2012 年 86 巻 6 号 p. 778-783
A 76-year-old woman undergoing hemodialysis and having a permanent pacemaker during care elsewhere developed a shunt infection with methicillin-resistant Staphylococcus aureus （MRSA）bacteremia. Vancomycin （VCM） and other antimicrobial agents were not effective even after her artificial shunt vessel was removed. Linezolid （LZD） was administered for 56 days to resolve fever. MRSA was detected repeatedly in blood culture for 7 months except while LZD was being administered, so she was referred to our hospital for further investigation and treatment. Blood culture isolated 3 MRSA strains, all having a minimum inhibitory concentration （MIC） of LZD above 16μg/mL, while that of VCM varied at 2-4μg/mL. Based on these findings, combined VCM, rifampicin, and arbekacin therapy was started but did not resolve the MRSA bacteremia problem. Transesophageal echocardiography showed flat vegetation around the pacemaker lead passing through the tricuspid valve. Based on strongly suspected pacemaker-lead infection, the pacemaker system was removed by heart surgeons using radiographic imaging on day 16 after admission. Her blood culture then became negative. She was returned to the previous hospital on day 66 after admission, where combination antibiotic therapy was continued for about one month. MRSA was not detected again after pacemaker system removal.