Preliminary characterization of an inhibitory activity of fetal bovine serum on the infectivity of rotavirus strain SA-11.

In the present work we studied non antibody inhibiting activity present in fetal bovine serum and active to Rotavirus infectivity and growth in cell cultures. This inhibitor was revealed by an in vitro neutralization test and characterized by gel filtration and chemical and enzymatic treatments. Furthermore, commercial preparations of bovine serum proteins were tested for inhibitory activity. Our results show that serum inhibition is partially resistant to trypsin and neuraminidase treatments but completely destroyed by KIO4. A similar activity was observed in a commercial serum bovine fraction containing predominantly alpha-globulins. These results seem to indicate that glycoproteins, and their glucidic components are the molecules predominantly involved in serum inhibition towards Rotavirus infectivity.