Helper phage mobilization of Staphylococcus aureus pathogenicity islands

Recent studies in the laboratory of Richard Novick have shown that infection by several helper phages causes the excision and replication of two superantigen-encoding pathogenicity islands (SaPI) in Staphylococcus aureus. These pathogenicity islands are then packaged into phage-like infectious particles that allow their horizontal transmission. We have initated studies into the basic phage biology underlying this process, by characterization of the virions of the helper phage and the SaPI particles and by comparative genomic studies of the helper phages and closely related staphylococcal phages that do not mobilize these genetic elements.