DNA Sequence Analysis of Glycoprotein G Gene of Bovie Ephemeral Fever Virus and Development of a Double Oil Emulsion Vaccine against Bovine Ephemeral Fever

Abstract

ABSTRACT. The surface glycoprotein G is considered as the major neutralizing and protective antigen of bovine ephemeral fever virus (BEFV). Comparison of the deduced amino acid sequence of G protein of BEFV isolates during the period 1984-2004 outbreaks in Taiwan showed amino acid substitutions in the neutralizing epitopes. All the isolates differ markedly in the neutralizing epitope at the same amino acid positions compared to the currently available killed vaccine strain (Tn73). Tn88128 strain isolated in 1999 showed the maximum variability of 12 amino acids, 5 amino acid in the neutralization epitope and 7 apart from, respectively. Combinations of both Tn88128 (1999) and commercially available vaccine strain (Tn73) were developed and its safety was evaluated in mice, guinea pigs, calves, and pregnant cows. None of the animals showed any adverse effect or clinical signs. Calves were immunized with commercial vaccine (Tn73) and, combined vaccine (Tn73 and Tn88128), respectively, with adjuvants such as Al-gel and water-in-oil-in-water (w/o/ w) oil and PBS alone and challenged with Tn88128 strains. Except PBS administered animals, all the vaccinated animals showed protective immune response. However, animals immunized with combined vaccine plus w/o/w adjuvant elicited stronger neutralization antibodies and long lasting immunity compared to other vaccines. KEY WORDS: bovine ephemeral fever virus, genotyping, vaccine.

Expression of the G1 epitope of bovine ephemeral fever virus G glycoprotein in eukaryotic cells

“…It has been confirmed that the G1 protein is specific to BEFV and only reacts with the anti-BEFV neutralising antibodies (Yin & Liu, 1997;Hsieh et al, 2006). The expressed G1 protein in a prokaryotic system, E. coli, had appropriate reaction activity and specificity with an anti-BEFV serum in immunoblot analysis (Zheng et al, 2007a;Beygi Nassiri et al, 2016).…”

Bovine ephemeral fever epidemics in Kingdom Saudi Arabia: clinical, epidemiological and molecular investigation

“…Our RT-PCR results support others [28] in the belief that RT-PCR is a superior test for the provision of rapid and specific data for BEFV detection. The conventional RT-PCR is sensitive, specific and rapid test for detection of BEFV in clinical samples [29], moreover we found the RT-PCR assay to be useful for testing RNA samples extracted from peripheral blood mononuclear cells and so it could be an important tool for the screening of BEF infection [30].…”

Global health

“…The Bovine Ephemeral Fever (BEF; also referred to as "Three-day sickness", "Bovine enzootic fever", "Dengue fever of cattle", "Lazy man's disease" or "Stiffsiekte") is caused by the Bovine Ephemeral Fever Virus (BEFV) of the genus Ephemerovirus of the family Rhabdoviridae (Della-Porta and Brown, 1979;Hsieh et al, 2005;St. George, 1990;Walker et al, 1991;Hamblin, 2008).…”

“…Virus particles are bullet shaped, enveloped with a length of on average 145 nm and a diameter of 70 nm with not completely parallel sides as well as an inner capsid (Holmes and Doherty, 1970). Five structural proteins are encoded by the negative-sense single stranded RNA (-ssRNA) including a surface protein G (Hsieh et al, 2005) and a non-structural protein (NS) (Hamblin, 2008). Walker et al (1991) found another protein with an unsolved function, which was detected in infected cells but not in virions.…”

“…The virus is sensitive to degreasing solvents and can be inactivated at pH-values of <5 or >10 (St. George, 1990). Phylogenetic investigations showed low substitution rates indicating a slow development of the virus (Hsieh et al, 2005). BEF was first described in South Africa in 1906, even though it is known that it had appeared earlier.…”