Brevibacterium casei: An Unusual Cause of Peritoneal Dialysis-Associated Peritonitis Managed by Catheter Salvage.

Peritoneal dialysis (PD)-associated peritonitis remains the leading infectious complication of the technique and a major cause of catheter loss and transfer to haemodialysis. Although it is usually caused by common Gram-positive organisms, rare pathogens such as Brevibacterium casei are occasionally implicated. These coryneform bacteria are easily mistaken for skin contaminants, since they are part of the commensal flora, and may require molecular methods for identification. They are typically resistant not only to first-line beta-lactams but also to third-generation cephalosporins, clindamycin and trimethoprim-sulfamethoxazole, while usually remaining susceptible to vancomycin. We report a rare case of B. casei PD-associated peritonitis in a 38-year-old man on automated PD awaiting simultaneous kidney-pancreas transplantation. Prompt microbiological identification enabled targeted intraperitoneal antibiotic therapy, resulting in complete clinical and cytological resolution, catheter preservation, and no relapse. This case highlights the potential for catheter salvage in selected cases, with early diagnosis, organism-directed treatment, and close monitoring.