Kinetic studies on the interaction of bacteriophage type 71 staphylococcal bacteriocin with susceptible bacteria

Kinetic studies on the interaction of the bacteriocin produced by phage type 71 Staphylococcus aureus with susceptible bacterial cells were undertaken. Survivors among susceptible bacteria to which the bacteriocin has been added can be rescued after trypsin treatment. The bacteriocin adsorbs very rapidly to susceptible streptococcal cells at a time when killing of the cells is only minimal. Heat-killed or mechanically disrupted cells are also effective in adsorbing the bacteriocin. Adsorption is comparable at 37 C and 25 C, but is less pronounced at 4 C. Elution of adsorbed bacteriocin could not be achieved by heating, by varying pH, or by using different concentrations of sodium chloride solutions. Surface M protein of streptococcal cells plays no role in the adsorptive process. Adsorption is specific in that only susceptible bacteria, but not resistant ones, are capable of adsorbing the bacteriocin.