Presentation Authors: Cristian Trejo*, Bryan, TX, Vivian Nguyen, Nicole J. DeNisco, Kelli L. Palmer, Richardson, TX, Philippe Zimmern, Dallas, TX
Introduction: Community-acquired urinary tract infections (UTIs) are the most commonly reported infection in adults and have a high rate of recurrence in postmenopausal women (1). In murine models, uropathogenic Escherichia coli (UPEC) invades the bladder urothelium and forms intracellular bacterial reservoirs (IBCs) as a key part of the infection cycle. However, UPEC strains had not been previously isolated from the bladder wall of human RUTI patients (2). The goal of this study was to isolate UPEC strains from bladder wall biopsies of postmenopausal RUTI patients ungergoing cystoscopy with fulguration of trigonitis (CFT) in order to study the virulence factors and adaptations important for effective colonization of the human bladder
Methods: Following IRB approval, bladder biopsies were obtained from consenting women meeting study criteria for antibiotic-refractory RUTIs who had elected CFT. Biopsies were obtained in the operating room under anesthesia, placed directly in a solution of 100 ug/mL penicillin and gentamicin, and incubated for >2 hours at room temperature to eliminate extracellular bacteria. Tissue was then washed with sterile 1X PBS three times, homogenized, and plated on Chromagar to culture bacteria. UPEC tissue isolates were obtained from two patients. Swim assays in 3% LB agar were performed on two tissue isolates from each patient as well as the lab E. coli strain DH5Î± as a control. Motility was recorded 24 and 48 hours post-inoculation.
Results: The figure depicts representative swim assay results at 24 and 48 hours post-inoculation for isolates from patients PNK004 (A) and PNK006 (B). All UPEC tissue isolates demonstrated enhanced swimming motility at both 24 and 48 hours post-inoculation compared to the control DH5Î± E. coli strain.
Conclusions: Previously, flagella-mediated swimming motility was found to be important for competitive colonization of the murine urinary tract by sepsis isolate CFT073 (3). In this preliminary study, the UPEC tissue isolates from RUTI patients demonstrated enhanced swimming motility compared to DH5Î±. These findings suggest that flagella-mediated swimming motility may be an important virulence factor for UPEC during human RUTI. Further work is needed to understand the molecular basis of hypermotility in these isolates._x000D_
REFERENCES1. J Infect Dis. 2001 Mar 1; Suppl 1, S1-42. Proc Natl Acad Sci U S A. 2004 Feb 3; 101:1333-13383. Infection and Immunity 2005 Nov; 73(11): 7644â€“7656