# Molecular mechanisms of uropathogenesis

> **NIH NIH R01** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 2020 · $491,010

## Abstract

Uropathogenic bacteria must acquire nutrients present in urine or those released by an inflamed or damaged
epithelium to successfully colonize the urinary tract. Our long term goal is to understand the contribution of each
virulence factor and core gene that allows uropathogens to colonize, persist, and damage the urinary tract. Our
overall objective is to identify and study essential transporters required by uropathogenic Escherichia coli
(UPEC), a cause of uncomplicated urinary tract infection (UTI), and Proteus mirabilis, a cause of catheter-
associated UTI, for growth and survival in the human urinary tract. Both E. coli and P. mirabilis are members of
the Enterobacteriaceae, are motile, produce numerous and distinct fimbriae with which they mediate adherence
to the uroepithelium, secrete hemolysins and proteases, and elaborate siderophores and heme-binding proteins
to capture iron from the host. While we have previously studied all of these classes of virulence determinants,
we now propose to focus on transport systems as critical functions for the survival of these two pathogens. In
this proposal, we will advance the central hypothesis that uropathogenic E. coli and P. mirabilis differentially
employ transport systems, unique to each species, to acquire peptides/amino acids and sugars, respectively, to
establish fitness advantages in the urinary tract. We will test this hypothesis by carrying out the following specific
aims: 1) Identify specific transport systems required for the development of urinary tract infection by
uropathogenic Escherichia coli and Proteus mirabilis. 2) Determine the kinetic parameters of unique and
common transporters that contribute to the virulence of uropathogenic Escherichia coli and Proteus mirabilis in
the urinary tract. In the first aim, we will identify genes from among 643 identified transporter genes of E. coli and
386 identified transport genes of P. mirabilis, that when mutated result in a fitness defect in the mouse model of
ascending UTI. We will use a Tn-seq screen of ordered transposon libraries of both species in the mouse model
of UTI, expression data from in vivo RNA-seq transcriptomes, transurethral cochallenge of mice with clean
deletion mutants vs the wild type strain, and urine metabolomes to select transporters for further study. In the
second aim, prioritized transporters will be characterized for growth in filter-sterilized human urine, minimal
medium containing the known or suspected substrate, and Biolog assays to confirm substrates and identify
transporters that share the same substrate. Kinetics of substrate uptake [KT (affinity for substrate) and Vmax (rate
of transport)] will be measured using radiolabeled substrates. Finally, a hierarchy of transporters will be
established for UPEC and P. mirabilis. The expected outcome of conducting these aims will be to characterize
key transport systems and their substrates of our two most troublesome uropathogens. The positive impact will
include...

## Key facts

- **NIH application ID:** 10048340
- **Project number:** 2R01AI059722-15A1
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **Principal Investigator:** HARRY L. MOBLEY
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $491,010
- **Award type:** 2
- **Project period:** 2005-08-01 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10048340

## Citation

> US National Institutes of Health, RePORTER application 10048340, Molecular mechanisms of uropathogenesis (2R01AI059722-15A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10048340. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*