Abstract:
:Nontypeable Haemophilus influenzae (NTHi) is a commensal microorganism of the human nasopharynx, and yet is also an opportunistic pathogen of the upper and lower respiratory tracts. Host microenvironments influence gene expression patterns, likely critical for NTHi persistence. The host sequesters iron as a mechanism to control microbial growth, and yet iron limitation influences gene expression and subsequent production of proteins involved in iron homeostasis. Careful regulation of iron uptake, via the ferric uptake regulator Fur, is essential in multiple bacteria, including NTHi. We hypothesized therefore that Fur contributes to iron homeostasis in NTHi, is critical for bacterial persistence, and likely regulates expression of virulence factors. Toward this end, fur was deleted in the prototypic NTHi clinical isolate, 86-028NP, and we assessed gene expression regulated by Fur. As expected, expression of the majority of genes that encode proteins with predicted roles in iron utilization was repressed by Fur. However, 14 Fur-regulated genes encode proteins with no known function, and yet may contribute to iron utilization or other biological functions. In a mammalian model of human otitis media, we determined that Fur was critical for bacterial persistence, indicating an important role for Fur-mediated iron homeostasis in disease progression. These data provide a profile of genes regulated by Fur in NTHi and likely identify additional regulatory pathways involved in iron utilization. Identification of such pathways will increase our understanding of how this pathogen can persist within host microenvironments, as a common commensal and, importantly, as a pathogen with significant clinical impact.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Harrison A,Santana EA,Szelestey BR,Newsom DE,White P,Mason KMdoi
10.1128/IAI.01227-12subject
Has Abstractpub_date
2013-04-01 00:00:00pages
1221-33issue
4eissn
0019-9567issn
1098-5522pii
IAI.01227-12journal_volume
81pub_type
杂志文章abstract::Radial immunodiffusion procedures have been developed for testing bovine sera for the presence of antibody activity against three foot-and-mouth disease virus types and a virus infection-associated antigen. Reactions with virus antigens were obtained as early as 4 days after infection, and the virus type causing the r...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.5.2.227-231.1972
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journal_title:Infection and immunity
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journal_title:Infection and immunity
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journal_title:Infection and immunity
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.7.2800-2805.1994
更新日期:1994-07-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.11.4.692-697.1975
更新日期:1975-04-01 00:00:00
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更新日期:1997-03-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.1.504-513.2005
更新日期:2005-01-01 00:00:00
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更新日期:1973-09-01 00:00:00
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journal_title:Infection and immunity
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更新日期:1989-02-01 00:00:00
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更新日期:2006-01-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
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更新日期:1977-07-01 00:00:00
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journal_title:Infection and immunity
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更新日期:1999-06-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
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更新日期:1976-04-01 00:00:00
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journal_title:Infection and immunity
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更新日期:2001-07-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
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更新日期:2005-05-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章,收录出版
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更新日期:2012-06-01 00:00:00
abstract::We have mapped a group of virulence genes of Porphyromonas gingivalis to a single large fragment of the genome. These genes (rgpA, kgp, and hagA) all contain a consensus repeat sequence (HArep). rgpA and kgp encode cysteine proteases with Arg-X and Lys-X specificity, respectively, and hagA encodes a hemagglutinin. Gen...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.5.2619-2623.1999
更新日期:1999-05-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.23.1.99-107.1979
更新日期:1979-01-01 00:00:00