title: Effect of intrastrain variation in the amount of capsular polysaccharide on genetic transformation of Streptococcus pneumoniae: implications for virulence studies of encapsulated strains.
abstract: The degrees of competence of opaque and transparent colony variants of Streptococcus pneumoniae were compared. The transparent variants were transformed at 9- to 670-fold-higher rates than the opaque variants, independent of the DNA incorporated, due to decreased expression of capsular polysaccharide. Genetic transformation, therefore, tends to select for a less-encapsulated subpopulation.
authors.affiliation: Departments of Pediatrics and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA. weiser@mail.med.upenn.edu
authors.forename: J N
authors.initials: JN
authors.lastname: Weiser
authors.forename: M
authors.initials: M
authors.lastname: Kapoor
mesh_terms: D016667:Bacterial Capsules / Q000235:genetics*; D014644:Genetic Variation; D006801:Humans; D011008:Pneumococcal Infections / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000235:genetics* / Q000472:pathogenicity; D014169:Transformation, Bacterial; D014774:Virulence / Q000235:genetics