Rifampin inhibition of the occluded virus form of a nuclear polyhedrosis virus.

Rifampin at concentrations toxic to noninfected cells but not to infected cells is a selective inhibitor of occluded virus of the group A Baculoviridae (nuclear polyhedrosis virus). However, the titer of nonoccluded virus is not affected. Rifampin blocks occlusion until late in the replication cycle (14 to 16 h), and its effects are reversible. Modes of action of polyhedral inclusion body production are unknown.