carne e ossos bovinos em dietas para poedeiras comerciais, por meio da análise dos ovos e de suas frações (gema e albúmen), pela técnica dos isótopos estáveis do carbono e nitrogênio e avaliar o índice analítico mínimo detectável. Foram utilizadas 240 galinhas poedeiras da linhagem Shaver White de 73 semanas de idade, distribuídas em delineamento inteiramente casualizado, com cinco tratamentos e seis repetições. Foram avaliados cinco níveis de inclusão (0; 1,5; 3,0; 4,5 e 6,0%) de farinha de carne e ossos bovinos em uma dieta à base de milho e farelo de soja. No 35º dia, foram tomados aleatoriamente 24 ovos por tratamento: 12 serviram para amostragem de gema e albúmen e os outros 12 para amostragem do ovo (gema + albúmen). Os resultados isotópicos foram submetidos à análise multivariada de variância e, a partir das matrizes de erro, com 95% de confiança, foram determinadas elipses para identificar as diferenças entre os resultados obtidos com o fornecimento das dietas experimentais e a dieta controle, sem farinha de carne e ossos bovinos. No ovo e na gema, a partir do par isotópico da dieta com 3,0% de farinha de carne e ossos, houve diferenciação do par do tratamento controle, enquanto, no albúmen, a diferenciação ocorreu a partir do nível de 1,5% de farinha de carne e ossos bovinos na dieta. Pela técnica dos isótopos estáveis, é possível rastrear o uso de farinha de carne e ossos bovinos na alimentação de poedeiras; no albúmen, o nível mínimo de inclusão detectável é de 1,5% e, no ovo e na gema, 3,0%.

Monitoração de anticorpos neutralizantes para o vírus da rinotraqueíte infecciosa bovina em bezerros

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo qualiquantitativo do biogás produzido por substratos em biodigestores tipo batelada

Aiming to study the biogas produced by 5 substrates from both quality and quantity point of view, this research was conducted at the Rural Engineering Department of FCAV/UNESP - Brazil, State of São Paulo. The substractes that were used in the anaerobic digestion were characterized as: 1 - Slaughter fowls' manure with napier grass bed (MFNG); 2 - Slaughter fowls' manure with triturate napier grass bed (MFNGT); 3 - Suine manure (SM); 4 - Bovine manure (BM) and 5 - Bovine manure mixed with 50% of sugarcane bagasse (BM50S). From the data collected it was concluded that: the substract (MFNG) and the substract containing SM produced higher and lower volumes of biogas respectively, when compared to the others; the mixture of sugarcane bagasse in the substract containing Bovine manure damages the accumulated biogas production and its quality; 57 days after filling the biodigestors, all substrates produced biogas with a methane level higher than 48% except for the substrates containing Suine manure; the triturate substrates (MFNGT) did not present such distinct characteristics from the non-triturate substrates (MFNG); the quality of biogas at the maximum production stage was similar, for all the studied substrates; the biogas which presented higher quantity of methane in its composition was the one produced with BM, overcoming the value up to 17.7% over the MFNGT production.

Distribution of antibodies against Neospora caninum, BVDV and BHV-1 among cows in brazilian dairy herds with reproductive disorders.

Neospora caninum, bovine viral diarrhea virus (BVDV) and bovine herpes virus 1 (BHV-1) are worldwide spread pathogens associated with reproductive problems in cattle. The present work aimed to observe the infection pattern of these three pathogens in two dairy herds with distinct reproductive managements from Triângulo Mineiro, Minas Gerais State, Brazil. The herds were not vaccinated against either N. caninum, BVDV or BHV-1. Blood samples were collected and analyzed for presence of specific antibodies, and N. caninum IgG avidity was measured in N. caninum positive samples. In herd 1, 34 out of 174 sampled cows (20%) had antibodies to N. caninum and the seropositivity of BVDV and BHV-1 were 62% and 86%, respectively. Of 69 sampled cows in herd 2. 7 (10%) had antibodies to N. caninum, and 49% and 39% were seropositive to BVDV and BHV-1, respectively. The IgG avidity profiles indicated that N. caninum had been present in both herds for some years and that herd 1 had an ongoing horizontal spread of the parasite. The results indicate that the studied reproductive pathogens were present in the herds and partly may have contributed to their reproductive problems.

Effects of vaccination against reproductive diseases on reproductive performance of beef cows submitted to fixed-timed AI in Brazilian cow-calf operations

The objectives were to assess incidence of pregnancy losses, associate this outcome with immunization programs against reproductive diseases, and evaluate the effects of vaccination against bovine herpesvirus-1 (BoHV-1), bovine viral diarrhea virus (BVDV), and Leptospira spp., on reproductive efficiency of Brazilian cow-calf operations. In experiment 1, 7614 lactating Nelore cows from 18 ranches were assigned to the same estrus synchronization and fixed-time AI protocol (ESFTAI; Days -11 to 0). Pregnancy status was determined with transrectal ultrasonography on Days 30 and 120 after AI. Pregnancy loss was deemed to have occurred when cows were pregnant on Day 30 but nonpregnant on Day 120. Incidence of pregnancy loss across all ranches was 4.1%; pregnancy losses were detected (P < 0.10) in 14 ranches but not detected (P > 0.11) in four ranches. Pregnancy loss was lower (P ≤ 0.02) in ranches that vaccinated against BoHV-1, BVDV, and Leptospira spp. compared with ranches that did not vaccinate, or only vaccinated against Leptospira spp. In experiments 2 and 3, lactating Nelore cows (N = 1950 and 2793, respectively) from ranches that did not have a history of vaccinating against reproductive diseases (experiment 2), or only vaccinated against Leptospira spp. (experiment 3), were assigned to the same ESFTAI used in experiment 1. Within each ranch, cows received (VAC) or not (CON) vaccination against BoHV-1, BVDV, and Leptospira spp. at the beginning of the ESFTAI (Day -11) and 30 days after (Day 41) AI. In experiment 2, VAC cows had greater (P ≤ 0.05) pregnancy rates compared with CON on Days 30 and 120. In experiments 2 and 3, pregnancy loss was reduced (P ≤ 0.03) in primiparous VAC cows compared with CON cohorts. In experiment 4, 367 primiparous, lactating Nelore cows previously vaccinated against Leptospira spp. were assigned to the same ESFTAI used in experiment 1. Cows received VAC, or the same vaccine 30 days before (Day -41) and at the beginning (Day -11) of the ESFTAI (PREVAC). Pregnancy rates on Days 30 and 120 were greater (P ≤ 0.05) in PREVAC cows compared with VAC cows. In conclusion, pregnancy losses affected reproductive and overall efficiency of Brazilian cow-calf operations, and might be directly associated with BoHV-1, BVDV, and Leptospira spp. infections. Hence, vaccinating cows against these pathogens, particularly when both doses are administered before fixed-time AI, improved reproductive performance in Brazilian cow-calf systems. © 2013 Elsevier Inc.

Effects of vaccination against reproductive diseases on reproductive performance of lactating dairy cows submitted to AI

Four experiments evaluated the effects of vaccination against bovine herpesvirus-1 (BoHV-1), bovine viral diarrhea virus (BVDV), and Leptospira spp. on reproductive performance of lactating dairy cows without (experiments 1, 2, and 3) or with previous vaccination against these diseases (experiment 4). Cows were assigned to a fixed-time AI protocol (FTAI; d -11 to 0) in all experiments, as well as AI 12. h upon estrus detection in experiment 3. Pregnancy status was determined with transrectal ultrasonography on d 30 and 71 (d 60 for experiment 3) after AI. Pregnancy loss was considered in cows pregnant on d 30 but non-pregnant on the subsequent evaluation. In experiment 1, 853 cows received (VAC) or not (CON) vaccination against BoHV-1, BVDV, and Leptospira spp. at the beginning of the FTAI (d -11) and 30. d after AI. Pregnancy loss was reduced (P=0.03) in VAC cows compared with CON. In experiment 2, 287 cows received VAC or CON 30. d prior to (d -41) and at the beginning (d -11) of the FTAI. Pregnancy rates on d 30 and 71 were greater (P≤0.03) in VAC cows compared with CON. In experiment 3, 1680 cows with more than 28. d in milk were randomly assigned to receive VAC or CON with doses administered 14. d apart, and inseminated within 15-135. d after the second dose. Pregnancy rates on d 30 and 60 were greater (P≤0.02) in VAC cows compared with CON. In experiment 4, 820 cows received (REVAC) or not (CON) revaccination against BoHV-1, BVDV, and Leptospira spp. at the beginning of the FTAI protocol (d -11). Pregnancy rates and loss were similar (P≥0.54) between treatments. Hence, vaccinating naïve cows against BoHV-1, BVDV, and Leptospira spp. improved reproductive efficiency in dairy production systems, particularly when both doses were administered prior to AI. © 2013 Elsevier B.V.