Molecular and antigenic characterization of bovine herpesvirus type 1 (BoHV-1) strains from cattle with diverse clinical cases in Turkey

The present study reports the molecular and antigenic characterization of 13 bovine herpesvirus type 1 (BoHV-1) field viruses obtained from cattle with different clinical cases in Turkey between 1992 and 2017. We selected glycoprotein C (gC) of BoHV-1 as a target to detect and/or verify presence of the virus in suspect materials followed by virus isolation (VI) in MDBK cells. In seven out of 13 BoHV-1 positive samples, cytophatic effects (CPEs) were observed in MDBK cell cultures, although only four virus samples reached a sufficient titer to use in phylogenetic assay, restriction endonuclease analysis (REA), and virus neutralization test (VNT). According to the results of sequence analysis of the 13 BoHV-1 positive samples, nine BoHV-1 field viruses were determined as BoHV-1.1 and four as BoHV-1.2. Using REA, we demonstrated that two of our isolated viruses could be categorized as BoHV-1.1 while the other two isolates were BoHV-1.2 subtypes. Differences between the BoHV-1.1 and BoHV-1.2 isolates were also detected in the VNT results by assaying 125 suspected serum samples after testing with isolated (KY748023, KY748022, KY748020, and KY748021) and reference viruses (BoHV-1 Cooper and BoHV-5 Texas 89). These results are indicating the need to correctly identify BoHV-1 field isolates to better understand the epidemiology and pathogenesis of infection. In addition, it would be useful to identify the subtypes circulating in the specific geographical area while determining vaccination preferences.