title: Adhesion of Moraxella catarrhalis to human bronchial epithelium characterized by a novel fluorescence-based assay.
abstract: Moraxella catarrhalis is a major cause of infectious exacerbations of chronic obstructive lung disease. Adhesion of this pathogen to epithelial cells is critical for its pathogenicity. Although much work has been done on identifying surface molecules of M. catarrhalis as adhesins, several adhesion assays were used in these studies which has never been validated or compared to each other. In the present study, we have examined the capacity of M. catarrhalis to adhere to different human epithelial cells. By using the two most commonly used adhesion assays based on the enumeration of colony-forming units or on the counting of adherent bacteria per epithelial cell by light microscopy, we identified significant limitations of both methods. These arose either from differences in strain-specific adhesion pattern on the epithelial cell surface or the dependence on the state of confluence of the epithelial cell layer. We developed a new fluorescence-based adhesion assay and compared our results to the two conventional methods. We demonstrated that the fluorescence-based adhesion assay offers a reliable and convenient method for the quantification of M. catarrhalis adhesion to confluent epithelial cell monolayers.
authors.affiliation: Department of Internal Medicine/Infectious Diseases, Charité - University Medicine Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. hortense.slevogt@charite.de
authors.forename: Hortense
authors.initials: H
authors.lastname: Slevogt
authors.forename: Krishna N
authors.initials: KN
authors.lastname: Tiwari
authors.forename: Bernd
authors.initials: B
authors.lastname: Schmeck
authors.forename: Andreas
authors.initials: A
authors.lastname: Hocke
authors.forename: Bastian
authors.initials: B
authors.lastname: Opitz
authors.forename: Norbert
authors.initials: N
authors.lastname: Suttorp
authors.forename: Joachim
authors.initials: J
authors.lastname: Seybold
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology*; D001980:Bronchi / Q000821:virology*; D002461:Cell Line, Transformed; D015169:Colony Count, Microbial / Q000379:methods; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods*; D006801:Humans; D018613:Microscopy, Confocal; D001936:Moraxella catarrhalis / Q000502:physiology*; D020545:Respiratory Mucosa / Q000821:virology*