The first case of a spinal epidural abscess caused by Roseomonas mucosa following instrumented posterior lumbar fusion is presented. Although rare, because of its highly resistant profile, Roseomonas species should be included in the differential diagnosis of epidural abscesses in both immunocompromised and immunocompetent hosts. CASE REPORTA 54-year-old woman was admitted to the Emergency Department of the University Hospital in Crete, Greece, with complaints of purulent drainage, mild pain, and redness at the site of incision. The patient had been operated on 15 days previously due to spinal stenosis. The type of surgery performed was decompressive lumbar laminectomy followed by instrumented posterior spinal fusion.Physical examination revealed a large, deep-wound dehiscence with exudates, erythema, pain, induration, edema, and cellulitis.The general condition of the patient was good. She was feverless, and results of the laboratory exams were the following: a white blood cell (WBC) count of 6,000/mm 3 , an erythrocyte sedimentation rate (ESR) of 97 mm/h, and a C-reactive protein (CRP) level of 4.82 mg/dl (normal range, 0.08 to 08 mg/dl). The patient underwent deep surgical debridement and was placed on empirical intravenous (i.v.) vancomycin and oral rifampin for a total of 24 days.Although the wound healed and the infection resolved, the results of the blood tests worsened. The inflammatory markers increased: the ESR was 113 mm/h, and the CRP level was 13.7 mg/dl. The patient's temperature increased to 39°C, and she complained of back pain. The magnetic resonance image (MRI) scan demonstrated the presence of a large epidural abscess anterior to the L2 and L3 vertebrae, compressing the thecal sac (Fig. 1). There was no evidence of osteomyelitic involvement. The patient underwent drainage of her epidural abscess, and cultures of the pus grew pink-pigmented colonies on Columbia and chocolate agar plates after 48 h of incubation at 36°C. The isolate was catalase and urease positive and weakly oxidase positive, and it assimilated arabinose, malate, citrate, and glucose. In Gram-stained smears, the organisms appeared as Gram-negative, plump coccobacilli in pairs. The isolate was identified as Roseomonas gilardii by using the Vitek 2 automated system (bioMérieux, Marcy L'Etoile, France). Sequencing analysis of 1,455 nucleotides of the 16S rRNA genes (a nearly complete sequence) was performed, and the derived sequence was queried against GenBank. The results showed that our strain exhibited the highest similarity with the Roseomonas mucosa 16S rRNA gene sequences. Multiple alignments were performed using the ClustalW program, and a distance tree was derived using the neighbor-joining method (1) offered in the MEGA 5 software package (2). Results indicated that our strain (Roseomonas sp. strain SM14032013) clustered together with Roseomonas mucosa, Roseomonas massiliae, and Roseomonas terpenica species, while Roseomonas gilardii strains formed a distinct group (Fig. 2).The agar gradient diffusion (Etest) method was e...