Absence of a chloramphenicol-insensitive phase of streptomycin action.

Plotz, Paul H. (Harvard Medical School, Boston, Mass.) and Bernard D. Davis. Absence of a chloramphenicol-insensitive phase of streptomycin action. J. Bacteriol. 83:802-805. 1962.-Previous findings have suggested the possibility that the damaging effect of streptomycin on the bacterial cell membrane is only preliminary to an intracellular lethal action. Since the membrane effect requires protein synthesis, a two-stage action might be recognized if the second stage did not require protein synthesis. Indeed, it has been reported that Escherichia coli cells, pretreated with streptomycin, are not protected by chloramphenicol from subsequent killing by streptomycin in a nitrogen-free medium. However, we were unable to confirm this report or to observe any chloramphenicol-insensitive phase of streptomycin action in a growth medium. It is, therefore, not yet possible to decide whether the lethal event occurs at the membrane or within the cell.