# GENETICS VIRULENCE IN PSEUDOMONAS AERUGINOSA

> **NIH NIH R01** · UNIVERSITY OF COLORADO DENVER · 1987 · $116,863

## Abstract

Pseudomonas aeruginosa produces a variety of extracellular products which
may play a significant role in the pathogenesis of Pseudomonas infections
in experimental animal models and in humans.  In addition we and others
have shown that the virulence of Pseudomonas is dependent upon its ability
to acquire iron (Fe) or inorganic phosphate (Pi) from the environment and
jthat production of some virulence determinants is regulated by these
ions.  Of the extracellular products of P. aeruginosa, two toxins along
with protease have been mentioned prominently in the Pseudomonas literature
as likey candidates for major virulence determinants.  They are Exotoxin A
which has a mechanism of action like diphtheria toxin and the Heat-labile
Hemolysin (Phospholipase C) which has a mechanism of action like the alpha
toxin of Clostridium perfringens.  However, the actual importance of  these
toxins in the pathogenesis of even on kind of Pseudomonas infection is not
yet fully understood.  In addition, the specific mechanism by which this
opportunistic pathogen is able to acquire Fe and Pi from the environment
and the importance of these mechanisms in the virulence of Pseudomonas have
not been elucidated.  The overall goal of this research is to elucidate the
genetic and biochemical bases for the virulence of P. aeruginosa.  These
studies may ultimately lead to the rational development of immunotherapy
and/or immunoprophylaxis for infections caused by this opportunistic
pathogen.  The immediate objectives are as follows:  1)  we will isolate
well-defined mutants whih are altered in their ability to produce virulence
factors (toxins) or which are altered in their ability to acquire Fe or Pi
from the environment.  To accomplish this objective, we will use in vitro
recombinant DNA techniques or we will use in vivo classical microbial
genetic techniques (e.g., generation of R' factors) to clone genes for
virulence determinants.  2) We will generate mutations in those cloned
genes by in vitro or in vivo methods and then transfer the mutant genes to
wild-type Pseudomonas strains.  3) We will characterize the mutants in
detail by genetic and biochemical methods.  4) We will compare the
virulence of these well-defined, well-characterized mutants to the isogenic
parental strains in appropriate experimental animal models.

## Key facts

- **NIH application ID:** 3126499
- **Project number:** 5R01AI015940-08
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **SAM.gov UEI:** MW8JHK6ZYEX8
- **Principal Investigator:** Michael L. Vasil
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $116,863
- **Award type:** 5
- **Project period:** 1979-04-01 → 1988-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3126499

## Citation

> US National Institutes of Health, RePORTER application 3126499, GENETICS VIRULENCE IN PSEUDOMONAS AERUGINOSA (5R01AI015940-08). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3126499. Licensed CC0.

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