Title : PD-associated peritonitis: A case first for Aquamicrobium
Abstract:
A 56-year-old male with end-stage renal disease undergoing home peritoneal dialysis presented with abdominal pain, nausea, and altered mental status. White blood cell count was 12.3 10e3/uL, urinalysis was positive for 2+ blood, and peritoneal fluid contained a total nucleated cell count of 1840 with 98% neutrophils. The patient was empirically treated with intravenous piperacillin-tazobactam and vancomycin, and a 2% mupirocin ointment was applied around his peritoneal catheter site. Following this treatment, he showed significant symptomatic improvement. On hospital day three, the patient’s fungal culture and Methicillin-resistant Staphylococcus aureus came back negative, but his aerobic/anaerobic culture was positive for Aquamicrobium lusatiense. Aquamicrobium is an aerobic gram-negative rod which until recently had only been isolated from wastewater and contaminated soil. In 2021, two cases of Aquamicrobium infection in humans were reported. Both resulted in endophthalmitis following cataract surgery. To our knowledge, this was the third case of Aquamicrobium infection in a human and the first example of this agent causing peritonitis. Following identification of the infectious agent, the patient was transitioned to intraperitoneal vancomycin and cefepime. Two days into the new treatment course, the patient’s peritoneal fluid demonstrated a total nucleated cell count of 5 with a 40% neutrophil composition. The patient was discharged home after a seven-day inpatient stay with instructions to continue cefepime 1g via intraperitoneal injection for three weeks. On the day of discharge, his white blood cell count was 4.4 10e3/uL.
