Novel iron uptake system specified by ColV plasmids: an important component in the virulence of invasive strains of Escherichia coli
- 1 December 1979
- journal article
- research article
- Published by American Society for Microbiology in Infection and Immunity
- Vol. 26 (3), 925-932
- https://doi.org/10.1128/iai.26.3.925-932.1979
Abstract
The enhanced virulence of invasive strains of Escherichia coli carrying ColV plasmids was shown to be due to a novel plasmid-mediated iron uptake system. Possession of a ColV plasmid conferred strong selective advantage on the host bacterial strain in experimental infections unless excess iron was administered in the inoculum. Moreover, supplementation of defined minimal medium with transferrin to complex available iron caused marked limitation of the growth of plasmid-free strains but had no effect on strains carrying a ColV plasmid. The activity of an efficient iron uptake process was clearly shown by experiments with a mutant of E. coli deficient in enterochelin biosynthesis. Although the mutant was dependent on the presence of citrate in the growth medium to facilitate iron transport, colicinogenic derivatives did not require added citrate for growth. Radioactive iron was shown to be taken up rapidly by nongrowing cells of the plasmid-carrying strain. Furthermore, it was observed that repression of the synthesis of specific outer membrane proteins normally induced by conditions of iron deficit was maintained after a shift of the colicinogenic strains from a rich medium to a medium low in iron. The ColV plasmid-mediated iron uptake system was independent of the active iron transport mechanisms known in E. coli, but like them it required tonB activity as a source of energy.This publication has 19 references indexed in Scilit:
- Cloned fragments of the plasmid ColV,I-K94 specifying virulence and serum resistanceNature, 1979
- Iron and infection.1978
- Further Observations on the Association of the Colicine V Plasmid of Escherichia coli with Pathogenicity and with Survival in the Alimentary TractJournal of General Microbiology, 1976
- A function common to iron‐enterochelin transport and action of colicins B, I, V in Escherichia coliFEBS Letters, 1975
- Membrane receptor dependent iron transport in Escherichia coliFEBS Letters, 1975
- A Search for Transmissible Pathogenic Characters in Invasive Strains of Escherichia coli: the Discovery of a Plasmid-controlled Toxin and a Plasmid-controlled Lethal Character Closely Associated, or Identical, with Colicine VJournal of General Microbiology, 1974
- The inducible citrate-dependent iron transport system in Escherichia coli K12Biochimica et Biophysica Acta (BBA) - Biomembranes, 1973
- Pedigrees of some mutant strains of Escherichia coli K-12.1972
- The structure of enterochelin and related 2,3-dihydroxy-N-benzoyne conjugates from Eschericha ColiBiochimica et Biophysica Acta (BBA) - General Subjects, 1970
- Elimination by Ethidium Bromide of Antibiotic Resistance in Enterobacteria and StaphylococciJournal of General Microbiology, 1968