How Long Do Middle Ear Pathogens Survive in Mucoid Effusion Material?

Abstract

Middle ear pathogens (S. pneumoniae, H. influenzae, B. catarrhalis, S. aureus and coagulase-negative staphylococci) were injected into 28 samples of mucoid effusion materials taken from 17 patients suffering from secretory otitis media. In every case the effusion material was sticky, hydrophilic and thick and contained no bacteria. S. pneumoniae and H. influenzae survived for only 1–2 days in mucoid effusion material incubated at 37°C, while B. catarrhalis and staphylococci survived for at least 18-36 days when incubated in this medium. It seems that mucoid effusion material filling the middle ear cavity during secretory otitis media has a dual function in providing protection against middle ear infections. Thanks to its physical properties the effusion material hinders bacteria from ascending from the nasopharynx and is a poor substrate for some microorganisms. In contrast, mucoid effusion material is a superior medium for B. catarrhalis and staphylococci.