P. Rettgeri: A Rare Cause of Spontaneous Bacterial Peritonitis

Introduction: Providencia rettgeri is a rare gram-negative, facultative anaerobic member of the Enterobacteriaceae family. Bacteremia is extremely rare, and spontaneous bacterial peritonitis (SBP) has only been documented in two known cases. It is commonly associated with patients with chronic indwelling foley catheters. We present a unique case of severe bacteremia and SBP caused P. rettgeri in a patient with underlying cirrhosis. Case Description/Methods: A 55-year-old man with a history of alcohol abuse and liver cirrhosis presented to the emergency department after falling at home. He had large volume coffee ground emesis and required intubation for airway protection. Physical examination revealed temporal wasting, scleral icterus, and a protuberant abdomen with positive fluid wave. Initial labs were remarkable for a lactate of 9.26mmol/L, hemoglobin of 6.3g/dL, platelets of 87,000/uL INR of 6.3, serum glucose of 20g/dL, albumin of 1.2g/dL, and total bilirubin of 7.0 mg/dL. The patient underwent an esophagogastroduodenoscopy (EGD) which revealed small esophageal varices that were banded. Diagnostic paracentesis was performed, and fluid analysis revealed bacterascites with a total cell count of 100, 43% neutrophils, ANC of 43, and 2,200/uL red blood cells. Cultures of the ascitic fluid and blood later identified Providencia rettgeri. The patient was treated with meropenem and albumin, but despite resuscitative efforts, he died on the fourth day of hospitalization. Discussion: Spontaneous bacterial peritonitis is the acute infection of ascites, characterized by an elevated neutrophil count of >250cells/µL. Bacterascites, on the other hand, is the presence of bacteria in ascites with a lower neutrophil count. Both conditions commonly occur in patients with decompensated cirrhosis and ascites. Gram-negative aerobic organisms, such as Klebsiella pneumoniae, are the main causative agents, while anaerobic bacteria are usually not seen due to high oxygen concentrations in ascitic fluid. Our case presents a rare instance of SBP caused by a gram-negative anaerobic organism, Providencia rettgeri, with concurrent bacteremia. This raises questions about the origin of the organism causing SBP. Although translocation of gut flora to the ascitic fluid is the most common mechanism, other pathways may contribute to pathogenic organism growth in ascitic fluid, leading to bacteremia and mortality. Our case underscores the importance of early paracentesis and identification of SBP or bacterascites for improved outcomes.