Electron microscopy, immune electron microscopy, enzyme immunoassay and immunofluorescent evaluation of rotaviruses isolated from individual calves and piglets.

Rotaviruses were isolated in primary bovine foetal kidney cells from 3 of 13 (23.1%) tested suckling calves and from 3 of 14 (21.4%) suckling piglets both suffering of acute diarrhoea, as confirmed by serological tests. The presence of rotaviral antigen in culture supernatant was revealed by double sandwich enzyme immunoassay (EIA) and direct immunofluorescence (IF). Transmission electron microscopy (TEM) and immune electron microscopy (IEM) showed particles with an average diameter of 70 nm. The strains adapted to continuous pig kidney cells PK-15 have lost their reactivity in EIA, although TEM revealed the presence of rotavirions.