Characteristics of Virulent, Attenuated, and Avirulent Mycoplasma pneumoniae Strains

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

Homologous pairs of virulent and attenuated or avirulent Mycoplasma pneumoniae strains were derived and compared in an effort to elucidate the mechanisms of virulence. These related strains were found to vary in growth, glycolysis, protein electrophoretic patterns, peroxide formation, morphology, and cytadsorption. Variations in the last two characteristics closely correlated with avirulence. T...

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

Detection of Mycoplasma pneumoniae adhesin (P1) in the nonhemadsorbing population of virulent Mycoplasma pneumoniae.

Mycoplasma pneumoniae organisms possessing a hemadsorbing-negative (HA-) phenotype comprise more than 50% of the population of virulent M. pneumoniae cultures. Monoclonal antibody to P1, the major adhesin of M. pneumoniae reacts with this HA- mycoplasma fraction based upon radioimmunoprecipitation and immunoblotting. Demonstration of P1 in the entire mycoplasma population suggests that topologi...

Differences in susceptibilities of virulent strains and avirulent strains of Neisseria gonorrhoeae to antimicrobial agents.

Virulent cells (T1 colony type) and avirulent cells (T4 colony type) of Neisseria gonorrhoeae were grown in a defined liquid medium in the presence of different antimicrobial agents. Bacteria of T1 colony type were found to be more resistant than bacteria of T4 colony type to the inhibitory effects of specific concentrations of ampicillin (0.50 mug/ml) and penicillin (0.01 mug/ml). Bacteria of ...

Surface proteins of Bordetella pertussis: comparison of virulent and avirulent strains and effects of phenotypic modulation.

The surface proteins of several Bordetella strains and their modulated derivatives were examined by surface radioiodination, cell fractionation, and Western blotting. A surface protein with a high Mr, missing in a mutant lacking the filamentous hemagglutinin, was identified in virulent Bordetella pertussis and Bordetella parapertussis cells and was absent in avirulent B. pertussis strains. The ...