Isolation of organisms in CAPD peritonitis: a comparison of two techniques.

The identification of organisms is important in the treatment of continuous ambulatory peritoneal dialysis (CAPD) peritonitis. We compared two techniques for isolating organisms in CAPD peritonitis. Clinical and microbiologic data on all episodes of peritonitis from 1991-1993 were prospectively recorded. The isolation of organisms from 77 episodes of peritonitis was done using the conventional centrifugation culture method from 1991-1992; the isolation of organisms from 121 episodes of peritonitis was done using the BACTEC method from 1992-1993. The total culture-positive rates were 75% for the BACTEC technique and 58% for the conventional technique (p = 0.05), with a higher isolation rate for gram-negative organisms (36% vs 18%, p < 0.05). In the isolation of organisms from new episodes of peritonitis, the culture-positive rates were significantly higher for the BACTEC than for the conventional technique (82% vs 55%, p < 0.01). The recovery rates of organisms for both techniques were similar for relapse peritonitis. The treatment outcomes of CAPD peritonitis for the two technique groups, and for the culture-positive and culture-negative groups were not significantly different. In conclusion, the BACTEC method yielded a higher rate of positive cultures for CAPD peritonitis, but did not affect treatment outcome of the infections.