Protection of staphylococci ingested by macrophages from the bactericidal action of rifampin

The ability of rifampin to kill Staphylococcus aureus which have been ingested by normal mouse peritoreal macrophages in vitro has been investigated. In contrast to data which have been reported from experiments with other cell types, in this system rifampin was no more active than was penicillin against the two strains tested.