[Capnocytophaga spp. peritonitis in a peritoneal dialysis: A case report]

Capnocytophaga spp. is a slow-growing bacterium that forms a part of the normal oral flora of dogs and cats. In peritoneal dialysis, only seven cases have been reported. We report the observation of a case of peritonitis with Capnocytophaga spp. in a patient on peritoneal dialysis who lives with a cat.

A 64-year-old woman with chronic end stage renal disease due to chronic interstitial nephropathy on automated peritoneal dialysis has been admitted for diffuse abdominal pain. The dialysis fluid was cloudy with 11,250 elements/mm³, of leukocytes. Direct examination was negative. The C-reactive protein was 165mg/L. Intraperitoneal probabilistic antibiotic therapy was initiated 1g of cefazolin and 1g of ceftazidime per day. After eight days, aerobic culture was negative, the anaerobic one was positive to gram negative bacilli, but the identification could not be possible with MALDI-TOF mass spectrometry. Antibiotic therapy was continued by ceftazidime for 21 days. The evolution was marked by the improvement of the clinical and biological state of the patient. The germ was finally identified using the genomic 16S rRNA sequencing technique. This is Capnocytophaga spp. Investigation then revealed that the patient's cat sometimes entered her room at the time of connection of peritoneal dialysis.

The case of our patient once again reveals the diagnostic difficulties posed by Capnocytophaga spp. Innovative techniques, such as MALDI-TOF-MS or genomic sequencing of ribosomal RNA, should be further used in peritoneal dialysis in the diagnosis of peritonitis.