Bovine viral diarrhea virus cytopathic and noncytopathic biotypes and type1 and 2 genotypes in diagnostic laboratory accessions: clinical and necropsy samples from cattle

One hundred three bovine samples submitted to the Oklahoma Animal Disease D iagnostic Laboratory (OADDL) that were positive for bovine viral diarrhea v irus (BVDV) were typed by a nested reverse transcription-polymerase chain r eaction for BVDV genotypes. These BVDV samples included supernatants from v irus isolation (79), serums (17), and buffy coats (7). The biotype, cytopat hic (CP) or noncytopathic (NCP), was determined by cell culture virus isola tion. Twenty-eight of 103 samples were submitted for herd screening for BVD V, 32 from OADDL necropsy cases, and 43 from live cattle with varied clinic al conditions. Two samples contained 2 bands indicating presence of both BV DV types 1 and 2. Of the 105 BVDV samples, 26 were type 1 CP strains (24.8% ), 38 were type 1 NCP strains (36.2%), 10 were type 2 CP strains (9.5%), an d 31 were type 2 NCP strains (29.5%). From the 105 BVDV isolates, NCP bioty pes were isolated more frequently (69, 65.7%) than CP biotypes (36, 34.3%), and type 1 genotypes were more frequently isolated (64, 61.00%) than type 2 genotypes (41, 39.0%). The NCP strains were more common than CP in herd s creening samples. Cattle with respiratory disease history at time of sampli ng had more NCP than CP biotypes and more type 1 than type 2 genotypes. Of the necropsy cases, more were type 1 than type 2 genotypes for the respirat ory cases with fibrinous pneumonia, more were type 1 than type 2 genotypes in cattle with enteritis/colitis without systemic lesions, and more were CP than NCP biotypes in cattle with enteritis/colitis with systemic lesions. No CP biotype was isolated from serum samples.