1 Department of Urology, Faculty of Medicine, Medical Center-University of Freiburg , Freiburg, Germany .
2 Institute of Medical Microbiology and Hygiene, Faculty of Medicine, Medical Center-University of Freiburg , Freiburg, Germany .
J Endourol. 2019 Mar;33(3):225-231. doi: 10.1089/end.2018.0616. Epub 2018 Dec 21.
Ureteral stenting is a widely used method for noninvasive 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 cross-linked poly(N,N-dimethylacrylamide) (PDMAA) hydrogel network, which is known for its nonfouling and protein-repellent characteristics.
To mimic the conditions encountered in vivo, PDMAA-coated and uncoated cyclic olefin polymer (COP) slides as well as polyurethane (PU)-coated glass slides were incubated in sterile human urine for 48 hours. Colonization was then simulated by adding known uropathogens, cultivated from clinical urine samples (such as Escherichia coli). After further incubation for 24 and 48 hours, slides were washed, and the remaining adherent bacteria were solubilized by ultrasound. CFUs were counted after plating and incubation for 48 hours of the resulting solution.
PDMAA reduced adherent E. coli about fivefold on coated PU glass slides as well as in PDMAA-coated COP slides. With adherent Enterococcus faecalis and Klebsiella 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. German Clinical Trial Register ID: DRKS00013264 (approved WHO primary register).
输尿管支架置入术是一种广泛应用于治疗输尿管梗阻的非侵入性尿引流方法。然而，由于短暂性菌尿，生物膜的发展可导致严重并发症，如随后的阻塞和复发性尿路感染。除了局部疾病，如尿痛，这会增加支架更换的频率和并发症的发生率。在这项工作中，我们研究了一种表面附着和交联的聚（N，N-二甲基丙烯酰胺）（PDMAA）水凝胶网络的体外细菌黏附，该水凝胶网络以其非粘性和抗蛋白特性而闻名。
为了模拟体内遇到的情况，将涂有和未涂有聚环烯烃（COP）的 PDMA 涂层以及涂有聚氨酯（PU）的玻璃载玻片在无菌人尿中孵育 48 小时。然后通过添加从临床尿液样本（如大肠杆菌）培养的已知尿路病原体来模拟定植。孵育 24 和 48 小时后，将载玻片洗涤，并用超声溶解剩余的黏附细菌。将所得溶液涂板并孵育 48 小时后，计算 CFU。
PDMAA 将黏附的大肠杆菌减少了约五倍，无论是在涂有 PDMA 的 PU 玻璃载玻片上，还是在涂有 PDMAA 的 COP 载玻片上。黏附的粪肠球菌和肺炎克雷伯菌的生物膜形成有减少的趋势，但差异无统计学意义。
PDMAA 显著减少了最常见的尿路病原体的表面黏附。对临床相关性和对其他尿路病原体的影响需要进一步的实验和临床评估。德国临床试验注册 ID：DRKS00013264（WHO 初级注册批准）。
