MRSA ST22-IVa [EMRSA-15 clone] in Palermo, Italy

Epidemic spread of methicillin-resistant Staphylococcus aureus [MRSA] strains carrying the Staphylococcal Chromosomal Cassettes [SCC] mec type IV is being increasingly reported in many geographical areas. A survey to determine the prevalence and characteristics of MRSA SCCmec IV isolates identified in four general hospitals in Palermo, Italy, was carried out. During the period February-June 2009, SCCmec type IVa has been found in12 out of 94 isolates. Nine isolates from all hospitals and all strains from a NICU outbreak occurring in the same period were attributed with the ST22-IVa [EMRSA-15] clone. In our setting, due to the changing MRSA epidemiology, detection of SCCmec IV could be poorly predictive of CA-MRSA