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 Listeria monocytogenes, 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 Listeria in cirrhotic patients who fail to respond to standard cephalosporin-based therapy and to promptly tailor antibiotics to culture results to optimize outcomes.