silicon and Otitis-Media

Nontypeable Haemophilus influenzae (NTHi) is a major cause of opportunistic respiratory tract infections, including otitis media and bronchitis. The persistence of NTHi in vivo is thought to involve bacterial persistence in a biofilm community. Therefore, there is a need for further definition of bacterial factors contributing to biofilm formation by NTHi. Like other bacteria inhabiting host mucosal surfaces, NTHi has on its surface a diverse array of lipooligosaccharides (LOS) that influence host-bacterial interactions. In this study, we show that LOS containing sialic (N-acetyl-neuraminic) acid promotes biofilm formation by NTHi in vitro and bacterial persistence within the middle ear or lung in vivo. LOS from NTHi in biofilms was sialylated, as determined by comparison of electrophoretic mobilities and immunochemical reactivities before and after neuraminidase treatment. Biofilm formation was significantly reduced in media lacking sialic acid, and a siaB (CMP-sialic acid synthetase) mutant was deficient in biofilm formation in three different in vitro model systems. The persistence of an asialylated siaB mutant was attenuated in a gerbil middle ear infection model system, as well as in a rat pulmonary challenge model system. These data show that sialylated LOS glycoforms promote biofilm formation by NTHi and persistence in vivo.

Topics: Acute Disease; Animals; Biofilms; Disease Models, Animal; Ear, Middle; Gerbillinae; Haemophilus Infections; Haemophilus influenzae; Lipopolysaccharides; Lung; Otitis Media; Rats; Rats, Sprague-Dawley; Respiratory Tract Infections; Sialic Acids; Silicon

Topics: Animals; Disease Models, Animal; Ear, Middle; Eustachian Tube; Haplorhini; Injections; Otitis Media; Rubber; Silicon; Tympanic Membrane

Topics: Cholesteatoma; Ear Canal; Ear Neoplasms; Ear Ossicles; Fistula; Humans; Labyrinth Diseases; Mastoid; Methods; Mucous Membrane; Neoplasm Recurrence, Local; Otitis Media; Postoperative Complications; Semicircular Canals; Silicon; Tympanoplasty