This article presents a case of a 17-year-old male involved in a rollover tractor accident in which he landed on his shoulder and suffered superficial abrasions. Over the ensuing 3 months, he developed progressive pain at the acromioclavicular joint without overt signs of infection or systemic illness. Magnetic resonance imaging demonstrated bony edema and cystic change at the acromion and distal clavicle suggestive of erosive post-traumatic arthritis; infectious arthritis was also considered. After failure of intra-articular injection, open debridement and distal clavicle excision were performed. Bone and fluid cultures grew Ochrobactrum anthropi, and the patient was subsequently treated with ciprofloxacin and trimethoprim/sulfamethoxazole. At 3 and 6 months postoperatively, he was pain-free with full shoulder range of motion and no clinical or radiographic signs of infection.
Ochrobactrum anthropi is a ubiquitous, aerobic, gram-negative bacillus of low virulence, most often acting as an opportunist pathogen in immunocompromised patients, especially infections related to indwelling catheters, drains, and intravenous lines in immunocompromised hosts. It has also been reported as a cause of localized pyogenic infections, meningitis, endocarditis, peritonitis, and osteomyletis. To the best of our knowledge, this case represents the first report of O. anthropi septic arthritis, in this instance occurring in an otherwise healthy teenager. Physicians should be aware that O. anthropi may be a cause of septic arthritis and that infection can occur in immunocompetent hosts, especially those with a history of accidental wounds. This report reviews the current scientific knowledge of the organism, including antibiotic sensitivities and resistances, and provides treatment recommendations based on our experience.