Photosensitive chemical and laser light treatments decrease epizootic hemorrhagic disease virus associated with in...

Area of Science:

• Veterinary Virology
• Reproductive Biology
• Photodynamic Therapy

Background:

• Bovine embryos produced in vitro are susceptible to viral infections like EHDV-2.
• Existing methods for viral elimination may impact embryo viability.
• Photoinactivation offers a potential non-invasive approach for pathogen removal.

Purpose of the Study:

• To evaluate the efficacy of photoinactivation using hematoporphyrin or hypericin combined with laser light for eliminating EHDV-2 from bovine zygotes.
• To assess the impact of these treatments on zygote developmental potential and blastocyst cell numbers.

Main Methods:

• Bovine zygotes were exposed to EHDV-2 and subsequently treated with photosensitive chemicals (hematoporphyrin, hypericin) and/or helium-neon laser light.
• Embryo development and blastocyst cell counts were assessed post-treatment.
• Viral inactivation was quantified by assessing contamination levels in zygote pools.

Main Results:

• Laser light or photosensitive chemicals alone did not affect zygote development.
• Combinations of hypericin (10 microM) with 5 min laser or hematoporphyrin (15 microM) with 2 min laser compromised developmental potential.
• Hematoporphyrin with 3 min laser light significantly reduced EHDV-2 contamination (16.7%) compared to untreated controls (88.9%).
• Hypericin with 3 min laser light showed an intermediate reduction in EHDV-2 contamination (55.6%).

Conclusions:

• Photoinactivation using hematoporphyrin and laser light is a promising strategy for reducing EHDV-2 contamination in bovine zygotes.
• Optimized treatment parameters are crucial to balance viral inactivation and embryo developmental potential.
• This technique could enhance the safety of in vitro produced bovine embryos.