To compare the efficacy of single versus combined antibiotic therapy for bacterial peritonitis in CAPD patients.

To compare relapse and recurrent rate of peritonitis between single and combined antibiotic regimens for bacterial peritonitis in CAPD patients.

Inclusion Criteria:

• age >/= 18 years old
• ESRD patients on continuous ambulatory peritoneal dialysis more than 4 weeks
• presence of symptom or sign of peritonitis
• presence of WBC >100cell/mm3 with PMN >50% in peritoneal dialysate or gram stain positive for gram positive or gram negative bacteria

Exclusion Criteria:

• presence of polymicrobial organism, non-fermentative gram negative organism, fungus, mycobacteria in peritoneal fluid or culture-negative
• peritonitis from the organisms that required combined antibiotic therapy according to ISPD guideline 2010
• hospital-acquired peritonitis
• presence of catheter-related infection
• history of peritonitis within 4 weeks
• currently taking antibiotic
• allergic to the antibiotic that used in the study(penicillin or cephalosporin or quinolone or aminoglycoside)