Characteristics of virulent, attenuated, and avirulent Mycoplasma pneumoniae strains.

Molecular basis for cytadsorption of Mycoplasma pneumoniae.

Hemadsorbing (HA+) virulent Mycoplasma pneumoniae and spontaneously derived nonhemadsorbing (HA-) avirulent mutants were compared by biochemical and ultrastructural techniques in an attempt to understand the molecular basis for cytadsorption. Lactoperoxidase-catalyzed iodination of intact mycoplasmas indicated that both virulent and avirulent mycoplasmas displayed similar surface protein patter...

Protective Effect of Vaccines in Experimental Mycoplasma pneumoniae Disease.

The mechanisms of immunity to Mycoplasma pneumoniae were investigated by evaluating different vaccination procedures in an experimental animal model. Hamsters were immunized by intranasal inoculation of broth cultures or by parenteral injections of saline-suspended organisms. All vaccinees received a standardized intranasal challenge which produced pneumonia in 94% of controls. Intranasal immun...

Population changes in Diplococcus pneumoniae.

Carta, G. (Wesleyan University, Middletown, Conn.) and W. Firshein. Population changes in Diplococcus pneumoniae. J. Bacteriol. 84:473-477. 1962.-Avirulent mutant strains derived from pneumococcal types I, II, III, and VII established themselves in initially virulent or predominantly virulent populations within 36 to 48 hr of incubation at 37 C in Brain Heart Infusion-blood broth. Aged blood-br...

Role of Interferon in Replication of Virulent and Attenuated Strains of Measles Virus

Infection of Cultured Mouse Macrophages with Shigella flexneri.

Virulent, avirulent, and attenuated hybrid strains of Shigella flexneri 2a are equally susceptible to phagocytosis by cultured mouse peritoneal macrophages. The virulent strain is highly lethal for the macrophages, whereas the avirulent is not and is killed. The attenuated hybrid strain is intermediate in its lethality. Comparable results were obtained by using virulent and avirulent S. flexner...