STM Article Repository

Background: Spontaneous Bacterial Peritonitis is a serious complication of ascites in patients with liver cirrhosis. Most commonly, the cause is monomicrobial, the usual suspects being E. Coli, K. pneumoniae, and sometimes, S. pneumoniae. Moraxella, a gram-negative coccobacillus, is a rare cause of secondary bacterial peritonitis in patients undergoing peritoneal dialysis. In this paper, we present a patient with spontaneous bacterial peritonitis, with no history of peritoneal catheterization or peritoneal dialysis, with Moraxella spp. as the causative agent. To the best of our knowledge, this is the only reported case of spontaneous Moraxella peritonitis.

Presentation: A 63-year-old gentleman, with alcoholic liver cirrhosis and chronic refractory ascites, was referred to the Emergency Room, from the Gastroenterology outpatient clinic, when he presented with the chief complaints of worsening abdominal distension and abdominal discomfort. Leukocytosis was noted and abdominal ultrasound showed moderate ascites. The patient underwent diagnostic and therapeutic paracentesis. The SAAG was calculated to be 0.8 with a total WBC count of 330 cells/mm3 (98% lymphocytes and 2% polymorphs). While the laboratory analysis of the ascitic fluid did not meet the criteria for spontaneous bacterial peritonitis (SBP), the cultures grew Moraxella spp. No other source of infection was identified. The patient was started on Doxycycline and Cefpodoxime for likely spontaneous bacterial peritonitis as sensitivities were not available, and the patient demonstrated clinical improvement, with a decrease in abdominal pain and tenderness, and a decrease in leukocytosis. He was discharged with an outpatient gastroenterology appointment and antibiotics for secondary prophylaxis.

Discussion: Although rare, there is data to establish Moraxella as an often-encountered pathogen causing peritonitis in peritoneal dialysis patients. However, there is insufficient literature regarding its role in SBP, resulting in delays in establishing a diagnosis and in initiating treatment. A greater understanding of this organism will help further the knowledge of its pathogenicity and help recognize optimal antibiotic choices.