Proposed evolutionary model for ACME acquisition within CC2 clusters and sub-clusters (CC2-I, CC2-II6, CC2-II5, CC2-II85, CC2-II89).

<p>Each dot represents a strain with specific characteristics with respect to ST and content of the different mobile genetic elements, namely, SCC<i>mec</i> (represented by types I-VI), SCC non-<i>mec</i> (represented by the allotype of <i>ccr</i>) and ACME types (represented by Roman numbers followed by Arabic numbers). The occurrence of genetic events involving a single MLST locus variation and/or SCC and ACME acquisition/deletion are indicated by arrows and the elements involved in the event are shown next to the arrow. Blue and white dots represent strains found within the collection studied, and black dots represent hypothetical <i>S. epidermidis</i> strains. ACME I.02 acquisition is represented in blue.</p

Mobilization of ACME in <i>S. epidermidis</i> 1457 by CcrAB.

<p>(A) Pulsed-field gel electrophoresis after <i>Sma</i>I restriction of chromosomal DNA, for the parental strain <i>S. epidermidis</i> 1457 (lane 1) and its ACME excision mutant (lane 2). M = Lambda ladder, and (B) hybridization of <i>Sma</i>I restriction patterns of strain 1457 (lane 1) and its ACME excision mutant (lane 2) with a DNA probe for ACME (<i>arcCB</i>).</p