Pathogenicity Islands and Their Role in Staphylococcal Biology

ABSTRACT Pathogenicity islands are members of a vast collection of genomic islands that encode important virulence, antibiotic resistance and other accessory functions and have a critical role in bacterial gene transfer.Staphylococcus aureusis host to a large family of such islands, known as SaPIs, which encode super antigen and other virulence determinants, are mobilized by helper phages and transferred at extremely high frequencies. They benefit their host cells by interfering with phage predation and enhancing horizontal gene transfer. This chapter describes their life cycle, the bases of their phage interference mechanisms, their transfer system and their conversion to antibacterial agents for treatment ofstaphylococcal infections.