The Pathogenesis of Disease Due to Type b Haemophilus influenzae

R, Aubrey; Tang, Christoph M.

doi:10.1385/1-59259-321-6:29

Cited by 7 publications

(7 citation statements)

References 129 publications

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“…Since Margaret Pittman's original description of capsular serotypes among H. influenzae isolates in 1931 (Pittman, 1931), H. influenzae serotype b (Hib) had been the most clinically significant strain causing invasive disease (e.g. meningitis, epiglottitis, septicaemia and osteomyelitis) in previously well infants and children (Aubrey & Tang, 2003). Since the early 1990s, routine administration of the Hib conjugate vaccines (which induce protective levels of anti-capsular antibody) has virtually eliminated Hib disease among infants and young children in developed countries (Agrawal & Murphy, 2011;Ladhani, 2012).…”

Section: Introductionmentioning

confidence: 99%

Adhesin genes and serum resistance in Haemophilus influenzae type f isolates

Watson

Nelson

Nguyen

et al. 2013

Journal of Medical Microbiology

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The incidence of invasive infections due to Haemophilus influenzae has decreased significantly in developed countries with high rates of vaccination against H. influenzae serotype b (Hib). This vaccine provides no protection against H. influenzae serotype f (Hif), typically associated with invasive infections in adults with chronic disease and/or immunodeficiency, and rarely in otherwise healthy adults and children. The specific properties of Hif associated with virulence remain largely uncharacterized. A panel of 26 Hif strains consisting of both invasive disease-associated and mucosal surface non-invasive disease-associated isolates was surveyed by DNA fingerprinting, biotyping and PCR detection of hmw1, hmw2, hsf, the hif fimbrial locus and the lipooligosaccharide (LOS) biosynthetic island, and assessment of b-lactamase expression and determination of resistance to the bactericidal activity of normal adult human serum. Repetitive sequence-based PCR fingerprinting differentiated the 26 strains into three clusters, with the majority of isolates (22/26, 84.6 %) clustered into a single indistinguishable group. Most isolates (24/26, 92.3 %) were of biotype I and two isolates produced b-lactamase with detection of a conjugative plasmid, and the isolates displayed a range of resistances to the bactericidal activity of human serum. All 26 isolates carried the adhesin hsf, 21 carried a partial hif fimbrial operon and 4 had the adhesin genes hmw1/2. A LOS biosynthetic island was detected in 20 isolates consisting of the genes lic2BC. It was concluded that Hif has many recognized virulence properties and comprises a relatively homogeneous group independent of the anatomical source from which it was isolated. INTRODUCTIONHaemophilus influenzae, a human-restricted Gram-negative coccobacillus, is a commensal of the upper respiratory mucosa and a pathogen commonly causing airway mucosal disease and occasional invasive disease. Since Margaret Pittman's original description of capsular serotypes among H. influenzae isolates in 1931 (Pittman, 1931), H. influenzae serotype b (Hib) had been the most clinically significant strain causing invasive disease (e.g. meningitis, epiglottitis, septicaemia and osteomyelitis) in previously well infants and children (Aubrey & Tang, 2003). Since the early 1990s, routine administration of the Hib conjugate vaccines (which induce protective levels of anti-capsular antibody) has virtually eliminated Hib disease among infants and young children in developed countries (Agrawal & Murphy, 2011;Ladhani, 2012). However, the vaccine provides no protection from infection due to nonb serotypes, including H. influenzae serotype f (Hif), which remains a rare but significant cause of invasive infection. Given the reduction in Hib carriage among Hib conjugate vaccine recipients, concern exists as to whether invasive disease due to Hif or other non-b encapsulated strains will become more prevalent due to serotype replacement Abbreviations: BLNAR, b-lactamase-negative ampicillin-resistant; CSF, cerebrospinal ...

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Section: Introductionmentioning

confidence: 99%

Adhesin genes and serum resistance in Haemophilus influenzae type f isolates

Watson

Nelson

Nguyen

et al. 2013

Journal of Medical Microbiology

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“…The Gram-negative, non-motile coccobacillus Haemophilus influenzae is a commensal of the upper respiratory tract and is involved in various infections including otitis media, epiglottitis, conjunctivitis and meningitis. H. influenzae is also frequently isolated from patients with chronic infections of the upper and lower respiratory tract (Aubrey & Tang, 2003;Kilian, 2005;Turk, 1984).…”

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Haemophilus influenzae may be untypable by the multilocus sequence typing scheme due to a complete deletion of the fucose operon

Ridderberg

Fenger

Nørskov‐Lauritsen

2010

Journal of Medical Microbiology

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“…The encapsulated strains cause invasive diseases, whereas the unencapsulated and hence nontypeable H. influenzae (NTHi) strains are mainly found in local upper and lower respiratory tract infections (2,35). However, NTHi is, after Streptococcus pneumoniae, the most common microbe found in children with acute otitis media and is the main cause of exacerbations in patients suffering from chronic obstructive pulmonary disease and bronchiectasis (3,4,13,28,32,34).…”

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Binding of Complement Regulators to Invasive Nontypeable Haemophilus influenzae Isolates Is Not Increased Compared to Nasopharyngeal Isolates, but Serum Resistance Is Linked to Disease Severity

et al. 2010

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The aim of the present study was to analyze the importance of nontypeable Haemophilus influenzae (NTHi) isolated from patients with sepsis (invasive isolates) compared to nasopharyngeal isolates from patients with upper respiratory tract infection for resistance to complement-mediated attack in human serum and to correlate this result with disease severity. We studied and characterized cases of invasive NTHi disease in detail. All patients with invasive NTHi isolates were adults, and 35% had a clinical presentation of severe sepsis according to the ACCP/SCCM classification of sepsis grading. Moreover, 41% of the patients had evidence of immune deficiency. The different isolates were analyzed for survival in human serum and for binding of 125 I-labeled, purified human complement inhibitors C4b-binding protein (C4BP), factor H, and vitronectin, in addition to binding of regulators directly from serum. No significant differences were found when blood-derived and nasopharyngeal isolates were compared, suggesting that interactions with the complement system are equally important for NTHi strains, irrespective of isolation site. Interestingly, a correlation between serum resistance and invasive disease severity was found. The ability to resist the attack of the complement system seems to be important for NTHi strains infecting the respiratory tract as well as the bloodstream.

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The Pathogenesis of Disease Due to Type b Haemophilus influenzae

Cited by 7 publications

References 129 publications

Adhesin genes and serum resistance in Haemophilus influenzae type f isolates

Adhesin genes and serum resistance in Haemophilus influenzae type f isolates

Haemophilus influenzae may be untypable by the multilocus sequence typing scheme due to a complete deletion of the fucose operon

Binding of Complement Regulators to Invasive Nontypeable Haemophilus influenzae Isolates Is Not Increased Compared to Nasopharyngeal Isolates, but Serum Resistance Is Linked to Disease Severity

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