Roles of iron in the survival, growth, and pathogenesis of Legionella pneumophila

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6696682

Quinn, F D

The essentially of iron for living cells has long been recognized, and the availability of host-iron has been proposed as a contributing factor to virulence in bacterial, fungal, and protozoan infections. The mechanism by which legionella pneumophila causes disease is unknown. Growth of fresh clinical or environmental isolates in pure culture requires 20 times more iron than is needed for most other bacteria. Thus, increased plasma iron levels may be needed for multiplication within human hosts. It was observed that: (1) this organism can be more readily deprived of iron by iron binding agents than all other bacteria studied, and this inhibition can be reversed by the addition of iron; (2) normal human blood serum kills L. pneumophila and the bactericidal action is decreased when complement is inactivated or enough iron to saturate serum transferrin is added to the system; (3) in assays with a radioactive isotope of iron (/sup 55/Fe), no specific iron sequestering system was detected; (4) in analysis of outer membrane proteins with /sup 55/Fe, SDS-polyacrylamide gel electrophoresis, and autoradiography, no specific outer membrane proteins responsible for iron acquisition were observed; and (5) in assays for protease, iron does not stimulate production of extracellular proteases. These observations indicate that L. pneumophila has no specific iron uptake mechanism, but instead relies on passive diffusion and/or non-specific mechanisms to obtain its iron.

• Research Organization: Indiana Univ., Bloomington (USA)
• OSTI ID: 6696682
• Country of Publication: United States
• Language: English

Related Subjects

550701* -- Microbiology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AUTORADIOGRAPHY
BACTERIA
BETA DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CELL CONSTITUENTS
CELL MEMBRANES
CELL PROLIFERATION
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
ELEMENTS
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
IRON
IRON 55
IRON ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LEGIONELLA PNEUMOPHILA
MEMBRANES
METALS
MICROORGANISMS
NUCLEI
RADIOISOTOPES
TRACER TECHNIQUES
TRANSITION ELEMENTS
YEARS LIVING RADIOISOTOPES