title: The outer membrane proteins UspA1 and UspA2 of Moraxella catarrhalis are highly conserved in nasopharyngeal isolates from young children.
abstract: UspA1 and UspA2 of Moraxella catarrhalis are vaccine candidates. The aims of this study were to determine: (1) the frequencies of occurrence and (2) the degrees of conservation of two surface-exposed epitopes of the uspA1 and uspA2 genes and their respective gene products in 108 nasopharyngeal isolates from young children. The uspA1 and uspA2 genes were detected in 107 (99%) and 108 (100%) isolates, respectively. Twenty-three of 108 uspA2 genes (21%) were identified as the variant gene uspA2H. One-hundred and five isolates (97%) expressed the mAb17C7-reactive epitope shared by UspA1 and UspA2, and 103 isolates (95%) reacted with the UspA1-specific mAb24B5. The only isolate which lacked a uspA1 gene demonstrated reduced adherence to HEp-2 cells and complement sensitivity. The data indicate that both uspA genes and the expression of at least two surface-exposed epitopes are virtually ubiquitous in isolates from a population at risk for otitis media. A vaccine capable of inducing a bactericidal immune response against the mAb17C7- and/or mAb24B5-reactive epitopes appears promising.
authors.affiliation: Institute for Infectious Diseases, University of Bern, Friedbuehlstrasse 51, CH-3010 Bern, Switzerland.
authors.forename: Patricia Stutzmann
authors.initials: PS
authors.lastname: Meier
authors.forename: Rolf
authors.initials: R
authors.lastname: Troller
authors.forename: Ioanna N
authors.initials: IN
authors.lastname: Grivea
authors.forename: George A
authors.initials: GA
authors.lastname: Syrogiannopoulos
authors.forename: Christoph
authors.initials: C
authors.lastname: Aebi
mesh_terms: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial / Q000235:genetics; D001422:Bacterial Adhesion / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000276:immunology; D001428:Bacterial Vaccines / Q000302:isolation & purification; D001483:Base Sequence; D003165:Complement System Proteins / Q000378:metabolism; D017124:Conserved Sequence; D004269:DNA, Bacterial / Q000235:genetics; D000939:Epitopes / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D007223:Infant; D001936:Moraxella catarrhalis / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification*; D009305:Nasopharynx / Q000382:microbiology; D016870:Neisseriaceae Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control; D010033:Otitis Media / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D004269:DNA, Bacterial; D000939:Epitopes; C089675:UspA protein, Moraxella catarrhalis; D003165:Complement System Proteins