Extra-chromosomal prophages of Staphylococcus aureus

Staphylococcus aureus is a human pathogen with well-characterized bacteriophage contributions to its virulence potential. In a previous report (PLoS ONE 9(6): e100502), plasmidial and episomal prophages were discovered in clinical S. aureus strains using an extra-chromosomal DNA isolation and sequencing approach, and were found to encode important virulence determinants. This study aimed to uncover additional extra-chromosomal prophages in S. aureus and assess their prevalence, selecting 15 diverse clinical isolates with known chromosomal sequences for extra-chromosomal DNA isolation and next-generation sequencing. Discovery of extra-chromosomal prophages by this focused sequencing approach may offer more complete genomic pictures and insights into the virulence potentials of S. aureus strains, as well as allow increased discovery of virulence and other important factors likely missed with chromosome or whole-genome DNA focused approaches.