Experimental otitis media with effusion following middle ear inoculation of nonviable h influenzae

Thomas F. Demaria, David J. Lim, Bruce R. Briggs, Nobuhiro Okazaki

Research output: Contribution to journalArticlepeer-review

113 Scopus citations


In order to test the hypothesis that nonviable bacteria can induce middle ear inflammation leading to persistent middle ear effusion (MEE), we conducted an animal experiment using formalin-killed Hemophilus influenzae, the bacterium reported to be the most common pathogen isolated from chronic MEEs. Over 70% of the chinchillas injected with formalin-killed H influenzae type b or a nontypeable isolate developed sterile, straw-colored serous MEEs, and exhibited histological evidence of extensive inflammatory changes of the middle ear mucosal connective tissue and epithelium. Control animals injected with pyrogen-free sterile saline did not exhibit any inflammatory changes or effusions in the middle ears. Our data suggest that endotoxin on the surface of H influenzae, a gram-negative bacterium, may be responsible for the induction of the otitis media with effusion. It is suggested that endotoxin (even when the organisms are no longer viable) may be responsible for the production of serous MEE and inflammatory changes in the middle ear.

Original languageEnglish (US)
Pages (from-to)52-56
Number of pages5
JournalAnnals of Otology, Rhinology & Laryngology
Issue number1
StatePublished - Jan 1984

ASJC Scopus subject areas

  • Otorhinolaryngology


Dive into the research topics of 'Experimental otitis media with effusion following middle ear inoculation of nonviable h influenzae'. Together they form a unique fingerprint.

Cite this