Relapsing Peritoneal Dialysis-Associated Peritonitis due to Kocuria rhizophila: A Case Report.

Introduction: The Kocuria genus, encompassing gram-positive coccoid actinobacteria belonging to the Micrococcaceae family, has recently been discovered residing on the human skin and oral flora. Reports of Kocuria-associated infections in humans have been scarce. Herein, we present the first case of relapsing peritoneal dialysis (PD)-associated peritonitis caused by Kocuria rhizophila.

Case presentation: The patient, a 78-year-old male, presented with turbid effluent PD fluid, accompanied by an elevated white blood cell count of 253 cells/μL, of which 59% were neutrophils. A diagnosis of PD-associated peritonitis was established, leading to the initiation of intraperitoneal administration of ceftazidime and vancomycin. Subsequently, Kocuria rhizophila was identified through the bacterial culture of the dialysate. On the seventh day of initial treatment, the antibiotic regimen was changed to penicillin G, and the patient underwent a 3-week course of antibiotics. However, 1 week after discharge, the patient's dialysis fluid became cloudy once again, with subsequent detection of Kocuria rhizophila in the fluid culture. Ultimately, the decision was made to remove the patient's PD catheter and transition to hemodialysis.

Conclusion: PD-associated peritonitis attributed to Kocuria species may be considered a potential risk for recurrence.