Abstract: Objective To explore the causes, pathogenic bacteria and outcome of peritoneal dialysis-related peritonitis in order to provide the bases for the prevention of peritonitis. Methods We recruited CAPD patients suffered from peritoneal dialysis-related peritonitis and treated in the Peritoneal Dialysis Center of Beijing Luhe Hospital, Capital Medical University in the period from Jan. 2013 to Dec. 2015. Their causes, pathogenic bacteria and outcome were analyzed. Results A total of 96 patients with peritoneal dialysis-related peritonitis were enrolled in this study. The main causes for peritoneal dialysis-related peritonitis were misconducted manipulation of fluid exchange (35 cases, 36.5%) and intestinal infection (27 cases, 28.1%). Bacterial culture for peritoneal fluid was positive in 63 cases (65.6%), including Gram-positive cocci (38 cases, 60.3%), Gram-negative bacilli (18 cases, 28.6%), fungi (4 cases, 6.3%), and mixed bacteria (3 cases). Drug sensitivity tests showed that Gram-positive cocci were sensitive to vancomycin and linezolid in all strains, and had higher resistance rate to erythromycin (69.2%), penicillin (68.4%), cefoxitin (46.7%) and cefazolin (45.9%). Gramnegative bacilli were sensitive to imipenem in all strains, and had higher resistance rate to cefazolin (53.8%) and ceftazidime (38.5%). The cure rate of gram-positive cocci peritonitis was higher than that of gram-negative bacilli (χ2=5.661, P=0.017), fungi (χ2=26.526, P＜0.001) and mixed bacteria peritonitis (χ2=11.907, P=0.001). The dropout rate of fungal peritonitis was higher than that of gram- positive cocci (χ2=26.526, P＜0.001), gram- negative bacilli (χ2=4.390, P=0.036) and microbial- negative peritonitis (χ2=11.485, P=0.010). The mortality rate of fungal peritonitis was higher than that of gram- positive cocci (χ2=26.526, P＜0.001), gram-negative bacilli (χ2=6.016, P=0.010) and microbial-negative peritonitis (χ2=32.918, P＜0.001). Conclusions The main causes of peritoneal dialysis-related peritonitis in this center were misconducted manipulation of fluid exchange and intestinal infection. Gram-positive cocci were the main pathogenic bacteria. The pathogenic bacteria had various degrees of resistance to cefazolin and ceftazidime that are recommended by the guidelines of International Society for Peritoneal Dialysis (ISPD). The cure rate of gram-positive cocci peritonitis was higher with better prognosis. The dropout rate and mortality rate of fungal peritonitis were higher with relatively poor prognosis.

Key words: Peritoneal dialysis, Peritoneal dialysis-related peritonitis, Pathogenic bacterium