Felten A, Desplaces N, Nizard R, Sedel L, Lagrange P
Service de Microbiologie, Hôpital Saint-Louis, Paris, France.
Pathol Biol (Paris). 1998 Jun;46(6):442-8.
We report a retrospective study of 14 Peptostreptococcus magnus bone and joint infections, following orthopaedic prostheses or implantation of fixation devices, diagnosed in two Paris hospitals between 1992 and 1996. Five patients experienced a knee joint infection after anterior cruciate ligament reconstruction with 4 artificial grafts, and 9 caught joint or wound infections, after limb traumatic injuries or bone neoplastic ruptures involving femur, tibia, calcaneum and humerus, treated by arthroplasty or osteosynthesis with implantation of biomaterials. Septic arthritis was experienced one week to one year after reconstructive surgery, and had evolved for several months to years before etiologic diagnosis in 5 cases. Specimens of pus, tissues or removed implants produced numerous slow growing small colonies of Gram positive cocci arranged in clumps on culture media incubated in anaerobic atmosphere only. In 10 patients, the same organism was disclosed in several separate specimens. The identification of P. magnus was assessed by the enzyme profile (rapid ID 32A API strips), gaz liquid chromatography, catalase and coagulase production, resistance to novobiocin and Na polyanethol sulphonate. Antibiotic sensitivity testing performed by disc method was constant to penicillin G, amoxicillin, cefuroxime, cefoxitin, imipenem and pristinamycin with penicillin G MICs < 0.125 mg/l and metronidazole MICs < 1 mg/l. Erythromycin, clindamycin, rifampicin, tetracycline and fosfomycin were active against more than 70% of P. magnus. All patients were cured after a prolonged course of various antibiotics and surgical removal of the foreign material whenever possible. We studied in vitro binding of P. magnus with extracellular matrix proteins adsorbed onto biomaterials, by particle agglutination assays of latex beads coated with proteins. Eighty one% of strains bound to collagen, 69% to fibrinogen and 46% to fibronectin. Comparison of orthopaedic strains with strains of other infections and from skin showed a correlation between P. magnus from bone and joint infections and their fibrinogen binding ability (69% against 20%, p < 0.05).
我们报告了一项回顾性研究，该研究涉及1992年至1996年间在巴黎两家医院诊断出的14例因骨科假体或固定装置植入后发生的大消化链球菌骨和关节感染。5例患者在使用4个人造移植物进行前交叉韧带重建后发生膝关节感染，9例患者在涉及股骨、胫骨、跟骨和肱骨的肢体创伤性损伤或骨肿瘤破裂后，通过关节成形术或植入生物材料的骨固定术后发生关节或伤口感染。5例患者在重建手术后1周至1年出现化脓性关节炎，在病因诊断前已发展数月至数年。仅在厌氧环境中培养的培养基上，脓液、组织或取出的植入物标本产生了许多生长缓慢的革兰氏阳性球菌小菌落，这些菌落呈团块状排列。10例患者的多个不同标本中发现了相同的病原体。通过酶谱（快速ID 32A API试纸条）、气相液相色谱法、过氧化氢酶和凝固酶产生情况、对新生霉素和聚茴香脑磺酸钠的耐药性来评估大消化链球菌的鉴定。采用纸片法进行的抗生素敏感性试验显示，对青霉素G、阿莫西林、头孢呋辛、头孢西丁、亚胺培南和 pristinamycin 恒定敏感，青霉素G的 MIC < 0.125 mg/l，甲硝唑的 MIC < 1 mg/l。红霉素、克林霉素、利福平、四环素和磷霉素对超过70%的大消化链球菌有活性。所有患者在接受长时间的各种抗生素治疗并尽可能手术取出异物后均治愈。我们通过包被有蛋白质的乳胶珠的颗粒凝集试验，研究了大消化链球菌与吸附在生物材料上的细胞外基质蛋白的体外结合情况。81%的菌株与胶原蛋白结合，69%与纤维蛋白原结合，46%与纤连蛋白结合。将骨科菌株与其他感染菌株及皮肤菌株进行比较，发现来自骨和关节感染的大消化链球菌与其纤维蛋白原结合能力之间存在相关性（69%对20%，p < 0.05）。
