scholarly journals Transcriptional Profile of Haemophilus influenzae: Effects of Iron and Heme

2006 ◽  
Vol 188 (15) ◽  
pp. 5640-5645 ◽  
Author(s):  
Paul W. Whitby ◽  
Timothy M. VanWagoner ◽  
Thomas W. Seale ◽  
Daniel J. Morton ◽  
Terrence L. Stull
Keyword(s):  
Haemophilus Influenzae ◽  
Transcriptional Profile ◽  
Iron Source ◽  
Iron Heme ◽  
Microarray Studies

ABSTRACT Haemophilus influenzae requires either heme or a porphyrin and iron source for growth. Microarray studies of H. influenzae strain Rd KW20 identified 162 iron/heme-regulated genes, representing ∼10% of the genome, with ≥1.5-fold changes in transcription in response to iron/heme availability in vitro. Eighty genes were preferentially expressed under iron/heme restriction; 82 genes were preferentially expressed under iron/heme-replete conditions.

scholarly journals Comparison of transcription of the Haemophilus influenzae iron/heme modulon genes in vitro and in vivo in the chinchilla middle ear

BMC Genomics ◽  
2013 ◽  
Vol 14 (1) ◽  
pp. 925 ◽  
Author(s):  
Paul W Whitby ◽  
Timothy M VanWagoner ◽  
Thomas W Seale ◽  
Daniel J Morton ◽  
Terrence L Stull
Keyword(s):  
Haemophilus Influenzae ◽  
Middle Ear ◽  
Iron Heme

Ultrastructural studies on the interaction of haemophilus influenzae with human endothelial cells in vitro

1990 ◽  
Vol 48 (3) ◽  
pp. 636-637
Author(s):  
D.J.P. Ferguson ◽  
M. Virji ◽  
H. Kayhty ◽  
E.R. Moxon
Keyword(s):  
Endothelial Cells ◽  
Haemophilus Influenzae ◽  
Intercellular Junctions ◽  
Blood Stream ◽  
Ultrastructural Studies ◽  
Endothelial Barriers ◽  
Serotype B ◽  
Meningitis In Children ◽  
Respiratory Epithelial

Haemophilus influenzae is a human pathogen which causes meningitis in children. Systemic H. influenzae infection is largely confined to encapsulated serotype b organisms and is a major cause of meningitis in the U.K. and elsewhere. However, the pathogenesis of the disease is still poorly understood. Studies in the infant rat model, in which intranasal challenge results in bacteraemia, have shown that H. influenzae enters submucosal tissues and disseminates to the blood stream within minutes. The rapidity of these events suggests that H. influenzae penetrates both respiratory epithelial and endothelial barriers with great efficiency. It is not known whether the bacteria penetrate via the intercellular junctions, are translocated within the cells or carried across the cellular barrier in 'trojan horse' fashion within phagocytes. In the present studies, we have challenged cultured human umbilical cord_vein endothelial cells (HUVECs) with both capsulated (b+) and capsule-deficient (b-) isogenic variants of one strain of H. influenzae in order to investigate the interaction between the bacteria and HUVEC and the effect of the capsule.

scholarly journals n‐3 polyunsaturated fatty acids provoke a specific transcriptional profile in rabbit adipose‐derived stem cells in vitro

2019 ◽  
Vol 103 (3) ◽  
pp. 925-934
Author(s):  
Eкaterina Vackova ◽  
Darko Bosnakovski ◽  
Bodil Bjørndal ◽  
Penka Yonkova ◽  
Natalia Grigorova ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Stem Cells ◽  
Polyunsaturated Fatty Acids ◽  
Transcriptional Profile ◽  
Adipose Derived Stem Cells

Nontypeable Haemophilus influenzae infection impedes Pseudomonas aeruginosa colonization and persistence in mouse respiratory tract

2021 ◽  
Author(s):  
Natalie Lindgren ◽  
Lea Novak ◽  
Benjamin C. Hunt ◽  
Melissa S. McDaniel ◽  
W. Edward Swords
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Respiratory Tract ◽  
Haemophilus Influenzae ◽  
Respiratory Infections ◽  
Bacterial Species ◽  
Young Patients ◽  
Nontypeable Haemophilus Influenzae ◽  
Potential Significance ◽  
And Diffusion

Patients with cystic fibrosis (CF) experience lifelong respiratory infections which are a significant cause of morbidity and mortality. These infections are polymicrobial in nature, and the predominant bacterial species undergo a predictable series of changes as patients age. Young patients have populations dominated by opportunists that are typically found within the microbiome of the human nasopharynx, such as nontypeable Haemophilus influenzae (NTHi); these are eventually supplanted and the population within the CF lung is later dominated by pathogens such as Pseudomonas aeruginosa ( Pa ). In this study, we investigated how initial colonization with NTHi impacts colonization and persistence of Pa in the respiratory tract. Analysis of polymicrobial biofilms in vitro by confocal microscopy revealed that NTHi promoted greater levels of Pa biofilm volume and diffusion. However, sequential respiratory infection of mice with NTHi followed by Pa resulted in significantly lower Pa as compared to infection with Pa alone. Coinfected mice also had reduced airway tissue damage and lower levels of inflammatory cytokines as compared with Pa infected mice. Similar results were observed after instillation of heat-inactivated NTHi bacteria or purified NTHi lipooligosaccharide (LOS) endotoxin prior to Pa introduction. Based on these results, we conclude that NTHi significantly reduces susceptibility to subsequent Pa infection, most likely due to priming of host innate immunity rather than a direct competitive interaction between species. These findings have potential significance with regard to therapeutic management of early life infections in patients with CF.

scholarly journals Mutagenesis and ultraviolet inactivation of transforming DNA of Haemophilus influenzae complexed with a Bacillus subtilis protein that alters DNA conformation.

1996 ◽  
Vol 43 (1) ◽  
pp. 107-114 ◽  
Author(s):  
J K Setlow ◽  
B C Setlow ◽  
P Setlow
Keyword(s):  
Bacillus Subtilis ◽  
Haemophilus Influenzae ◽  
Dna Conformation ◽  
Erythromycin Resistance ◽  
Bacillus Subtilis Spore ◽  
Pyrimidine Dimers ◽  
Resistance Markers ◽  
Selection For

The wild-type Bacillus subtilis spore protein, SspCwt, binds to DNA in vitro and in vivo and changes the conformation of DNA from B to A. Synthesis of the cloned SspCwt gene in Escherichia coli also causes large increases in mutation frequency. Binding of SspCwt to transforming DNA from Haemophilus influenzae made the DNA resistant to ultraviolet (UV) radiation. The mutant protein, SspCala, which does not bind DNA, did not change the UV resistance. The UV sensitivity of the DNA/SspCwt complex was not increased when the recipients of the DNA were defective in excision of pyrimidine dimers. These data indicate that the H. influenzae excision mechanism does not operate on the spore photoproduct formed by UV irradiation of the complex. Selection for the streptomycin- or erythromycin-resistance markers on the transforming DNA evidenced significant mutations at loci closely linked to these, but not at other loci. SspCwt apparently entered the cell attached to the transforming DNA, and caused mutations in adjacent loci. The amount of such mutations decreased when the transforming DNA was UV irradiated, because UV unlinks linked markers.

scholarly journals In vitro immunological activities of the polysaccharide fraction from Haemophilus influenzae type a endotoxin.

1982 ◽  
Vol 36 (2) ◽  
pp. 603-608 ◽  
Author(s):  
M Guenounou ◽  
D Raichvarg ◽  
D Hatat ◽  
C Brossard ◽  
J Agneray
Keyword(s):  
Haemophilus Influenzae ◽  
Type A ◽  
Haemophilus Influenzae Type ◽  
Polysaccharide Fraction

In Vitro Activation of Human T Lymphocytes by Haemophilus influenzae Type b Capsular Polysaccharides

1992 ◽  
Vol 35 (2) ◽  
pp. 137-148 ◽  
Author(s):  
C. C. A. M. PEETERS ◽  
A.-M. TENBERGEN-MEEKES ◽  
C. J. HEIJNEN ◽  
J. T. POOLMAN ◽  
B. J. M. ZEGERS ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Haemophilus Influenzae ◽  
Haemophilus Influenzae Type ◽  
Haemophilus Influenzae Type B ◽  
Capsular Polysaccharides ◽  
Type B ◽  
Human T Lymphocytes ◽  
In Vitro Activation

scholarly journals In Vitro Activity of Tebipenem, a New Oral Carbapenem Antibiotic, against β-Lactamase-Nonproducing, Ampicillin-Resistant Haemophilus influenzae

2010 ◽  
Vol 54 (9) ◽  
pp. 3970-3973 ◽  
Author(s):  
Kozue Kishii ◽  
Naoko Chiba ◽  
Miyuki Morozumi ◽  
Akiko Ono ◽  
Takashi Ida ◽  
...  
Keyword(s):  
Haemophilus Influenzae ◽  
Bactericidal Activity ◽  
Gene Mutations ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Oral Antibiotics ◽  
Pcr Identification ◽  
Minimal Concentration ◽  
Carbapenem Antibiotic

ABSTRACT In vitro activity of tebipenem, a new oral carbapenem antibiotic, against clinical Haemophilus influenzae isolates was compared with those of 8 reference agents. Isolates were classified into 6 resistance classes after PCR identification of β-lactamase genes and ftsI gene mutations. For all isolates, the minimal concentration at which 90% of isolates were inhibited was lower for tebipenem than for the reference oral antibiotics, except for cefditoren. Tebipenem also showed excellent bactericidal activity against β-lactamase-nonproducing, ampicillin-resistant isolates.

The activity of clarithromycin and its 14-hydroxy metabolite against Haemophilus influenzae, determined by in-vitro and serum bactericidal tests

1991 ◽  
Vol 27 (suppl A) ◽  
pp. 19-30 ◽  
Author(s):  
H. Dabernat ◽  
C. Delmas ◽  
M. Seguy ◽  
J. B. Fourtillan ◽  
J. Girault ◽  
...  
Keyword(s):  
Haemophilus Influenzae ◽  
Hydroxy Metabolite
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