Haemophilus influenzae
Molecular PathogenesisAntibody Binding and Complement-Mediated Killing of Invasive Haemophilus influenzae Isolates from Spain, Portugal, and the NetherlandsHaemophilus influenzae is a Gram-negative bacterium that can be classified into typeable (types a through f) and nontypeable (NTHi) groups. This opportunistic pathogen asymptomatically colonizes the mucosal epithelium of the upper respiratory tract, from where it spreads to other neighboring regions, potentially leading to disease. Infection with NTHi can cause otitis...
Bacterial InfectionsNasal Delivery of a Commensal Pasteurellaceae Species Inhibits Nontypeable Haemophilus influenzae Colonization and Delays Onset of Otitis Media in MiceNasopharyngeal colonization with nontypeable Haemophilus influenzae (NTHi) is a prerequisite for developing NTHi-associated infections, including otitis media. Therapies that block NTHi colonization may prevent disease development. We previously demonstrated that Haemophilus haemolyticus, a closely...
Molecular PathogenesisUnderlying Glycans Determine the Ability of Sialylated Lipooligosaccharide To Protect Nontypeable Haemophilus influenzae from Serum IgM and ComplementNontypeable Haemophilus influenzae (NTHi) efficiently colonizes the human nasopharynx asymptomatically but also causes respiratory mucosal infections, including otitis media, sinusitis, and bronchitis. The lipooligosaccharide (LOS) on the cell surface of NTHi displays complex glycans that mimic host structures, allowing it to evade immune recognition. However, LOS...
Microbial Immunity and Vaccines | SpotlightDesign and Characterization of Protein E-PilA, a Candidate Fusion Antigen for Nontypeable Haemophilus influenzae VaccineNontypeable Haemophilus influenzae (NTHi) is a pathogen known for being a frequent cause of acute otitis media in children and respiratory tract infections in adults with chronic obstructive pulmonary disease. In the present study, a vaccine antigen based on the fusion of two known NTHi adhesive proteins, protein E (PE) and a pilin subunit (PilA), was developed. The...
Microbial Immunity and Vaccines | SpotlightA Protein E-PilA Fusion Protein Shows Vaccine Potential against Nontypeable Haemophilus influenzae in Mice and ChinchillasPE-PilA is a fusion protein composed of immunologically relevant parts of protein E (PE) and the majority subunit of the type IV pilus (PilA), two major antigens of nontypeable Haemophilus influenzae (NTHi). Here we report on the preclinical evaluation of PE-PilA as a vaccine antigen. The immunogenic potential of the PE and PilA within the fusion was compared with...
Molecular PathogenesisSerum IgM and C-Reactive Protein Binding to Phosphorylcholine of Nontypeable Haemophilus influenzae Increases Complement-Mediated Killing...Nontypeable Haemophilus influenzae (NTHi) colonizes the human upper respiratory tract without causing disease symptoms, but it is also a major cause of upper and lower respiratory tract infections in children and elderly, respectively. NTHi synthesizes various molecules to decorate its lipooligosaccharide (LOS), which modulates the level of virulence.
Molecular PathogenesisUptake of Sialic Acid by Nontypeable Haemophilus influenzae Increases Complement Resistance through Decreasing IgM-Dependent Complement ActivationAlthough nontypeable Haemophilus influenzae (NTHi) is a human-specific nasopharyngeal commensal bacterium, it also causes upper respiratory tract infections in children and lower respiratory tract infections in the elderly, resulting in frequent antibiotic use. The transition from symbiotic colonizing bacterium to opportunistic pathogen is not completely understood....
Molecular PathogenesisNontypeable Haemophilus influenzae Invasive Blood Isolates Are Mainly Phosphorylcholine Negative and Show Decreased Complement-Mediated Killing That Is Associated with Lower Binding of IgM and CRP in Comparison to Colonizing Isolates from the OropharynxNontypeable Haemophilus influenzae (NTHi) bacteria express various molecules that contribute to their virulence. The presence of phosphocholine (PCho) on NTHi lipooligosaccharide increases adhesion to epithelial cells and is an advantage for the bacterium, enabling nasopharyngeal colonization, as measured in humans and animal models.
Host-Associated Microbial CommunitiesAutoinducer 2 (AI-2) Production by Nontypeable Haemophilus influenzae 86-028NP Promotes Expression of a Predicted Glycosyltransferase That Is a Determinant of Biofilm Maturation, Prevention of Dispersal, and Persistence In VivoNontypeable Haemophilus influenzae (NTHi) is an extremely common human pathobiont that persists on the airway mucosal surface within biofilm communities, and our previous work has shown that NTHi biofilm maturation is coordinated by the production and uptake of autoinducer 2 (AI-2) quorum signals. To directly test roles for AI-2 in maturation and...
- Bacterial InfectionsOtitis Media and Nasopharyngeal Colonization in ccl3−/− Mice