Occurrence of phlyctenules after immunization with ribitol teichoic acid of Staphylococcus aureus

We immunized rabbits to ribitol teichoic acid (RTA), a component of the cell wall of Staphylococcus aureus, by intravenous injections of RTA-sensitized sheep RBCs. Hemagglutination titers to RTA and corneal phlyctenules developed in these rabbits after topical challenge with viable S aureus, but did not develop in control rabbits immunized with unsensitized sheep RBCs. These results suggest that hypersensitivity to RTA, the major antigenic determinant of S aureus, plays a role in the development of corneal phlyctenules.