Colonization-Resistant Antimicrobial-Coated Peritoneal Dialysis Catheters: Evaluation in a Newly Developed Rat Model of Persistent Pseudomonas Aeruginosa Peritonitis

OBJECTIVE: Development of a rat model of persistent peritonitis and evaluation of the ability of liposomal ciprofloxacin hydrogel-coated silicone to resist colonization. DESIGN: A newly developed model of persistent Pseudomonas aeruginosa peritonitis to compare the ability of liposomal ciprofloxacin hydrogel (LCH)-coated silicone versus plain silicone for resistance to bacterial colonization. ANIMALS: Male Sprague-Dawley rats. RESULTS: Inoculating the peritoneum of rats with 1 mL 0.5% agar containing 10(6) colony-forming units (cfu)/mL P. aeruginosa in the presence of a plain silicone coupon resulted in persistent peritonitis for at least 7 days. Plain silicone coupons in all 40 rats were colonized (median 2.54 x 10(3) cfu/cm2; range 5.0 x 10(1)-1.0 x 10(6) cfu/cm2) and peritoneal washings were consistently culture-positive. In contrast, the LCH coupons removed after 7 days from the 40 test rats were sterile, as were the peritoneal washings, and there was no evidence of peritonitis. Blood cultures were negative in both groups. CONCLUSIONS: Liposomal ciprofloxacin hydrogel-coated silicone resists colonization in this rat model of persistent P. aeruginosa peritonitis.