Introduction:

Paracoccus yeei is a Gram-negative coccobacilli which is often an environmental organism. However, infection of patients usually with underlying immunosuppression has been described in the last decades, mainly due to the emergence of diagnostic molecular methods.
Case presentation:
We describe here a case of P. yeei peritonitis in a patient undergoing peritoneal dialysis. Turbidity of the peritoneal dialysate was the sole clinical manifestation. Inflammatory markers were not raised. A peritoneal fluid specimen showed increased white-cell count, but no organisms were seen on Gram stain. MALDI-TOF mass spectrometry identified P. yeei as the infectious agent. Patient was successfully treated with gentamicin. Minimum inhibitory concentration analysis suggested P. yeei to be sensitive to aminoglycosides and specific betalactams but not to ciprofloxacin and ceftazidime, in line with previous literature.
Discussion:
This case of P. yeei peritoneal-dialysis peritonitis contributes to accumulating evidence on the emergent role of this organism as a relevant human pathogen. It also provides information about antibiotic resistance patterns that helps to guide therapy more specifically and effectively.