Ewingella americana Peritonitis in a Patient on Peritoneal Dialysis: A Case Report and Review of the Literature

Most episodes of peritoneal dialysis (PD)-associated peritonitis are caused by skin-dwelling gram-positive bacteria and gram-negative bacteria colonizing gut and urinary tract. Occasionally, however, uncommon bacteria can cause peritonitis in PD patients. We describe a case of Ewingella americana peritonitis, the first such case reported from the United States. A 68-year-old woman with end-stage kidney disease due to hypertension was initiated on PD 2 years prior to the present event. She presented with abdominal pain associated with nausea and vomiting. She was afebrile and hemodynamically stable. Abdomen was diffusely tender with guarding and rebound. No obvious root cause was apparent. Initial PD fluid white count was 502/mm 3 with 87% neutrophils. Gram stain was negative. Culture grew gram-negative rods, which were later identified as Ewingella americana, resistant to ampicillin and cefazolin but sensitive to gentamicin, ceftazidime, and cefepime. After empiric intraperitoneal vancomycin and gentamicin, she was continued on intraperitoneal gentamicin for a total period of 21 days. She responded to the treatment rapidly with complete recovery. PD fluid on day four showed 40 nucleated cells with 12% neutrophils. Patient remained on PD without consequences. Ewingella americana is a gram-negative facultative anaerobic bacillus that can survive in water, including domestic water. Inadequate hand hygiene is a potential root cause of infection. Although rare, Ewingella peritonitis can be observed in PD patients and is treatable. Clinicians should be aware of Ewingella as a potential cause of PD peritonitis.