The University of Southampton
University of Southampton Institutional Repository

Influence of iron-limited and replete continuous culture on the physiology and virulence of Neisseria gonorrhoeae

Influence of iron-limited and replete continuous culture on the physiology and virulence of Neisseria gonorrhoeae
Influence of iron-limited and replete continuous culture on the physiology and virulence of Neisseria gonorrhoeae

Neisseria gonorrhoeae strains P9-2 (Pen(S)) and KW2 (Pen(R)) were grown in chemostats of nonferrous design at constant growth rate, pH and dissolved oxygen tension. Iron limitation (μ(max) 0.1 h -1 ) was imposed by omitting iron salts from the defined medium and titrating increasing concentrations of the non-metabolizable iron chelators ovotransferrin and Desferal, to progressively decrease the growth yield. Metabolic activity during iron limitation was very high, with a q(Glc) which was 2- or 11-fold greater than during cystine- or glucose-limited growth, respectively. More aspartate and isoleucine were metabolized during cystine-limited growth, while more glutamate, proline and serine were metabolized during glucose- or iron-limited growth. Significant concentrations of alanine or valine were excreted during cystine- or glucose-limited growth, respectively. Iron-limited growth of an initial inoculum of non-piliated, transparent colony-forming (P - O - ) gonococci resulted in the selection of 100% piliated bacteria. Initial inocula of P + O - gonococci retained this phenotype for over 100 generations. Iron-limited gonococci were extremely virulent in the guinea-pig subcutaneous chamber model and inocula of even 12 bacteria grew rapidly and persisted. By contrast, cystine-limited (iron-replete) gonococci retained piliation but did not survive in the chambers. Transition from iron-limited to glucose-limited growth resulted in marked loss of piliation but the bacteria remained virulent. Loss of virulence did not correlate with susceptibility to killing by normal human serum, nor with changes in the content or composition of lipooligosaccharide, which contained 2.9, 3.7, 4.3 and 4.8 kDa moieties. Additional proteins were detectable in Sarkosyl-purified outer membranes of iron-limited gonococci but several proteins with molecular masses similar to those described in the literature for iron-restricted gonococci were detectable in cystine- or glucose-limited bacteria.

0022-1287
851-863
Keevil, C. W.
cb7de0a7-ce33-4cfa-af52-07f99e5650eb
Davies, D. B.
3774a46d-d278-4e5d-99d4-0ea046bf4172
Spillane, B. J.
705474fa-14b5-49af-b658-33235143b7d3
Mahenthiralingam, E.
d4b5826c-6b25-4e9c-b0b3-2626bc5b9039
Keevil, C. W.
cb7de0a7-ce33-4cfa-af52-07f99e5650eb
Davies, D. B.
3774a46d-d278-4e5d-99d4-0ea046bf4172
Spillane, B. J.
705474fa-14b5-49af-b658-33235143b7d3
Mahenthiralingam, E.
d4b5826c-6b25-4e9c-b0b3-2626bc5b9039

Keevil, C. W., Davies, D. B., Spillane, B. J. and Mahenthiralingam, E. (1989) Influence of iron-limited and replete continuous culture on the physiology and virulence of Neisseria gonorrhoeae. Journal of General Microbiology, 135 (4), 851-863. (doi:10.1099/00221287-135-4-851).

Record type: Article

Abstract

Neisseria gonorrhoeae strains P9-2 (Pen(S)) and KW2 (Pen(R)) were grown in chemostats of nonferrous design at constant growth rate, pH and dissolved oxygen tension. Iron limitation (μ(max) 0.1 h -1 ) was imposed by omitting iron salts from the defined medium and titrating increasing concentrations of the non-metabolizable iron chelators ovotransferrin and Desferal, to progressively decrease the growth yield. Metabolic activity during iron limitation was very high, with a q(Glc) which was 2- or 11-fold greater than during cystine- or glucose-limited growth, respectively. More aspartate and isoleucine were metabolized during cystine-limited growth, while more glutamate, proline and serine were metabolized during glucose- or iron-limited growth. Significant concentrations of alanine or valine were excreted during cystine- or glucose-limited growth, respectively. Iron-limited growth of an initial inoculum of non-piliated, transparent colony-forming (P - O - ) gonococci resulted in the selection of 100% piliated bacteria. Initial inocula of P + O - gonococci retained this phenotype for over 100 generations. Iron-limited gonococci were extremely virulent in the guinea-pig subcutaneous chamber model and inocula of even 12 bacteria grew rapidly and persisted. By contrast, cystine-limited (iron-replete) gonococci retained piliation but did not survive in the chambers. Transition from iron-limited to glucose-limited growth resulted in marked loss of piliation but the bacteria remained virulent. Loss of virulence did not correlate with susceptibility to killing by normal human serum, nor with changes in the content or composition of lipooligosaccharide, which contained 2.9, 3.7, 4.3 and 4.8 kDa moieties. Additional proteins were detectable in Sarkosyl-purified outer membranes of iron-limited gonococci but several proteins with molecular masses similar to those described in the literature for iron-restricted gonococci were detectable in cystine- or glucose-limited bacteria.

Full text not available from this repository.

More information

Published date: April 1989

Identifiers

Local EPrints ID: 431328
URI: http://eprints.soton.ac.uk/id/eprint/431328
ISSN: 0022-1287
PURE UUID: b4f6e88e-5ea9-4daa-933e-1c9646cb161f
ORCID for C. W. Keevil: ORCID iD orcid.org/0000-0003-1917-7706

Catalogue record

Date deposited: 29 May 2019 16:30
Last modified: 30 May 2019 00:36

Export record

Altmetrics

Contributors

Author: C. W. Keevil ORCID iD
Author: D. B. Davies
Author: B. J. Spillane
Author: E. Mahenthiralingam

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×