Bacterial viruses enable their host to recruit antibiotic resistance genes from competitors

Prophages are quiescent viruses that reside in the chromosomes of bacteria. In the human21 pathogen, Staphylococcus aureus, prophages are omnipresent and believed to be22 responsible for the spread of antibiotic resistance genes. Here, we demonstrate that release23 of phages from a subpopulation of cells enables the intact, prophage-containing population24 to acquire beneficial genes from competing, phage-susceptible strains present in the same25 environment. By phage-infection, competitors are killed and bits of their DNA occasionally26 captured in transducing particles. Return of such particles to the prophage-containing27 population drives transfer of genes encoding useful traits such as antibiotic resistance into28 this population. The process which can be viewed as ‘auto-transduction’, allows S.29 aureus to efficiently acquire antibiotic resistance both in vitro and in in vivo and enables it30 to proliferate under strong antibiotic selection pressure. Our results may explain the rapid31 exchange of antibiotic resistance genes observed in S. aureus