Hemorrhagic Disease Virus Serotype Research Articles

Complete Genome Sequence of Epizootic hemorrhagic disease virus Serotype 6, Isolated from Florida White-Tailed Deer (Odocoileus virginianus).

ABSTRACTHere, we report the complete genome sequence of Epizootic hemorrhagic disease virus (EHDV) serotype 6 (EHDV-6), isolated from a Florida white-tailed deer (Odocoileus virginianus) in 2016. To our knowledge, this is the first full genome sequence determined for an EHDV-6 isolate from Florida.

A pair of novel primers for universal detection of the NS1 gene from various bluetongue virus serotypes

Twenty five serotypes of Bluetongue virus (BTV) have been identified worldwide. Rapid and reliable methods of virus universal detection are essential for fighting against bluetongue (BT). We have therefore developed and evaluated a pair of primers which can detect various serotypes of BTV by RT-PCR. Analysis of the viral protein 7 (VP7) and the non-structural protein (NS1) gene from different serotypes of BTV by DNAstar showed that the 5′ end of the NS1 gene is the most conserved region. The primer pairs (P1 and P2) were designed based on the highly conserved region of NS1. The novel primers were evaluated by detecting BTV serotypes 1, 3, 5, 8, 10, 11, 21 and 22. The specificity of the primers was estimated by comparing to gene sequences of viruses published in GenBank, and further assessed by detecting BTV serotype 1–12 and Epizootic hemorrhagic disease virus (EHDV) serotype 1–4. The sensitivity and repeatability of PCR with the novel primers were evaluated by successfully detecting the recombinant plasmid pGEM-T121 containing the diagnosed nucleotide sequence. Our results suggest that these unique primers can be used in high throughout and universal detection of the NS1 gene from various BTV serotypes.

Detection of Epizootic Hemorrhagic Disease Virus in Culicoides variipennis (Diptera: Ceratopogonidae)

Nucleic acid hybridization was used to detect epizootic hemorrhagic disease (EHD) virus serotype 1 and serotype 2 in Culicoides variipennis (Coquillett). Adult females were inoculated intrathoracically with virus, then were assayed daily for the presence of viral RNA for 2 wk, at which time maximum virus replication is likely to occur. Viral RNA of EHD serotypes 1 and 2 was first detected by hybridization on days 9 and 7 after infection, respectively, and then for up to 14 days after infection. EHD serotype 1 viral RNA was detected by hybridization in infected flies fixed in ethanol at room temperature for 7 d and in unfixed (frozen) infected flies. However, weak false positives diminished prospects for application of this method.

A comparison of different cloned genome segments of Epizootic haemorrhagic disease virus as serogroup-specific probes

The eight largest double-stranded (ds) RNA genome segments of epizootic haemorrhagic disease virus (EHDV) serotype 2 (Alberta strain) have been cloned. Of these, segments 4, 5, 6, 7, and 8 are represented by clones that correspond in size to those predicted for full-length clones. The different clones were used as nucleic acid probes to study the nucleic acid homology of cognate genes of four different EHDV serotypes. The results indicated that the 4 isolates may be subdivided in two geographic groups which include Ibaraki virus as the sole member of one group and EHDV1 (New Jersey), EHDV2 (Alberta) and EHDV6 (XBM 67--isolated in South Africa) as a second. Genome segments 1, 3, 4, 6, and 8 were found to be highly conserved with more than 90% homology amongst cognate genes of three of the members of the EHDV serogroup. Of these, segments 1 and 3 showed the largest degree of homology with cognate genes of members of the BTV serogroup. Segment 6 and 8 probes of EHDV2 (Alberta) on the other hand did not hybridize with BTV dsRNA under conditions of moderate to low stringency and are recommended for use as EHDV group-specific probes.

Immunodetection of Bluetongue Virus and Epizoötic Hemorrhagic Disease Virus in Culicoides variipennis (Diptera: Ceratopogonidae)

The avidin-biotin complex immunoperoxidase system has been used with nitrocellulose membranes to detect bluetongue virus serotypes 10 (BTV-10) and 11 (BTV-11) and epizootic hemorrhagic disease virus (EHDV) serotype 1 (EHDV-1) in individual specimens of Culicoides variipennis (Coquillett). The cross reactivity between BTV-10 and BTV-11 indicates that polyclonal antisera cannot be used to distinguish between flies infected with BTV-10 and BTV-11; however, the procedure can be used to discriminate flies infected with BTV-10 or BTV-11 from flies infected with EHDV-1. Because the test is rapid and sensitive and does not require expensive equipment, it could be used in the field to determine the relative numbers of flies infected with BTV or EHDV.

Growth of Epizootic Hemorrhagic Disease, Akabane, and Ephemeral Fever Viruses in Aedes albopictus Cells Maintained at Various Temperatures

The growth curves of one epizootic hemorrhagic disease (EHD) virus serotype (Reoviridae), two Akabane virus strains (Bunyaviridae) and three bovine ephemeral fever (BEF) group viruses (Rhabdoviridae) were determined in Aedes albopictus cells maintained at 15, 20, 28 and 33 degrees C. Ae albopictus cells supported the growth of all the viruses although not necessarily at all temperatures. Because none of the viruses exhibited cytopathic effect in Ae albopictus cells, growth was assayed in baby hamster kidney 21 (BHK21) cells maintained at 37 degrees C. The temperature at which the Ae albopictus cells were maintained had a marked effect on the growth and yield for each virus studied. EHD virus was heat-stable and grew after 4 days at 28 and 33 degrees C, and after 8 days at 20 degrees C. No growth was recorded up to 12 days at 15 degrees C. The two Akabane viruses were heat-sensitive and exhibited different growth patterns. One strain (B8935) showed no growth at 15 degrees C and only minimal growth at 20, 28 and 33 degrees C. The other strain (CSIRO 16) showed growth after 1-2 days at all temperatures with higher titres reached at 15 and 20 degrees C than at 28 and 33 degrees C. The BEF group viruses grew to approximately the same titres at all temperatures. At the higher temperatures (28 and 33 degrees C) most of BEF group viruses had disappeared within 9 days. In contrast at the lower temperatures (15 and 20 degrees C), there was still virus present 18 days after inoculation.(ABSTRACT TRUNCATED AT 250 WORDS)