Fig. 1

Methicillin resistance and phylogenetic relationships of S. aureus isolates. a Yearly sampling of methicillin resistance based on either cefoxitin or oxacillin phenotypic screenings. b Yearly distribution of sequence types (ST) throughout the study period. Gray bars indicate STs either previously unknown or rare (< 3 individuals). c Midpoint-rooted maximum likelihood tree showing phylogenetic structure of 323 S. aureus isolates. Clade colors on the branches represent sequence clusters (SC) defined by the BAPS program. Inner ring shows the phenotypic results of methicillin resistance screening as described above. Outer ring shows the distribution of different STs