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Conditional killing effect of staphylococcin 1580 and repair of sublethal injury in Staphylococcus aureus
Abstract:
Treatment of sensitive cells with staphylococcin 1580, a bacteriocin of Staphylococcus epidermidis, rapidly induced gross changes in the permeability of the membrane. However, only a small fraction of the cells was killed when treated cells were plated on media containing low amounts of salts. Killing was greatly enhanced by increasing the amounts of small cations incorporated in the plate medium and raising the alkalinity of the medium. The effect of cations correlated inversely with the ion radius. These conditions are shown to affect the repair mechanism of the sublethally injured cells rather than the interaction of staphylococcin 1580 with the cells. A model is proposed in which the killing effect of staphylococcin 1580 is a result of the inability of cells to maintain the protonmotive force at neutral or alkaline pH as a result of the permeation of cations. Recovery of sublethal damage appears to be a complex process requiring protein and probably also ribonucleic acid synthesis and the addition of a suitable energy source.
Insights
Staphylococcin 1580 damages bacterial cell membranes, but survival depends on environmental conditions. Optimal recovery requires specific ion concentrations and pH, highlighting cellular repair mechanisms.
Area of Science:
- Microbiology
- Cell Biology
- Biochemistry
Background:
- Staphylococcin 1580, a bacteriocin from Staphylococcus epidermidis, affects bacterial membrane permeability.
- Sublethal damage to bacterial cells can be influenced by environmental factors.
Purpose of the Study:
- To investigate the factors influencing the killing of bacteria treated with staphylococcin 1580.
- To elucidate the mechanism by which staphylococcin 1580 induces cell death and the conditions for bacterial recovery.
Main Methods:
- Treatment of sensitive bacterial cells with staphylococcin 1580.
- Plating treated cells on media with varying salt concentrations, cation composition, and pH.
- Analysis of bacterial survival and recovery processes.
Main Results:
- Staphylococcin 1580 treatment caused rapid membrane permeability changes.
- Bacterial killing was significantly enhanced by increased cation concentration (inversely related to ion radius) and alkaline pH.
- These conditions appear to affect cellular repair mechanisms rather than staphylococcin 1580 interaction.
Conclusions:
- Bacterial death induced by staphylococcin 1580 is linked to the inability to maintain protonmotive force at alkaline pH due to cation permeation.
- Cellular recovery from sublethal damage is a complex process involving protein and RNA synthesis, requiring an energy source.