Antibiotic prophylaxis in an animal model of chronic peritoneal exposure

Acute infection in an animal model of chronic peritoneal dialysis (PD) induces structural changes in the peritoneum and altersfunctional characteristics of transport. These changes may compromise observations of the chronic effects of dialysis solutions. To test the hypothesis that antibiotics would prevent acute infection without affecting transport and structural properties, we characterized the frequency of infection in our rat model of PD and examined whether the inclusion of antibiotics in the dialysis solution altered the transport and structural properties of the peritoneum.

Female Sprague-Dawley rats were aseptically injected daily under gas anesthesia with 30 - 40 mL of a sterile solution for 2 months via a peritoneal catheter tunneled to a subcutaneous port. Solutions used were Krebs-Ringer bicarbonate (KRB) alone, KRB with antibiotics (cefazolin 200 mg/L and gentamicin 2 mg/L), KRB with 4% glucose, and KRB with both glucose and antibiotics. After 2 months, osmotic filtration andsolute transport were assessed in each animal and peritoneal fluid was collected for bacterial culture. Angiogenesis was evaluated by quantitative image analysis of tissue sections stained with CD31. Tissue content of collagen, hyaluronic acid, and sulfated glycosaminoglycan was determined.

Technique survival (successful PD for 2 months) and infection rate were comparable among all treated groups. There were no differences between the groups in transport properties. Structural changes were comparable between groups, with or without antibiotics.

Addition of antibiotics to the dialysis solution did not affect thetransport characteristics of the peritoneum or the pathologic reaction of the tissue to the PD solution.