RESUMEN
Coagulase-negative staphylococci, part of the normal skin flora, frequently colonize bioprosthetic devices and are the most common cause of peritonitis in patients undergoing peritoneal dialysis. Using the API STAPH-IDENT system (Analytab Products, Plainview, New York) and plasmid pattern analysis, we investigated the importance of chronic carriage of coagulase-negative staphylococci in the development of peritonitis due to these organisms. During a nine-month period, 182 surveillance cultures of pericatheter skin and anterior nares from 30 patients yielded 102 strains of coagulase-negative staphylococci. Twelve of these patients had 20 episodes of peritonitis due to these organisms. Staphylococcus epidermidis accounted for 75% of surveillance and 79% of peritonitis-associated strains. By plasmid pattern analysis of 47 surveillance and 16 peritonitis-associated strains, only three patients carried identical coagulase-negative staphylococci on two or more occasions, and only three patients developed peritonitis due to organisms cultured previously from body surface sites.