An elderly hemodialysis patient with Lactobacillus rhamnosus bacteremia: a case report

Abstract Background Lactobacillus rhamnosus is a commensal organism of the human microbiota and is widely used as a probiotic; however, it can rarely cause invasive infections, particularly in immunocompromised hosts. Reports in patients receiving maintenance hemodialysis are extremely limited. Case presentation An 85-year-old man with end-stage renal disease secondary to anti-glomerular basement membrane nephritis, receiving maintenance hemodialysis, was admitted with high-grade fever and systemic inflammatory response. His history was notable for thoracic endovascular aortic repair with prosthetic graft placement, surgical aortic valve replacement, and low-dose prednisolone therapy. Blood cultures obtained at admission yielded Gram-positive rods, later identified as Lactobacillus rhamnosus . The organism was resistant to vancomycin and ampicillin, and antimicrobial therapy was ultimately switched to piperacillin/tazobactam. Despite no evidence of infective endocarditis on transesophageal echocardiography, persistent inflammation prompted further evaluation. Whole-body magnetic resonance imaging suggested possible infection around the thoracic aortic graft. Following targeted antimicrobial therapy, the patient’s condition improved and subsequent blood cultures were negative. Conclusions This case highlights that Lactobacillus rhamnosus can cause bacteremia in elderly hemodialysis patients, particularly in the presence of prosthetic materials and immunosuppression. Whole-body magnetic resonance imaging may be a useful tool for identifying an occult infectious focus when conventional diagnostic modalities are inconclusive.