Hardware Infection with Corynebacterium spp.: a Case Report and Review of the Literature (original) (raw)

2014, Clinical Microbiology Newsletter

A 58-year-old man with a history of psoriatic arthritis presented with a post-operative spine infection 4 months following an L3-4 spinal fusion and laminectomy. His past medical history included coronary artery disease, hypertension, dyslipidemia, type II diabetes, squamous cell skin cancer, and an initial post-operative course complicated by a surgical site infection due to group B streptococcus approximately 1 month after initial hardware placement, which was managed by irrigation and debridement (I&D), 9 days of parenteral therapy (predominantly cefazolin), and 8 weeks of cephalexin. Several subsequent I&Ds produced no organisms recovered by culture. At the time of presentation, he had a large amount of drainage from the distal aspect of his surgical wound, which again required I&D. The patient's intraoperative cultures included three swabs and one tissue sample taken directly from the surgical site. White blood cells were present in low density in 3 of 4 smears, but no organisms were seen in any of the four direct Gram stain smears. Only the lumbar tissue sample was positive for growth. Growth on sheep blood agar at 35°C in CO 2 revealed an essentially pure culture of 0.5mm pinpoint, grey-white, round, non-hemolytic colonies, and the Gram stain demonstrated palisading coryneform gram-positive bacilli. No fungi, anaerobes, or acid-fast bacteria (AFB) were recovered by culture.. The organism was phenotypically identified as Corynebacterium jeikeium by the API ® Coryne test kit (identification number 2100304; bioMériuex, Marcy l'Etoile, France). However, 16S rRNA gene sequencing revealed that the sequence was not identical to that of C. jeikeium but was found in a closely related genogroup (Fig. 1) that differed by ten base pair deletions (Fig. 2). The organism was resistant to penicillin, erythromycin, and clindamycin (by disk diffusion using Staphylococcus breakpoints according to CLSI M100 (1). It was susceptible to vancomycin (MIC, 1.0 μg/ml), linezolid (MIC, 0.38 μg/ml), doxycycline (MIC, 0.38 μg/ml), and rifampin (MIC, 1.0 μg/ml) but resistant to ciprofloxacin (MIC, 12 μg/ml) by