Background:

Abiotrophia defectiva is a fastidious aerobic gram-positive bacterium which is part of the normal flora of the human oral cavity. It is an unusual cause of peritoneal dialysis-related peritonitis.
Case presentation:
We present a case of a man in his fifties with end-stage renal failure secondary to polycystic kidney disease who presented with a cloudy peritoneal fluid effluent and a cell count of 35 620 × 106 cells/L with 90% polymorphonuclear cells. The fluid was cultured per unit protocol, and the organism was identified as Abiotrophia defectiva. Post-peritonitis dialysis technique review revealed frequent lapses in the use of facemask and hand washing during cycler connection and disconnection. The patient responded well to vancomycin; however, he subsequently developed ultrafiltration failure and symptoms of fluid overload and uremia and was transferred to home hemodialysis.
Conclusions:

Abiotrophia defectiva is an unusual cause of peritoneal dialysis-related peritonitis. The organism is a normal commensal of the oral cavity and may cause peritonitis in patients with nonadherence to dialysis technique. In our case, the infection was followed by peritoneal membrane failure and transfer to hemodialysis. It remains to be seen if peritonitis with Abiotrophia defectiva heralds a worse outcome.