<i>Enterococcus faecalis</i> Polymicrobial Interactions Facilitate Biofilm Formation, Antibiotic Recalcitrance, and Persistent Colonization of the Catheterized Urinary Tract

• Main Authors: Jordan R. Gaston, Marissa J. Andersen, Alexandra O. Johnson, Kirsten L. Bair, Christopher M. Sullivan, L. Beryl Guterman, Ashely N. White, Aimee L. Brauer, Brian S. Learman, Ana L. Flores-Mireles, Chelsie E. Armbruster
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: Pathogens
• Subjects: proteus mirabilis; enterococcus faecalis; polymicrobial; biofilm; catheter; urinary tract infection
• Online Access: https://www.mdpi.com/2076-0817/9/10/835

Indwelling urinary catheters are common in health care settings and can lead to catheter-associated urinary tract infection (CAUTI). Long-term catheterization causes polymicrobial colonization of the catheter and urine, for which the clinical significance is poorly understood. Through prospective assessment of catheter urine colonization, we identified <i>Enterococcus faecalis</i> and <i>Proteus mirabilis</i> as the most prevalent and persistent co-colonizers. Clinical isolates of both species successfully co-colonized in a murine model of CAUTI, and they were observed to co-localize on catheter biofilms during infection. We further demonstrate that <i>P. mirabilis</i> preferentially adheres to <i>E. faecalis</i> during biofilm formation, and that contact-dependent interactions between <i>E. faecalis</i> and <i>P. mirabilis</i> facilitate establishment of a robust biofilm architecture that enhances antimicrobial resistance for both species. <i>E. faecalis</i> may therefore act as a pioneer species on urinary catheters, establishing an ideal surface for persistent colonization by more traditional pathogens such as <i>P. mirabilis</i>.