The demonstration of a herpesvirus, related to bovine herpesvirus 1, in reindeer with ulcerative and necrotizing lesions of the upper alimentary tract and nose

In 11 male reindeer, all esposed to transportation stress, signs of conjunctivitis and later on ulcerative and necrotizing lesions of the mucosa of the nostrils and mouth were recorded. Blood and secretions from the nose were sampled. Antibodies to bovine herpesvirus 1 (BHV-1) were detected in 2 animals. No animal had antibodies to bovine viral diarrhoea virus (BVDV). Virus isolation was negative. The sampling was repeated 2 weeks later and complemented with biopsies from the mouth lesions, fixed in formalin. At this occasion 3 animals were seropositive to BHV-1 and in biopsies from 2 of these intranuclear herpesvirus-like particles were found by means of electron microscopy. Four animals, 3 of them seropositive, were treated with cortison during 8 days. The size of the ulcers in the mouth increased in all animals. A herpesvirus was isolated from 3 of them at 10 different occasions. The ultrastructural investigation of the virus suspension demonstrated the presence of typical herpesvirus particles. On day 11 all 4 animals suffered from a severe diarrhoea and anorexia. On day 12 one animal died and on day 13 post challenge with cortison two additional animals died. The remaining animal was slaughtered on day 13. Bacteriological investigation revealed growth of Fusobacterium necrophorum from the spleen and oral wounds of all 4 animals. The animals were obviously subjected to an infection with a herpesvirus colsely related to BHV-1. Virus could be liberated by cortison treatment. It is possible that infections with the found herpesvirus, and the lesions caused by it, may be the background to earlier recorded severe outbreaks of necrobacillosis of the alimentary tract in reindeer herds

Evaluation of western blotting for the diagnosis of enzootic bovine leukemia Avaliação da técnica de western blot no diagnóstico da leucose enzoótica bovina

A western blotting (WB) procedure has been developed for detecting antibodies to bovine leukosis virus (BLV) in cattle sera. Two hundred and thirty three serum samples from naturally infected cattle with BLV virus and serial bleedings from experimentally BLV infected cows were used. An agar gel immunodiffusion test (AGID) was used for comparing with the results obtained by WB. The AGID positive sera showed a different degree of reactivity by WB test against the two most important viral antigens (gp51 and p24), or against one of them. Other proteins (gp30, p15, p12 and p10) were not detected with any AGID positive sera, being observed occasionally three bands corresponding to the p24 protein. Using sera obtained by BLV experimental inoculation, the antibodies directed to p24 appeared early (between the 2nd and 4th week post inoculation) and thereafter antibodies to gp51were detected in some animals. The analysis of field serum samples by AGID as compared to WB showed an agreement of 90.9%. Only 1.7% of sera were negative by AGID and positive by WB and 7.2% that were not conclusive by AGID and were defined by WB (4.2% as positive and 3.0% as negative).<br>Um sistema de western blotting (WB) foi desenvolvido para detecção de anticorpos contra o vírus da leucose em soros de bovinos. Foram utilizadas amostras de soros de 233 animais naturalmente infectados e soros de vacas experimentalmente infectadas. O teste de imunodifusão em ágar (AGID) foi usado para comparação dos resultados. Graus diferentes de reatividade foram observados em soros positivos ao AGID, quando testados em WB frente a um ou aos dois antígenos mais importantes (gp51 e p24). Outras proteínas (gp30, p15, p12 e p10) não foram detectadas por nenhum soro positivo ao AGID, sendo que três bandas correspondentes à proteína p24 foram observadas ocasionalmente. Em soros obtidos por inoculação experimental, anticorpos contra a proteína p24 foram detectados entre a segunda e a quarta semanas após a inoculação e, em alguns animais, detectaram-se anticorpos anti-gp51 mais tardiamente. O estudo de soros de campo com AGID e WB mostrou concordância de 90,9% sendo que apenas 1,7% dos soros negativos pelo AGID foram positivos ao WB e 7,2% dos resultados não conclusivos por AGID foram definidos por WB (4,2% como positivos e 3% como negativos)

A rapid and sensitive diagnosis of bovine leukaemia virus infection using the nested shuttle polymerase chain reaction Diagnóstico rápido e sensível da infecção com o vírus da Leucemia Bovina através de Shuttle Nested Polymerase Chain Reaction

Bovine leukaemia virus (BLV) is the causative agent of enzootic bovine leukosis (EBL). In Argentina, where a program to eradicate EBL has been introduced, sensitive and reliable diagnosis has attained high priority. Although the importance of the agar gel immunodiffusion test remains unchanged for routine work, an additional diagnostic technique is necessary to confirm cases of sera with equivocal results or of calves carrying maternal antibodies.Utilizing a nested shuttle polymerase chain reaction, the proviral DNA was detected from cows experimentally infected with as little as 5 ml of whole blood from BLV seropositive cows that were nonetheless normal in haematological terms. It proved to be a very sensitive technique, since it rapidly revealed the presence of the provirus, frequently at 2 weeks postinoculation and using a two-round procedure of nested PCR taking only 3 hours. Additionally, the primers used flanked a portion of the viral genome often employed to differentiate BLV type applying BamHI digestion. It is concluded that this method might offer a highly promising diagnostic tool for BLV infection.<br>O Vírus da leucemia bovina (BLV) é o agente causal da Leucose Enzoótica Bovina (EBL). Na Argentina, iniciou-se um programa de erradicação da EBL. Neste estágio, é prioritário possuir uma ferramenta de diagnóstico confiável. Embora seja indiscutível a importância do teste de agar gel imunodifusão, empregado rotineiramente no diagnóstico serológico da EBL, faz-se necessária uma técnica de diagnóstico adicional capaz de confirmar os resultados duvidosos. Foi possivel detectar ADN proviral aplicando Nested-PCR em novilhos experimentalmente infectados com pequenas doses de sangue total (5ml) obtidas de um bovino BLV soropositivo. Esta técnica, cujo procedimento leva 3 horas, demonstrou ser muito sensível, uma vez que foi capaz de detectar a presença do provirus duas semanas após a inoculação. Os primers utilizados são os que detectam uma porção do genoma viral que geralmente é usado para diferenciar os tipos de BLV, utilizando a digestão com BamHI. Sugerimos que este método possa ser um instrumento válido para o diagnóstico precoce da infeção pelo BLV