- The mec gene complex is composed of mecA, its regulatory genes, and associated insertion sequences.
- The class A mec gene complex (class A mec) is the prototype complex, which contains mecA, the complete mecR1 and mecI regulatory genes upstream of mecA, and the hypervariable region (HVR) and insertion sequence IS431 downstream of mecA.
- The class B mec gene complex is composed of mecA, a truncated mecR1 resulting from the insertion of IS1272 up- stream of mecA, and HVR and IS431 downstream of mecA.
- The class C mec gene complex contains mecA and truncated mecR1 by the insertion of IS431 upstream of mecA and HVR and IS431 downstream of mecA.
List of mecA homologues and phylogenetic relationships by maximum likelihood method
IWG-SCC commentary Antimicrob Agents Chemother 2012 Oct;56(10):4997-9.