Antibacterial agents and release of periplasmic pertussis toxin from Bordetella pertussis

Pertussis toxin accumulates in the periplasm of Bordetella pertussis prior to secretion, and we examined its fate following treatment with antimicrobi al agents. Both antibiotics that inhibit protein synthesis (erythromycin an d chloramphenicol), transcription (rifampin), or cell wall biosynthesis (ce foperazone and piperacillin) and magnesium sulfate (which inhibits transcri ption of pertussis toxin, but not bacterial growth) did not prevent release of preformed toxin, In contrast, agents that affect bacterial membranes, s uch as polymyxin B, lidocaine, procaine, and ethanol, inhibited release of preformed pertussis toxin. These results suggest new protein synthesis is n ot required for pertussis toxin secretion, but a functional membrane comple x is required.