Use of pulsed-field gel electrophoresis in the analysis of recurrent Staphylococcus aureus infections in patients on continuous ambulatory peritoneal dialysis

Background/Aim: The purpose of this study was to evaluate pusled-field gel electrophoresis (PFGE) for distinguishing between relapse and reinfection of Staphylococcus aureus infections in patients on continuous ambulatory peritoneal dialysis (CAPD). Methods: Between July 1993 and May 1997, 4 patients with recurrent CAPD-associated infections caused by S. aureus we enrolled in this study. There were nine episodes of peritonitis, one episode of temporary double lumen catheter infection, a nd one episode of Hickman catheter infection. A total of eleven S. aureus isolates were collected from peritoneal fluid (n = 9) and blood (n = 2). PFGE typing was applied. Results: In our study, from PFGE typing, the 11 S. aureus isolates were classified into seven patterns. Antibiogram profiling classified only four patterns. Patient A had a reinfection by another strain of S. aureus, and patient B had three episodes of peritonitis caused by the same strain of S. aureus due to exit site infections. Patient C had two episodes of CAPD peritonitis caused by two different strains, respectively. Patient D had four episodes of S. aureus infection (three CAPD peritonitis and one bacteremia); the first two episodes of peritonitis were caused by an identical strain of S. aureus, whereas the subsequent two infections were caused by other organisms. Conclusion: PFGE has a high discriminatory power and can be an assistant method to antibiogram profiling for distinguishing relapse from reinfection in CAPD-associated peritonitis. Copyright (C) 2000 S. Karger AG, Basel.