Inactivation of bovine herpesvirus-1 and bovine viral diarrhea virus in association with preimplantation bovine embryos using photosensitive agents.

Hematoporphyrin (HP), hematoporphyrin derivative (HPD), and thiopyronine (TP) are photosensitive agents (PSA) that have a germicidal effect when they are activated by light: helium neon laser (He/Ne) light (HP, HPD), white light (HP, HPD), and yellow-green light (TP). Experiments were conducted with appropriate controls to determine the effect of photosensitive agents a) for inactivating bovine herpesvirus-1 (BHV-1; titre 10(6) TCID50/ml) and bovine viral diarrhea virus (BVDV; titre 10(6) TCID50/ml); b) for disinfecting Day-7, zona pellucida-intact (ZP-I) bovine embryos that had been exposed to BHV-1 (titre 10(6) TCID50/ml) or BVDV (titre 10(6) TCID50/ml); and c) on the in vitro development of embryos. Exposure to HP, HPD and TP followed by light irradiation inactivated BHV-1 and BVDV. Embryos exposed to BHV-I were disinfected by HP or HPD (5 microg/ml) in combination with He Ne light, or by HP or HPD (10 microg/ml) in combination with white light. Embryos exposed to BVDV were disinfected by HPD (5 and 10 microg/ml) followed by He Ne or white light irradiation. Exposure of embryos to light alone or to light and HP or HPD had no detrimental effect on their in vitro development; however, exposure of embryos to TP (5 microg/ml) followed by irradiation caused embryonic degeneration. Exposure of embryos to 5 microg of HPD followed by He Ne light, or 10 microg/ml of HP or HPD, followed by white light, is simple methods of disinfecting them of BHV-I and BVDV.