Bacterial interference using non-pathogenic Escherichia coli 83972 is a novel strategy for preventing catheter-associated urinary tract infection (CAUTI). Crucial to the success of this strategy is to establish a high coverage and stable biofilm of the non-pathogenic bacteria on the catheter surface. However, this non-pathogenic strain is sluggish to form biofilms on silicone as the most widely used material for urinary catheters. We have addressed this issue by modifying the silicone catheter surfaces with mannosides that promote the biofilm formation, but the stability of the non-pathogenic biofilms challenged by uropathogens over long-term remains a concern. Herein, we report our study on the stability of the non-pathogenic biofilms grown on propynylphenyl mannoside-modified silicone. The result shows that 94% non-pathogenic bacteria were retained on the modified silicone under >0.5 Pa shear stress. After being challenged by three multidrug-resistant uropathogenic isolates in artificial urine for 11 days, large amounts (>4 × 106 CFU cm-2) of the non-pathogenic bacteria remained on the surfaces. These non-pathogenic biofilms reduced the colonization of the uropathogens by >3.2-log.
In bacterial interference, the non-pathogenic Escherichia coli strains are sluggish to form biofilms on the catheter surfaces, due to rapid removal by urine flow. We have demonstrated a solution to this bottleneck by pre-functionalization of mannosides on the silicone surfaces to promote E. coli biofilm formation. A pre-conjugated high affinity propynylphenyl mannoside ligand tethered to the nanometric amino-terminated poly(amido amine) (PAMAM) dendrimer is used for binding to a major E. coli adhesin FimH. It greatly improves the efficiency for the catheter modification, the non-pathogenic biofilm coverage, as well as the (long-term) stability for prevention of uropathogen infections.
Acta biomaterialia. 2017 Oct 09 [Epub]
Zhiling Zhu, Fei Yu, Haoqing Chen, Jun Wang, Analette I Lopez, Quan Chen, Siheng Li, Yuyu Long, Rabih O Darouiche, Richard A Hull, Lijuan Zhang, Chengzhi Cai
Department of Chemistry, University of Houston, Houston, TX 77204, United States., School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China., Center for Prostheses Infection and Departments of Medicine, Surgery, and Physical Medicine and Rehabilitation, Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, TX 77030, United States., Department of Molecular Biology and Microbiology, Baylor College of Medicine, Houston, TX 77030, United States., Department of Chemistry, University of Houston, Houston, TX 77204, United States. Electronic address: .