A Case of Peritoneal Dialysis-Related Peritonitis Caused by Kocuria rhizophila

A 63-year-old woman undergoing peritoneal dialysis (PD) presented to our hospital with abdominal pain, diarrhea, and cloudy PD effluent. An elevated white blood cell count in the PD effluent led to a diagnosis of PD-associated peritonitis. She was subsequently started on intraperitoneal cefazolin and ceftazidime, after which her condition improved rapidly. The peritonitis resolved after 21 days of therapy, with no subsequent relapse. Centrifuged PD effluent samples identified Kocuria rhizophila as the causative organism. Reports of PD-associated peritonitis caused by K. rhizophila are rare, with reported adult cases requiring PD catheter removal due to relapse. In contrast, this case was successfully resolved without catheter removal. The increasing use of advanced technologies, such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, is expected to lead to more reports of K. rhizophila-associated PD peritonitis in the future. Although biofilm formation by K. rhizophila is known to increase the risk of recurrent peritonitis, this case suggests that catheter removal may not always be necessary.