# PATHOBIOLOGY OF LEGIONELLA MICDADEI

> **NIH NIH R01** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 1987 · $167,189

## Abstract

Legionella micdadel is the etiological agent of an acute pneumonia which
occurs primarily among immunosuppressed patients, particularly organ
transplant recipients.  This project will examine several aspects of the
virulence of, immunity to, and antimicrobial susceptibility of this
organism.

L. micdadei, an intracellular pathogen, appears to escape the normal
bactericidal defense mechanisms provided by phagocytic cells such
polymorphonuclear leukocytes, alveolar macrophages and blood monocytes.  In
vitro studies of the interaction between the organism and the above
phagocytic cells will be performed in an effort to determine if components
or properties of the bacterial cell are responsible for the depression of
the antibacterial mechanisms of the phagocytic cells.  In particular, the
role of a recently discovered cytotoxin in the depression of phagocytic
killing will be examined.

A guinea pig model of immunity following pulmonary infection with L.
micdadei has been developed and will be used to study the interaction
between the organism and the humoral and cellular components of the immune
system in an effort to identify which elements are protective for the
immune animal.  It has already been determined that alveolar macrophages
from immune animals do not alone inhibit the growth of the organism.  The
contribution of other cellular components of the immune system, namely
lymphocytes, to the killing of L. micdadei by phagocytic cells will be
measured in vitro and in vivo.

Finally, the effect of the intracellular location on the antimicrobial
susceptibility of L. micdadei will be studied.  The intracellular
concentration of antimicrobials which are known to be therapeutically
effective against the bacterium will be compared to those of agents which
are known to be ineffective.

## Key facts

- **NIH application ID:** 3126967
- **Project number:** 5R01AI017047-06
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **SAM.gov UEI:** MKAGLD59JRL1
- **Principal Investigator:** A WILLIAM PASCULLE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $167,189
- **Award type:** 5
- **Project period:** 1980-08-01 → 1989-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3126967

## Citation

> US National Institutes of Health, RePORTER application 3126967, PATHOBIOLOGY OF LEGIONELLA MICDADEI (5R01AI017047-06). Retrieved via MORVS 2026-10-26 from https://api.morvs.ai/grant/nih/3126967. Licensed CC0.

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