The outer membrane proteins UspA1 and UspA2 of Moraxella catarrhalis are highly conserved in nasopharyngeal isolates from young children.
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.
Meier
Patricia Stutzmann
PS
Institute for Infectious Diseases, University of Bern, Friedbuehlstrasse 51, CH-3010 Bern, Switzerland.
Troller
Rolf
R
Grivea
Ioanna N
IN
Syrogiannopoulos
George A
GA
Aebi
Christoph
C
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
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