Abstract
Moraxella catarrhalis is a normal resident of the human nasopharyngeal flora, but it is also isolated from middle ear fluid of acute otitis media and otitis media with effusion patients. To determine whether M. catarrhalis has direct pathogenicity in the middle ear, heat-killed M. catarrhalis was inoculated into the middle ear bullae of guinea pigs, and the inflammatory response was investigated. Middle ear mucosal histopathology observed in M. catarrhalis-inoculated ears included subepithelial edema, capillary dilatation, thickening of lamina propria mucosa, inflammatory cell and erythrocyte infiltration into the lamina propria mucosa. Inflammatory cell numbers, lysozyme and myeloperoxidase concentrations in the middle ear washing suspensions of M. catarrhalis-inoculated ears were significantly higher than control ears throughout the experiment. Therefore, nonviable M. catarrhalis induced middle ear inflammation and mucoperiosteal histopathology, which might be caused by direct injury of the nonviable bacteria (e.g. lipooligosaccharide or outer membrane proteins) and metabolic products of inflammatory cells.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
