Peritoneal Dialysis-Related Peritonitis Caused by Microbacterium paraoxydans

A 54-year-old woman receiving continuous ambulatory peritoneal dialysis was admitted, complaining of diffuse abdominal pain. Peritoneal fluid cell analysis showed that the white blood cell count was 2,990 cells/mm(3), with a neutrophil count of 2,510 cells/mm(3). The patient was treated empirically with intraperitoneal cefazolin and ceftazidime. After 6 days, Microbacterium species grew on a peritoneal dialysate culture that had been collected on the day of admission. We analyzed the 16S rRNA gene nucleotide sequence and identified the organism as Microbacterium paraoxydans. Based on the results of the antibiotic susceptibility test, the patient was treated with intraperitoneal vancomycin and oral clarithromycin. She recovered uneventfully without interruption of peritoneal dialysis. This is a unique case of peritoneal dialysis-related peritonitis due to M. paraoxydans.