Adhesin Expression in Matched Nasopharyngeal and Middle Ear Isolates of Nontypable Haemophilus influenzae from Children with Acute Otitis Media † 866

Krasan, Graham P.; Cutter, David; Block, Stan L.; Geme, Joseph W. St.

doi:10.1203/00006450-199804001-00887

Cited by 25 publications

(35 citation statements)

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“…Adhesins on the surface of H. influenzae include polymeric structures such as hemagglutinating pili and monomeric or oligomeric molecules, including HMW1, HMW2, Hia, and Hap. Nontypable strain 12 does not express pili (3,50), yet this strain was capable of activating epithelial cell ICAM-1 expression, suggesting that other H. influenzae factors mediate this response. Isogenic mutants lacking HMW1, HMW2, Hia, and/or Hap retained the capacity to induce epithelial cell ICAM-1, suggesting that these adhesins are not essential for this effect.…”

Section: Discussionmentioning

confidence: 99%

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Haemophilus influenzaeStimulates ICAM-1 Expression on Respiratory Epithelial Cells

Frick¹,

Joseph²,

Pang³

et al. 2000

The Journal of Immunology

119

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Epithelial cells interact directly with bacteria in the environment and play a critical role in airway defense against microbial pathogens. In this study, we examined the response of respiratory epithelial cells to infection with nontypable Haemophilus influenzae. Using an in vitro cell culture model, we found that epithelial cell monolayers released significant quantities of IL-8 and expressed increased levels of ICAM-1 mRNA and surface protein in response to H. influenzae. In contrast, levels of IL-1β, TNF-α, and MHC class I were not significantly affected, suggesting preferential activation of a specific subset of epithelial genes directed toward defense against bacteria. Induction of ICAM-1 required direct bacterial interaction with the epithelial cell surface and was not reproduced by purified H. influenzae lipooligosaccharide. Consistent with a functional role for this response, induction of ICAM-1 by H. influenzae mediated increased neutrophil adherence to the epithelial cell surface. Furthermore, in an in vivo murine model of airway infection with H. influenzae, increased epithelial cell ICAM-1 expression coincided with increased chemokine levels and neutrophil recruitment in the airway. These results indicate that ICAM-1 expression on human respiratory epithelial cells is induced by epithelial cell interaction with H. influenzae and suggest that an ICAM-1-dependent mechanism can mediate neutrophil adherence to these cells independent of inflammatory mediator release by other cell types. Direct induction of specific epithelial cell genes (such as ICAM-1 and IL-8) by bacterial infection may allow for rapid and efficient innate defense in the airway.

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Section: Discussionmentioning

confidence: 99%

“…Another H. influenzae adhesin is the Hap serine protease (48), which is present in strains expressing HMW1 and HMW2 and possibly in other strains as well. In addition, selected isolates express hemaglutinating pili (49,50).…”

Section: Role Of Known Bacterial Adhesins In H Influenzae Induction mentioning

confidence: 99%

Haemophilus influenzaeStimulates ICAM-1 Expression on Respiratory Epithelial Cells

Frick¹,

Joseph²,

Pang³

et al. 2000

The Journal of Immunology

119

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“…One H. haemolyticus type strain, ATCC 33390, was also used. The remaining strains were parts of various collections obtained by the laboratory of the Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, or by other laboratories in previous studies (11,16,29,38,40,50,54) (Table 1). Briefly, the H. influenzae strains were isolated from the throats of healthy children attending day care, the throats of healthy adults in a longitudinal carriage study, or the middle ear aspirates of children with otitis media.…”

Section: Methodsmentioning

confidence: 99%

“…The H. influenzae and nonhemolytic H. haemolyticus strains were originally defined and tested again in this study by typical colony morphology on chocolate agar, X and V growth factor dependency, and no reaction in the porphyrin test (11,16,29,38,54). Hemolysis, used to differentiate hemolytic H. haemolyticus strains, was assessed as zones of beta-hemolysis surrounding individual colonies grown on horse blood agar (Remel, Lenexa, KS).…”

Section: Methodsmentioning

confidence: 99%

Relationships of Nontypeable Haemophilus influenzae Strains to Hemolytic and Nonhemolytic Haemophilus haemolyticus Strains

et al. 2008

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Haemophilus influenzae is both a human respiratory pathogen and pharyngeal commensal, while H. haemolyticus, the closest phylogenetic relative of H. influenzae, is arguably a strict pharyngeal commensal. A hemolytic phenotype has historically differentiated H. haemolyticus from H. influenzae, but the recent recognition of significant nonhemolytic H. haemolyticus colonization has decreased this trait's resolvability. Given this and the potential of recombination between the species, we examined the distribution of microbiologic and molecular traits between collections of H. influenzae and H. haemolyticus strains separated within a dendrogram obtained by multilocus sequence analysis (MLSA). All strains hybridizing with a probe to iga, a gene encoding an immunoglobulin A protease of H. influenzae, clustered apart from strains that did not hybridize with the probe. Other traits also segregated significantly along this division, suggesting a separation of the species. Of note, the LOS genes licA, lic2A, and lgtC of H. influenzae were approximately 2, 6, and 54 times, respectively, more prevalent in H. influenzae than in H. haemolyticus. In contrast to species separation, interspecies recombination was evidenced by the inability of single gene sequences to phylogenetically separate the species and by the "fuzzy" distribution of some species-specific traits across the species dividing line. Together, these data support the historically accurate and pragmatic division of these species while recognizing their potential for recombination. Future comparative genomic studies identifying common and distinctive genes could be useful in evaluating their role in the commensal or virulent growth, respectively, of H. influenzae.Haemophilus influenzae is one of eight Haemophilus species that reside as commensal organisms in the pharyngeal cavity of humans. These other commensal Haemophilus species include H. parainfluenzae, H. haemolyticus, H. parahaemolyticus, H. paraphrohaemolyticus, H. segnis, H. aphrophilus, and H. paraphrophilus. H. influenzae is by far the most pathogenic member of the genus in humans. Strains possessing a type b capsule are often associated with invasive diseases, such as meningitis, sepsis, and pneumonia; and strains lacking a capsule (referred to as nontypeable [NT]) are associated with localized mucosal diseases, such as otitis media, sinusitis, and bronchitis. Other haemophili are considered to be rarely associated with disease, and H. haemolyticus has never been implicated as an infectious disease agent (1).In contrast to other haemophili, H. haemolyticus and H. influenzae both depend on X (hemin) and V (NAD) growth factors, both lack the ability to ferment sucrose, both share similar GϩC contents, and both are nearly indistinguishable by their colony and cellular morphologies (25). Initial phylogenetic studies performed by using DNA-DNA hybridization revealed that H. haemolyticus associated with H. influenzae in a cluster of the family Pasteurellaceae termed Haemophilus sensu stricto (6,41,47), and t...

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“…pSC-B21 was similar to the HMW1 adhesin of non-typable Haemophilus in¯uenzae (NTHi) [42,43]. The HMW proteins of NTHi are considered to be major virulence determinants at many stages of NTHi disease [44,45]. The pSC-B21 sequence was present in only two strains as determined by slot-blot analysis (see Fig.…”

Section: Nucleotide Sequence Analysis Of Subtracted Librarymentioning

confidence: 99%

Cloning and analysis of genomic differences unique to Burkholderia pseudomallei by comparison with B. thailandensis

Brown

Beacham

2000

Journal of Medical Microbiology

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Melioidosis is an infectious disease caused by Burkholderia pseudomallei. Genomic subtractive hybridisation was performed with the closely related avirulent species B. thailandensis to identify virulence genes of B. pseudomallei. The subtractive hybridisation products were highly speci®c for B. pseudomallei. Sequence analysis revealed a number of putative virulence factors, as well as apparently novel sequences of unknown function. The subtracted library contained DNA regions of relatively low G C mol% content, which were distributed throughout the B. pseudomallei genome. The distribution of subtracted sequences amongst a collection of 22 B. pseudomallei isolates was found to be variable, with the exception of three strains which almost universally lacked the subtracted sequences. These three strains also differed in that they were highly haemolytic, indicating a possible separate virotype.

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Adhesin Expression in Matched Nasopharyngeal and Middle Ear Isolates of Nontypable Haemophilus influenzae from Children with Acute Otitis Media † 866

Cited by 25 publications

References 0 publications

Haemophilus influenzaeStimulates ICAM-1 Expression on Respiratory Epithelial Cells

Haemophilus influenzaeStimulates ICAM-1 Expression on Respiratory Epithelial Cells

Relationships of Nontypeable Haemophilus influenzae Strains to Hemolytic and Nonhemolytic Haemophilus haemolyticus Strains

Cloning and analysis of genomic differences unique to Burkholderia pseudomallei by comparison with B. thailandensis

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