Roberto Soares de Castro

Conidiobolomycosis in sheep in Brazil.

Conidiobolomycosis is reported in the state of Piauí, in the semiarid region of northeastern Brazil. Affected sheep had depression, weight loss, serous or mucohemorrhagic nasal discharge, and cranium-facial asymmetry from exophthalmos of 1 eye, generally with increased volume of the eyeball, keratitis, and corneal ulceration. At necropsy of 60 sheep, friable masses were observed in the posterior region of the nasal cavity, often destroying the ethmoturbinate bones. Frequently, the lesions invaded the nasal sinuses, cribiform plate, orbit, and brain. The masses were irregular, granular with moist surfaces, and soft and friable with white, yellow, or tan coloration. Dissemination of the lesion to lungs was observed in 27 sheep, to the brain in 26, to lymph nodes in 3, to the kidney in 2, and to the gallbladder and heart in 1. The microscopic examination showed granulomatous inflammation composed of central necrosis surrounded by lymphocytes, epithelioid and giant cells, and fibrous tissue. In all lesions, negatively stained structures representing hyphae were surrounded by Splendore-Hoeppli material. Coagulative necrosis, thrombosis, and vasculitis were also observed. Grocott methenamine silver stain showed 8–30-μm-thick hyphae, rarely septate or ramified, irregular in shape, and with black contoured wall, sometimes with bulbous dilatation in the extremities. On electron microscopy, the hyphae had a thick double wall surrounded by cellular remnants and an inflammatory exudate. Conidiobolus coronatus was isolated from the lesions of 6 sheep. Conidiobolomycosis is an important disease of sheep in the state of Piauí, and other regions of northeastern Brazil.

Lentivírus de pequenos ruminantes (CAEV e Maedi-Visna): revisão e perspectivas

Small ruminant lentiviruses (SRLV), whose prototypes are Caprine Arthritis-Encephalitis virus (CAEV) and Maedi-Visna virus, are the causative agents of slow progressive degenerative diseases of goats and sheep (infected animals), responsible for significant economic losses. These viruses cause persistent infections with long periods of incubation and induce inflammatory and degenerative lesions. The lesions are induced in target organs of the host such as joints, CNS, lungs and mammary glands due to viral replication in cells of the monocyte/macrophage lineage which is the main target cell. Infections occur particularly in the young and are acquired through ingestion of virus in milk or colostrum from infected does or ewes. The induction of immune response is variable and does not protect against the infection. Diagnosis is primarily based on the presence of SRLV antibodies usually detected by agar gel immunodiffusion (AGID) or enzyme linked immunosorbent assays (ELISA). As no vaccine is available, most often employed schemes to prevent spread of SRLV are based on segregation or/and culling of positive animals associated with management practices, especially the offspring. The strategies of SRLV for dealing with the immune system make difficult to accomplish diagnosis of infection, control or prevention of the viral spread. This review shows aspects of SRLV based on their phylogenetic studies of fields isolates, clinical, and immuno-pathological features.

Sinais clínicos, distribuição das lesões no sistema nervoso e epidemiologia da raiva em herbívoros na região Nordeste do Brasil

Twenty four outbreaks of rabies in cattle, 4 in horses, 2 in sheep, and 2 in goats are reported in northeastern Brazil. All outbreaks occurred in the state of Paraiba, except one in horses that occurred in the state of Rio Grande do Norte. All outbreaks, except one in sheep, were probably transmitted by vampire-bats, but the transmission by foxes (Dusicyon vetulus) is also possible. Clinical signs were characteristic for distribution of the lesions in the central nervous system (CNS). In cattle, signs were mainly of the paralytic form of rabies, caused by lesions on the spinal cord, brain stem and cerebellum; but some animals showed also depression, excitation and other signs due to cerebral lesions. In 3 out of 5 horses, the main clinical signs were due to lesions in the cerebrum, and 2 had the paralytic form. From 4 sheep and 2 goats affected, 4 showed clinical signs of the paralytic form; but in 1 goat and 1 sheep the main clinical signs were caused by cerebral lesions. All affected animals, except 1 goat, had a clinical manifestation period of 2-8 days. The only gross lesions were distention of the urinary bladder in 4 cattle and distention of the rectum in 2 others. Two horses had skin lesions due to traumatic injury. Histologic lesions were diffuse non-suppurative encephalomyelitis and meningitis. In the horses, and in one goat with a clinical manifestation period of 35 days, the lesions were more severe, with neuronal necrosis, neuronophagia, and presence of axonal spheroids. Negri bodies were found in 87% (20/23) of the cattle cases examined histologically. In small ruminants Negri bodies were found in 83% (5/6) of the cases. In sheep, goats and cattle, Negri bodies were more frequent in the cerebellum, but they were found also in brain stem, spinal cord and cerebrum. In horses, Negri bodies were found in small amounts only in the cortex of one animal, and in the cortex and hippocampus of another. Histologic lesions and Negri bodies in the trigeminal ganglia were less frequent than in the CNS. These results show that in rabies of herbivores, clinical signs and distribution of lesions in the CNS are variable, so that for the diagnosis and adequate clinical evaluation and the histologic study of different areas of the CNS are necessary. This also suggests that when the fluorescent antibody test and mouse inoculation test are negative, they should be repeated with samples from different areas of the brain and spinal cord. Frequency data of diseases from 4 diagnostic laboratories were used to estimate cattle deaths due to rabies in 3 Brazilian states. In Paraiba, with a population of 918,262 cattle, the annual death rate is estimated in 8,609 heads. In Mato Grosso do Sul, with a population of 23 millions cattle, deaths caused by rabies are estimated in 149,500 heads, and in Rio Grande do Sul, with a cattle population of 13 millions, cattle deaths due to rabies are estimated in 13,000 to 16,250 heads. If these data are used to estimate cattle losses in Brazil, with a cattle population of 195 millions, it can be estimated that 842,688 deaths are caused annually by rabies.

Seroprevalence of caprine arthritis-encephalitis virus in goats in the Cariri region, Paraiba state, Brazil.

The seroprevalence of caprine arthritis-encephalitis virus (CAEV) in the Cariri Region of Paraíba State, Brazil, was determined in 60 goat herds using the agar gel immunodiffusion test. The overall seroprevalence was 8.2%, with seropositivity in 21/60 (35%) herds and 13/15 (86.6%) municipalities. Bucks had a significantly higher frequency of infection (28.3%) than does (5.9%), and bucks that originated in other states had a significantly higher frequency of infection (76.5%) than those from Paraíba State (9.3%).

Contagious agalactia by Mycoplasma agalactiae in small ruminants in Brazil: first report

Two outbreaks of contagious agalactia by Mycoplasma agalactiae occurred in Paraiba State, Northeastern Region of Brazil are reported. The disease was characterized by mastitis, agalactia and polyarthritis in does and polyarthritis and conjunctivitis in kids and lambs. Fever and anorexia were also observed. Morbidy was from 26.1% to 100% in does, 36.5 to 100% in kids and 49% in lambs. In one farm 14.3% of the lactating goats and 6.4% of the kids died or were euthanized. In the other, 3.3% of the does, 36.5% of the kids and 22.9% of the lambs died and 84 affected goats were euthanized to control the disease. M. agalactiae was isolated from milk, joint exudates, nasal swabs and ear washings. The colonies were characteristic of Mycoplasma and the agent did not ferment both glucose and arginin. It was typed as Mycoplasma agalactiae by immunoperoxidase and PCR. This is the first report of M. agalactiae infection in Brazil, but the source of the infection remains unknown.

Produção de antígeno nucleoprotéico do vírus da artrite-encefalite caprina e comparação com o do vírus Maedi-Visna para utilização em teste de imunodifusão em ágar gel

A comparison of Maedi-Visna virus (MVV) and Caprine Arthritis-encephalitis virus (CAEV) antigens for detection of antibodies to CAEV was performed using sera from 120 goats. The sensitivity and specificity of the immunodiffusion test using MVV antigen compared to that of CAEV antigen was 77.3% and 100%, respectively (X2, p < 0.01). These results suggested that only CAEV antigen should be used in immunodiffusion tests for CAEV diagnosis.

Epidemiologia e sinais clínicos da conidiobolomicose em ovinos no Estado do Piauí

Conidiobolomycosis is reported in 25 farms, from January 2002 to December 2004, in the state of Piaui. The disease affects only sheep, mainly in April-June. The mean morbidity rate was 2.80%, but was higher in the first semester (2.1%), during the raining period, than in the second one (0.69%), during the dry period. Morbidity rate among flocks varied from 0.1-14.3%. Case fatality rate was 100%, and the clinical manifestation period varied from 1-5 weeks. Clinical signs were serous, mucous and/or bloody nasal secretion, respiratory distress, snoring respiration, cranium-facial asymmetry, exophthalmia, fever and progressive emaciation. Marked depression, sometimes with the head down or head pressing was observed in some cases. Gross, microscopic and ultrastructural lesions and identification of the agent are reported elsewhere. This is the first report of conidiobolomycosis in Brazil, which is endemic and has a high frequency in sheep in the State of Piaui, associated with high rainfalls (1000-1600mm annually) and high temperature (19-36oC).

A Labelled Avidin–Biotin ELISA to Detect Antibodies to Caprine Arthritis-encephalitis Virus in Goats' Sera

A labelled avidin–biotin ELISA (lab-ELISA) was developed and compared with indirect ELISA (i-ELISA) and agar-gel immunodiffusion assay (AGID) for its efficacy in detecting antibodies against caprine arthritis-encephalitis virus (CAEV) in goat sera. The enzyme immunoassays were standardized using 113 sera from CAEV-negative goat flocks. The tests were compared using the results from 339 serum samples. The lab-ELISA showed the greatest number of positive results (94/339) as compared with AGID (51) and i-ELISA (64). The comparison of the other two tests with the lab-ELISA showed an agreement of 87.3% with AGID and 90.6% with i-ELISA. The lab-ELISA may be useful for screening large populations for CAEV antibodies, in epidemiological surveys and in the control of caprine arthritis-encephalitis.

Anticorpos contra lentivírus de pequenos ruminantes em caprinos e ovinos em abatedouros do estado de Pernambuco

The prevalence of small ruminant lentivirus (SRL) infection was evaluated in goats and sheep in two counties of Pernambuco State, Brasil. Seriological examinations were performed from a total of 672 goats and 325 sheep, one year of age and older, at two abattoirs. Sera were analyzed by agar gel immunodiffusion using Maedi-Visna K-1514 antigens. There were 42 reactive samples (95% confidence interval 3.6% to 4.9%) in both slaughter houses. In Sao Lourenco da Mata county, 3.2% and 4.0% of goat and sheep sera were responsive, whereas in Paulista county, 5.1% of goat samples and 8.2% of sheep were reactive. Thus, the prevalence of small ruminant lentivirus was low in goats and sheep sampled from the region.

Hemograma, proteinograma, ionograma e dosagens bioquímicas e enzimáticas de ovinos acometidos por conidiobolomicose no nordeste do Brasil

Hematologic values, serum levels of albumin, globulins, total proteins, calcium, phosphorus, magnesium, chloride, urea nitrogen, creatinine, total, direct and indirect bilirrubin, and serum activities of aspartate aminotransferase (AST), alkalin phosphatase (AF) and gama-glutamyltransferase (GGT) were determined in 56 hair sheep with conidiobolomycosis and 371 healthy hair sheep from the same flocks. Sheep with conidiobolomycosis had nonregenerative, normocytic and normochromic anemia, leucocytosis with neutrophilia and increased nutrophil:lymphocyte rate, moderate monocytosis, moderate thrombocytosis, hypoproteinemia (hypoglobulinemia), hypomagnesemia, hypocalcemia and increased values of phosphorus. Serum activities of AST and GGT were increased and serum activity of FA decreased. Serum values of urea and creatinine were within normal values. Hypoglycemia and hyperbilirrubinemia were also observed. These results can be used for experimental studies with the disease, for treatments trials, and to detect early cases of the disease without clinical signs. Otherwise the hematologic and blood biochemistry values of healthy sheep can be used as reference values for hair sheep in the semi-arid region of Brazil.