Melhus A, Hermansson A, Akkoyunlu M, Forsgren A, Prellner K. Experimental recurrent otitis media induced by Haemophilus influenzae: protection and serum antibodies.
Am J Otolaryngol 1995;
16:383-90. [PMID:
8572254 DOI:
10.1016/0196-0709(95)90075-6]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE
To study whether acute otitis media caused by encapsulated or nontypeable Haemophilus influenzae confers cross-reactive protective immunity in an animal model system and to explore the possible involvement of various humoral specific antibodies in protection.
MATERIALS AND METHODS
Rats were intrabullarly challenged with H influenzae type b and two different nontypeable H influenzae strains. One month after the initial infection, the animals were rechallenged ipsilaterally or contralaterally with either a homologous or heterologous strain, and the susceptibility to reinfection was investigated by otomicroscopy.
RESULTS
The animals challenged and rechallenged with the type b strain were well-protected ipsilaterally and contralaterally, while the protection after homologous rechallenge with a nontypeable strain was partial in the ipsilateral ear and very poor in the contralateral ear. Middle ears previously infected with a nontypeable strain remained fully susceptible to infections with heterologous strains, but there was an indication of cross-protection in the animal groups where the first episode of acute otitis media was caused by type b and the second by a nontypeable strain. Using the Western blot technique and an enzyme linked immunosorbant assay, the serological response to different outer membrane proteins, especially protein D, of H influenzae during and after middle ear infection were investigated. The serological response from the type b infected animals were generally more distinct, while the antibody levels against protein D were lower in these groups compared with the groups infected with nontypeable strains.
CONCLUSIONS
These data indicate that H influenzae type-b-induced experimental otitis media results in a better protection than a nontypeable-induced, and H influenzae b confers a cross protection.
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