Daptomycin (DAP) is key in treating multidrug-resistant Staphylococcus infections. Diminished susceptibility to DAP is emerging among Staphylococcus epidermidis strains although mechanisms for non-susceptibility (NS) remain poorly understood. We report a case of persistent S. epidermidis bacteremia in which loss of DAP susceptibility arose during prolonged treatment. Whole genome sequencing identified two mutations, Q371del and P415L, in a single-affected gene, WalK, that coincided with the emergence of DAP-NS. Protein modeling of the mutations predicted a disruption of WalK protein configuration. The emergence of mutations in a single-gene during DAP exposure raises concerns in an era of increasingly treatment-resistant infections.

中文翻译：

---

临床表皮葡萄球菌感染中达托霉素敏感性下降与WalK变异同时发生

达托霉素（DAP）是治疗耐多药葡萄球菌感染的关键。表皮葡萄球菌菌株对DAP的敏感性正在降低，尽管对非敏感性（NS）的机制仍知之甚少。我们报告一例持续性表皮葡萄球菌菌血症，其中在长期治疗期间DAP敏感性下降。全基因组测序在单一影响的基因WalK中鉴定了两个突变Q371del和P415L，与DAP-NS的出现相吻合。突变的蛋白质模型预测了WalK蛋白质构型的破坏。在暴露于DAP的过程中，单一基因中突变的出现引起了人们的关注，在一个越来越具有治疗抗性的感染时代。