Antimicrob Agents Chemother 2002 Apr;46(4):1147-52

Novel Type of Staphylococcal Cassette Chromosome mec Identified in Community-Acquired Methicillin-Resistant Staphylococcus aureus Strains.

Ma XX, Ito T, Tiensasitorn C, Jamklang M, Chongtrakool P, Boyle-Vavra S, Daum RS, Hiramatsu K.

Department of Bacteriology, Juntendo University, Tokyo, Japan. Department of Pediatrics, University of Chicago Children's Hospital, Chicago, Illinois.

We identified a new type of staphylococcal cassette chromosome mec (SCCmec) from two community-acquired methicillin-resistant Staphylococcus aureus (MRSA) strains. The novel element, designated type IV SCCmec, had a unique combination of the class B mec gene complex and the type 2 ccr gene complex and was much smaller in size (21 to 24 kb) than previously identified SCCmec elements of hospital-acquired MRSA. Consistent with the strains' susceptibilities to various non-beta-lactam antibiotics, the type IV SCCmec was devoid of any antibiotic resistance genes other than the mecA gene.