Detection of Toxoplasma gondii DNA in milk of dairy cows from southern Brazil.

Consumption of unpasteurized cow's milk may be a transmission route for some pathogenic microorganisms, but there is little information about the risk of Toxoplasma gondii infection. Blood and milk samples were collected in a paired and random fashion from 106 dairy cows and bulk-tank milk samples were also collected from each of the six farms, in southern Brazil. Serum anti-T.gondii antibodies (IgG) were detected by an indirect fluorescent antibody test (IFAT) with a cutoff point of 1:64. Nested PCR targeting the ITS1 was performed on milk samples to detect the Sarcocystidae family, confirmed to be T.gondii by Sanger sequencing. The occurrence of anti-T.gondii antibodies in the herds was 14.1%, (15/106) with seropositive cows in all herds. Antibody titers in positive samples ranged from 64 to 128. T.gondii DNA was detected in 2.8% (03/106) of the milk samples. The ITS1 sequences generated in this study were ON809793 - ON809794 and the sequencing revealed 98-100% identity with T. gondii DNA sequences deposited in GenBank. All cows PCR positive for T.gondii in milk were negative for IgG antibodies in serum, suggesting that naturally infected cows may shed T. gondii in milk in the acute phase of infection. The results of this study demonstrate that T. gondii DNA may be detected in raw cow's milk, so the potential risks of lactogenic infection should be considered. The presence of T. gondii DNA in milk does not confirm that the protozoa are viable and infective, and further investigations into the role of cow's milk in the epidemiology of toxoplasmosis are needed.

Transplacental transmission of Neospora caninum to lambs in successive pregnancies of naturally infected sheep in Southern Brazil.

This study aims to report the detection of N. caninum DNA in a newborn lamb (1) with neurological signs and congenital neosporosis and in a stillborn lamb (2), both born from the same ewe in a herd of Southern Brazil. The lambs were born during different pregnancies of a Suffolk ewe seropositive to N. caninum and seronegative to T. gondii. Histopathological lesions were observed only in the central nervous system of the lambs. The newborn lamb (1) showed mild and focal gliosis in the frontal lobe. In the hippocampal region of the stillborn lamb (2), lymphoplasmacytic perivascular cuffs and N. caninum cysts were observed in the cytoplasm of neurons and confirmed by IHC. PCR was performed using brain samples to detect the protozoa N. caninum and Toxoplasma gondii. The infection with N. caninum was confirmed in the newborn lamb (1) by PCR and in the stillborn lamb (2) by histopathology, immunohistochemistry, and PCR tests.