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Nontypeable Haemophilus influenzae strains with the capsule-associated insertion element IS1016 may mimic encapsulated strains

Karlsson, Eva and Melhus, Åsa LU (2006) In APMIS : acta pathologica, microbiologica, et immunologica Scandinavica 114(9). p.633-640
Abstract
With the elimination of Haemophilus influenzae type b through vaccination, it has been suggested that other types of H. influenzae strains might acquire virulence traits and emerge as important pathogens. The gene sequence IS1016 has been associated with an increased capacity to cause severe infections. It is usually present in encapsulated strains but is sometimes harbored by nontypeable H. influenzae strains. To explore this further, 118 H. influenzae isolates, collected from both patients and healthy carriers, were investigated with PCR with reference to this gene sequence. Isolates positive for the insertion element were bio- and serotyped. The presence of hmw genes for adherence, the genetic profile, and the ability to form biofilm in... (More)
With the elimination of Haemophilus influenzae type b through vaccination, it has been suggested that other types of H. influenzae strains might acquire virulence traits and emerge as important pathogens. The gene sequence IS1016 has been associated with an increased capacity to cause severe infections. It is usually present in encapsulated strains but is sometimes harbored by nontypeable H. influenzae strains. To explore this further, 118 H. influenzae isolates, collected from both patients and healthy carriers, were investigated with PCR with reference to this gene sequence. Isolates positive for the insertion element were bio- and serotyped. The presence of hmw genes for adherence, the genetic profile, and the ability to form biofilm in vitro were investigated. A total of 15 isolates were IS1016-positive, whereof 12 were nontypeable. All 12 nontypeable isolates were obtained from healthy carriers, and 92% of the isolates were biotype I. They cross-reacted to some extent with type-specific antisera or exhibited a restricted genetic diversity like encapsulated strains. Furthermore, they lacked hmw-genes, and their ability to form biofilms was comparable with a capsule-deficient type b strain. Although this subset of strains mimicked traits usually exhibited by encapsulated strains, the isolation frequency did not seem to have been affected by vaccination. (Less)
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organization
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type
Contribution to journal
publication status
published
subject
keywords
cross-reaction, nontypeable Haemophilus influenzae, serotype, genes, biofilm, hmw
in
APMIS : acta pathologica, microbiologica, et immunologica Scandinavica
volume
114
issue
9
pages
633 - 640
publisher
John Wiley and Sons
external identifiers
  • wos:000240206800006
  • pmid:16948816
  • scopus:33748349658
ISSN
1600-0463
DOI
10.1111/j.1600-0463.2006.apm_333.x
language
English
LU publication?
yes
id
74ceba28-affa-401a-8f0d-bce59d8e7802 (old id 394900)
date added to LUP
2016-04-01 12:31:49
date last changed
2021-02-17 03:43:56
@article{74ceba28-affa-401a-8f0d-bce59d8e7802,
  abstract     = {With the elimination of Haemophilus influenzae type b through vaccination, it has been suggested that other types of H. influenzae strains might acquire virulence traits and emerge as important pathogens. The gene sequence IS1016 has been associated with an increased capacity to cause severe infections. It is usually present in encapsulated strains but is sometimes harbored by nontypeable H. influenzae strains. To explore this further, 118 H. influenzae isolates, collected from both patients and healthy carriers, were investigated with PCR with reference to this gene sequence. Isolates positive for the insertion element were bio- and serotyped. The presence of hmw genes for adherence, the genetic profile, and the ability to form biofilm in vitro were investigated. A total of 15 isolates were IS1016-positive, whereof 12 were nontypeable. All 12 nontypeable isolates were obtained from healthy carriers, and 92% of the isolates were biotype I. They cross-reacted to some extent with type-specific antisera or exhibited a restricted genetic diversity like encapsulated strains. Furthermore, they lacked hmw-genes, and their ability to form biofilms was comparable with a capsule-deficient type b strain. Although this subset of strains mimicked traits usually exhibited by encapsulated strains, the isolation frequency did not seem to have been affected by vaccination.},
  author       = {Karlsson, Eva and Melhus, Åsa},
  issn         = {1600-0463},
  language     = {eng},
  number       = {9},
  pages        = {633--640},
  publisher    = {John Wiley and Sons},
  series       = {APMIS : acta pathologica, microbiologica, et immunologica Scandinavica},
  title        = {Nontypeable Haemophilus influenzae strains with the capsule-associated insertion element IS1016 may mimic encapsulated strains},
  url          = {http://dx.doi.org/10.1111/j.1600-0463.2006.apm_333.x},
  doi          = {10.1111/j.1600-0463.2006.apm_333.x},
  volume       = {114},
  year         = {2006},
}