Affiliations: Department of Medical Microbiology and Infectious
Diseases, Erasmus MC, Rotterdam, The Netherlands
Note: [] Correspondence: John P. Hays, PhD, Department of Medical
Microbiology and Infectious Diseases, Erasmus MC, `s Gravendijkwal 230, 3000
CA, Rotterdam, The Netherlands. Tel.: +44 10 7032177; Fax: +44 10 703875;
E-mail: j.hays@erasmusmc.nl
Abstract: Moraxella catarrhalis is a human-specific bacterium previously
discounted as a simple commensal organism with only limited pathogenic
potential. This view has changed considerably and we now know that M.
catarrhalis is associated with a range of disease states affecting both
children and adults. In particular, M. catarrhalis tends to be associated with
upper respiratory tract infections, including otitis media and sinusitis in
children and lower respiratory tract infections in adults with pre-existing
pulmonary disease, e.g., exacerbations of chronic obstructive pulmonary
disease. Colonization with this bacterium is especially common in infants and
young children, the age group most affected by M. catarrhalis-mediated disease.
Research is just beginning to unravel the complex interaction between this
pathogen and the human host and is providing insights into its diverse genetic
population structure and numerous virulence traits. These latter markers
include multiple potential cellular adhesion molecules that are currently being
researched as potential vaccine candidates. This mini-review is intended to
provide the reader with a short introduction to M. catarrhalis as a pathogen
and includes recent advances in the understanding of mechanisms associated with
bacterial virulence.