Single Versus Combined Antibiotic Therapy 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)