Epidural abscess caused by community-associated methicillin-resistant Staphylococcus aureus strain USA300 in Japan

We report a case of epidural abscess caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strain USA300 in a previously healthy 25-year-old American woman who lived in Japan for more than 1 year. She started to complain of severe headache that continued for about 10 days after improvement of subcutaneous abscesses caused by MRSA. Computed tomography (CT) and magnetic resonance imaging (MRI) showed epidural abscess. As epidural abscess was not improved by treatment with vancomycin and ceftriaxone, craniotomy and drainage were performed, and the severe headache disappeared. Characteristics of the MRSA strain isolated from the abscess were identical to those of strain USA300; multilocus sequence typing sequence type 8, staphylococcal cassette chromosome mec type IVa, Panton-Valentine leukocidin positive, arginine catabolic mobile element positive, and pulsed-field gel electrophoresis type USA300. This may be the first report of epidural abscess caused by USA300 strain in Japan. Because CA-MRSA strains, including USA300, have begun to spread in Japan, epidural abscess should be taken into account in the diagnosis of previously healthy patients with persistent headache accompanied by skin lesions.