Molecular Characterization of Recent Isolates of Bef Virus in Egypt
A.M.Albehwar1, W.M.Ismaeil2, H.M. Fakhry1 and H.S.El-Emam1""
Abstract
The present work was conducted to identify and characterize recent isolate of bovine ephemeral fever virus (BEFV) in Egypt. 103 serum samples were obtained from 1600 vaccinated animals in El-Salhia dairy farm during the period of July to August 2015. The 103 animals were found to have non-protective low titers of BEF antibodies (≤2-8) as tested by serum neutralization test (SNT), showing BEF signs (fever; harried respiration; lameness and recumbency). Three buffy coat and five blood plasma samples from the 103 suspected infected dairy cattle were collected. Trials of virus isolation in baby mice brain and BHK21 cell culture revealed that three samples of buffy coat and five blood plasma samples were suspected to contain BEFV. Virus identification using virus neutralization tests (VNT) and direct fluorescent antibody technique (FAT) confirmed the presence of BEFV. In addition, PCR, sequencing analysis and phylogenetic tree showed that the obtained isolate is closely related to Egypt-2005 strain. These findings indicated that the locally produced vaccine is highly immunogenic inducing a protection rate of 93.6%. Appearance of disease signs in cattle with low immune levels could be due to parturition and high lactation stress factors in addition to suspected other infection leading to poor immune response (immune suppression) to the vaccine.
Key words
Bovine ephemeral fever (BEFV) , Isolation, Identification, PCR , FAT.
Key words
Bovine ephemeral fever (BEFV) , Isolation, Identification, PCR , FAT.