Spontaneous Bacterial Peritonitis Caused by Listeria monocytogenes

Abstract

Introduction: Diagnosis of SBP is made if the ascitic fluid shows polymorph nuclear cell count more than 250 cells/mm. Listeria monocytogenes, is an uncommon cause of SBP in the United States. Case Presentation: Patient is a 57-year-old man with a past medical history significant for non-Hodgkin's lymphoma diagnosed three years prior to hospital presentation status post six rounds of Rituximab, Cyclophosphosphamide, Doxorubicin Hydrochloride, Vincristine Sulfate and Prednisone therapy. He presented to the hospital secondary to generalized weakness, consistent temperature of 99.2 Fahrenheit and chills. He had a tunneled indwelling peritoneal catheter for recurrent ascites secondary to peritoneal metastasis. During presentation his vitals were temperature: 98.2 F, heart rate of 101 beats/ min, BP 84/40 mmHg while on norepinephrine, and saturating at 94% on 2 L of nasal cannula. His abdomen was distended, tense with ascites and tender to palpation. His laboratory results were as noted in Table 1. Evaluation with a CT abdomen and pelvis showed moderate ascites and small bilateral pleural effusion. His serum-ascites albumin gradient was 1.3. He was further worked up for an infectious etiology with thoracentesis and peritoneal tap. He was found to have listeria bacteremia as well as positive pleural and ascites cultures for listeria. He initially had received an empiric dose of ceftriaxone and gentamicin, but was transitioned to ampicillin and gentamicin once listeria was identified in the peritoneal fluid and blood cultures. After 7 days of treatment with ampicillin, he remained afebrile with resolution of general weakness and myalgia. He was discharged on ampicillin 2g intravenous every 4 hours for a total of 14 days of treatment. At the time of discharge his repeat blood and peritoneal cultures remained sterile.Table: Table. Laboratory resultsDiscussion: SBP caused by listeria monocytogenes should be considered when there is an inappropriate response to treatment in the first 48-72 hours with patients treated for SBP. Third generation cephalosporin are commonly used for treatment of SBP, however these antibiotics do not have a reliable action against listeria. Ampicillin with or without an aminoglycoside is the treatment of choice. In conclusion listeria is a rare but potentially fatal cause of spontaneous bacterial peritonitis. This case emphasizes the importance of looking beyond meningitis when approaching listeriosis in immunocompromised hosts.