SCCmec
SCCmec, or staphylococcal cassette chromosome mec, is a mobile genetic element of Staphylococcus bacterial species. This genetic sequence includes the mecA gene coding for resistance to the antibiotic methicillin and is the only known way for Staphylococcus strains to spread the gene in the wild by horizontal gene transfer.[1]
Classification
Not all SCCmec elements are identical (in fact, SCC elements without the mecA gene do exist.[1]) SCCmec elements have been classified into twelve types (I through XII) on the basis of two specific regions of their nucleotide sequences. One region is the mec complex including the mecA gene. The other is the ccr gene complex including genes coding for recombinases.[2]
The mec complex is divided further into five types (I through V) based on the arrangement of regulatory genetic features such as mecR1, an inducer.[3]
Distribution
The SCCmec found in methicillin-resistant Staphylococcus aureus likely originated in coagulase-negative staphylococcal species and was acquired by S. aureus.[4]
Staphylococcal strains isolated from pig farms were found to carry several different types of SCCmec, suggesting that they may serve as a reservoir of these elements.[5]
See also
References
- ^ a b Hanssen, Anne-Merethe; Ericson Sollid, Johanna U. (1 February 2006). "SCCmec in staphylococci: genes on the move". FEMS Immunology & Medical Microbiology. 46 (1): 8–20. doi:10.1111/j.1574-695X.2005.00009.x. PMID 16420592.
- ^ Hiramatsu, K; Cui, L; Kuroda, M; Ito, T (Oct 2001). "The emergence and evolution of methicillin-resistant Staphylococcus aureus". Trends in Microbiology. 9 (10): 486–93. doi:10.1016/s0966-842x(01)02175-8. PMID 11597450.
- ^ Katayama, Y; Ito, T; Hiramatsu, K (Jul 2001). "Genetic organization of the chromosome region surrounding mecA in clinical staphylococcal strains: role of IS431-mediated mecI deletion in expression of resistance in mecA-carrying, low-level methicillin-resistant Staphylococcus haemolyticus". Antimicrobial Agents and Chemotherapy. 45 (7): 1955–63. doi:10.1128/AAC.45.7.1955-1963.2001. PMC 90585. PMID 11408208.
- ^ Tsubakishita, S; Kuwahara-Arai, K; Sasaki, T; Hiramatsu, K (Oct 2010). "Origin and molecular evolution of the determinant of methicillin resistance in staphylococci". Antimicrobial Agents and Chemotherapy. 54 (10): 4352–9. doi:10.1128/AAC.00356-10. PMC 2944575. PMID 20679504.
- ^ Tulinski, P; Fluit, AC; Wagenaar, JA; Mevius, D; van de Vijver, L; Duim, B (2011-11-11). "Methicillin-resistant coagulase-negative staphylococci on pig farms act as a reservoir of heterogeneous SCCmec elements". Applied and Environmental Microbiology. 78 (2): 299–304. doi:10.1128/AEM.05594-11. PMC 3255757. PMID 22081567.