Klebsiella aerogenes Discitis in a 78-Year-Old Male Patient With End-Stage Renal Disease on Hemodialysis: A Case Report.

Vertebral osteomyelitis is a well-recognized complication in hemodialysis patients, though it is most commonly attributed to Gram-positive organisms, such as Staphylococcus aureus. Gram-negative pathogens, while less frequently implicated, are increasingly appreciated in this population given the unique confluence of immune dysfunction, recurrent vascular access manipulation, and frequent healthcare exposure. We describe the case of a 78-year-old man on hemodialysis who presented with progressive lower back pain and was ultimately found to have L4-L5 discitis caused by Klebsiella aerogenes. The diagnosis required repeat disc aspiration after initial cultures were unrevealing. The source of infection was not definitively established; while hematogenous seeding from the hemodialysis vascular access was considered given the patient's recurrent bloodstream exposure, a genitourinary origin could not be excluded, as Klebsiella species are well-known colonizers of the urinary tract and a recognized source of Gram-negative bacteremia. He responded well to a prolonged course of targeted intravenous antibiotic therapy. This case underscores the importance of maintaining a broad differential for vertebral osteomyelitis in hemodialysis patients, considering both vascular access-related and genitourinary sources of infection, and pursuing repeat sampling when clinical suspicion persists despite a negative initial workup.