A Clonal Complex 12 Methicillin-Resistant Staphylococcus aureus Strain, West Australian MRSA-59, Harbors a Novel Pseudo-SCC mec Element

An Australian MRSA strain (WA-MRSA-59) was characterized by microarray and sequencing. Its pseudo-SCCmec element comprised dcs, Q9XB68-dcs, mvaS-SCC, Q5HJW6, dru, ugpQ, ydeM, mecA+mecR+mecI, txbi mecI, tnp IS431, copA2+mco (copper resistance), ydhK, arsC+arsB+arsR (arsenic resistance), ORF PT43 and per2. Recombinase genes, xylR/mecR2 and PSM-mec (phenol-soluble modulin) were absent. We suggest that the mec complex A should be split into two subtypes. One harbors PSM-mec and xylR/mecR2. It is found in SCCmec II, III and VIII. The second subtype as described herein is present in WA-MRSA-59 and some coagulase-negative staphylococci.