Assuntos
Ixodidae/virologia , Vírus da Doença do Carneiro de Nairobi/genética , RNA Viral , Animais , Vetores Aracnídeos/virologia , China , Dados de Sequência Molecular , Vírus da Doença do Carneiro de Nairobi/classificação , Vírus da Doença do Carneiro de Nairobi/isolamento & purificação , FilogeniaRESUMO
Partly due to climate change, and partly due to changes of human habitat occupation, the impact of tick-borne viruses is increasing. Nairobi sheep disease virus (NSDV) and Ganjam virus (GV) are two names for the same virus, which causes disease in sheep and goats and is currently known to be circulating in India and East Africa. The virus is transmitted by ixodid ticks and causes a severe hemorrhagic disease. We have developed a real-time PCR assay for the virus genome and validated it in a pilot study of the pathogenicity induced by two different isolates of NSDV/GV. One isolate was highly adapted to tissue culture, grew in most cell lines tested, and was essentially apathogenic in sheep. The second isolate appeared to be poorly adapted to cell culture and retained pathogenicity in sheep. The real-time PCR assay for virus easily detected 4 copies or less of the viral genome, and allowed a quantitative measure of the virus in whole blood. Measurement of the changes in cytokine mRNAs showed similar changes to those observed in humans infected by the closely related virus Crimean Congo hemorrhagic fever virus.
Assuntos
Citocinas/genética , Doenças das Cabras/genética , Doença dos Ovinos de Nairobi/genética , Vírus da Doença do Carneiro de Nairobi/patogenicidade , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , Citocinas/metabolismo , Doenças das Cabras/imunologia , Doenças das Cabras/virologia , Cabras , Doença dos Ovinos de Nairobi/imunologia , Doença dos Ovinos de Nairobi/virologia , Vírus da Doença do Carneiro de Nairobi/classificação , Vírus da Doença do Carneiro de Nairobi/genética , Vírus da Doença do Carneiro de Nairobi/isolamento & purificação , RNA Viral/análise , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Ovinos , Virulência , Replicação ViralRESUMO
We have previously described isolation and preliminary identification of a virus related to Dugbe virus (DUGV), family Bunyaviridae, genus Nairovirus. Six isolates of the virus were obtained from pools of Amblyomma gemma and Rhipicephalus pulchellus ticks collected from hides of cattle in Nairobi, Kenya, in October 1999. We report results of further characterization of this virus, including growth kinetics in cell culture and full-length genome sequencing and genetic characterization, which show it to be distinct from DUGV. We suggest that this is a new virus in the family Bunyaviridae, genus Nairovirus, and we propose that it be designated Kupe virus.
Assuntos
Ixodidae/virologia , Vírus da Doença do Carneiro de Nairobi/classificação , Vírus da Doença do Carneiro de Nairobi/genética , Rhipicephalus/virologia , Aedes/virologia , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Linhagem Celular , Chlorocebus aethiops , Humanos , Quênia , Vírus da Doença do Carneiro de Nairobi/crescimento & desenvolvimento , Vírus da Doença do Carneiro de Nairobi/isolamento & purificação , Filogenia , Análise de Sequência de DNA , Especificidade da Espécie , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterinária , Células VeroRESUMO
Nairobi sheep disease (NSD) virus is the prototype of the tick-borne NSD serogroup, genus Nairovirus, family Bunyaviridae. It is highly pathogenic for sheep and goats, causes disease in humans, and is widespread throughout East Africa. Ganjam virus has caused disease in goats and humans in India. Due to their occurrence on different continents and association with different ticks, these viruses were considered distinct despite serologic cross-reactivity. Their S RNA genome segments and encoded nucleocapsid proteins were found to be 1590 nucleotides and 482 amino acids in length and differed by only 10 and 3% at nucleotide and amino acid levels, respectively. Genetic and serologic data demonstrate that Ganjam virus is an Asian variant of NSD virus. These viruses were phylogenetically more closely related to Hazara virus than Dugbe virus.