A comparison of four culture methods for diagnosing infection in continuous ambulatory peritoneal dialysis.

Dialysate effluent from 41 patients presenting with 54 episodes of CAPD peritonitis was examined by four culture techniques, three employing methods for the lysis of peritoneal leucocytes. The most efficient method employed a distilled water lysis-centrifugation technique (81% of episodes culture-positive). Filtration (without leucocyte lysis) was less effective (74% culture-positive). The results of a mechanical leucocyte lysis technique were less satisfactory still, the culture positive rate of 74% being compromised by the recovery of the infecting organism in low numbers, and by an association with a high incidence of plate contamination. The results of a bile-salt lysis technique were the least satisfactory (67% culture-positive).