Genome characterization of Salem virus reveals its evolutionary intermediate status in the subfamily Paramyxovirinae

10.1007/s00705-012-1388-6Archives of Virology157101989-1993ARVI

Detection of bovine immunodeficiency virus DNA in the blood and semen of experimentally infected bulls

Five 18- to 24-month-old bulls were inoculated with either a cell suspension containing bovine immunodeficiency virus (BIV-FL112; 3 bulls) or a BIV-free cell suspension (2 bulls). Blood and semen specimens were collected once a week for 14 weeks, and seroconversion was confirmed by indirect immunofluorescent antibody (IFA) testing. The presence of BIV in blood and semen was determined by virus isolation and/or polymerase chain reaction (PCR) assays. Antibodies to BIV were detected in the 3 experimentally infected bulls as early as day post inoculation (DPI) 17, and levels peaked at DPI 37–58. BIV was isolated from the peripheral blood mononuclear cells (MNCs) of the infected bulls at DPI 9 (2 bulls) and DPI 23 (1 bull), and could be isolated from one animal up to DPI 65. PCR analysis of MNC DNA, using BIV pol gene primers, detected virus in all three of the experimentally infected bulls from DPI 9 until the termination of the experiment at DPI 98. Efforts to isolate a significant number of non-spermatozoal cells (NSC) by gradient separation from the semen of the experimentally infected bulls were unsuccessful. Two methods for the extraction of total NSC DNA from up to 2 ml of non-extended semen were employed; however, no BIV pol fragment was amplified from these DNA preparations. Additionally, 30 bulls from artificial insemination (AI) centers were evaluated for BIV infection by PCR. No amplification products were obtained from MNC DNA from the AI submissions using primer sets for both the BIV pol and env genes

The effect of protected areas on pathogen exposure in endangered African wild dog (Lycaon pictus) populations

Infectious diseases impact African wilddogs (Lycaonpictus), but the nature and magnitude of this threat likely varies among populations according to different factors, such as the presence and prevalence of pathogens and land-use characteristics. We systematically evaluated these factors to assist development of locally appropriate strategies to mitigate disease risk. Wilddogs from 16 sites representing five unconnected populations were examined for rabies virus, canine distemper virus (CDV), canine parvovirus, canine coronavirus, and Babesia spp. exposure. Analyses revealed widespread exposure to viral pathogens, but Babesia was never detected. Exposure to CDV was associated with unprotected and protected-unfenced areas where wilddogs likely have a high probability of domestic dog contact and, in the case of protected-unfenced areas, likely reside amongst high wildlife densities. Our findings also suggest that domestic dog contact may increase rabies and coronavirus exposure risk. Therefore, domestic dogs may be a source of CDV, rabies and coronavirus, while wildlife may also play an important role in CDV transmission dynamics. Relatively high parvovirus seroprevalence across land-use types suggests that it might persist in the absence of spillover from domestic dogs. Should intervention be needed to control pathogens in wilddogs, efforts to prevent rabies and coronavirus exposure might be directed at reducing infection in the presumed domestic dog reservoir through vaccination. If prevention of CDV and parvovirus infections were deemed a management necessity, control of disease in domestic dogs may be insufficient to reduce transmission risks, and vaccination of wilddogs themselves may be the optimal strategy

Ocorrência de animais persistentemente infectados pelo vírus da diarréia viral bovina em rebanhos bovinos nos Estados de Minas Gerais e São Paulo

A pesquisa de animais persistentemente infectados (PI) pelo vírus da diarréia viral bovina (BVDV) foi realizada em 26 rebanhos bovinos, não vacinados contra o BVDV, localizados nos Estados de Minas Gerais e São Paulo, Brasil. Utilizando uma estratégia de amostragem, de cada rebanho foram obtidas cinco amostras de sangue de bezerros, entre 6 e 12 meses de idade, e os soros sanguíneos foram submetidos ao teste de virusneutralização (VN) para o BVDV-1 e o BVDV-2. Os rebanhos que apresentaram pelo menos três das cinco amostras reagentes a um dos genótipos do BVDV, e com títulos de anticorpos superiores a 128, foram selecionados para a pesquisa de animais PI. Em três rebanhos que apresentaram tal condição, foram colhidas amostras pareadas de sangue de todos os bovinos do rebanho, com intervalo de 30 dias entre as colheitas, e o soro sanguíneo foi submetido ao teste de VN para o BVDV-1 e o BVDV-2. Nas amostras não reagentes a pelo menos um dos genótipos do BVDV e naquelas provenientes de bovinos com menos de seis meses de idade, realizou-se a pesquisa do BVDV pela reação em cadeia da polimerase precedida pela transcrição reversa (RT-PCR). Dos rebanhos analisados, foram detectados dois animais PI a partir de amostras obtidas nas colheitas pareadas provenientes de um rebanho localizado no Estado de Minas Gerais

RT-PCR em pools de soros sangüíneos para o diagnóstico da infecção aguda e de animais persistentemente infectados pelo vírus da diarréia viral bovina RT-PCR in pools of bovine blood serum to detect acute infection and persistently infected animals with bovine viral diarrhea virus

Utilizou-se a técnica da RT-PCR para a detecção da região 5' UTR do genoma do vírus da diarréia viral bovina (BVDV) em pools de soros sangüíneos provenientes de um rebanho, constituído por 226 animais, que apresentava distúrbios da reprodução. A partir das amostras individuais de soro e de acordo com a categoria dos animais e o número de animais por categoria foram formados 10 pools (A a J) de soros. A primeira avaliação revelou a amplificação de um produto com 290pb nas reações referentes aos grupos D (35 vacas) e H (25 bezerros lactentes) que, após o desmembramento em amostras individuais, resultou na identificação de 11 vacas lactantes e 12 bezerros em amamentação positivos. Para a identificação de animais persistentemente infectados (PI) entre os 23 positivos na primeira avaliação, realizou-se a segunda colheita de soros sangüíneos, três meses após. A RT-PCR das amostras individuais de soro revelou resultado positivo em cinco bezerros. Em dois, foi possível isolar o BVDV em cultivo de células MDBK. A especificidade das reações da RT-PCR foi confirmada pelo seqüenciamento dos produtos amplificados a partir do soro de uma vaca com infecção aguda, de um bezerro PI e das duas amostras do BVDV isoladas em cultivo celular. A utilização da RT-PCR em pools de soros sangüíneos demonstrou ser uma estratégia rápida de diagnóstico etiológico e de baixo custo tanto para a detecção de infecção aguda quanto de animais PI.<br>The 5' untranslated region of the bovine viral diarrhea virus (BVDV) genome was detected by RT-PCR assay in pools of blood sera samples collected from a cattle herd (n=226 animals) with reproductive failures. Based on the classes of animal and the number of animals per class, the individual blood serum samples were distributed in 10 sera pools (A to J). During the first evaluation a 290bp amplicon was amplified in reactions from groups D (35 cows) and H (25 sucking calves). The individual analysis of serum from groups D and H resulted in positive reactions in serum samples from 11 cows and 12 calves. For the identification of persistently infected (PI) animals, three months after the first examination, blood serum samples from 23 positive animals were reevaluated by RT-PCR, resulting in five positive calves. In two of these calves the BVDV was isolated in MDBK cell culture. The specificity of RT-PCR amplicons from one cow with acute infection, one PI calf, and two wild type BVDV strains isolated in cell culture were confirmed by nucleotide sequencing. The use of RT-PCR in pools of blood sera proved to be a quick and low cost strategy for the etiological diagnosis of the acute infection as well as to detect PI animals thereby favoring the implementation of control and prophylaxis measures