Fig 1. Phylogenetic analysis of S. aureus strains.

Strains are identified by MicroSEQ ID_sequence type (ST). MRSA and PVL status along with selected clinical factors of interest are linked with strains. Legend: Strain/isolate numbers are listed as S###, followed by _ then sequence type (ST); PVL = Panton Valentine Leukocidin; IVDU = intravenous drug use; MRSA = methicillin resistant Staphylococcus aureus; CATH = presence of intravenous catheter; HEMO = on hemodialysis; Both PVL+ and PVL- strains included both methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) strains with the PVL+ isolates predominately MRSA. A high percentage of patients infected with strains from the larger PVL-positive cluster had a history of intravenous drug use (IVDU).