title: Changes in causative organisms and their antimicrobial susceptibilities in CAPD peritonitis: a single center's experience over one decade.
abstract: BACKGROUND
  In recent years, the rate of peritonitis during continuous ambulatory peritoneal dialysis (CAPD) has been significantly reduced. However, peritonitis remains a major complication of CAPD, accounting for considerable mortality and hospitalization among CAPD patients.
  
  
  OBJECTIVE
  To generate a "center tailored" treatment protocol for CAPD peritonitis by examining the changes of causative organisms and their susceptibilities to antimicrobial agents over the past 10 years.
  
  
  METHODS
  Retrospective review of the medical records of 1015 CAPD patients (1108 episodes of peritonitis) who were followed up from 1992 through 2001.
  
  
  RESULTS
  The overall incidence of peritonitis was 0.40 episodes/patient-year. The annual rate of peritonitis and the incidence of peritonitis caused by a single gram-positive organism were significantly higher in 1992 and 1993 compared with those in the rest of the years (p < 0.05). The incidence of peritonitis due to coagulase-negative staphylococcus (CoNS) decreased significantly over time, whereas there was no significant change in the incidence of Staphylococcus aureus (SA)-induced peritonitis. Among CoNS, resistance to methicillin increased from 18.4% in 1992-1993 to 41.7% in 2000-2001 (p < 0.05). In contrast, the incidence of methicillin-resistant SA was not different according to the calendar year. Catheter removal rates were significantly higher in peritonitis due to a single gram-negative organism (16.6%) compared with gram-positive peritonitis (4.8%, p < 0.005). The mortality associated with peritonitis was also higher in gram-negative (3.7%) compared with gram-positive peritonitis (1.4%), but there was no statistical significance. Among single gram-positive organism-induced peritonitis, catheter removal rates were significantly higher in SA (9.3%) than those in CoNS (2.9%, p < 0.01) and other gram-positive organisms (2.9%, p < 0.05). In peritonitis caused by CoNS, the methicillin-resistant group showed significantly higher removal rates than the methicillin-susceptible group (8.2% vs 1.0%, p < 0.01).
  
  
  CONCLUSIONS
  The incidence of peritonitis for 2001 decreased to less than half that for 1992, due mainly to a significant decrease in CoNS-induced peritonitis, whereas the proportions of peritonitis due to a single gram-negative organism and methicillin-resistant CoNS increased. These findings suggest that it is necessary to prepare new center-based guidelines for the initial empirical treatment of CAPD peritonitis.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Dong Ki
authors.initials: DK
authors.lastname: Kim
authors.forename: Tae-Hyun
authors.initials: TH
authors.lastname: Yoo
authors.forename: Dong-Ryeol
authors.initials: DR
authors.lastname: Ryu
authors.forename: Zhong-Gao
authors.initials: ZG
authors.lastname: Xu
authors.forename: Hyun Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Kyu Hun
authors.initials: KH
authors.lastname: Choi
authors.forename: Ho Yung
authors.initials: HY
authors.lastname: Lee
authors.forename: Dae-Suk
authors.initials: DS
authors.lastname: Han
authors.forename: Shin-Wook
authors.initials: SW
authors.lastname: Kang
mesh_terms: D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000009:adverse effects*; D010538:Peritonitis / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D012189:Retrospective Studies; D013997:Time Factors