In vitro Effects of a Novel Coating Agent on Bacterial Biofilm Development on Ureteral Stents.

Ureteral stenting is a widely used method for non-invasive urinary drainage in ureteral obstruction. However, biofilm development due to transient bacteriuria can cause severe complications such as incrustation with subsequent obstruction as well as recurrent urinary tract infection. Apart from local ailment such as dysuria, this increases both stent replacement frequency and incidence of complications. In this work, we investigated in vitro the bacterial adhesion to a surface-attached and crosslinked poly(N,N-dimethylacrylamide) (PDMAA) hydrogel network, which is known for its non-fouling and protein repellent characteristics.

To mimic the conditions encountered in vivo, PDMAA coated and uncoated Cyclic Olefin Polymer (COP) slides as well as polyurethane coated glass slides were incubated in sterile human urine for 48 h. Colonization was then simulated by adding known uropathogens, cultivated from clinical urine samples (such as E. coli). After further incubation for 24 and 48 h, slides were washed and remaining, adherent bacteria solubilized by ultrasound. CFUs were counted after plating and incubation for 48 h of the resulting solution.

PDMAA reduced adherent E. coli about 5-fold on coated polyurethane glass slides as well as in PDMAA coated COP slides. With adherent E. faecalis and K. pneumoniae there was a tendency to decreased biofilm formation, but the difference was not statistically significant.

PDMAA reduces surface adherence of the most common uropathogen significantly. Assessment of clinical relevance and of the effect on further uropathogens needs further experimental and clinical evaluations.

Journal of endourology. 2018 Nov 20 [Epub ahead of print]

Tamas Szell, Franz Dressler, Hanna Goelz, Benjamin Bluemel, Arkadiusz Miernik, Thomas Brandstetter, Frank Scherag, Dominik Stefan Schoeb

University Medical Center Freiburg, Urology, Freiburg, Germany ; ., University Medical Center Freiburg, Urology, Freiburg, Germany ; ., Medical Center - University of Freiburg, Institute of Medical Microbiology and Hygiene, Freiburg, Germany ; ., Medical Center - University of Freiburg, Institute of Medical Microbiology and Hygiene, Freiburg, Germany ; ., University Medical Center Freiburg, Urology , Hugstetterstr. 55 , Freiburg, Germany , 79106 ; ., University of Freiburg, Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), , Freiburg, Germany ; ., University of Freiburg, Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), , Freiburg, Germany ; ., University Medical Center Freiburg, Department of Urology , Hugstetter Stra├če 55 , Freiburg, Germany , 79104 ; .