Streptomycin as an Antiviral Agent: Mode of Action

In host bacteria resistant to the antibiotic, streptomycin inhibits phage replication by inhibiting the process of injection. This effect is competitively reversed by certain divalent cations, polyamines, and streptidine. It is proposed that streptomycin inhibits injection by attaching to the phage DNA while it is still folded within the phage head, and in this way it prevents the unfolding which is essential for the injection process. The reversal agents probably function by displacing the antibiotic from the phage, but they also promote injection themselves.