Identification ofTheileriainfections in living salivary glands of ticks

SUMMARYIt was found that interference contrast microscopy gave good morphological differentiation of the living and intact salivary glands from adult ixodid ticks,Rhipicephalus appendiculatusandAmblyomrna variegatum, removed by dissection. In many cases the individual cell types of the acini could be recognized. When the salivary glands of infected adult ticks were examinedTheileriaparasites were detected.Theileria parva, T. taurotragiandT. mutanscould be detected in the salivary glands after they reached the mature secondary sporoblast stage achieved even in unfed ticks. Parasites were detected only in type III acini. The morphology of tertiary sporoblasts and sporozoites of theseTheileriaspp. was clearly recognized in feeding ticks. Sporozoites ofT. parvaproved to be infective to cattle and to peripheral blood leucocytes of cattlein vitroafter interference contrast examination. Interference contrast examination of living salivary glands was used for selection of salivary glands with high infections ofT. parvasporozoites and the sporozoites could be separated in large numbers from these salivary glands. Using this technique it appeared possible to cloneTheileriaparasites from salivary glands with 1 infected acinus.