1. Avirulent R pneumococci derived from S forms of a specific type may be changed by growth in broth containing anti-R serum and a heated, filtered extract of S pneumococci of a different type, into virulent S organisms identical in type with the bacteria extracted. This has been accomplished in the case of R strains derived from Type II pneumococci, employing extracts prepared from Type III an...

1. Immune sera prepared with the degraded or variant forms of pneumococci (R strains) are similar in their reactions to sera prepared with the protein or cell solutions of pneumococci. They contain antibodies reactive with the protein of all types of pneumococci, but no antibodies reactive with the type-specific substances. 2. Pneumococci of the variant or R form, regardless of type derivation,...

Children 12-18 months old were randomized to receive one dose of a conjugate heptavalent pneumococcal vaccine, two doses of the same vaccine, or one dose of a 23-valent native polysaccharide vaccine. Before immunization, pneumococci included in the conjugate vaccine were isolated from 24% of the children, and an antibiotic-resistant pneumococcus was isolated from 22% of the children. The vaccin...

It has proved possible to transform an extreme rough variant of pneumococcus back to the rough state by the action of the desoxyribonucleate fractions of either rough or Type III smooth pneumococci. In a second step, the rough pneumococci produced by this transformation were further changed to the Type III smooth state by means of the desoxyribonucleate fraction of Type III smooth organisms. Wi...

Austrian, Robert (The University of Pennsylvania School of Medicine, Philadelphia), and Patricia Collins. Importance of carbon dioxide in the isolation of pneumococci. J. Bacteriol. 92:1281-1284. 1966.-Of the strains of pneumococci isolated from man, 8% manifest a requirement for CO(2) if detectable growth is to occur on the surface of solid media. The pneumococci most frequently manifesting th...

In preceding papers (1) it has been shown that virulent pneumococci generally disappear from the lungs of normal mice within a few hours after inhalation and do not give rise to generalized infection. In alcohol-intoxicated mice, however, pneumococci persist in the lungs for a longer period and a fatal septicemia frequently follows. I t has further been shown (2) that a high degree of immunity ...

Morgenroth and his collaborators grew pneumococci in a medium containing optochin and derived variant forms of bacteria therefrom which were considered to be streptococci of the viridans group. We have repeated these experiments and have also derived variant forms. These atypical races, however, we have found to be identical with the R form of pneumococci which have been obtained by various oth...

Pneumonia with bacteremia accounts for the majority (70%) of cases of invasive pneumococcal diseases. Laboratory characterization of pneumococci is routinely done by sensitivity to optochin. We identified an atypical presentation of optochin-resistant pneumococci in blood isolate of a patient with sepsis. Polymerase chain reaction for autolysin (lytA) and pneumolysin (ply) was positive in the b...

Tomasz, Alexander (The Rockefeller Institute, New York, N.Y.), and Samuel M. Beiser. Relationship between the competence antigen and the competence-activator substance in pneumococci. J. Bacteriol. 90:1226-1232. 1965.-Antisera prepared against pneumococci in their competent phase inhibit deoxyribonuoleic acid (DNA)-mediated genetic transformation as well as binding of radioactive DNA by the cel...