Abstract
Biliary stent blockage represents the main limitation of the use of such devices in relieving obstructive jaundice due to a variety of malignant and benign conditions. Microbiological and morphological analysis of the occluding sludge present on the inner surface of 30 biliary stents was performed to evaluate the different components of such material and the effect of the antibiotic treatment on the biofilm formation. A highly organized biofilm, constituted by microbial cells embedded in an amorphous matrix together with crystallized bile salts, was observed Enterococcus spp. represented the most common isolate from both occluded and non-occluded stents. The antibiotic therapy, while selecting for multi-resistant bacteria and fungi, might possibly delay the biofilm formation.