Detection ofNeospora caninumin aborted bovine fetuses and dam blood samples by nested PCR and ELISA and seroprevalence in Beijing and Tianjin, China

Abstract

Neospora caninum infection is a significant cause of abortion in cattle. We investigated the tissue distribution of N. caninum in aborted bovine fetuses and dam blood samples by a nested PCR assay, and compared the nested PCR with ELISA in the diagnosis of N. caninum infection. In total, 26 aborted fetuses and 813 blood samples were collected from 8 dairy herds in Beijing (n=212) and Tianjin (n=601), China. Fifteen fetuses (57.7%) were tested N. caninum-positive by the nested PCR. N. caninum DNA was detected from the brain of 52%, kidneys of 22%, skeletal muscle of 18%, and heart of 4% of the aborted fetuses. The PCR-positive cases (55%, 11/20) were higher than seropositive cows (40%, 8/20) in a subset of 20 fetuses, but the PCR results of blood samples of the 20 cows were all negative. The seroprevalence of the 813 samples was 15.5% (43.4% of samples from Beijing, 5.7% of samples from Tianjin), compared to the PCR-positive blood samples of 0.9%. Our study showed that the nested PCR is a valuable diagnostic tool for the primary diagnosis of N. caninum in aborted fetuses, while ELISA is the preferred assay for testing blood samples collected from cows. The two assays are complementary in determining whether abortions are associated with N. caninum infection in cattle.

Occurrence of abortions induced by Neospora caninum in dairy cattle from Santa Catarina, southern Brazil

“…Nevertheless, these results confirm the (SERRANO-MARTINEZ et al, 2007), and the results from this study have demonstrated that 38.8% (14/36) of the aborted fetuses were positive. Similar findings were described by nested PCR where 80% and 57.7% (MEDINA et al, 2006;YAO et al, 2009) of aborted fetuses were positive for N. caninum, in Mexico and China, respectively. However, other studies (PEREIRA-BUENO et al, 2003;RAZMI et al, 2006RAZMI et al, , 2010SAGER et al, 2001) have described values that ranged from 11.9 to 33%.…”

Neospora caninum: evaluation of vertical transmission in slaughtered dairy cows (Bos taurus)

“…Fluctuations in the results similar to these have previously been described (McINNES et al, 2006;DIJKSTRA et al, 2008;MORÉ et al, 2009;YAO et al, 2009;MARQUES et al, 2011). McInnes et al (2006) reported that there was no correlation between the serological tests on dams and the PCR on their fetuses, and a high percentage of infected fetuses had serologically negative dams.…”

Neosporose em ruminantes

“…A neosporose é uma doença causada pelo N. caninum, parasito intracelular obrigatório formador de cistos, que pode infectar uma série de hospedeiros de interesse produtivo, como os ruminantes (YAO et al, 2009). …”