Avaliaçäo pós-vacinal de lobos guarás Chrysocyon brachyurus (Illiger, 1811) contra os vírus da cinomose e parvovirose caninas / Immune response of maned wolves Chrysocyon brachyurus (Illiger, 1811) after vaccination against canine distemper virus (CDV) and canine parvovirus (CPV)

Este estudo teve como objetivos acompanhar a resposta sorológica pós-vacinal de lobos guará cativos imunizados contra os vírus da cinomose (CDV) e da parvovirose (CPV) caninas com vacina vírus vivo modificado (VVM) produzida para cäes domésticos e determinar um programa de vacinaçäo para a espécie. Amostras de soro foram coletadas de 47 lobos com idades variadas, provenientes de seis zôos. Foram utilizados os testes de soroneutralizaçäo (SN) e inibiçäo da hemaglutinaçäo (HI) para mensurar os títulos de anticorpos contra CDV e CPV, respectivamente, sendo testadas 361 amostras para CDV e 353 para CPV. A avaliaçäo pós-vacinal demonstrou que 72 por cento dos espécimes desenvolveram títulos de SN >-100 contra CDV e 98 por cento desenvolveram títulos de HI >- 80 contra CPV. Lobos guarás sem histórico de vacinaçäo apresentaram soroconversäo após a vacinaçäo. Espécimes com histórico de vacinaçäo e títulos considerados protetores para cäes domésticos mantiveram títulos estáveis ao longo de 12 meses após a vacinaçäo. A VVM utilizada (CDV atenuado por passagens em ovos embrionados de aves SPF e posteriormente adaptado às células da linhagem VERO) mostrou-se segura para os lobos guarás adultos e filhotes

Detection of BHV-1 in a naturally infected bovine fetus by a nested PCR assay.

Bovine herpesvirus 1 (BHV-1) is frequently associated with abortion in naturally and experimentally infected cattle. Most of the virus isolation and immunofluorescent antibody protocols described in the literature for detecting BHV-1 in bovine foetuses are rather laborious, costly and time-consuming. The detection is described of BHV-1 in the tissues of a naturally aborted bovine foetus by a nested PCR assay with no further hybridization procedures. Optimal results were achieved by filtering the foetal tissues on a chromatography column before DNA extraction, by using two pairs of primers in a nested PCR and by evaluating the amplification products on silver-stained polyacrylamide gels. This nested PCR was faster and easier to perform than the virus isolation test. To our knowledge, this is the first time that BHV-1 has been detected in the tissues of a naturally infected bovine foetus by means of a nested PCR. The test seems to be a practical alternative for rapid detection of BHV-1 in bovine foetus.

A high sensitivity-nested PCR assay for BHV-1 detection in semen of naturally infected bulls.

Several different PCR protocols for the detection of Bovine herpesvirus-1 (BHV-1) in bovine semen, are available in the literature. Most of them are rather laborious and the majority were performed on laboratory samples, artificially contaminated semen or semen provided from experimentally inoculated animals. Furthermore, to obtain higher levels of sensitivity, additional dot-blot procedures are frequently necessary. We describe the detection of BHV-1 in bovine semen and the supernatant of cell cultures with titres of 0.001 TCID50/50 microliter by a nested PCR assay, with no further hybridization procedures. The high sensitivity was achieved by filtering the semen samples on chromatography columns before DNA extraction, by using two pairs of primers in a nested PCR and by evaluating the amplification products on silver-stained polyacrylamide gels. Specificity of the amplified fragments was confirmed by RFLP and sequence analysis of the PCR products. This nested PCR procedure was performed in parallel with viral isolation (VI) on 101 semen samples provided from naturally infected bulls housed at an artificial insemination centre. The nested PCR was shown to be more sensitive, faster and easier to perform than the standard VI test. To our knowledge, it is the most sensitive PCR test for BHV-1 detection in bovine semen and could be easily used for routine diagnosis.

HIV-1 detection and subtyping by PCR and heteroduplex mobility assay in blood donors: can these tests help to elucidate conflicting serological results?

Testing blood donors for the human immunodeficiency viruses (HIV-1 and 2), requires serological tests that are frequently inconclusive. Peripheral blood mononuclear cells of 50 blood donors with the screening test (ELISA) reactive to HIV-1, but with indeterminate results in the first Western Blot (WB) performed, were submitted to the polymerase chain reaction (PCR) and heteroduplex mobility assay (HMA), a nonsequencing method that can distinguish between HIV-1 subtypes (A to I). PCR amplification of HIV-1 env gene regions has been obtained in 12 (24.0%) samples. HMA of the amplified DNA showed that 12 belonged to HIV-1 B subtype and one to F subtype. PCR testing of the amplified DNA helped to elucidate doubtful serological results and HMA proved to be a relatively simple and rapid way of subtyping HIV-1 for epidemiological purposes.

Viruses with tri-segmented double-stranded RNA in broiler chicken feces in Brazil

Eletroforese em gel de poliacrilamida de ácidos nucléicos extraídos de fezes de frangos de corte revelou a presença de três bandas em uma amostra. Essas bandas foram digeridas pela RNase A pancreática mas näo pela RNase T1 e DNase, sugerindo que devem ser constituídas de RNA fita dupla. Para exame em microscopia eletrônica, uma suspensäo diluída de fezes foi ultracentrifugada através de um colchäo de sacarose e no sedimento foram observadas partículas de 35 mm de diâmetro semelhante a vírus