Veterinary Research Forum

Abstract Bovine viral diarrhea virus is a pestivirus of the Flaviviridae family including two biotypes, cytopathic (CP) and non-CP (NCP). This study aimed to evaluate DNA damage and apoptosis in Madin-Darby bovine kidney cells following infection with both biotypes. The MDBK monolayers were inoculated with a final dose of virus (1.00 × 10³ Tissue Culture Infectious Dose 50% mL-1) and incubated for 24 hr. DNA strand integrity was assessed using alkaline single-cell gel electrophoresis, and DNA damage was quantified through tail moment and olive tail moment indices (n = 3). Apoptosis was evaluated using annexin V–fluorescein isothiocyanate/propidium iodide flow cytometry to determine early and late apoptotic cell populations. Both biotypes significantly increased DNA fragmentation compared to the control group. The tail moment values were 15.89 ± 2.13 (control), 57.63 ± 16.20 (NCP), and 68.15 ± 9.93 (CP); while, olive tail moment values were 8.71 ± 1.01 (control), 29.35 ± 9.18 (NCP), and 35.14 ± 6.90 (CP). Apoptosis analysis showed a higher percentage of apoptotic cells in infected groups, with CP biotype of bovine viral diarrhea virus inducing the greatest early and late apoptotic responses, being consistent with its CP nature. Overall, both biotypes caused notable genomic injury and apoptosis in Madin-Darby bovine kidney cells, with CP producing the highest level of damage, confirming single-cell gel electrophoresis combined with apoptosis assays as sensitive tools for detecting virus-mediated genomic instability and supporting their potential application in breeding programs aimed at enhancing resistance to infectious diseases.

Abstract This study aimed to investigate the potential presence of bovine herpes virus type 1 (BHV-1) and bovine viral diarrhea virus (BVDV) in cattle uteri that did not display any clinical and macroscopic signs of infection. Virus detection involved polymerase chain reaction (PCR) test, double immunohistochemistry (IHC), and double immunofluorescence (IF). One hundred cornu uterus samples were collected from cattle aged 1 year and older. The BVDV was detected by PCR or by double IHC/IF in the collected samples from slaughterhouses in Kayseri city (Central Anatolia, Türkiye) from 2021 - 2022. By contrast, BHV-1 was detected by PCR and double IHC/IF at a rate of 16.00% and 21.00%, respectively. In the IHC and IF detection, BHV-1 was detected in endometrial epithelial cells and in some mononuclear cells in the lamina propria, periglandular areas and myometrium. Although no macroscopic lesion was found in the BHV-1-positive samples (n = 21), histopathological detection showed that two had acute endometritis, eight had subacute endometritis, eight had chronic endometritis and the three others showed no signs of endometritis. This prevalence study demonstrated for the first time that even while BVDV could not be detected in the samples, BHV-1 posed a critical potential reproductive risk in pregnant animals, as it can specifically cause abortions when it resides in cattle uteri that do not show clinical or macroscopic and even microscopic signs of infection. Additionally, this study was the first to combine PCR and double IHC/IF for BHV-1 and BVDV detection in cattle uteri.

Abstract Bovine viral diarrhea virus (BVDV) is an important viral agent causing reproductive failure in cattle. The objectives of the current study were to investigate the interaction between two BVDV biotypes, cytopathic (CP) and Non-cytopathic (NCP) and bovine gametes during in vitro fertilization (IVF) processing, the existence of the virus within embryonic cells and early embryonic development rates. Sperm and ova were exposed separately to CP and NCP BVDV at two concentrations of 10^4.5 and 10^5.5 tissue culture infectious dose 50.00% (TCID₅₀) mL^-1 prior to IVF, respectively. After five days post-IVF, early embryonic development rates of infected groups were assessed. Several embryos of each group, normal and degenerated, were selected for a viral assay using reverse transcription polymerase chain reaction technique. The result showed that the early embryonic development rates were decreased in treatment groups. The rates in the CP groups were lower than the NCP groups. In the CP groups, the proportions were, respectively, 10.00, 6.00 and 11.00, and 6.00% in the infected sperm and oocyte groups (10^4.5 and 10^5.5 TCID₅₀ mL^-1) that were higher than 50.00% in the control group. In NCP groups, the rates were, respectively, 25.00, 18.00 and 24.00, and 21.00% in the infected groups compared to 48.00% in the control group. In the CP groups, no BVDV was detected in normal embryos, whereas, all degenerated embryos were completely virus-positive. In the NCP groups, the virus was detected in both normal and degenerated embryos. In conclusion, this study supported detrimental impacts of CP and NCP BVDV on early embryonic development and the role of sperm and the zona pellucida layer as carriers of the virus.