# MOLECULAR BASIS OF E. COLI COLONIZATION

> **NIH NIH R01** · UNIVERSITY OF RHODE ISLAND · 1989 · $115,598

## Abstract

The molecular basis of E. coli colonization of the intestinal tract will be
investigated using a mouse model.  The proposed research focuses on the
nature of the molecular interactions which occur at the mucosal surface and
the role of such interactions in colonization.  The proposal consists of
three parts.  In part one, the role of bacterial motility, chemotaxis, and
adhesion, in colonization of the large intestine will be investigated using
mutants of normal human fecal E. coli and avirulent S. typhimurium.  Two
general categories of mutants will be employed.  First, mutants of E. coli
and S. typhimurium known to possess an impaired ability to colonize the
large intestines of streptomycin-treated mice, relative to the parent
strain, will be assayed for chemotaxis toward mucus and the ability to
penetrate mucus in vitro.  Second, mutants of E. coli and s. typhimurium
will be selected for specific defects in motility, chemotaxis, adhesion to
mucosal components, and ability to penetrate mucus in vitro, and the
relative colonizing abilities of the mutants will be assessed in vivo.  In
part two, the receptors and bacterial adhesins responsible for in vitro
adhesion to mucus and epithelial cell brush borders will be identified,
purified and characterized.  These studies include further characterization
of the outer membrane adhesins of E. coli F-18, E. coli F-17, and S.
typhimurium, and the respective cecal and colonic mucus and brush border
receptors for these strains.  In addition, the adhesive properties of a
wide variety of nonpathogenic E. coli will be assessed for their ability to
adhere to mucus and brush border receptors immobilized on polystyrene, and
the receptors involve in adhesion will be separated and identified by means
of gel filtration, SDS-PAGE, and Western blot analysis.  In part three, the
mucus and brush border receptors responsible for the adhesion of selected
enterotoxigenic E. coli to the mucosal surface of the small intestine will
be identified, characterized and compared.  Additional experiments designed
to examine the relationship between in vitro adhesion to specific receptors
and in vivo colonization will be conducted.  The overall objectives of the
proposed research are to further characterize the interactions which occur
at the mucosal surface, further investigate and characterize the components
involved in these interactions, and clarify the role of such interactions
in the bacterial colonization of the intestinal tract.

## Key facts

- **NIH application ID:** 3126645
- **Project number:** 5R01AI016370-10
- **Recipient organization:** UNIVERSITY OF RHODE ISLAND
- **SAM.gov UEI:** CJDNG9D14MW7
- **Principal Investigator:** Paul S. Cohen
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1989
- **Award amount:** $115,598
- **Award type:** 5
- **Project period:** 1980-09-01 → 1991-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3126645

## Citation

> US National Institutes of Health, RePORTER application 3126645, MOLECULAR BASIS OF E. COLI COLONIZATION (5R01AI016370-10). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3126645. Licensed CC0.

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