Relative Contributions of Lipooligosaccharide Inner and Outer Core Modifications to Nontypeable Haemophilus influenzae Pathogenesis

Morey, Pau; Viadas, Cristina; Euba, Begoña; Hood, Derek W.; Barberán, M.; Gil, Carmen; Grilló, María Jesús; Bengoechea, José A.; Garmendia, Junkal

doi:10.1128/iai.00492-13

Cited by 49 publications

(79 citation statements)

References 70 publications

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“…In that study, a licD gene deletion mutant deficient for PCho showed decreased biofilm formation, whereas a phase-locked licA gene variant showed increased PCho incorporation and increased biofilm maturation compared to wild-type (WT) strain 2019. These results corroborate recent findings by Morey et al, who showed decreased biofilm formation for a lic1 mutant of NTHi strain 375 (20). Furthermore, NTHi licD mutants of strains 2019 and 86-028NP showed decreased biofilm density and increased clearance in a chinchilla model for OM compared to WT strains (18,19).…”

supporting

confidence: 82%

Incorporation of Phosphorylcholine into the Lipooligosaccharide of Nontypeable Haemophilus influenzae Does Not Correlate with the Level of Biofilm Formation In Vitro

et al. 2014

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Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen that causes otitis media in children and communityacquired pneumonia or exacerbations of chronic obstructive pulmonary disease in adults. A large variety of studies suggest that biofilm formation by NTHi may be an important step in the pathogenesis of this bacterium. The objective of this report was to determine the relationship between the presence of phosphorylcholine in the lipooligosaccharide of NTHi and the level of biofilm formation. The study was performed on 111 NTHi clinical isolates collected from oropharyngeal samples of healthy children, middle ear fluid of children with otitis media, and sputum samples of patients with chronic obstructive pulmonary disease or community-acquired pneumonia. NTHi clinical isolates presented a large variation in the level of biofilm formation in a static assay and phosphorylcholine content. Isolates collected from the oropharynx and middle ear fluid of children tended to have more phosphorylcholine and made denser biofilms than isolates collected from sputum samples of patients with chronic obstructive pulmonary disease or community-acquired pneumonia. No correlation was observed between biofilm formation and the presence of phosphorylcholine in the lipooligosaccharide for either planktonic or biofilm growth. This lack of correlation was confirmed by abrogating phosphorylcholine incorporation into lipooligosaccharide through licA gene deletion, which had strain-specific effects on biofilm formation. Altogether, we present strong evidence to conclude that there is no correlation between biofilm formation in a static assay and the presence of phosphorylcholine in lipooligosaccharide in a large collection of clinical NTHi isolates collected from different groups of patients.

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confidence: 82%

Incorporation of Phosphorylcholine into the Lipooligosaccharide of Nontypeable Haemophilus influenzae Does Not Correlate with the Level of Biofilm Formation In Vitro

et al. 2014

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“…The addition of ChoP has been previously observed in a number of NTHi strains and can occur at any of the three core heptose (Hep) units (Fig. 4) (41,(44)(45)(46)(47)(48). These findings are in contrast to the most prevalent glycoforms expressed by NTHi strain 2019 (see Fig.…”

Section: -Keto-3-deoxyoctonate (Kdo) (40-44)contrasting

confidence: 54%

“…In NTHi, all three core heptoses can be further substituted with oligosaccharide chains, free phosphate (P), phosphoethanolamine (PEA), ChoP, acetate groups, and glycine (13,(41)(42)(43)(44)(45)(46)(47)(48). The addition of these various moieties can create highly heterogeneous LOS structures both between strains and within a strain.…”

Section: -Keto-3-deoxyoctonate (Kdo) (40-44)mentioning

confidence: 99%

Comparative Analyses of the Lipooligosaccharides from Nontypeable Haemophilus influenzae and Haemophilus haemolyticus Show Differences in Sialic Acid and Phosphorylcholine Modifications

et al. 2016

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Haemophilus haemolyticus and nontypeable Haemophilus influenzae (NTHi) are closely related upper airway commensal bacteria that are difficult to distinguish phenotypically. NTHi causes upper and lower airway tract infections in individuals with compromised airways, while H. haemolyticus rarely causes such infections. The lipooligosaccharide (LOS) is an outer membrane component of both species and plays a role in NTHi pathogenesis. In this study, comparative analyses of the LOS structures and corresponding biosynthesis genes were performed. Mass spectrometric and immunochemical analyses showed that NTHi LOS contained terminal sialic acid more frequently and to a higher extent than H. haemolyticus LOS did. Genomic analyses of 10 strains demonstrated that H. haemolyticus lacked the sialyltransferase genes lic3A and lic3B (9/10) and siaA (10/10), but all strains contained the sialic acid uptake genes siaP and siaT (10/10). However, isothermal titration calorimetry analyses of SiaP from two H. haemolyticus strains showed a 3.4-to 7.3-fold lower affinity for sialic acid compared to that of NTHi SiaP. Additionally, mass spectrometric and immunochemical analyses showed that the LOS from H. haemolyticus contained phosphorylcholine (ChoP) less frequently than the LOS from NTHi strains. These differences observed in the levels of sialic acid and ChoP incorporation in the LOS structures from H. haemolyticus and NTHi may explain some of the differences in their propensities to cause disease. Nontypeable Haemophilus influenzae (NTHi) is a common commensal organism of the nasopharynx. NTHi can also cause disease in individuals with compromised upper airways (1-3). In adults, this organism is typically associated with causing pneumonia and bronchitis in individuals with chronic obstructive pulmonary disease (COPD) (4, 5), and in children, it is a causative agent of otitis media (6, 7). NTHi bacteria typically cause localized infections such as sinusitis or bronchitis, but they do have the ability to cause systemic infections such as bacteremia or meningitis (6). Haemophilus haemolyticus is also a commensal organism of the nasopharynx; it is generally considered a colonizer and is typically not associated with disease. The application of ribosomal analysis and specific gene differences has enabled resolution of these closely related organisms (8-12).Lipooligosaccharides (LOS) are the major surface glycolipids expressed by both NTHi and H. haemolyticus. LOS has been shown to be a major factor in the pathogenesis of NTHi (13-17). LOS structures that terminate in N-acetyl-5-neuraminic acid (Neu5Ac), commonly referred to as sialic acid, have been shown to be important in resistance to complement killing (13,15,17) and in the ability of the organism to cause otitis media in the chinchilla model of infection (15,16). Additionally, Weiser et al. have shown that phosphorylcholine (ChoP) can be expressed on NTHi LOS in a phase variable manner (18). The interaction between the platelet-activating factor (PAF) receptor and ChoP has been sh...

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“…These include type IV pili (PilA) overexpression (14), the presence of fimbriae (13), quorum sensing (15), the presence of outer membrane proteins (OMPs) P2 and P5 (16), and the presence of phosphorylcholine (PCho) and sialic acid in the lipooligosaccharide (LOS) molecule (17,18). Despite the previously shown role of PCho in biofilm growth (19), a longitudinal study on NT H. influenzae isolates from patients with chronic respiratory disease found no clear correlation between biofilm growth and the presence of PCho in the LOS molecule (20). We previously showed the absence of a clear correlation between in vitro biofilm formation and the presence of PCho in the LOS of NT H. influenzae using a collection of 111 clinical isolates from different clinical sources (21).…”

Section: N Ontypeable (Nt)mentioning

confidence: 99%

Increased Biofilm Formation by Nontypeable Haemophilus influenzae Isolates from Patients with Invasive Disease or Otitis Media versus Strains Recovered from Cases of Respiratory Infections

Puig

Domenech

Garmendia

et al. 2014

Appl Environ Microbiol

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f Biofilm formation by nontypeable (NT) Haemophilus influenzae remains a controversial topic. Nevertheless, biofilm-like structures have been observed in the middle-ear mucosa of experimental chinchilla models of otitis media (OM). To date, there have been no studies of biofilm formation in large collections of clinical isolates. This study aimed to investigate the initial adhesion to a solid surface and biofilm formation by NT H. influenzae by comparing isolates from healthy carriers, those with noninvasive respiratory disease, and those with invasive respiratory disease. We used 352 isolates from patients with nonbacteremic community-acquired pneumonia (NB-CAP), chronic obstructive pulmonary disease (COPD), OM, and invasive disease and a group of healthy colonized children. We then determined the speed of initial adhesion to a solid surface by the BioFilm ring test and quantified biofilm formation by crystal violet staining. Isolates from different clinical sources displayed high levels of biofilm formation on a static solid support after growth for 24 h. We observed clear differences in initial attachment and biofilm formation depending on the pathology associated with NT H. influenzae isolation, with significantly increased biofilm formation for NT H. influenzae isolates collected from patients with invasive disease and OM compared with NT H. influenzae isolates from patients with NB-CAP or COPD and healthy colonized subjects. In all cases, biofilm structures were detached by proteinase K treatment, suggesting an important role for proteins in the initial adhesion and static biofilm formation measured by crystal violet staining.

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Relative Contributions of Lipooligosaccharide Inner and Outer Core Modifications to Nontypeable Haemophilus influenzae Pathogenesis

Cited by 49 publications

References 70 publications

Incorporation of Phosphorylcholine into the Lipooligosaccharide of Nontypeable Haemophilus influenzae Does Not Correlate with the Level of Biofilm Formation In Vitro

Incorporation of Phosphorylcholine into the Lipooligosaccharide of Nontypeable Haemophilus influenzae Does Not Correlate with the Level of Biofilm Formation In Vitro

Comparative Analyses of the Lipooligosaccharides from Nontypeable Haemophilus influenzae and Haemophilus haemolyticus Show Differences in Sialic Acid and Phosphorylcholine Modifications

Increased Biofilm Formation by Nontypeable Haemophilus influenzae Isolates from Patients with Invasive Disease or Otitis Media versus Strains Recovered from Cases of Respiratory Infections

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