Staphylococcus aureus

Abstract

Staphvlococcus aureus occupies a dominant position in bacterial diseases of the eye. In addition to causing direct infections of the eye, it is responsible for hypersensitivity diseases of the external eye, including corneal phlyctenules, catarrhal infiltrates, and blepharitis. We have developed rabbit models of these entities that have enabled us to study the immune response associated with these important diseases. We determined that the development of these external diseases was associated with hypersensitivity to the cell wall of S. aureus, and particularly the ribitol teichoic acid (RTA) that it contains. Antibody rather than delayed hypersensitivity to RTA appeared to be involved in the immunopathogenesis of these lesions. Further studies suggested that antibodies to RTA in rabbit serum, tears, and cornea may be influenced by exposure to staphylococcal antigens not only in the external eye but also in sites remote from the eye. Corneal antibodies to RTA correlated with the development of hypersensitivity lesions. Vaccination with StaphyjMWçus.jjuie.us phage lysate vaccine was not found to have a beneficial effect on the development of hypersensitivity lesions in our rabbit model. In fact, more rabbits with blepharitis and corneal lesions were seen in the vaccinated group. In general, the antibody response to RTA was enhanced, while the delayed hypersensitivity response was depressed by vaccination.