Clostridioides difficile associated peritonitis in peritoneal dialysis patients - a case series based review of an under-recognized entity with therapeutic challenges.

BACKGROUND: Initial presentation of peritoneal dialysis associated infectious peritonitis can be clinically indistinguishable from Clostridioides difficile infection (CDI) and both may demonstrate a cloudy dialysate. Empiric treatment of the former entails use of 3rd-generation cephalosporins, which could worsen CDI. We present a logical management approach of this clinical scenario providing examples of two cases with CDI associated peritonitis of varying severity where the initial picture was concerning for peritonitis and treatment for CDI resulted in successful cure. CASE PRESENTATION: A 73-year-old male with ESRD managed with PD presented with fever, abdominal pain, leukocytosis and significant diarrhea. Cell count of the peritoneal dialysis effluent revealed 1050 WBCs/mm3 with 71% neutrophils. C. difficile PCR on the stool was positive. Patient was started on intra-peritoneal (IP) cefepime and vancomycin for treatment of the peritonitis and intravenous (IV) metronidazole and oral vancomycin for treatment of the C. difficile colitis but worsened. PD fluid culture showed no growth. He responded well to IV tigecycline, oral vancomycin and vancomycin enemas. Similarly, a 55-year-old male with ESRD with PD developed acute diarrhea and on the third day noted a cloudy effluent from his dialysis catheter. PD fluid analysis showed 1450 WBCs/mm3 with 49% neutrophils. IP cefepime and vancomycin were initiated. CT of the abdomen showed rectosigmoid colitis. C. difficile PCR on the stool was positive. IP cefepime and vancomycin were promptly discontinued. Treatment with oral vancomycin 125 mg every six hours and IV Tigecycline was initiated. PD fluid culture produced no growth. PD catheter was retained. CONCLUSIONS: In patients presenting with diarrhea with risk factors for CDI, traditional empiric treatment of PD peritonitis may need to be reexamined as they could have detrimental effects on CDI course and patient outcomes.

Pseudomembranous colitis secondary to methicillin-resistant Staphylococcus aureus (MRSA).

A 37-year-old woman with a history of type II diabetes and Crohn's disease, status postcholecystectomy, presented with a >2-week history of cramping abdominal pain, nausea, non-bloody/non-bilious emesis and, later, diarrhoea. A flexible sigmoidoscopy was performed, revealing that 'a segmental pseudomembrane was found from rectum to sigmoid colon'. Clostridium difficile PCR on the stool was repeated twice and resulted negative both times. A food history prior to onset of symptoms was consistent with Staphylococcal food poisoning and a stool culture was positive for heavy growth of methicillin-resistant Staphylococcus aureus and the absence of enteric flora. The patient was successfully treated with oral vancomycin.