Inhibitors of TonB Function Identified by a High-Throughput Screen for Inhibitors of Iron Acquisition in Uropathogenic <named-content content-type="genus-species">Escherichia coli</named-content> CFT073

ABSTRACT The urinary tract is one of the most common sites of infection in humans, and uropathogenic Escherichia coli (UPEC) is the main causative agent of urinary tract infections. Bacteria colonizing the urinary tract face extremely low iron availability. To counteract this, UPEC expresses a wide...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Alejandra Yep, Thomas McQuade, Paul Kirchhoff, Martha Larsen, Harry L. T. Mobley
Formato:	article
Lenguaje:	EN
Publicado:	American Society for Microbiology 2014
Materias:	Microbiology QR1-502
Acceso en línea:	https://doaj.org/article/fbadacd5e77445aeb1f946cfc9932c28
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:fbadacd5e77445aeb1f946cfc9932c28
record_format	dspace
spelling	oai:doaj.org-article:fbadacd5e77445aeb1f946cfc9932c282021-11-15T15:45:12ZInhibitors of TonB Function Identified by a High-Throughput Screen for Inhibitors of Iron Acquisition in Uropathogenic <named-content content-type="genus-species">Escherichia coli</named-content> CFT07310.1128/mBio.01089-132150-7511https://doaj.org/article/fbadacd5e77445aeb1f946cfc9932c282014-05-01T00:00:00Zhttps://journals.asm.org/doi/10.1128/mBio.01089-13https://doaj.org/toc/2150-7511ABSTRACT The urinary tract is one of the most common sites of infection in humans, and uropathogenic Escherichia coli (UPEC) is the main causative agent of urinary tract infections. Bacteria colonizing the urinary tract face extremely low iron availability. To counteract this, UPEC expresses a wide variety of iron acquisition systems. To exploit iron acquisition in UPEC as a global target for small-molecule inhibition, we developed and carried out a whole-cell growth-based high throughput screen of 149,243 compounds. Our primary assay was carried out under iron-limiting conditions. Hits in the primary screen were assayed using two counterscreens that ruled out iron chelators and compounds that inhibit growth by means other than inhibition of iron acquisition. We determined dose-response curves under two different iron conditions and purchased fresh compounds for selected hits. After retesting dose-response relationships, we identified 16 compounds that arrest growth of UPEC only under iron-limiting conditions. All compounds are bacteriostatic and do not inhibit proton motive force. A loss-of-target strategy was employed to identify the cellular target of these inhibitors. Two compounds lost inhibitory activity against a strain lacking TonB and were shown to inhibit irreversible adsorption of a TonB-dependent bacteriophage. Our results validate iron acquisition as a target for antibacterial strategies against UPEC and identify TonB as one of the cellular targets. IMPORTANCE Half of women will suffer at least one episode of urinary tract infection (UTI) during their lifetime. The current treatment for UTI involves antibiotic therapy. Resistance to currently used antibiotics has steadily increased over the last decade, generating a pressing need for the development of new therapeutic agents. Since iron is essential for colonization and scarce in the urinary tract, targeting iron acquisition would seem to be an attractive strategy. However, the multiplicity and redundancy of iron acquisition systems in uropathogenic Escherichia coli (UPEC) make it difficult to pinpoint a specific cellular target. Here, we identified 16 iron acquisition inhibitors through a whole-cell high-throughput screen, validating iron acquisition as a target for antibacterial strategies against UPEC. We also identified the cellular target of two of the inhibitors as the TonB system.Alejandra YepThomas McQuadePaul KirchhoffMartha LarsenHarry L. T. MobleyAmerican Society for MicrobiologyarticleMicrobiologyQR1-502ENmBio, Vol 5, Iss 2 (2014)
institution	DOAJ
collection	DOAJ
language	EN
topic	Microbiology QR1-502
spellingShingle	Microbiology QR1-502 Alejandra Yep Thomas McQuade Paul Kirchhoff Martha Larsen Harry L. T. Mobley Inhibitors of TonB Function Identified by a High-Throughput Screen for Inhibitors of Iron Acquisition in Uropathogenic <named-content content-type="genus-species">Escherichia coli</named-content> CFT073
description	ABSTRACT The urinary tract is one of the most common sites of infection in humans, and uropathogenic Escherichia coli (UPEC) is the main causative agent of urinary tract infections. Bacteria colonizing the urinary tract face extremely low iron availability. To counteract this, UPEC expresses a wide variety of iron acquisition systems. To exploit iron acquisition in UPEC as a global target for small-molecule inhibition, we developed and carried out a whole-cell growth-based high throughput screen of 149,243 compounds. Our primary assay was carried out under iron-limiting conditions. Hits in the primary screen were assayed using two counterscreens that ruled out iron chelators and compounds that inhibit growth by means other than inhibition of iron acquisition. We determined dose-response curves under two different iron conditions and purchased fresh compounds for selected hits. After retesting dose-response relationships, we identified 16 compounds that arrest growth of UPEC only under iron-limiting conditions. All compounds are bacteriostatic and do not inhibit proton motive force. A loss-of-target strategy was employed to identify the cellular target of these inhibitors. Two compounds lost inhibitory activity against a strain lacking TonB and were shown to inhibit irreversible adsorption of a TonB-dependent bacteriophage. Our results validate iron acquisition as a target for antibacterial strategies against UPEC and identify TonB as one of the cellular targets. IMPORTANCE Half of women will suffer at least one episode of urinary tract infection (UTI) during their lifetime. The current treatment for UTI involves antibiotic therapy. Resistance to currently used antibiotics has steadily increased over the last decade, generating a pressing need for the development of new therapeutic agents. Since iron is essential for colonization and scarce in the urinary tract, targeting iron acquisition would seem to be an attractive strategy. However, the multiplicity and redundancy of iron acquisition systems in uropathogenic Escherichia coli (UPEC) make it difficult to pinpoint a specific cellular target. Here, we identified 16 iron acquisition inhibitors through a whole-cell high-throughput screen, validating iron acquisition as a target for antibacterial strategies against UPEC. We also identified the cellular target of two of the inhibitors as the TonB system.
format	article
author	Alejandra Yep Thomas McQuade Paul Kirchhoff Martha Larsen Harry L. T. Mobley
author_facet	Alejandra Yep Thomas McQuade Paul Kirchhoff Martha Larsen Harry L. T. Mobley
author_sort	Alejandra Yep
title	Inhibitors of TonB Function Identified by a High-Throughput Screen for Inhibitors of Iron Acquisition in Uropathogenic <named-content content-type="genus-species">Escherichia coli</named-content> CFT073
title_short	Inhibitors of TonB Function Identified by a High-Throughput Screen for Inhibitors of Iron Acquisition in Uropathogenic <named-content content-type="genus-species">Escherichia coli</named-content> CFT073
title_full	Inhibitors of TonB Function Identified by a High-Throughput Screen for Inhibitors of Iron Acquisition in Uropathogenic <named-content content-type="genus-species">Escherichia coli</named-content> CFT073
title_fullStr	Inhibitors of TonB Function Identified by a High-Throughput Screen for Inhibitors of Iron Acquisition in Uropathogenic <named-content content-type="genus-species">Escherichia coli</named-content> CFT073
title_full_unstemmed	Inhibitors of TonB Function Identified by a High-Throughput Screen for Inhibitors of Iron Acquisition in Uropathogenic <named-content content-type="genus-species">Escherichia coli</named-content> CFT073
title_sort	inhibitors of tonb function identified by a high-throughput screen for inhibitors of iron acquisition in uropathogenic <named-content content-type="genus-species">escherichia coli</named-content> cft073
publisher	American Society for Microbiology
publishDate	2014
url	https://doaj.org/article/fbadacd5e77445aeb1f946cfc9932c28
work_keys_str_mv	AT alejandrayep inhibitorsoftonbfunctionidentifiedbyahighthroughputscreenforinhibitorsofironacquisitioninuropathogenicnamedcontentcontenttypegenusspeciesescherichiacolinamedcontentcft073 AT thomasmcquade inhibitorsoftonbfunctionidentifiedbyahighthroughputscreenforinhibitorsofironacquisitioninuropathogenicnamedcontentcontenttypegenusspeciesescherichiacolinamedcontentcft073 AT paulkirchhoff inhibitorsoftonbfunctionidentifiedbyahighthroughputscreenforinhibitorsofironacquisitioninuropathogenicnamedcontentcontenttypegenusspeciesescherichiacolinamedcontentcft073 AT marthalarsen inhibitorsoftonbfunctionidentifiedbyahighthroughputscreenforinhibitorsofironacquisitioninuropathogenicnamedcontentcontenttypegenusspeciesescherichiacolinamedcontentcft073 AT harryltmobley inhibitorsoftonbfunctionidentifiedbyahighthroughputscreenforinhibitorsofironacquisitioninuropathogenicnamedcontentcontenttypegenusspeciesescherichiacolinamedcontentcft073
_version_	1718427621807620096

Inhibitors of TonB Function Identified by a High-Throughput Screen for Inhibitors of Iron Acquisition in Uropathogenic <named-content content-type="genus-species">Escherichia coli</named-content> CFT073

Ejemplares similares