Patient's cells colonize the biofilm of Tenckhoff catheters used in peritoneal dialysis

Abstract

Peritoneal dialysis (PD) is a renal substitutive therapy based on the infusion of a dialysate in the peritoneum, which induces through an osmotic gradient the ultrafiltration of water and the clearance of blood stream impurities by the peritoneal membrane. The colonization of Tenckhoff catheters (TCs) used in PD by pathogenic microorganisms can lead to peritonitis, and probably catheter removal. Here, optical microscopy and scanning electron microscopy were applied to study biofilm formation in 11 TCs. Biofilms varied in their morphology and thickness. Short-term catheters (6 months) presented thinner deposits (3 μm) with granular or flat morphologies, either on the intraluminal or external surfaces. Bacterial colonies were found on catheters from infected patients. A tendency was observed for long-term catheters (6–8 years) to present thicker biofilms (30–35 μm). Surprisingly, patients' cells colonized the deep layers of the thicker biofilms, forming a complex multicelullar community. It was concluded that the presence of a biofilm is not necessarily related with peritonitis, and biofilm features may correlate to the therapy time.

Keywords:

• biofilm
• optical microscopy
• peritoneal dialysis
• peritonitis
• SEM
• Tenckhoff catheter

Acknowledgements

The authors thank Nicole Thompson (NIDCD, NIH, Bethesda, MD) for the English revision; Dr Cláudia S. Ribeiro, Dr Arnauld Kaufman and Dr Luis Carlos Pereira (GAMEN, RJ) for the catheter harvesting and laboratory support, and Dr André Barreira for the critical reading of the manuscript. Andre Guerra e Silva was a Master student of the Programa de Ciências Morfológicas (PCM), ICB, UFRJ. This study was supported by Conselho Nacional de Desenvolvimento Tecnologico (CNPq).