Interactions between the ciliated protozoan Tetrahymena pyriformis and the simian rotavirus SA11

To study ciliate-virus interactions, Tetrahymena pyriformis and the simian rotavirus SA11 were placed in contact in PPYS, the standard ciliate culture medium. By electron microscopy, some phagocytized viral particles were observed in the digestive vacuoles of the ciliate. The assay of SA11 in the supernatants by immunofluorescence after the ciliate-virus contact showed an instantaneous disappearance of a proportion of infectious particles followed by a rate reappearance, A similar result was obtained when viral antigen was detected by the ELISA test. In that case the contact medium was EMEM. According to these results, SA11 did not replicate in Tetrahymena. In the presence of this ciliate, an early and reversible adsorption of SA11 onto the ciliate might occur. This would not necessarily lead to viral penetration.