Fig. 1

K-mer based unrooted UPGMA tree of all 21 S. aureus isolates used in this study. The tree was generated using CLC Genomics Workbench (k-mer size 15; distance calculation method was “Mahalanobis”) using the de novo assembled contigs or complete genome sequences of the respective isolates. The four isolates marked with an asterisk were isolated from another sampling source compared to the unmarked isolates from the same spa type obtained in the same year without exhibiting any differences on the genomic level (Additional File 5). Moreover, the MLST sequence types are given for each sample in parenthesis