|Vilcek, Stephan - SLOVAK REPUBLIC|
|Bolin, Steven - MICHIGAN STATE UNIVERSITY|
|Carman, S - UNIVERSITY OF GUELPH|
Submitted to: American Society for Virology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: July 20, 2001
Publication Date: N/A
Technical Abstract: Bovine viral diarrhea viruses (BVDV) from the type 2 genotype may be virulent or avirulent based on their ability to cause clinically severe disease as the result of acute infection. Previously it was shown that cytopathology in tissue culture correlated with genomic insertions at the junction of NS2 and the NS3 coding sequences. Genomic insertions were found in cytopathic but not noncytopathic BVDV. However, no correlation was found between cytopathology in tissue culture and acute clinical disease in vivo. Recently, highly virulent strains of BVDV from the type 2 genotype (BVDV2) have been identified. These strains were all classified as noncytopathic viruses based on activity in tissue culture and processing of the NS2/3 viral polypeptide. Comparison of complete sequences for four virulent and two avirulent noncytopathic BVDV2 revealed three of the virulent viruses had mutations in either the 5' or 3' regions flanking the NS2 coding sequence. Subsequent surveys of noncytopathic BVDV2 associated with clinically severe or clinically mild symptoms in disease outbreaks identified two additional virulent BVDV2 with mutations in the NS2 flanking regions. Mutations could be characterized as insertions, deletions and/or multiple amino acid substitutions. No such mutations were found in avirulent BVDV2.