Il rischio nascosto: trasmissione di microrganismi patogeni mediante Embryo Transfer bovino.

Abstract

The embryo transfer is a worldwide and growing technique employee in cattle husbandry. Over the years, more e more new technologies have been applied in the field and along with them the need to evaluate methods and materials which can be crucial in order to enhance the system’s efficiency and the risky for the transmission of pathogens. The emergence of new microorganisms and the introduction in free areas of viral strains by means of animal products, increased over the last few decades the watchfulness and awareness regarding the shipment of hazard materials. Moving embryos appears to be the safer (from a sanitary stand point) and cheaper way to transport genetic material around the world than shipping live animals. Recently, the world trade market of embryos has raised tremendously, the increasing demand led to an accurate evaluation of all those pathogens which may be transmitted by E.T. Has a result, standard protocols for the in-vivo technique has been drawn up, conversely, for the in-vitro technique there are no guidelines yet, indeed, the evaluation of risk transmission has been trivially overlooked, overlapping the results ad methods from in-vivo technique to IVP. Studies demonstrated that in-vitro produced embryos slightly differ from embryos obtained with in-vivo technique. The dimensions of pores in the ZP of IVP embryos are greater compared with the ones present in-vivo derived embryo’s surface, moreover with IVP the ZP pores do not obliterate after fertilization leading to a possible penetration and transmission of some pathogen. In addition, microorganisms like: Bovine Viral Diarrhea Virus (BVDV), Bovine Herpesvirus-1(BoHV-1), Bovine Herpesvirus-4 (BoHV-4), Blue tongue virus (BTV), Chlamydophila spp., Coxilella burnetii, Histophilus somnus, Leptospira spp., Mycobacterium avium sub.Paratuberculosis (MAP), Mycoplasma spp. and Tritichomonas foetus have the tendency to adhere strongly to the surface of embryos obtained by IVP, and washing procedure with Dulbecco’s phosphate buffered saline (dPBS) and trypsin suggested by International Embryo Transfer Society (IETS). fails to remove them. A topic which is not much considered is the influence of the recipients to obtain a good E.T outcome. In order to achieve high results, the selection have to account for both donor and recipient. Nutrition, cow condition, uterine health, as well as a good management around calving, heavily impact the future fertility and the likelihood that the embryo’s implantation will successfully happen. The goal of this work is to provide a wide overview on the embryo’s production, by:-describing and comparing different techniques,-discussing donors, recipients and bulls issues, -and indeed a deep analysis about the transmission of pathogens in IVP. In the second part of the text, the all discussion has been adapted to each microorganism took into account.