Listeria monocytogenes Spontaneous Bacterial Peritonitis in a Patient With Decompensated Cirrhosis

A 54-year-old man with decompensated alcohol-related cirrhosis presented with worsening abdominal pain, recurrent ascites, and acute kidney injury on chronic kidney disease. Initial diagnostic paracentesis showed a polymorphonuclear (PMN) count of 75 cells/μL, which lowered suspicion for spontaneous bacterial peritonitis (SBP). However, ascitic fluid culture subsequently isolated <i>Listeria monocytogenes</i>, a rare cause of SBP that is intrinsically resistant to third-generation cephalosporins. Empiric ceftriaxone would not provide reliable coverage. Therapy was escalated to high-dose intravenous ampicillin, with subsequent transition to oral trimethoprim-sulfamethoxazole to complete therapy, together with large-volume paracentesis, albumin supplementation, and supportive management of hepatorenal dysfunction. The patient improved clinically and biochemically and was discharged in stable condition. This case underscores the need to consider <i>Listeria</i> in cirrhotic patients who fail to respond to standard cephalosporin-based therapy and to promptly tailor antibiotics to culture results to optimize outcomes.