Detection of Theileria sergenti schizonts in bovine lymph node.

The growth of Theileria sergenti schizonts in bovine lymph nodes was examined by experimental infection. Six naive Holstein calves were inoculated with a sporozoite stabilate into the superficial cervical and subiliac lymph nodes. Biopsy samples from the inoculated calves were collected every 24 h for 10 days. Histological examination demonstrated the schizont of T. sergenti on day 4 post-inoculation. The growth of schizonts in the lymph node was observed on days 4-8 post-inoculation. Electron microscopic observation disclosed that the core of the schizont has a high density central core surrounded by numerous electron-dense spherules.