Abstract
Biofilm formation on catheters is thought to contribute to persistence of catheter-associated urinary tract infections (CAUTI) which represent the most frequent nosocomial infections. Understanding of factors relevant for CAUTI pathogenesis and evaluation of new therapeutics or interference strategies requires a model system that mirrors the physico-chemical conditions prevailing in a catheterized human bladder. The described in vitro dynamic model of a catheterized bladder enables to emulate many of the characteristics of a catheterized human bladder albeit in the absence of a bladder epithelium. A minor modification compared to the original model system (Stickler, et al., 1999) allows temperature maintenance of the top 10 cm of the catheter, thereby enabling reproducible monitoring of biofilm formation on the internal catheter surface.
Materials and Reagents
Equipment
Procedure
Representative data
Figure 7. Effect of random mutations on competitive bladder and catheter colonization. Dynamic catheterized bladder models were inoculated with equal amounts of Proteus mirabilis HI4320 wild type and transposon mutant cells HI4320mut1 and HI4320mut2, respectively. Following irrigation with artificial urine for 24 h, population distribution in the residual urine of the artificial bladder and on the internal catheter surface was determined based on CFU. CI values indicate the ratio between the mutant type and the wild type strain in the output (bladder suspension or catheter) divided by the ratio of the two strains in the inoculum. Symbols represent CI values obtained in individual experiments, the line indicates the mean CI value.
Notes
Recipes
Acknowledgments
Establishment of the protocol in the lab was funded by the Austrian Science Fund FWF: P21434-B18 (to A.R.). The protocol is adapted and modified from a previous protocol (Stickler et al., 1999).
References
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