Active Immunization with Pneumolysin versus 23-Valent Polysaccharide Vaccine for Streptococcus pneumoniae Keratitis.

Purpose: The purpose of this study was to determine whether active immunization against pneumolysin (PLY), or polysaccharide capsule, protects against the corneal damage associated with Streptococcus pneumoniae keratitis.

Methods: New Zealand White rabbits were actively immunized with Freund's adjuvant mixed with pneumolysin toxoid (ψPLY), Pneumovax 23 (PPSV23; Merck, Whitehouse Station, NJ), or phosphate-buffered saline (PBS), before corneal infection with 10⁵ colony-forming units (CFU) of S. pneumoniae.

"Boom" and "Bust" cycles in virus growth suggest multiple selective forces in influenza a evolution.

Background: Influenza A virus evolution in humans is driven at least in part by mutations allowing the virus to escape antibody neutralization. Little is known about the evolution of influenza in birds, a major reservoir of influenza A.

Methods: Neutralizing polyclonal antiserum was raised in chicken against reassortant influenza virus, CalX, bearing the hemagglutinin (HA) and neuraminidase (NA) of A/California/7/2004 [H3N2].

Cholesterol as treatment for pneumococcal keratitis: cholesterol-specific inhibition of pneumolysin in the cornea.

Purpose: The purpose of this study was to determine whether cholesterol, the host cell receptor for pneumolysin of Streptococcus pneumoniae, could effectively treat pneumococcal keratitis.

Methods: New Zealand White rabbits were intrastromally injected with 10(5) colony-forming units (CFUs) of S. pneumoniae D39.