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Adhesin expression in matched nasopharyngeal and middle ear isolates of nontypeable Haemophilus influenzae from children with acute otitis media.
Infect Immun. 1999 Jan; 67(1):449-54.II

Abstract

The HMW1 and HMW2 proteins, Hia, and hemagglutinating pili are important adherence factors in nontypeable Haemophilus influenzae. To gain insight into the relative importance of these adhesins in nasopharyngeal colonization and localized respiratory tract disease, we assessed their expression in matched nasopharyngeal and middle ear isolates of nontypeable H. influenzae from 17 children with acute otitis media. In all patients, including 11 with bilateral disease, the matched isolates were isogenic based on total protein profiles and genomic fingerprints. Of the nasopharyngeal isolates, 14 expressed only HMW1/HMW2-like proteins, 1 expressed only Hia, 1 expressed only pili, and 1 expressed both Hia and pili. Further analysis revealed concordance between nasopharyngeal isolates and the matched middle ear isolates for expression of the HMW1/HMW2-like proteins and Hia. In contrast, in the two children whose nasopharynges were colonized by piliated organisms, the corresponding middle ear isolates were nonpiliated and could not be enriched for piliation. Nevertheless, Southern analysis revealed that these two middle ear isolates contained all five hif genes required for pilus biogenesis and had no evidence of major genetic rearrangement. In summary, the vast majority of isolates of nontypeable H. influenzae associated with acute otitis media express HMW1/HMW2-like proteins, with expression present in both the nasopharynx and the middle ear. A smaller fraction of nasopharyngeal isolates express pili, while isogenic strains recovered from the middle ear are often refractory to enrichment for piliation. We speculate that the HMW adhesins and Hia are important at multiple steps in the pathogenesis of otitis media while pili contribute to early colonization and then become dispensable.

Authors+Show Affiliations

Edward Mallinckrodt Department of Pediatrics and Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA. krasan_g@kids.wustl.eduNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

9864255

Citation

Krasan, G P., et al. "Adhesin Expression in Matched Nasopharyngeal and Middle Ear Isolates of Nontypeable Haemophilus Influenzae From Children With Acute Otitis Media." Infection and Immunity, vol. 67, no. 1, 1999, pp. 449-54.
Krasan GP, Cutter D, Block SL, et al. Adhesin expression in matched nasopharyngeal and middle ear isolates of nontypeable Haemophilus influenzae from children with acute otitis media. Infect Immun. 1999;67(1):449-54.
Krasan, G. P., Cutter, D., Block, S. L., & St Geme, J. W. (1999). Adhesin expression in matched nasopharyngeal and middle ear isolates of nontypeable Haemophilus influenzae from children with acute otitis media. Infection and Immunity, 67(1), 449-54.
Krasan GP, et al. Adhesin Expression in Matched Nasopharyngeal and Middle Ear Isolates of Nontypeable Haemophilus Influenzae From Children With Acute Otitis Media. Infect Immun. 1999;67(1):449-54. PubMed PMID: 9864255.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Adhesin expression in matched nasopharyngeal and middle ear isolates of nontypeable Haemophilus influenzae from children with acute otitis media. AU - Krasan,G P, AU - Cutter,D, AU - Block,S L, AU - St Geme,J W,3rd PY - 1998/12/24/pubmed PY - 2001/3/28/medline PY - 1998/12/24/entrez SP - 449 EP - 54 JF - Infection and immunity JO - Infect Immun VL - 67 IS - 1 N2 - The HMW1 and HMW2 proteins, Hia, and hemagglutinating pili are important adherence factors in nontypeable Haemophilus influenzae. To gain insight into the relative importance of these adhesins in nasopharyngeal colonization and localized respiratory tract disease, we assessed their expression in matched nasopharyngeal and middle ear isolates of nontypeable H. influenzae from 17 children with acute otitis media. In all patients, including 11 with bilateral disease, the matched isolates were isogenic based on total protein profiles and genomic fingerprints. Of the nasopharyngeal isolates, 14 expressed only HMW1/HMW2-like proteins, 1 expressed only Hia, 1 expressed only pili, and 1 expressed both Hia and pili. Further analysis revealed concordance between nasopharyngeal isolates and the matched middle ear isolates for expression of the HMW1/HMW2-like proteins and Hia. In contrast, in the two children whose nasopharynges were colonized by piliated organisms, the corresponding middle ear isolates were nonpiliated and could not be enriched for piliation. Nevertheless, Southern analysis revealed that these two middle ear isolates contained all five hif genes required for pilus biogenesis and had no evidence of major genetic rearrangement. In summary, the vast majority of isolates of nontypeable H. influenzae associated with acute otitis media express HMW1/HMW2-like proteins, with expression present in both the nasopharynx and the middle ear. A smaller fraction of nasopharyngeal isolates express pili, while isogenic strains recovered from the middle ear are often refractory to enrichment for piliation. We speculate that the HMW adhesins and Hia are important at multiple steps in the pathogenesis of otitis media while pili contribute to early colonization and then become dispensable. SN - 0019-9567 UR - https://www.unboundmedicine.com/medline/citation/9864255/Adhesin_expression_in_matched_nasopharyngeal_and_middle_ear_isolates_of_nontypeable_Haemophilus_influenzae_from_children_with_acute_otitis_media_ L2 - http://iai.asm.org/cgi/pmidlookup?view=long&pmid=9864255 DB - PRIME DP - Unbound Medicine ER -