Twelve cases of viral meningoencephalitis in Brazilian cattle were submitted to immunohistochemical analysis for inflammatory response description. All the cases showed severe neurological signs followed by death. Mild to moderate histological inflammatory changes in the brain and cerebellum characterized the neurological infection showing meningitis, mononuclear perivascular cuffing, gliosis, haemorrhage, and macrophages (gitter cells) accompanying great areas of malacia. None of the cases showed intranuclear inclusion bodies. However, in five of them it was possible to isolate the BoHV-5. In order to collect data to allow the description of the inflammatory response in these cases, brain samples from all of the cases were analyzed by immunohistochemistry using polyclonal antibodies against CD3 to detect T cells, and against GFAP to detect astrocytes. On the other hand, monoclonal antibodies were used against BLA to detect B cells and, against MAC 387 to detect macrophages. The results indicate different degrees of prominent astrocytic response, and at the same time, T lymphocytes constituted a high percentage of the mononuclear cells which characterized the inflammatory response

Doce casos de meningoencefalitis viral en ganado bovino brasilero fueron sometidos a un análisis inmunohistoquímico para describir la respuesta inflamatoria. Todos los casos mostraron severos signos neurológicos seguidos por la muerte. Histológicamente los cambios inflamatorios en el cerebro y el cerebelo que caracterizaron la infección neurológica muestran meningitis, manguitos perivasculares mononucleares, gliosis, hemorragias y macrófagos (células gitter) acompañando grandes áreas de malacia. Ninguno de los casos mostró cuerpos de inclusión intranucleares; sin embargo, en cinco de ellos fue posible el aislamiento del HVB-5. Con el fin de recolectar datos que permitan describir la respuesta inflamatoria en estos casos, muestras de cerebro de todos los casos se analizaron por inmunohistoquímica usando anticuerpos policlonales contra CD3 para detectar linfocitos T y contra GFAP para detectar astrocitos. Por otro lado, se usaron anticuerpos monoclonales contra BLA para detectar células B y MAC 387 para detectar macrófagos. Los resultados indican que la respuesta inflamatoria se caracterizó por linfocitos T en los infiltrados perivasculares y por los astrocitos en otras partes del órgano. Los macrófagos (células gitter) estuvieron siempre asociados a grandes áreas de malacia y los linfocitos B tuvieron una discreta participación sobre todo en los infiltrados celulares perivasculares. Estos hallazgos facilitarán futuras investigaciones tendientes al entendimiento de la patogénesis de este tipo de encefalitis

This study aimed at evaluating the susceptibility of commercial laying hens to Salmonella Gallinarum (SG). Two experiments were carried using a mutant strain of Salmonella Gallinarum resistant to nalidix acid (SGNALr). In the first trial, the resistance of birds was evaluated based on clinical signs, faecal shedding, and mortality. It was carried out with six lines of commercial layers being three light white layers, considered to be resistant to SG (W1, W2, W3), and three semi-heavy brown varieties (B1, B2, B3), considered susceptible to SG. Each group contained 15 one-day-old birds. Hens were inoculated in the crop at 5 days of age with 0.2 mL of SGNALr neat culture. In addition, to each brown variety, a new group of 15 birds was challenged with 0.2mL of the same SGNALr culture diluted at 10-3. At the end of the first experiment, the surviving birds were sacrificed, and microbiological culture of liver and spleen was performed. In the second experiment, white and brown birds were inoculated with neat culture at five days of age. Samples were collected for evaluation of blood parameters and histopathology assessment at 1, 3, 5, 7, 9, 12, and 14 days post-infection. The results of the first experiment showed higher resistance of white birds (p<0.05), although there was no uniformity in the responses against fowl typhoid among the birds within these groups. In the second experiment, there were differences between white and brown birds both in blood parameters and in organ lesion intensity.

This experiment aimed at evaluating the effects of the interactions between aflatoxin (500 or 250 ppb) and ochratoxin (500 or 250 ppb), and the possible benefits of adding yeast cell wall to prevent the effects of these mycotoxins in broiler chickens. Relative organ weight gain and live performance were evaluated at 21 and 42 days of age. Results indicated that at the levels of mycotoxins included in the experimental diets, ochratoxin reduced feed intake and body weight gain, and aflatoxin only affect feed intake of 21-day-old birds. No interaction was observed between aflatoxin and ochratoxin at the levels used in experimental study. Yeast cell wall did not significantly reduced the deleterious effects of ochratoxins. No significant differences were observed in relative organ weight gain. Yeast cell wall improved feed conversion ratio when birds were fed either contaminated or non-contaminated feeds.