Description of MRSA clones. a) Distribution of the MRSA clones in periods A (1990–1999) and B (2000–2007); b) Description of the molecular backgrounds (ST, SCCmec and CC) of main clones isolated in Italy, correlated to their previous names; c) Graphical representation of alternation of MRSA clones in Italy during the 27-year period of study. *Italian and Southern Germany clones belong to the same ST228-MRSA-I, but they differ for their PFGE profile. **UK EMRSA-15 was often reported in literature as gentamicin-susceptible MRSA (GS-MRSA) clone. (ST: Sequence-Type; SCCmec: Staphylococcal Cassette Chromosome mec; CC: Clonal-Complex).