Efficient plasmid transduction to Staphylococcus aureus strains insensitive to the lytic action of transducing phage

摘要

The transduction mediated by bacteriophages is considered to be one of the primary driving forces in horizontal gene transfer in staphylococci, which is crucial to their adaptation and successful evolution. For a transduction to be effective, it is generally accepted that the recipient strain should be susceptible to the transducing phage. In this study, we demonstrate that the plasmid DNAs are effectively transduced into the recipient Staphylococcus aureus strains in spite of their insensitivity to the lytic action of the transducing phage, provided that these phages adsorb effectively to the bacterial cells. The tetracycline and penicillinase plasmids were transduced to insensitive laboratory and clinical strains by bacteriophages phi 29, phi 52A and phi 80 alpha as well as by prophage phi 53 and naturally occurring prophages induced from donor lysogenic strains. Comparable frequencies of transduction were achieved in both phage-sensitive and phage-insensitive recipient strains. We have demonstrated that such mechanisms as the restriction of DNA and lysogenic immunity which are responsible for insensitivity of cells to phages may not be a barrier to the transfer, maintenance and effective spread of plasmids to a wider range of potential recipients in the staphylococcal population.