少动鞘氨醇单胞菌(Sphingomonas paucimobilis) 是一种少见的条件致病菌。可引起手术后感染、创伤后腿部溃疡、菌血症、脑膜炎、慢性蜂窝织炎、手术后眼内炎等，未查见累及心瓣膜的报道。本文报道1例临床观察到的少动鞘氨醇单胞菌所致感染性心内膜炎。该患者为中年男性，因“反复发热2月余”入院。以发热伴左上腹痛为首发症状，影像学显示脾梗死，查体发现皮肤瘀点、心脏杂音，辅助检查发现有一过性贫血、镜下血尿，类风湿因子阳性，心超显示新出现的瓣膜返流，抗菌药物治疗有效。外周血培养报告，4次培养出少动鞘氨醇单胞菌。药敏结果示全敏感菌，给予抗感染治疗及二尖瓣置换术后痊愈。文献中该菌常引起血流感染，大多发生在免疫缺陷患者中，以院内感染多见。此例少动鞘氨醇单胞菌引起心内膜炎为社区感染，发生在免疫力正常人中，且为全敏感菌，甚为少见。

Sphingomonas paucimobilis (S. paucimobilis) is Gram-negative bacillus that is widely distributed in the natural environment. It has been reported to cause opportunistic infection in immunocompromized hosts. The infection has been reported in the postoperative wound, post-traumatic leg ulcer, septicemia, meningitis, chronic cellulitis and postoperative endophthalmitis. No previous cases of infective endocarditis caused by S. paucimobilis have been reported. Here a case of infective endocarditis caused by S. paucimobilis was reported to help understand this disease. The middle-aged male patient was admitted to the hospital because of recurrent fever for more than two months. The first episode was high fever companied with pain in the left-upper abdomen. Computer topography (CT) suggested an infarction in spleen. Physical examination revealed that skin petechiae and heart murmur. Laboratory examination revealed transient anemia, microscopic hematuria, positive rheumatoid  factor, and echocardiography suggested emerging valvular regurgitation. Anti-infection treatment was effective. The same S. paucimobilis was isolated from peripheral blood culture four times and thus the diagnosis of endocarditis by S. paucimobilis was confirmed. The results of drug sensitivity testing showed pan-susceptible. The patient fully recovered by anti-infection treatment with mitral valve replacement operation. He was a healthy man without systematic diseases and the infection was community-aquired, which was different from most reports.