# Building a community: examining polymicrobial Interactions within urinary catheter biofilms and their contribution to infection severity

> **NIH NIH F31** · STATE UNIVERSITY OF NEW YORK AT BUFFALO · 2024 · $33,776

## Abstract

Project Summary
Urinary tract infections are among the most common healthcare associated infection, of which up to 80% are
due to a urinary catheter. Catheter associated urinary tract infections (CAUTIs) are linked to an increased risk
of recurrent infection, renal damage, and secondary bacteremia. These types of infections have been found to
be largely polymicrobial, with 3 or more species of bacteria present during both asymptomatic colonization and
active infection. We and others have shown that the most common partners are Proteus mirabilis (Pm),
Escherichia coli (Ec), and Enterococcus faecalis (Ef), all of which form robust catheter. Previous work done by
our lab has shown that co-culture of Pm and Ef causes a dramatic increase in biofilm biomass that is mediated
by an increase in biofilm-associated proteins content, and specific adhesins, fimbria, and metabolism-related
proteins were enriched in the polymicrobial biofilm. Our lab has also shown that coinfection with Pm and Ef
increases disease severity in a mouse model of CAUTI, and that biofilm-enhancing interactions contribute to
this process. Considering that CAUTIs often involve various combinations of Pm, Ec, and Ef, and not all dual-
species interactions increase biofilm biomass, there is a gap in knowledge regarding how interactions between
each of these three species influence catheter biofilm formation and infection progression. We aim to examine
the impact of polymicrobial interactions on biofilm architecture, to identify protein mediators of polymicrobial
biofilm enhancement, and determine their contribution to the progression and severity of polymicrobial CAUTI.
Aim 1 will examine the architecture and spatial distribution of each species in single, double, and triple species
biofilms using a combination of scanning electron microscopy and high-resolution fluorescence microscopy.
Aim 2 will identify and characterize protein mediators of biofilm enhancement using LC-MS/MS. The top three
proteins enriched in polymicrobial biofilms with increased biomass will be selected for further study, and
mutants will be made in each. Using a two-pronged approach, we will determine the contribution of enriched
proteins to biofilm enhancement in our standard 24- well plate assay and in our established “glass bladder”
model, in which biofilms are formed directly on Foley catheters under simulated urine flow. This system is a
physiologically relevant in vitro assay that closely mimics conditions occurring in a catheterized patient. Aim 3
will determine the impact of triple species interactions on infection and severity. Previous data from our lab has
demonstrated that dual species interactions increase the incidence of bacteremia and urolithiasis in the CAUTI
mouse model. We will examine differences in the progression and severity of triple species infection compared
to each dual species infection, and will also determine the contribution of one protein mediator of biofilm
enhancement to polymicro...

## Key facts

- **NIH application ID:** 10901185
- **Project number:** 1F31AI183838-01
- **Recipient organization:** STATE UNIVERSITY OF NEW YORK AT BUFFALO
- **Principal Investigator:** Steven Marcel Taddei
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $33,776
- **Award type:** 1
- **Project period:** 2024-06-01 → 2027-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10901185

## Citation

> US National Institutes of Health, RePORTER application 10901185, Building a community: examining polymicrobial Interactions within urinary catheter biofilms and their contribution to infection severity (1F31AI183838-01). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10901185. Licensed CC0.

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