Detection of Neospora caninum in dog organs using real time PCR systems.

Neospora caninum is a parasite responsible for paresis in dogs. The dog can harbour enkysted parasites in several organs. The
detection of N. caninum was performed using 3 different real time PCR systems all amplifying the NC5 DNA region. One system
was based on Sybr1green, one on PlexorTM technology and the last on Taqman1 probe. Comparison of the three methods indicated
that the detection limit was 1 equivalent genome on pure DNA but that this detection limit increased in the presence of foreign DNA
using the Sybrgreen and Plexor systems. Therefore, the Taqman system was chosen to detect N. caninum in liver and spleen of
naturally infected dogs. The overall prevalence was 32.2%. Comparison between PCR results and serological results using IFAT
showed that among the 28 PCR positive dogs only 9 were seropositive and that 8 seropositive dogs were PCR negative. Therefore
serology can underestimate the real carriage in dogs. However, PCR methods must be improved in terms of sensitivity and inhibition
problems.