Infections on foreign body: bacterial colonization of ureteric stents

Infection on foreign body : bacterial colonization of ureteric stents. The most frequent cause of the early removal of ureteric endoprostheses (double J) is generally nlte to bacterial colonization. In order to prevent or to restrict the prosthesis colonization, it is necessary to understand the maj or steps and the factors influencing the colonization. This is the reason w hy we aimed to extract the most relevant parameters influencing the bacteri al colonization from the observations made in vivo thanks to in vitro analy ses. We have studied in vivo the relationship between the bacterial coloniz ation of the endoprostheses, the urinary infections and the antibiotherapy. In vitro, we have defined the conditions promoting the primary adhesion of the mostly frequently isolated bacteria on endoprostheses. Surface propert ies of bacteria and materials have been compared to: - the bacterial count of infected double J samples with respect to bacterial species, - the bacte rial count of the infected samples with respect to pH and Ca2+, Mg2+ concen tration. The results show a great variability of the biomaterial surface pr operties which could be optimized, the fact that the urinary medium acidifi cation could lower the bacterial adhesion and the ambiguous role of Ca2+ an d Mg2+ ions which is discussed in this paper In the case of in vivo analyse s, the conflicting results between leucocyturia and bacteriuria lead to the detection of the bacterial colonization under antibiotic treatment. The ch aracterized urinary infection must warm the risk of pyelonephritis.