Suspension culture of Neospora caninum by Theileria annulata-infected cell line.

There are some limiting aspects of scaling up the Neospora caninum tachyzoites in continuous cell lines, particularly as related to the absence of surface attachment. In this study, suspension cell culture of Theileria annulata-infected lymphoblastoid (TIL) was used as a host cell for the continous production of N. caninum tachyzoites. The numbers of free tachyzoites in the medium supernatant were showed regularly increased up to the day 6 post-cultivation. Transmission electron microscopy demonstrated that N. caninum tachyzoites invaded the TIL cells and multiplied intracellularly. This showed that the tachyzoites were successfully proliferated in TIL cells and were released in complete Dulbecco's modified Eagle's medium. This is a successful report of in vitro cultivation of N. caninum tachyzoites achieved by using suspension host cell culture.