Plasmid Profile and Slime Analysis of Coagulase-Negative Staphylococci from Capd Patients with Peritonitis

Little is known about the epidemiology of infections causing peritonitis in continuous ambulatory peritoneal dialysis (CAPD). The commonest cause, coagulase-negative staphylococci (C-NS), are normal skin flora. The main source is thought to be organisms from the patient's own skin or environment. Using plasmid profiles as an epidemiological marker, the authors identified cases in which surveillance skin cultures taken just before an episode of peritonitis were identical to those isolated from the effluent. On comparing the plasmid profiles from the effluent of patients who had multiple episodes over eight weeks, they identified two patterns. One group had different plasmid profiles between episodes of infection. The second group (the majority of the cases) had identical plasmid profiles between the initial episode and the second which occurred between 10 days and four weeks after stopping antibiotics. This suggests that, in most cases of recurrent infection studied, the second episode represented a reinfection or recurrence with the same organism (as the initial episode). Slime production did not discriminate those patients who would develop recurring peritonitis.