Detection of non-spermatozoal cells of Neospora caninum in fresh semen of naturally infected bulls / Detection of non-spermatozoal cells of Neospora caninum in fresh semen of naturally infected bulls

ABSTRACT

Background: Neospora caninum (N. caninum) is a cyst-forming coccidian parasite closely related to Toxoplasma gondii which has emerged as an important cause of reproductive failure in cattle worldwide. Routes of Neospora transmission include transplacental infection through tachyzoites, ingestion of tissues harbouring cysts and oral uptake of sporozoitecontaining oocysts. Transplacental transmission seems to be very efficient for N. caninum in naturally infected cattle and plays a major role in the maintenance and spread of the disease. Other sources of vertical transmission, such as cow to calf transmission via pooled colostrum or milk could also be possible but until now this has not been proven in naturally infected cattle. The possibility of N. caninum transmission via semen requires profound repercussions on the trade of cattles semen. In the present study, fresh non-extended semen of bulls was evaluated with naturally-acquired neosporosis for the presence of N. caninum by means of PCR.Materials, Methods & Results: Serum samples were analyzed for antibody activity to N. caninum by using the commercially available ELISA kit. Sera samples were obtained before the first semen sampling and after the last one (days 0 and 60). Thirteen seropositive and five seronegative bulls were selected for the next steps of the study. Genomic DNA was extracted from non-spermatozoal cells

RESUMO

Background: Neospora caninum (N. caninum) is a cyst-forming coccidian parasite closely related to Toxoplasma gondii which has emerged as an important cause of reproductive failure in cattle worldwide. Routes of Neospora transmission include transplacental infection through tachyzoites, ingestion of tissues harbouring cysts and oral uptake of sporozoitecontaining oocysts. Transplacental transmission seems to be very efficient for N. caninum in naturally infected cattle and plays a major role in the maintenance and spread of the disease. Other sources of vertical transmission, such as cow to calf transmission via pooled colostrum or milk could also be possible but until now this has not been proven in naturally infected cattle. The possibility of N. caninum transmission via semen requires profound repercussions on the trade of cattles semen. In the present study, fresh non-extended semen of bulls was evaluated with naturally-acquired neosporosis for the presence of N. caninum by means of PCR.Materials, Methods & Results: Serum samples were analyzed for antibody activity to N. caninum by using the commercially available ELISA kit. Sera samples were obtained before the first semen sampling and after the last one (days 0 and 60). Thirteen seropositive and five seronegative bulls were selected for the next steps of the study. Genomic DNA was extracted from non-spermatozoal cells