title: Haemagglutination properties of Moraxella (Branhamella) catarrhalis.
abstract: The ability of 30 isolates of Moraxella (Branhamella) catarrhalis to haemagglutinate erythrocytes of five species was examined. Two haemagglutination phenotypes of M. catarrhalis were observed: phenotype I isolates (n = 10) agglutinated human erythrocytes, while phenotype II isolates (n = 7) agglutinated both human and rabbit erythrocytes. No haemagglutination was observed with chick, sheep or horse erythrocytes. Haemagglutination by both phenotype I and II isolates was abolished following treatment of these isolates with pronase and trypsin, while heat treatment at 70 degrees C markedly reduced the level of haemagglutination by both sets of isolates. Haemagglutination by phenotype II isolates was inhibited by galactose, whereas haemagglutination by phenotype I isolates was not inhibited by this carbohydrate. Transmission electron microscopy (TEM) studies showed that very close cell-surface interactions occurred when both phenotypes of M. catarrhalis adhered to the human erythrocyte. Fimbrial attachment was not apparent. Haemagglutinating isolates of both phenotypes had a trypsin-sensitive outer fibrillar coat when examined by TEM.
authors.affiliation: Department of Biological Sciences, Dublin Institute of Technology, Ireland.
authors.forename: M
authors.initials: M
authors.lastname: Fitzgerald
authors.forename: S
authors.initials: S
authors.lastname: Murphy
authors.forename: R
authors.initials: R
authors.lastname: Mulcahy
authors.forename: C
authors.initials: C
authors.lastname: Keane
authors.forename: D
authors.initials: D
authors.lastname: Coakley
authors.forename: T
authors.initials: T
authors.lastname: Scott
mesh_terms: D000818:Animals; D004912:Erythrocytes / Q000648:ultrastructure; D006384:Hemagglutination / Q000187:drug effects; D006801:Humans; D008854:Microscopy, Electron; D001936:Moraxella catarrhalis / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D011817:Rabbits