Transformation During Mixed Pneumococcal Infection of Mice

Conversion of deletions during recombination in pneumococcal transformation.

Genetic analysis of 16 deletions obtained in the amiA locus of pneumococcus is described. When present on donor DNA, all deletions increased drastically the frequency of wild-type recombinants in two-point crosses. This effect was maximal for deletions longer than 200 bases. It was reduced for heterologies shorter than 76 bases and did not exist for very short deletions. In three-point crosses ...

Transformation of Pneumococcal in Vitro

The Transformation of Pneumococcal Types

R forms of Pneumococcus may be converted into S forms of the homologous Type. In addition to the methods previously reported,-(1) animal passage and (2) growth in anti-R sera,-conversion may be effected by the following procedures as employed by Griffith; (1) The subcutaneous injection, in white mice, of large amounts of living R organisms. (2) The subcutaneous injection, in white mice, of smal...

Host cellular immune response to pneumococcal lung infection in mice.

Although there is substantial evidence that pneumolysin is an important virulence factor in pneumococcal pneumonia, relatively little is known about how it influences cellular infiltration into the lungs. We investigated how the inability of mutant pneumococci to produce pneumolysin altered the pattern of inflammation and cellular infiltration into the lungs. The effect on bacterial growth in t...

Pneumococcal Transformation -A Backward View