The full genome sequence of three strains of Jamestown Canyon virus and their pathogenesis in mice or monkeys.

BACKGROUND: Jamestown Canyon virus (JCV), family Bunyaviridae, is a mosquito-borne pathogen endemic in the United States and Canada that can cause encephalitis in humans and is considered an emerging threat to public health. The virus is genetically similar to Inkoo virus circulating in Europe, suggesting that much of the northern hemisphere contains JCV or similar variants. RESULTS: We have completed the sequence of three isolates of JCV collected in geographically diverse locations over a 57 year time span. The nucleotide identity for the three strains is 90, 83, and 85% for the S, M, and L segments respectively whereas the percent identify for the predicted amino acid sequences of the N, NSS, M poly, GN, NSM, GC, and L proteins was 97, 91, 94, 98, 91, 94, and 97%, respectively. In Swiss Webster mice, each JCV isolate exhibits low neuroinvasiveness but high infectivity. Two of the three JCV isolates were highly neurovirulent after IC inoculation whereas one isolate, JCV/03/CT, exhibited low neurovirulence. In rhesus monkeys, JCV infection is accompanied by a low-titered viremia, lack of clinical disease, but a robust neutralizing antibody response. CONCLUSIONS: The first complete sequence of JCV is reported for three separate isolates, and a relatively high level of amino acid sequence conservation was observed even for viruses isolated 57 years apart indicating that the virus is in relative evolutionary stasis. JCV is highly infectious for mice and monkeys, and these animals, especially mice, represent useful experimental hosts for further study.

Analysis of oropouche virus L protein amino acid sequence showed the presence of an additional conserved region that could harbour an important role for the polymerase activity.

We described here the complete nucleotide sequence of the L RNA segment of Oropouche virus (genus Orthobunyavirus, family Bunyaviridae). We found the L RNA segment is 6846 nucleotides long and encodes a putative RNA polymerase of 2250 amino acids. Phylogenetic analysis showed that ORO virus cluster to the Orthobunyavirus genus confirming the serological classification. It also showed that Bunyamwera and California viruses, from the Orthobunyavirus genus, are more closely related to each other than to ORO virus. Sequence comparisons performed between the L proteins of 15 bunyaviruses and the PB1 proteins of 3 influenza viruses revealed that ORO L protein contains the 3 regions characteristic of arenaviruses and bunyaviruses. These comparisons also showed the existence of an additional fourth conserved region in the L protein of bunyaviruses that contains at least two active sites.

Nucleotide sequence and deduced amino acid sequence of the medium RNA segment of Oropouche, a Simbu serogroup virus: comparison with the middle RNA of Bunyamwera and California serogroup viruses.

The Bunyavirus genus of the family Bunyaviridae contains 18 serogroups. To date nucleotide sequence data has been obtained for three serogroups, Bunyamwera, California and Simbu, based on analysis of the small (S) RNA segment. In comparison, there is only nucleotide sequence data for the large and medium (M) RNA segments for members of the Bunyamwera and California serogroups. In this paper we report the nucleotide sequence of the M RNA of Oropouche (ORO) virus, a member of the Simbu serogroup. The M RNA was 4396 nucleotides in length with G1, G2 and NSm proteins similar in size to those reported for members of the Bunyamwera and California serogroups. However, there was limited nucleotide (50-52%) and amino acid (30-32%) homology between ORO virus M RNA and those of published members of the other two serogroups. The Bunyamwera and California serogroups are more closely related to each other than the Simbu serogroup virus Oropouche. These data were consistent with that previously reported for the S RNA (Saeed et al., 2000. J. Gen. Virol. 81, 743-748). It has been noted previously that three of four potential N-linked glycosylation sites of the Bunayamwera and California serogroups are conserved in G1 and G2 proteins. In contrast, ORO virus was found to have only three potential N-linked glycosylation sites of which only one, in G1, was conserved with members of the other two serogroups. Comparison of M RNA sequences of different strains of ORO virus revealed genetic variation consistent with that reported previously for the S RNA.

Three unique viral RNA species of snowshoe hare and La Crosse bunyaviruses.

Two-dimensional gel electrophoreses of RNase T1-derived oligonucleotides of the three individual RNA segments of the bunyavirus snowshow hare virus indicate that its three RNA segments possess distinct nucleotide sequences. The fingerprints of the RNA species of snowshoe hare virus differ from those of the antigenically closely related La Crosse virus. Three viral RNA species have been identified in preparations of Melao and Trivittatus as well as snowshoe hare, Lumbo, and La Crosse bunyaviruses.