Division of Pediatric Infectious Diseases, Department of Paediatrics;
Can J Infect Dis Med Microbiol. 2010 Summer;21(2):89-93. doi: 10.1155/2010/618953.
Daptomycin resistance in Staphylococcus aureus has been previously reported, but the development of resistance while on therapy with subsequent clinical failure for endocarditis has been infrequently reported. A case of persistent methicillin-resistant S aureus (MRSA) bacteremia in the setting of right-sided endocarditis in a 38-year-old man with a history of intravenous drug use is presented. He developed de novo resistance to daptomycin during therapy after several courses of antibiotics, with subsequent clinical failure. Isolates were identified by molecular characterization to be community-acquired MRSA 10 (USA300). To the authors' knowledge, the present case was the first in Canada to involve the de novo development of daptomycin resistance with clinical failure due to MRSA during therapy for endocarditis. Clinicians and microbiologists must be aware of this phenomenon given the implications for treatment and transmission of the strain. It also raises questions regarding the use of daptomycin in settings of heavily pretreated patients with persistent MRSA bacteremia.
金黄色葡萄球菌对达托霉素的耐药性以前已有报道，但在治疗心内膜炎过程中发生耐药并随后临床治疗失败的情况则很少见。本文报告了 1 例 38 岁男性既往有静脉吸毒史，在右侧心内膜炎背景下发生持续耐甲氧西林金黄色葡萄球菌（MRSA）菌血症的病例。该患者在经历数轮抗生素治疗后，出现了达托霉素治疗相关性新发耐药，随后临床治疗失败。通过分子特征鉴定，分离株为社区获得性 MRSA 10（USA300）。据作者所知，本病例是加拿大首例因心内膜炎治疗过程中 MRSA 而出现达托霉素治疗相关性新发耐药并临床治疗失败的病例。鉴于该菌株的治疗和传播意义，临床医生和微生物学家必须意识到这一现象。这也引发了关于在大量经预处理的持续 MRSA 菌血症患者中使用达托霉素的问题。
