Open AccessSCC mec in staphylococci: genes on the move
Author(s) -
Hanssen AnneMerethe,
Ericson Sollid Johanna U.
Publication year - 2006
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2005.00009.x
Subject(s) - sccmec , recombinase , biology , horizontal gene transfer , genetics , chromosome , mobile genetic elements , gene , staphylococcus , genome , coagulase , staphylococcus aureus , microbiology and biotechnology , bacteria , recombination , methicillin resistant staphylococcus aureus
Staphylococcal cassette chromosome (SCC) elements are, so far, the only vectors described for the mecA gene encoding methicillin resistance in staphylococci. SCC mec elements are classified according to the type of recombinase they carry and their general genetic composition. SCC mec types I–V have been described, and SCC elements lacking mecA have also been reported. In this review, we summarize the current knowledge about SCC structure and distribution, including genetic variants and rudiments of the elements. Its origin is still unknown, but one assumes that staphylococcal cassette chromosome is transferred between staphylococci, and mecA ‐positive coagulase‐negative staphylococci may be a potential reservoir for these elements. Staphylococcal genomes seem to change continuously as genetic elements move in and out, but no mechanism of transfer has been found responsible for moving SCC elements between different staphylococcal species. Observations suggesting de novo production of methicillin‐resistant staphylococci and horizontal gene transfer of SCC mec will be discussed.