CLINICAL-SIGNIFICANCE OF EXIT-SITE INFECTIONS DUE TO XANTHOMONAS IN CAPD PATIENTS - A COMPARISON WITH PSEUDOMONAS INFECTION

We have assessed the clinical significance of exit-site infections sec ondary to Xanthomonas maltophilia in continuous ambulatory peritoneal dialysis (CAPD) patients, and compared them with episodes due to Pseud omonas. The study was a retrospective survey of all episodes of Xantho monas and Pseudomonas-related exit-site infections (ESI) in all patien ts treated in our unit between 1983 and 1992. Thirteen episodes of Xan thomonas-related ESI were observed in eight patients and 17 episodes o f Pseudomonas-related ESI were seen in 15 patients. Xanthomonas-relate d ESI was frequently associated with other microorganisms, while Pseud omonas-related ESI was not (66% versus 5%, P < 0.02). Only one episode of Xanthomonas-related ESI resulted in peritonitis and subsequent cat heter removal. after 15 months of resistant colonization. Another case was considered to be chronic and indolent, as the Xanthomonas-related ESI continued after 23 months of local treatment. The other 11 episod es were resolved either without treatment or with an antibiotic cream after 7-120 days. However, all but two episodes of Pseudomonas-related ESI required intravenous antibiotics (usually ceftazidime); seven pat ients developed peritonitis, and 11 required surgical catheter manipul ation (five external cuff extrusion, and six catheter removal) (1/13 X anthomonas-related versus 11/17 Pseudomonas-related ESI, P < 0.03). Mo st Xanthomonas-related ESI do not lead to peritonitis, and constitute a mild condition, easily treatable without parenteral antibiotics or c atheter replacement. The appearance of other associated organisms and the favourable evolution with local treatment suggest a saprophytic be haviour for Xanthomonas in our CAPD patients. On the contrary, Pseudom onas-related ESI is usually seven, requires parenteral antibiotics, fr equently leads to peritonitis, and requires catheter replacement.