Virulence mechanisms of Moraxella in the pathogenesis of infection.
OBJECTIVE
Moraxella catarrhalis is an emerging human-specific pathogen responsible for upper and lower respiratory tract infections. Understanding the events in the complex pathogenesis and underlying mechanisms during M. catarrhalis infection is a key to the development of novel therapeutics and vaccines.


RESULTS
Several novel findings have been reported on Moraxella pathogenesis and, in parts, explain how the species stands as a commensal in preschool children and survives in the host. Molecular structures for different adhesins in addition to target ligands with respect to signalling and invasion have been defined. Evasion of the complement system allows Moraxella to survive in the mucosa and by neutralizing [alpha]1-antichymotrypsin the protease activity is increased, resulting in tissue destruction and thus promotion of bacterial attachment. Moraxella-dependent cell activation via immunoglobulin D in addition to toll-like receptors and specific epithelial cell inhibition by cross-linking of carcinoembryonic antigen-related cell adhesion molecule-1 in the early innate immune response and, finally, the ability of M. catarrhalis to form biofilms are other specific research areas of interest.


CONCLUSIONS
Recent advances have allowed a more detailed picture of the processes involved in bacteria-host cell interactions, the cause of inflammatory processes and specific host defense responses against the intriguing species Moraxella.
Perez Vidakovics
M Laura
ML
Division of Medical Microbiology, Department of Laboratory Medicine, University Hospital Malmö, Lund University, Malmö, Sweden.
Riesbeck
Kristian
K
D001426:Bacterial Proteins / Q000502:physiology; D035843:Biomedical Research / Q000639:trends; D002675:Child, Preschool; D006801:Humans; D001936:Moraxella catarrhalis / Q000276:immunology / Q000472:pathogenicity*; D045828:Moraxellaceae Infections / Q000382:microbiology*; D012141:Respiratory Tract Infections / Q000382:microbiology*; D014774:Virulence; D037521:Virulence Factors / Q000502:physiology*
D001426:Bacterial Proteins; D037521:Virulence Factors