Global Veterinaria 3 (5): 383-389, 2009 ISSN 1992-6197 © IDOSI Publications, 2009 Corresponding Author: Yasser G.M. Abd El-Hafeiz, Virology Research Unit, Animal Reproduction Research Institute (ARRI), Giza, Egypt 383 Molecular Characterization of the Isolated Strains of Bovine Viral Diarrhea Virus Y.G.M. Abd El-Hafeiz, S.M. Abd El Hafez and H.M. Hassan 1 2 2 Virology Research Unit, Animal Reproduction Research Institute (ARRI), Giza, Egypt 1 Immunobiology and Immunopharmacology Unit, 2 Animal Reproduction Research Institute (ARRI), Giza, Egypt Abstract: Infection with bovine viral diarrhea virus (BVDV) occurs globally and is imposing large direct and indirect productivity losses on the beef and dairy industries. During 2005, bovine viral diarrhea (BVD) was added to the OIE list of the diseases and at that time, BVD was already notifiable in seven EU countries. The target of this study was to isolate a new virus from died calf in a private farm suffered from BVDV infection and compared its molecular characterization with the different Egyptian strains of BVDV. An international reference strain (NADL: National Animal Disease Laboratory; Ames Iowa, USA), the Egyptian strains (Iman and Kenna) as cp-BVDV-I that isolated at 1975 and 1982, respectively and Behera-CP 58/99 that isolated from the milk and identified as cp-BVDV-II were cultured, Concentrated and purified. A new isolate was isolated with antigenic and genetic identification. The soluble proteins of the five strains were analyzed using SDS-PAGE and revealed that many apparently homologous proteins migrate heterogeneously. These differences suggest genetic variability in the respective regions of their genomes coding for these polypeptides. Concerning to the dendrogram analysis, the relatedness percentage between the different Egyptian strains and NADL strain was 53.49% and this supports the hypothesis that large discrepancies present among the Egyptian strains as well as the international reference one. From the results, there are high antigenic and genetic variation among the local strains and the international one. These developments alter the pressure for control and will probably result in important changes relating to national BVD control. Vaccine prepared from the local strains that include both genotypes must be use. Key words: BVDV Egyptian strains Molecular characterization INTRODUCTION BVDVs are genetically variable, containing a Bovine viral diarrhea virus (BVDV) infection is 12.5 kilo base (kb) in length. The viral genome imposing large direct and indirect productivity losses contains a single large open reading frame (ORF) on the beef and dairy industries. Severe financial losses flanked by 5’ and 3' untranslated regions (UTR) [8, 9]. incurred as reduced rates of ovulation, fertilization, The ORF encodes a proximately 3988 amino acids and embryonic survival, fetal survival, perinatal survival, milk ultimately yields 11 to 12 final cleavage polyprotein production, respiratory disorders, abortion, congenital products (NH2---N -C-E -E1-E2-p7-NS2-NS3-NS4A- defects and growth retardation [1, 2]. NS4B-NS5A-NS5B---COOH) through co- and post- Two distinct genotypes were existing, BVDV-I and translational processing by cellular and viral proteases BVDV-II, together with border disease virus (BDV), [10 - 12]. classical swine fever virus (CSFV) and Giraffe, constitute There are two forms of infection associated with the genus Pestivirus of the family Flaviviridae [3]. BVDV: acute or transient infection and persistent BVDV-II was detected initially in cattle of North America infection (PI). Acute infection is post-natal infection in [4, 5] and later sporadically in several other countries [6]. an immunocompetent host. In contrast, PI only However, according to cell culture behavior, BVDV occur in utero infection of the developing fetus with occurs in two biotypes, non-cytopathic (ncp) and ncp-BVDV prior to the development of cytopathic (cp) [7]. immunocompetence [13]. single positive-stranded RNA of approximately pro rns