[The effect of valinomycin and nigericin on the efficacy of bacteriophage infection of staphylococcal cells].

The effect of ionophore antibiotics, valinomycin and nigericin, on the generation of the membrane potential, the pH gradient and the efficacy of phage infection in tetracycline-resistant staphylococci has been studied. Valinomycin at a concentration of 0.5 microM induces the dissipation of the membrane potential, and nigericin at a concentration of 12.0 microM decreases the value of the pH gradient on the membrane of staphylococci. The separate use of antibiotics has no essential influence on the efficacy of phage infection. The combined use of valinomycin and nigerimycin produces the maximum inhibition of phage infection (64.5%) at the stage of the introduction of DNA into the bacterial cell, which is indicative of a definite role played by the membrane potential and the pH gradient in the transport of phage DNA into staphylococcal cells.