Abstract:
:Fimbriae, lipopolysaccharide (LPS), and extracellular polymeric substance (EPS) all contribute to biofilm formation by the periodontopathogen Aggregatibacter actinomycetemcomitans. To understand how individual biofilm determinants respond to changing environmental conditions, the transcription of genes responsible for fimbria, LPS, and EPS production, as well as the translation of these components, was determined in rough (Rv) and isogenic smooth (Sv) variants of A. actinomycetemcomitans cultured in half-strength and full-strength culture medium under anaerobic or aerobic conditions, and in iron-supplemented and iron-chelated medium. The transcription of tadV (fimbrial assembly), pgaC (extracellular polysaccharide synthesis), and orf8 or rmlB (lipopolysaccharide synthesis) was measured by real-time PCR. The amounts of fimbriae, LPS, and EPS were also estimated from stained sodium dodecyl sulfate-polyacrylamide gels and verified by Western blotting and enzyme-linked immunoadsorbent assay using specific antibodies. Each gene was significantly upregulated in the Rv compared to in the Sv. The transcription of fimbrial, LPS, and EPS genes in the Rv was increased approximately twofold in cells cultured in full-strength medium under anaerobic conditions compared to that in cells cultured under aerobic conditions. Under anaerobic conditions, the transcription of fimbrial and EPS enzymes was elevated in both Rv and Sv cells cultured in half-strength medium, compared to that in full-strength medium. Iron chelation also increased the transcription and translation of all biofilm determinants compared to their expression with iron supplementation, yet the quantity of biofilm was not significantly changed by any environmental perturbation except iron limitation. Thus, anaerobic conditions, nutrient stress, and iron limitation each upregulate known biofilm determinants of A. actinomycetemcomitans to contribute to biofilm formation.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Amarasinghe JJ,Scannapieco FA,Haase EMdoi
10.1128/IAI.00126-09subject
Has Abstractpub_date
2009-07-01 00:00:00pages
2896-907issue
7eissn
0019-9567issn
1098-5522pii
IAI.00126-09journal_volume
77pub_type
杂志文章abstract::Platelet microbicidal proteins (PMPs) are small, cationic peptides which possess potent microbicidal activities against common bloodstream pathogens, such as Staphylococcus aureus. We previously showed that S. aureus strains exhibiting resistance to thrombin-induced PMP (tPMP-1) in vitro have an enhanced capacity to c...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.6.3548-3553.2000
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00278-07
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.25.1.127-132.1979
更新日期:1979-07-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.2.547-553.1995
更新日期:1995-02-01 00:00:00
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journal_title:Infection and immunity
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doi:10.1128/IAI.61.1.295-302.1993
更新日期:1993-01-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.4.1465-1472.1992
更新日期:1992-04-01 00:00:00
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journal_title:Infection and immunity
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journal_title:Infection and immunity
pub_type: 杂志文章
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更新日期:1988-08-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.16.2.510-512.1977
更新日期:1977-05-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00159-06
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.45.1.118-121.1984
更新日期:1984-07-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.48.3.629-633.1985
更新日期:1985-06-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.12.8237-8246.2005
更新日期:2005-12-01 00:00:00
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pub_type: 杂志文章
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.12.5491-5497.1994
更新日期:1994-12-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.8.3199-3208.1993
更新日期:1993-08-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.6.3469-3474.2000
更新日期:2000-06-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.9.2234-2239.1987
更新日期:1987-09-01 00:00:00
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doi:10.1128/IAI.15.2.453-460.1977
更新日期:1977-02-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.59.1.168-171.1991
更新日期:1991-01-01 00:00:00
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更新日期:2001-08-01 00:00:00
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pub_type: 杂志文章
doi:10.1128/iai.68.5.2685-2691.2000
更新日期:2000-05-01 00:00:00
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pub_type: 杂志文章
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更新日期:2011-04-01 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:2014-02-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.12.4.833-840.1975
更新日期:1975-10-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.4.1314-1321.1992
更新日期:1992-04-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.03016-14
更新日期:2015-05-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.05580-11
更新日期:2011-12-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.3.1138-1141.1995
更新日期:1995-03-01 00:00:00
abstract::A single intradermal administration of recombinant interleukin-7 (IL-7) has been shown to aggravate the course of murine schistosomiasis, to favor the development of Th2-associated antibodies specific for the parasite, and to alter migration kinetics and/or migratory route of the parasite within its vertebrate host. H...
journal_title:Infection and immunity
pub_type: 杂志文章
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更新日期:1999-08-01 00:00:00