Seven Novel Variants of the Staphylococcal Chromosomal Cassette mec in Methicillin-Resistant Staphylococcus aureus Isolates from Ireland

Abstract

Methicillin-resistant

Subtyping of ST22-MRSA-IV (Barnim epidemic MRSA strain) at a university clinic in Germany from 2002 to 2005

“…A combination of MLST with SCCmec typing permits the unambiguous assignment of collections of MRSA isolates to known or new MRSA clones (Enright et al, 2000;Grundmann et al, 2002). Interestingly, in our study, all analysed isolates carried SCCmec subtype IVa (see below), which defined this epidemic MRSA primarily as a regional clone (Shore et al, 2005).…”

Spontaneous Deletion of the Methicillin Resistance Determinant, mecA , Partially Compensates for the Fitness Cost Associated with High-Level Vancomycin Resistance in Staphylococcus aureus

“…Reipert et al also noted a chromosomal deletion encompassing mecA in a vancomycin-resistant S. aureus strain, and this deletion also mapped to the IS431 element present downstream of mecA (36). IS431 is present in all known SCCmec elements just downstream of the mecA operon, and in some cases, the mec operon is flanked by IS431 on either side (35,40). These findings suggest a role for IS431 in the deletion of portions of SCCmec, and therefore, it is possible that IS431 transposition/recombination may also play a role in the mobility and transfer of mecA.…”

Emergence of SCCmec Type IV as the Most Common Type of Methicillin-Resistant Staphylococcus aureus in a University Hospital

“…Hospital-associated MRSA (HA-MRSA) isolates are typically resistant to multiple antibiotics, negative for Panton-Valentine leukocidin (PVL) encoding genes and primarily harbor SCCmec types I, II, III, and rarely IV [1,3,4]. Up to six main types of SCCmec and many variants, especially of type IV are known [1,5,6]. Type IV is present in many more genetic backgrounds than other types suggesting an enhanced mobility [7][8][9].…”