Competence-programmed predation of noncompetent cells in the human pathogen Streptococcus pneumoniae: genetic requirements

Research output: Contribution to journalArticle

Authors

Colleges, School and Institutes

Abstract

Natural competence for genetic transformation is the best-characterized feature of the major human pathogen Streptococcus pneumoniae. Recent studies have shown the virulence of competence-deficient mutants to be attenuated, but the nature of the connection between competence and virulence remained unknown. Here we document the release, triggered by competent cells, of virulence factors (e.g., the cytolytic toxin pneumolysin) from noncompetent cells. This phenomenon, which we name allolysis, involves a previously undescribed bacteriocin system consisting of a two-peptide bacteriocin, CibAB, and its immunity factor, CibC; the major autolysin, LytA, and lysozyme, LytC; and a proposed new amidase, CbpD. We show that CibAB are absolutely required for allolysis, whereas LytA and LytC can be supplied either by the competent cells or by the targeted cells. We propose that allolysis constitutes a competence-programmed mechanism of predation of noncompetent cells, which benefits to the competent cells and contributes to virulence by coordinating the release of virulence factors.

Details

Original languageEnglish
Pages (from-to)8710-5
Number of pages6
JournalNational Academy of Sciences. Proceedings
Volume102
Issue number24
Publication statusPublished - 14 Jun 2005

Keywords

  • Amidohydrolases, Bacterial Proteins, Bacteriocins, Bacteriolysis, DNA Primers, Models, Biological, Mutagenesis, N-Acetylmuramoyl-L-alanine Amidase, Plasmids, Streptococcus pneumoniae, Streptolysins, Transformation, Bacterial, Virulence, Virulence Factors