Listeria monocytogenes Infective Endocarditis With Concurrent Bacterial Meningitis and Systemic Embolization: A Case Report and Literature Review

Listeria monocytogenes is an uncommon cause of infective endocarditis (IE), and the concurrent occurrence of Listeria IE with bacterial meningitis and systemic septic embolization is exceedingly rare. We report the case of a 74-year-old man who presented with fever and altered mental status and was found to have L. monocytogenes IE complicated by concurrent meningitis and multiple septic emboli, including cerebral infarcts, a splenic infarct, and hepatic microabscesses. Blood and cerebrospinal fluid cultures grew L. monocytogenes, confirming the diagnosis. He was treated with high-dose intravenous ampicillin plus gentamicin, as L. monocytogenes is intrinsically resistant to cephalosporins and the combination of an aminopenicillin with an aminoglycoside is the treatment of choice. The patient improved with therapy and completed a six-week course of antibiotics, achieving a favorable outcome. This case highlights the importance of rapid diagnosis and timely initiation of targeted antimicrobial therapy, as early treatment with ampicillin and gentamicin remains crucial for patient recovery and for reducing the high mortality associated with this rare but life-threatening infection.