Antibiotic inhibition of protease production by Pseudomonas aeruginosa

Abstract
The effects of tetracycline, chloramphenicol and polymyxin B on growth and protease production by P. aeruginosa were studied. Tetracycline inhibited protease production at concentrations much lower than those required to cause growth inhibition; the effect was not due to inhibition of protease activity by the antibiotic. Chloramphenicol and polymyxin B inhibited protease production in direct proportion to the inhibition of growth. Lysozyme-release experiments with washed tetracycline-treated cells indicated that the protease did not accumulate intracellularly. The protease-inhibiting effect of tetracycline might have therapeutic significance if it occurs in vivo.