Continuous ambulatory peritoneal dialysis (CAPD) peritonitis: the effect of antibiotic on the adherence of coagulase-negative staphylococci to silicone rubber catheter material.

Peritonitis is the major complication of continuous ambulatory peritoneal dialysis (CAPD) and is caused predominantly by coagulase-negative staphylococci (CNS). Adherence to the silicone rubber Tenckhoff catheter has been identified as one factor in the pathogenesis and persistence of these infections. We have studied the adherence of CNS from patients and controls to silicone rubber in an in vitro model to determine whether this phenomenon can be modified by antibiotics. Adherence was strong for 7/27 (26%) CAPD isolates and for 3/27 (11%) of control strains. The strongly adherent CAPD isolates, when exposed to subinhibitory concentrations of vancomycin, cefuroxime, and ciprofloxacin, showed minimal alteration in adherence with vancomycin in both broth and used dialysate, whereas cefuroxime and ciprofloxacin both significantly reduced it. These observations may have implications for drug selection and prevention of CAPD peritonitis caused by CNS.