Detecting Bacterial Growth in Continuous Ambulatory Peritoneal Dialysis Effluent Using Two Culture Methods

BACKGROUND/AIMS: The aim of this study was to evaluate the peritonitis-causing bacteria detected in peritoneal fluid using a blood culture bottle in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). METHODS: One-hundred and eleven dialysates from 43 patients suspected of peritonitis related to CAPD were retrospectively evaluated between May 2000 and February 2008. In all cases, 5 to 10 mL of dialysate was inoculated into a pair of BacT/Alert blood culture bottles, and 50 mL of centrifuged dialysate was simultaneously inoculated into a solid culture media for conventional culture. The results were compared to those of the conventional culture method. Isolated microorganisms were compared between the two methods. RESULTS: The blood culture method was positive in 78.6% (88 / 112) of dialysate specimens and the conventional culture method in 50% (56 / 112, p < 0.001). CONCLUSIONS: The blood culture method using the BacT/Alert system is useful for culturing dialysates and improves the positive culture rate in patients with suspected peritonitis compared to the conventional culture method.