Human Adenoidal Organ Culture: A Model to Study Nontypable Haemophilus Influenzae (NTHI) and other Bacterial Interactions with Nasopharyngeal Mucosa—Implications in Otitis Media

Abstract

Nontypable Haemophilus influenzae (NTHI) has become the predominant cause of both acute suppurative otitis media and chronic otitis media with effusion. It has now been well-demonstrated that both outer membrane proteins and restriction fragment analysis of the bacterial genomes of concomitant nasopharyngeal and middle ear effusion isolates of NTHI are identical. It is therefore of critical importance to understand the mechanisms whereby bacteria that are present in normal healthy children in small numbers become the predominant organism in the nasopharynx in otitis media. The studies presented here suggest that nontypable Haemophilus influenzae can effectively decrease ciliary function as measured by stroboscopic illumination of ciliary beat frequency on human adenoidal organ culture. This organism also produces significant histopathologic and ultrastructural damage to the epithelial cells and cilia of adenoid organ culture, demonstrated by both light microscopy and scanning electron microscopy. The data suggest the following hypothesis: Nontypable Haemophilus Influenzae can destroy mucociliary function and allow increased bacterial replication in the mucus overlying the nasopharyngeal mucosa. The mucociliary system of the eustachian tube may also be involved in a a similar manner, thus allowing bacteria to enter the middle ear space via the eustachian tube.