The inhibition of bacteriophage multiplication by proflavine and its reversal by certain polyamines

Abstract

Phage 3 contains the polyamines putrescine and spermidine. The multiplication of the phage is inhibited by proflavine and this inhibition is reversed by putrescine, spermidine and agmatine. Spermidine in high concentration inhibits phage multiplication. Spermine is highly inhibitory to phage multiplication but agmatine is inactive and putrescine shows only a slight activity in the highest concentration tested. Proflavine does not damage mature particles but blocks some stage in the intracellular development of the phage. Delayed treatment with putrescine indicates that the block is in the latter half of the latent period, the maturation stage. The proflavine block is thought to be due to interference in the incorporation of the polyamines into the newly synthesized phage deoxyribonucleic acid, which then cannot be oreintated to form the core of the phage head.