John Chen and Richard P. Novick: Phage-Mediated Intergeneric Transfer of Toxin Genes.
"Because bacteriophages generally parasitize only closely related bacteria,
it is assumed that phage-mediated genetic exchange occurs primarily within species.
Here we report that staphylococcal pathogenenicity islands, containing superantigen genes,
and other mobile elements transferred to Listeria monocytogenes at the
same high frequencies as they transfer within Staphylococcus aureus.
Several staphylococcal phages transduced L. monocytogenes but could not form plaques.
In an experiment modeling phage therapy for bovine mastitis, we observed
pathogenicity island transfer between S. aureus and L. monocytogenes in raw milk.
Thus, phages may participate in a far more expansive network of genetic information exchange
among bacteria of different species than originally thought, with important implications for
the evolution of human pathogens", Science 2 January 2009, DOI: 10.1126/science.1164783