scholarly journals Analysis of Nontypeable Haemophilus influenzae Phase-Variable Genes During Experimental Human Nasopharyngeal Colonization

2013 ◽  
Vol 208 (5) ◽  
pp. 720-727 ◽  
Author(s):  
Jessica Poole ◽  
Eric Foster ◽  
Kathryn Chaloner ◽  
Jason Hunt ◽  
Michael P. Jennings ◽  
...  
Keyword(s):  
Haemophilus Influenzae ◽  
Phase Variable ◽  
Nontypeable Haemophilus Influenzae ◽  
Nasopharyngeal Colonization ◽  
Variable Genes

Epidemiology of Nasopharyngeal Colonization with Nontypeable Haemophilus influenzae in the First 2 Years of Life

1995 ◽  
Vol 172 (1) ◽  
pp. 132-135 ◽  
Author(s):  
H. Faden ◽  
L. Duffy ◽  
A. Williams ◽  
D. A. Krystofik ◽  
J. Wolf ◽  
...  
Keyword(s):  
Haemophilus Influenzae ◽  
Nontypeable Haemophilus Influenzae ◽  
Nasopharyngeal Colonization

scholarly journals Multiple Consecutive Lavage Samplings Reveal Greater Burden of Disease and Provide Direct Access to the Nontypeable Haemophilus influenzae Biofilm in Experimental Otitis Media

2007 ◽  
Vol 75 (8) ◽  
pp. 4158-4172 ◽  
Author(s):  
Magali Leroy ◽  
Howard Cabral ◽  
Marisol Figueira ◽  
Valérie Bouchet ◽  
Heather Huot ◽  
...  
Keyword(s):  
Gene Expression ◽  
Haemophilus Influenzae ◽  
Otitis Media ◽  
Vaccine Development ◽  
Ex Vivo ◽  
Direct Analysis ◽  
Direct Access ◽  
Nontypeable Haemophilus Influenzae ◽  
Nasopharyngeal Colonization

ABSTRACT The typically recovered quantity of nontypeable Haemophilus influenzae (NTHi) bacteria in an ex vivo middle ear (ME) aspirate from the chinchilla model of experimental otitis media is insufficient for direct analysis of gene expression by microarray or of lipopolysaccharide glycoforms by mass spectrometry. This prompted us to investigate a strategy of multiple consecutive lavage samplings to increase ex vivo bacterial recovery. As multiple consecutive lavage samples significantly increased the total number of bacterial CFU collected during nasopharyngeal colonization or ME infection, this led us to evaluate whether bacteria sequentially acquired from consecutive lavages were similar. Comparative observation of complete ex vivo sample series by microscopy initially revealed ME inflammatory fluid consisting solely of planktonic-phase NTHi. In contrast, subsequent lavage samplings of the same infected ear revealed the existence of bacteria in two additional growth states, filamentous and biofilm encased. Gene expression analysis of such ex vivo samples was in accord with different bacterial growth phases in sequential lavage specimens. The existence of morphologically distinct NTHi subpopulations with varying levels of gene expression indicates that the pooling of specimens requires caution until methods for their separation are developed. This study based on multiple consecutive lavages is consistent with prior reports that NTHi forms a biofilm in vivo, describes the means to directly acquire ex vivo biofilm samples without sacrificing the animal, and has broad applicability for a study of mucosal infections. Moreover, this approach revealed that the actual burden of bacteria in experimental otitis media is significantly greater than was previously reported. Such findings may have direct implications for antibiotic treatment and vaccine development against NTHi.

scholarly journals Closed Complete Genome Sequences of Two Nontypeable Haemophilus influenzae Strains Containing Novel modA Alleles from the Sputum of Patients with Chronic Obstructive Pulmonary Disease

2018 ◽  
Vol 7 (2) ◽  
Author(s):  
John M. Atack ◽  
Timothy F. Murphy ◽  
Lauren O. Bakaletz ◽  
Kate L. Seib ◽  
Michael P. Jennings
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Haemophilus Influenzae ◽  
Pulmonary Disease ◽  
Complete Genome ◽  
Chronic Obstructive ◽  
Phase Variable ◽  
Nontypeable Haemophilus Influenzae ◽  
Genome Sequences ◽  
Obstructive Pulmonary Disease ◽  
Content Type

Nontypeable Haemophilus influenzae (NTHi) is an important bacterial pathogen that causes otitis media and exacerbations of chronic obstructive pulmonary disease (COPD). Here, we report the complete genome sequences of NTHi strains 10P129H1 and 84P36H1, isolated from COPD patients, which contain the phase-variable epigenetic regulators ModA15 and ModA18, respectively.

scholarly journals Phosphorylcholine Decreases Early Inflammation and Promotes the Establishment of Stable Biofilm Communities of Nontypeable Haemophilus influenzae Strain 86-028NP in a Chinchilla Model of Otitis Media

2006 ◽  
Vol 75 (2) ◽  
pp. 958-965 ◽  
Author(s):  
Wenzhou Hong ◽  
Kevin Mason ◽  
Joseph Jurcisek ◽  
Laura Novotny ◽  
Lauren O. Bakaletz ◽  
...  
Keyword(s):  
Haemophilus Influenzae ◽  
Otitis Media ◽  
Fluorescent Antibody ◽  
Phase Variable ◽  
Nontypeable Haemophilus Influenzae ◽  
Bacterial Surface ◽  
Culture Cells ◽  
Antibody Staining

ABSTRACT Nontypeable Haemophilus influenzae (NTHi) is a leading causative agent of otitis media. Much of the inflammation occurring during NTHi disease is initiated by lipooligosaccharides (LOS) on the bacterial surface. Phosphorylcholine (PCho) is added to some LOS forms in a phase-variable manner, and these PCho+ variants predominate in vivo. Thus, we asked whether this modification confers some advantage during infection. Virulence of an otitis media isolate (NTHi strain 86-028NP) was compared with that of an isogenic PCho transferase (licD) mutant using a chinchilla (Chinchilla lanigera) model of otitis media. Animals infected with NTHi 86-028NP licD demonstrated increased early inflammation and a delayed increase in bacterial counts compared to animals infected with NTHi 86-028NP. LOS purified from chinchilla-passed NTHi 86-028NP had increased PCho content compared to LOS purified from the inoculum. Both strains were recovered from middle ear fluids as long as 14 days postinfection. Biofilms were macroscopically visible in the middle ears of euthanized animals infected with NTHi 86-028NP 7 days and 14 days postchallenge. Conversely, less dense biofilms were observed in animals infected with NTHi 86-028NP licD 7 days postinfection, and none of the animals infected with NTHi 86-028NP licD had a visible biofilm by 14 days. Fluorescent antibody staining revealed PCho+ variants within biofilms, similar to our prior results with tissue culture cells in vitro (S. L. West-Barnette, A. Rockel, and W. E. Swords, Infect. Immun. 74:1828-1836, 2006). Animals coinfected with equal proportions of both strains had equal persistence of each strain and somewhat greater severity of disease. We thus conclude that PCho promotes NTHi infection and persistence by reducing the host inflammatory response and by promoting formation of stable biofilm communities.

scholarly journals High-Depth RNA-Seq Data Sets for Studying Gene Expression Changes Mediated by Phase-Variable DNA Methyltransferases in Nontypeable Haemophilus influenzae

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
John M. Atack ◽  
Lauren O. Bakaletz ◽  
Michael P. Jennings
Keyword(s):  
Haemophilus Influenzae ◽  
Bacterial Pathogen ◽  
Dna Methyltransferases ◽  
Multiple Infections ◽  
Data Sets ◽  
Phase Variable ◽  
Rna Seq ◽  
Nontypeable Haemophilus Influenzae ◽  
Content Type ◽  
High Depth

Nontypeable Haemophilus influenzae (NTHi) is a major bacterial pathogen that causes multiple infections. We report high-depth-coverage RNA-Seq data from three NTHi strains, each of which encodes a different phase-variable methyltransferase.

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