Deteccao da infecçäo pelo virus da artrite - encefalite caprina: imunodifusao em agar e reacao em cadeia da polimerase com primers degenerados / Detection of caprine arthritis-encephalitis virus infection: agar gel immunodiffusion and polymerase chain reaction with degenerated primers

O objetivo deste trabalho foi analisar amostras de soro e de células sangüíneas de caprinos para detecçäo de anticorpos e DNA proviral do vírus da artrite-encefalite caprina (CAEV), respectivamente. Utilizou-se a técnica de imunodifusäo em ágar (AGID) e a reaçäo em cadeia da polimerase (PCR) com "primers" degenerados. Foram analisadas amostras de diferentes procedências: 39 de Mato Grosso do Sul (MS), 19 de Säo Paulo (SP) e 22 do Ceará (CE), dessas últimas, 12 oriundas de animais importados do Canadá. Os resultados de AGID e PCR foram discordantes, pois o primeiro permitiu a detecçäo de 25 animais soropositivos, enquanto a PCR detectou DNA proviral de CAEV em 16 amostras. Pela PCR foi possível identificar animais infectados cujos testes sorológicos foram negativos pela AGID: oito amostras do MS e um do CE. Säo discutidos diferentes aspectos que poderiam estar envolvidos na discordância dos resultados

Clinical, pathological and antigenic aspects of bovine viral diarrhea virus (BVDV) type 2 isolates identified in Brazil.

Nucleotide sequencing and phylogenetic analysis of Brazilian bovine viral diarrhea virus (BVDV) field isolates identified four viruses belonging to the genotype 2. Comparison of 5' UTR sequences from these isolates to those of North American BVDV type 2 revealed genomic variations that correlated with the geographic origins of the isolates. Two of the Brazilian type 2 viruses were isolated from clinical cases of gastroenteric/respiratory disease and two were isolated from healthy bovine fetuses. The clinical cases affected young animals (8- and 18-months-old) and were characterized by diarrhea, respiratory signs, extensive oral and digestive tract erosions, conjunctival and vulvar congestion, occasional digestive bleeding and vulvar and heart petechial hemorrhage. Antigenic analysis of these isolates with a panel of 10 monoclonal antibodies revealed marked antigenic differences in the major envelope glycoprotein, gp53/E2, compared to standard laboratory and vaccine BVDV strains. In addition, virus-specific antisera raised to Brazilian BVDV type 2 viruses displayed very low serological cross-reactivity with standard BVDV type 1 strains. Differences up to 64-fold in cross-neutralization titers were observed between BVDV type 1 and Brazilian BVDV type 2 isolates. The identification of BVDV type 2 among Brazilian cattle may have important implications for epidemiological studies, diagnostic and immunization strategies. Furthermore, the low neutralizing activity of BVDV type 1 antisera against the recently identified Brazilian BVDV type 2 isolates raises the question about the degree of protection conferred by BVDV vaccines, most of them based on a single type 1 strain.

Caprine arthritis-encephalitis virus: isolation and identification in Rio Grande do Sul, Brazil.

We describe the first report of caprine arthritis-encephalitis virus (CAEV) isolation in Brazil. In December 1989 a four-year old anglonubian arthritic doe was submitted to euthanasia and its synovial membranes were cultured by explantation. This doe was positive for antibodies to the caprine arthritis-encephalitis virus (CAEV). The reverse transcriptase activity detected in culture supernatants, the characteristic cytopathic effect of lentivirus in these cultures, the detection of viral antigens in concentrated supernatants by the agar gel immunodiffusion test, and the results of the fluorescent antibody test and of Northern blot analyses are consistent with the isolation of the CAEV.

Caprine arthritis-encephalitis virus: isolation and identification in Rio Grande do Sul, Brazil

We describe the first report of caprine arthritis-encephalitis virus (CAEV) isolation in Brazil. In December 1989 a four-year old anglonubian arthritic doe was submitted to euthanasia and its synovial membranes were cultured by explantation. This doe was positive for antibodies to the caprine arthritis-encephalitis virus (CAEV). The reverse transcriptase activity detected in culture supernatants, the characteristic cytopathic effect of lentivirus in these cultures, the detection of viral antigens in concentrated supernatants by the agar gel immunodiffusion test, and the results of the fluorescent antibody test and of Northern blot analyses are consistent with the isolation of the CAEV