Larson A Noelle, Razonable Raymund R, Hanssen Arlen D
Department of Orthopaedics, Mayo Clinic, Rochester, MN, USA.
Clin Orthop Relat Res. 2009 Jun;467(6):1634-8. doi: 10.1007/s11999-008-0658-9. Epub 2008 Dec 9.
We report the case of a 59-year-old man with Waldenstrom's macroglobulinemia and active alcohol use who presented with bilateral knee pain 5 years after a bilateral staged TKA. Cultures of synovial fluid and periprosthetic tissue specimens from both knees yielded, after prolonged anaerobic incubation, a catalase- and oxidase-positive gram-negative bacillus, which was identified as Capnocytophaga canimorsus by 16S ribosomal RNA PCR analysis. C. canimorsus, an organism that is commonly found in dog and cat saliva, is a rare cause of various infections in immunocompromised and healthy individuals. However, a review of the medical literature indicates C. canimorsus has not been reported previously to cause infection after joint arthroplasty. The patient was immunocompromised by cytotoxic chemotherapy, corticosteroids, and alcohol use. The patient was managed successfully with bilateral two-stage exchange and 6 weeks of intravenous ertapenem therapy. Because of its fastidious and slow-growing characteristics, C. canimorsus may be an unrecognized cause of culture-negative joint arthroplasty infections, especially in cases when dog and cat exposure is evident in the clinical history.
我们报告了一例59岁患有华氏巨球蛋白血症且有酗酒史的男性患者，其在双侧分期全膝关节置换术（TKA）5年后出现双侧膝关节疼痛。对双膝的滑液和假体周围组织标本进行培养，经过长时间厌氧培养后，分离出一种过氧化氢酶和氧化酶阳性的革兰氏阴性杆菌，经16S核糖体RNA聚合酶链反应（PCR）分析鉴定为犬咬二氧化碳嗜纤维菌。犬咬二氧化碳嗜纤维菌是一种常见于狗和猫唾液中的微生物，是免疫功能低下和健康个体发生各种感染的罕见原因。然而，查阅医学文献发现，此前尚未有犬咬二氧化碳嗜纤维菌导致关节置换术后感染的报道。该患者因细胞毒性化疗、皮质类固醇和酗酒而免疫功能低下。患者通过双侧两阶段翻修术和6周的静脉注射厄他培南治疗成功治愈。由于犬咬二氧化碳嗜纤维菌苛求且生长缓慢的特性，它可能是培养阴性的关节置换术感染未被识别的原因，尤其是在临床病史中有明显猫狗接触史的病例中。
