Case Presentation: A 63- year-old man with a history of seizures, hepatitis C infection and multiple spinal fusion surgeries presented to the emergency room (ER) for the evaluation of back pain. Back pain was said to have commenced 3 days prior to presentation. Pain was mainly located in the lumbar region, dull in nature, rated about 10/10, exacerbated by movement, attenuated by rest, and radiating to the lower extremities with associated numbness. Physical examination revealed a man in mild painful distress and inability to ambulate. Sensation and reflexes were preserved. Laboratory investigation on presentation was significant for an elevated lactic acid of 2.53 mmol/L (N: 0.5-1.99 mmol/L) and positive benzodiazepines and opiates on urine toxicology screen. ESR, CRP, urine and blood cultures were within normal limits. An MRI showed severe canal stenosis with impingement of exiting nerve roots at L2/L3 and L3/L4 and an abnormal enhancement along the posterior inferior aspect of the L3 vertebral body concerning for infection/osteomyelitis. Otherwise no evidence of acute lumbar spine abnormalities in the setting of stable post-surgical changes. The neurosurgical team was consulted, and the patient successfully had a L3 laminectomy, L3/4 diskectomy, partial L2 laminectomy and removal of prior instrumentation at L3/L4. Biopsy of L3/L4 disc and L3 vertebral body mass were also done. Culture results returned positive for C. parasilosis and eventually for R. radiobacter. Infectious disease team was consulted, and patient was discharged home on appropriate intravenous antimicrobials.
Discussion: Vertebral osteomyelitis (VO) affects about 2.9-5.4 persons per 100,000 yearly in the United States. About 50% of cases are said to be due to Staphylococcus aureus while pyogenic and non-pyogenic Streptococci, coagulase negative staphylococci, Pseudomonas aeruginosa, Mycobacterium tuberculosis and Brucella have also been documented. There has been a few cases of documented osteomyelitis of the knee caused by C. parapsilosis, however no known reported cases of VO caused by this organism has been documented. The organism is often seen in domestic animals and on the soil but frequently found on human hands. Similarly, R. radiobacter is also an organism that causes opportunistic infections mostly in immunocompromised humans and is typically found in the soil as well. A few cases of infections have been reported following prolonged indwelling catheters, as a possible cause of direct inoculation post-cataract surgery and also as a source of direct inoculation of soil into a vascular access in a case of Munchausen syndrome. Nevertheless, it is entirely unclear at this time what, if any relationship exists between these soil-ubiquitous organisms found in the lumbar vertebra of our patient. Regardless, there is a need for continued documenting of similar cases such as our patient and he continues to remain under close follow up.
Conclusions: Our report highlights a rare case of co-existing soil-ubiquitous C. parapsilosis and R. radiobacter from the lumbar vertebrae of a patient. To the best of our knowledge, no similar cases have been reported in literature. In patients presenting to the ER, a high index of suspicion and possible awareness of non-conventional organisms is required by Hospitalists who often serve as the first point of contact and the primary physicians to patients such as our index patient.