The University of Georgia College of Veterinary Medicine

Georgia Veterinary Scholars Program

GVSP Summer 2009 Scholars

Georgia Veterinary Scholar

Faculty Mentor

Jaclyn Enners
University of Georgia
Class of 2011

Dr. Eric LaFontaine
Department of Infectious Diseases

UGA College of Veterinary Medicine

Mapping binding epitopes of the Moraxella catarrhalis Hag adhesin

* J. Enners, R. Balder, E. R. Lafontaine

Moraxella catarrhalis is a Gram-negative bacterium that is among the leading causes of otitis media in children and lower respiratory infections in adults with Chronic Obtrusive Pulmonary Disease (COPD). The organism has acquired beta-lactamase activity in more than ninety percent of isolates tested thereby rendering most strains resistant to ampicillin, amoxicillin, piperacillin, and penicillin. This growing antibiotic resistance coupled with the frequency of M. catarrhalis ear infections in children has prompted research into vaccine development for the pathogen. Adherence to epithelial cells is a key component in the pathogenesis of M. catarrhalis and therefore the proteins that mediate this adherence could make excellent vaccine targets. Previous studies have shown that the surface protein Hag is a key mediator in adherence of this bacterium to middle ear cells, NCIH292 lung cells, and A549 type II pneumocytes. In order to further characterize the Hag protein and explore its role in adhesion, recombinant Haemophilus influenza DB117 strains were engineered to express specific sections of the Hag protein designated 4.16, 5.12, and 10.32. These constructs will be used to map adherence epitopes of the Hag protein by testing their binding to normal human bronchial epithelial cultures (NHBE). It is our hypothesis that the adherence epitopes characterized in this study would be quality vaccine antigens.