Characterization of a variant of the SCCmec element in a bloodstream isolate of Staphylococcus intermedius.

Here we report for the first time, a detailed characterization of a variant of the SCCmec element, in a methicillin-resistant Staphylococcus intermedius human isolate. S. intermedius is a coagulase-positive zoonotic microrganism, recently classified as a separate species. In routine clinical laboratory practice, the coagulase production is used as criterion of pathogenicity related to S. aureus, but S. intermedius is frequently misidentified-being mistaken for S. aureus-and consequently its real incidence underestimated. S. intermedius have been found only occasionally in human beings, and methicillin-resistance is very rare for this organism. Even if the genetic element responsible for methicillin-resistance--the mecA gene carried by diverse staphylococcal chromosomal cassettes--has been described in various staphylococcal species, the current literature doesn't report any case of S. intermedius isolate carrying SCCmec-like elements. Our study could be useful to explain the mechanism and routes of transfer of the chromosomal cassette carrying the mec complex, among staphylococci.